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1997 Chevrolet S10 Pickup D - ADJUSTMENTS - 2.2L 1997 ENGINE PERFORMANCE General Motors - On-Vehicle Adjustments - 2.2L

D - ADJUSTMENTS - 2.2L 1997 ENGINE PERFORMANCE General Motors - On-Vehicle Adjustments - 2.2L

ENGINE MECHANICAL Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.

VALVE CLEARANCE NOTE:

All models are equipped with hydraulic lifters. Adjustments are not required.

IGNITION TIMING NOTE:

Ignition timing is controlled by control module and is not adjustable.

IDLE SPEED & MIXTURE IDLE SPEED & MIXTURE NOTE:

DO NOT attempt to adjust idle mixture and idle speed. Both are controlled by Powertrain Control Module (PCM). Incorrect idle speeds are normally caused by dirty throttle plate or vacuum leaks. Ensure all vacuum components are functioning properly.

NOTE:

Controlled idle speed and IAC count can be checked using scan tool. See CONTROLLED IDLE SPEED & IAC COUNT table.

Controlled Idle Speed Check

1. Ensure no trouble code(s) are present, IAC system is okay, and ignition timing is correct. Block drive wheels. Apply parking brake. Connect Tech 1 scan tool to Data Link Connector (DLC). Put scan tool into OPEN mode. 2. Start engine and bring to normal operating temperature. Check for correct state of transmission range switch on scan tool. Check if idle speed and IAC valve pintle position (counts) are as specified. See CONTROLLED IDLE SPEED & IAC COUNT table. 3. If idle speed is not within specification, refer to the TESTS W/O CODES - 2.2L article. CONTROLLED IDLE SPEED & IAC COUNT Application

Idle RPM

(1) IAC Counts

Auto. Trans. (2)

(4)

5-50

Man. Trans. (3)

(4)

5-50

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1997 Chevrolet S10 Pickup D - ADJUSTMENTS - 2.2L 1997 ENGINE PERFORMANCE General Motors - On-Vehicle Adjustments - 2.2L

(1) Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. (2) Automatic transmission in Drive. (3) Manual transmission in Neutral. Tech 1 scan tool will display "RDL" with transmission in Neutral. (4) Information not available at time of publication.

THROTTLE POSITION (TP) SENSOR TP sensor output voltage should be .85 volt or less at idle (closed throttle) and is not adjustable.

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

INTRODUCTION The following diagnostic steps help prevent overlooking simple problems. This is also where to begin diagnosis for no-start condition. The first step in diagnosing any driveability problem is verifying the customer's complaint by test driving vehicle under the conditions in which the problem reportedly occurred. Before entering self-diagnostics, perform a careful and complete visual inspection. Most engine control problems result from mechanical breakdowns, poor electrical connections or damaged/misrouted vacuum hoses. Before condemning the computerized system, perform each test listed in this article. NOTE:

Unless otherwise instructed in test procedures, perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance.

GENERAL MOTORS REFERENCE System Or Component Malfunction Indicator Light (MIL) DLC & MIL On Steady No Scan Tool Data No-Start Diagnosis Injector Circuit Diagnosis Fuel Pump Relay Fuel System Diagnosis Injector Balance Test MAP Sensor Transmission Range Switch IAC Valve Fuel Evaporation Control Ignition Control Circuit

Diagnostic Information Location See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK See NO START - ENGINE CRANKS OKAY See BASIC FUEL SYSTEM CHECKS See MODULES, MOTORS, RELAYS & SOLENOIDS in SYSTEM/COMPONENT TESTS article See BASIC FUEL SYSTEM CHECKS See FUEL SYSTEM in SYSTEM/COMPONENT TESTS article See ENGINE SENSORS & SWITCHES in SYSTEM/COMPONENT TESTS article See ENGINE SENSORS & SWITCHES in SYSTEM/COMPONENT TESTS article See IDLE CONTROL SYSTEM under FUEL SYSTEM in SYSTEM/COMPONENT TESTS article See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM/COMPONENT TESTS article See IGNITION SYSTEM in SYSTEM/COMPONENT TESTS article

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

Knock Sensor Check EGR System

See IGNITION SYSTEM in SYSTEM/COMPONENT TESTS article See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM/COMPONENT TESTS article

Torque Converter Clutch

(1) See MISCELLANEOUS PCM/VCM CONTROLS

Manual Trans. Shift Lights

(1) See MISCELLANEOUS PCM/VCM CONTROLS

A/C Clutch Control

in SYSTEM/COMPONENT TESTS article See MISCELLANEOUS PCM/VCM CONTROLS in SYSTEM/COMPONENT TESTS article

Elec.Cooling Fan Control

(2) See MISCELLANEOUS PCM/VCM CONTROLS

in SYSTEM/COMPONENT TESTS article

in SYSTEM/COMPONENT TESTS article (1) Complete coverage in TRANSMISSION SERVICING article. (2) Covered in entirety in A/C-HEATER SYSTEM article.

PRELIMINARY INSPECTION & ADJUSTMENTS VISUAL INSPECTION Visually inspect all electrical wiring. Look for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and not pinched or cut. If necessary, see VACUUM DIAGRAMS article to verify routing and connections. Inspect air induction system for possible vacuum leaks. MECHANICAL INSPECTION Compression

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions. For compression specifications, see the SPECIFICATIONS article. WARNING: Because fuel injectors on many models are triggered by ignition switch during cranking mode, DO NOT use ignition switch during compression tests. Use a remote starter to crank engine to prevent fire hazard or engine's oiling system contamination. Exhaust System Backpressure

Before replacing any components, check exhaust system for restrictions. Use a vacuum gauge or a low-pressure (0-5 psi) gauge to check exhaust system. If a vacuum gauge is used, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Partially open throttle and hold steady. If vacuum gauge reading slowly drops after Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

stabilizing, exhaust system should be checked for a restriction. If using a low pressure gauge, connect gauge in the following manner: 

Check At Oxygen Sensor Remove oxygen sensor. Install backpressure tester in place of oxygen sensor. After test is completed, coat oxygen sensor threads with anti-seize compound before installation.

Diagnosis

1. Start engine and bring to operating temperature. Increase engine speed to 2000-2500 RPM and note gauge. If reading exceeds 1.25 psi (.09 kg/cm2 ), exhaust system is restricted. 2. Check exhaust system for collapsed pipe, heat distress and possible internal muffler failure. If none of these conditions exist, check for restricted catalytic converter. Replace as required.

NO-START DIAGNOSIS NOTE:

For terminal and circuit ID, see the WIRING DIAGRAMS article.

DEFINITION No-start is defined as engine cranks okay but does not start. Engine may fire a few times. NO START - ENGINE CRANKS OKAY NOTE:

Before performing following tests, check battery condition, engine cranking speed and fuel supply.

General Inspection

1. Ensure proper starting procedure is being used. Visually check vacuum hoses for splits, kinks and proper connections as shown on Vehicle Emission Control Information label. Check ignition wires for cracking, hardness and proper connections at both coil pack and spark plugs. 2. Remove spark plugs. Check and replace as necessary. In very cold temperatures, ensure oil is proper viscosity and not contaminated with gasoline. Ignition System

1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step. 2. Check for Diagnostic Trouble Codes (DTCs). If DTC P0601, P0602 or P1621 is present, diagnose DTC (s). See the TESTS W/CODES article. If DTC(s) is not present, go to next step. 3. Check PCM ground connection at engine block. Repair as necessary. After repairs, go to next step. If ground connection is okay, go to step 5). 4. Check fuel pump and injector ignition feed fuse. If fuse is okay, go to step 6). If fuse is blown, go to step Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

5. 6. 7. 8.

10.

11.

12. 13. 14.

15.

16.

17.

18.

19. 20. 21.

7). Repair PCM ground connection. After repairs, go to step 42). Check fuel level in tank and add fuel if necessary. If fuel level is okay, go to step 8). If fuel level was low and fuel needed to be added, go to step 42). Check for short to ground in fuel pump and injector ignition feed circuit. Repair as necessary. Replace defective fuse. After repairs, go to step 42). Install scan tool. Turn ignition on, with engine off. Ensure throttle is closed. Scan TP sensor. TP sensor value should be less than one volt. If TP sensor value is as specified, go to next step. If TP sensor value is not as specified, diagnose problem using DTC P0123. See the TESTS W/CODES article. Using scan tool, monitor Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor values. Both values should be about the same. If values are the same, go to next step. If values are not the same, diagnose problem using DTC P0118. See the TESTS W/CODES article. Check MAP sensor value with ignition on and engine cranking. If MAP sensor value is greater than 4 volts, then changes while cranking engine, go to next step. If MAP sensor value is less than 4 volts and does not change while cranking engine, go to step 12). Using scan tool, check Crankshaft Position (CKP) sensor activity while cranking engine. If CKP ACTIVITY COUNTER increments while cranking, go to step 14). If CKP ACTIVITY COUNTER does not increment, go to step 15). If serial data was lost while cranking engine, go to next step. If serial data was not lost while cranking engine, diagnose MAP sensor. See the SYSTEM/COMPONENT TESTS article. Repair voltage loss to PCM from ignition switch. After repairs, go to step 42). Install Spark Tester (J-26792) to cylinder No. 1, 2, 3 and 4 (one at a time). Connect the spark plug wire of companion cylinder to ground. Crank engine and observe spark tester. If spark is present, go to step 38). If spark is not present, go to step 21). Turn ignition off. Disconnect 6-pin Ignition Control Module (ICM) connector. Turn ignition on. Connect DVOM between ICM connector CKP sensor ground terminal and CKP sensor signal terminal. See the WIRING DIAGRAMS article. Check combined CKP sensor and resistance. Resistance should be 7001300 ohms. If resistance is as specified, go to step 17). If resistance is not as specified, go to next step. Remove CKP sensor. Ensure CKP sensor is still magnetized and terminals are not damaged. Using DVOM, check CKP resistance. Resistance should be 700-1300 ohms. If resistance is as specified, go to step 19). If resistance is not as specified, go to step 20). Set DVOM to AC scale. Connect DVOM between ICM connector CKP sensor ground terminal and CKP sensor signal terminal. See the WIRING DIAGRAMS article. Crank engine. Voltage reading should be greater than 200 millivolts (mV). If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 20). Using a test light connected to battery positive, touch ICM connector 7X reference signal terminal, then reference low terminal. See the WIRING DIAGRAMS article. Monitor CKP ACTIVITY COUNTER increment on scan tool. If increment changes one count as test light is touched to ICM reference low terminal, go to step 31). If increment does not change, go to step 25). Repair open or short in CKP sensor. After repairs, go to step 42). Replace CKP sensor. After replacing CKP sensor, go to step 42). If spark is present at one or more cylinders, go to step 27). If spark is not present at one or more cylinders, go to next step.

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

22. Turn ignition off. Disconnect 2-pin Ignition Control Module (ICM) connector. Turn ignition on. Using a test light, probe ICM connector ignition positive voltage terminal and ground terminal. See the WIRING DIAGRAMS article. If test light illuminates, go to step 27). If test light does not illuminate, go to next step. 23. Using a test light connected to ground, probe ICM connector ignition positive voltage terminal. If test light illuminates, go to next step. If test light does not illuminate, go to step 26). 24. Repair faulty ground circuit. After repairs, go to step 42). 25. Check CKP activity (7X reference) circuit for an open or short. Repair circuit as necessary. After repairs, go to step 42). If circuit is okay, go to step 32). 26. Repair faulty power circuit. After repairs, go to step 42). 27. Measure resistance of cable that would not produce spark with spark tester. If resistance is less than 30,000 ohms, go to next step. If resistance is greater than 30,000 ohms, go to step 36). 28. Check secondary resistance of ignition coil that did not produce a spark. Resistance should be 5000-8000 ohms. If resistance is not as specified, go to step 37). If resistance is as specified, go to next step. 29. Turn ignition off. Disconnect 6-pin Ignition Control Module (ICM) connector. Using a DVOM connected to ground, probe ICM connector ignition control terminals. See the WIRING DIAGRAMS article. If resistance is 600-2600 ohms, go to next step. If resistance is not 600-2600 ohms, go to step 33). 30. Install a known-good ignition coil. Reconnect ICM connector. Install Spark Tester (J-26792) to faulty cylinder. Connect the spark plug wire of companion cylinder to ground. Crank engine and observe spark tester. If spark is present, go to step 42). If spark is not present, go to next step. 31. Replace ICM. After replacing ICM, go to step 42). 32. Check for faulty PCM connector or connection. If connector and connection are okay, go to step 35). If connector and connection are faulty, go to step 34). 33. Check ignition control circuit of faulty cylinder for an open or short. Repair circuit as necessary. After repairs, go to step 42). If circuit is okay, go to step 35). 34. Repair connector or connection. After repairs, go to step 42). 35. Replace PCM. Perform PCM relearn procedures. After replacing PCM, go to step 42). 36. Replace faulty spark plug wires. After repairs, go to step 42). 37. Replace faulty ignition coils. After repairs, go to step 42). 38. Disconnect all injector connectors. Connect injector test light to injector No. 1, 2, 3 and 4 (one at a time). Crank engine and observe injector test light. Test light should flash on all tests. If test light flashed, go to next step. If test light did not flash on all tests, or flashed only on one of the tests, or was on steady on one or all tests, go to step 41). 39. Install fuel pressure gauge. Turn ignition on and note fuel pressure after 2 seconds. Fuel pressure should be 41-47 psi (2.9-3.3 kg/cm2 ). If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to FUEL SYSTEM. 40. Check for fouled spark plugs. Replace as necessary. If spark plugs were fouled, go to step 42). If spark plugs were okay, check for water in fuel system. Check for basic engine problem (low compression). Ensure spark plugs are of resistor type. Check fuel pump operation with scan tool. 41. Repair open in fuel pump and injector ignition feed circuit. After repairs, go to next step. 42. Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts but dies, go to step 2). Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

43. Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to the TESTS W/CODES article. If DTC(s) are not present, system is okay. Fuel System

1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step. 2. Ensure fuel pump relay fuse is okay. If fuse is okay, go to next step. If fuse is faulty, go to step 20). 3. Install scan tool. Turn ignition on. Using scan tool, command fuel pump on. Fuel pump should operate for about 2 seconds. If fuel pump operates as specified, diagnose fuel system. See BASIC FUEL SYSTEM CHECKS . If fuel pump does not operate, go to next step. 4. Remove fuel pump relay. Using a fused jumper wire, jumper fuel pump relay feed terminal and fuel pump relay ignition feed terminal. See the WIRING DIAGRAMS article. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 6). 5. Using a test light connected to ground, probe fuel pump relay control terminal. See the WIRING DIAGRAMS article. Using scan tool, command fuel pump on. If test light illuminates, go to step 7). If test light does not illuminate, go to step 8). 6. Using a test light connected to ground, probe fuel pump relay ignition feed terminal. See the WIRING DIAGRAMS article. If test light illuminates, go to step 9). If test light does not illuminate, go to step 10). 7. Using a test light connected to battery voltage, probe fuel pump relay ground terminal. See the WIRING DIAGRAMS article. If test light illuminates, go to step 11). If test light does not illuminate, go to step 12). 8. Check for an open or short to ground in fuel pump relay control circuit. Repair as necessary. After repairs, go to step 25). If circuit is okay, go to step 13). 9. Reinstall fuel pump relay. Disconnect fuel pump connector at fuel pump. Using a test light connected to ground, probe fuel pump connector feed terminal (body side). Using scan tool, command fuel pump on. If test light illuminates, go to step 14). If test light does not illuminate, go to step 15). 10. Repair open in ignition feed circuit to fuel pump relay. After repairs, go to step 25). 11. Replace fuel pump relay. After repairs, go to step 25). 12. Repair open in ground circuit to fuel pump relay. After repairs, go to step 25). 13. Check connections and terminals to PCM. Repair as necessary. After repairs, go to step 25). If connections and terminals are okay, go to step 16). 14. Using a test light connected to battery voltage, probe fuel pump ground terminal (body side). If test light illuminates, go to step 17). If test light does not illuminate, go to step 18). 15. Repair open in fuel pump feed circuit. After repairs, go to step 25). 16. Replace PCM. Perform PCM relearn procedures. After replacing PCM, go to step 25). 17. Check for an open in fuel pump feed circuit and ground circuit. Repair as necessary. After repairs, go to step 25). If circuit is okay, go to step 19). 18. Repair open in fuel pump ground circuit. After repairs, go to step 25). 19. Replace fuel pump. After repairs, go to step 25). 20. Disconnect fuel pump connector at fuel pump. Remove fuel pump relay. Turn ignition off. Using a test light connected to battery voltage, probe fuel pump feed terminal. If test light illuminates, go to next step. Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

21. 22. 23. 24. 25. 26.

If test light does not illuminate, go to step 22). Repair short to ground in fuel pump feed circuit. After repairs, go to step 25). Using a test light connected to battery voltage, probe fuel pump relay ignition feed terminal. If test light illuminates, go to next step. If test light does not illuminate, go to step 24). Repair short to ground in fuel pump relay ignition feed circuit. After repairs, go to step 25). Check for short to ground in fuel pump fuel pump feed circuit. Repair as necessary. After repairs, go to next step. If circuit is okay, go to step 19). Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts but dies, go to step 2). Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to the TESTS W/CODES article. If DTC(s) are not present, system is okay.

BASIC FUEL SYSTEM CHECKS FUEL SYSTEM PRESSURE RELIEF WARNING: Begin fuel system trouble shooting and diagnosis with fuel system pressure test. Relieve fuel system pressure before disconnecting any components or installing fuel pressure gauge. Fuel system is under pressure, which must be relieved before servicing fuel system. Fuel pressure may be relieved by the following method: 

Disconnect negative battery cable. Loosen fuel filler cap. Install Fuel Pressure Gauge (J-34730-1A) to fuel pressure test head. Wrap shop towel around pressure connection when installing fuel pressure gauge to absorb fuel leakage. Place gauge bleed hose in container. Open bleed valve to relieve fuel pressure.

FUEL SYSTEM PRESSURE TEST WARNING: Begin fuel system trouble shooting and diagnosis with fuel system pressure test. Relieve fuel system pressure before disconnecting any components or installing fuel pressure gauge. 1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step. 2. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF . Connect Fuel Pressure Gauge Kit (J-29658-D) to fuel pressure connector. Turn ignition on with engine off. With fuel pump running, fuel pressure should be 41-47 psi (2.9-3.3 kg/cm2 ). If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to step 12). 3. Wait for fuel pump to stop running. Observe fuel pressure after 10 minutes. Fuel pressure should remain within 5 psi (.35 kg/cm2 ) of specified pressure. If pressure drops more than 5 psi (.35 kg/cm2 ), go to step 10). If pressure remains within 5 psi (.35 kg/cm2 ) of specified pressure, go to next step. 4. Relieve fuel pressure until pressure is 10 psi (.7 kg/cm2 ). Observe fuel pressure after 10 minutes. Fuel Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

5. 6. 7.

10.

11.

pressure should remain within 2 psi (.14 kg/cm2 ) of specified pressure. If pressure drops more than 2 psi (.14 kg/cm2 ), go to step 21). If pressure remains within 2 psi (.14 kg/cm2 ) of specified pressure, go to next step. If fuel pressure is suspected of dropping off during acceleration, cruise or hard cornering, go to next step. If fuel pressure is as specified, go step 8). Inspect fuel filter and fuel supply line. Repair or replace as necessary. After repairs, go to step 23). If fuel filter and fuel supply line are okay, go to next step. Remove fuel sending unit from fuel tank. Inspect fuel pump strainer for restriction, fuel pump flex pipe for leaks, or verify if fuel pump is of right application. Repair or replace as necessary. After repairs, go to step 23). If no problems are found, go to step 20). Start and warm engine to normal operating temperature. Allow engine to idle. Observe fuel pressure gauge. Fuel pressure should drop 3-10 psi (.2-.7 kg/cm2 ). If fuel pressure drop is as specified, see the TESTS W/O CODES article. If fuel pressure drop is not as specified, go to next step. Disconnect vacuum hose to fuel pressure regulator. With engine at idle, apply 12-14" Hg vacuum to fuel pressure regulator using a vacuum pump. Fuel pressure should drop 3-10 psi (.2-.7 kg/cm2 ). If fuel pressure drop is as specified, go to step 19). If fuel pressure drop is not as specified, go to step 20). Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF . Connect Fuel Pressure Gauge Kit (J-29658-D) to fuel pressure connector. Using scan tool, pressurize fuel system. Bleed air out of fuel gauge. Wait for pressure to build up. Pinch fuel return hose. If fuel pressure remains constant, go to step 21). If fuel pressure does not remain constant, go to next step. Using scan tool, pressurize fuel system. Wait for pressure to build up. Pinch fuel return hose. If fuel pressure remains constant, go to step 20). If fuel pressure does not remain constant, go to step 22).

12. If fuel pressure is greater than 47 psi (3.3 kg/cm2 ), go to next step. If fuel pressure is less than 47 psi (3.3 kg/cm2 ), go to step 15). 13. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF . Disconnect fuel return line from fuel rail. Attach a piece of fuel hose to return line and place in a container. Turn ignition off for about 10 seconds. Turn ignition on. Observe fuel pressure with fuel pump operating. Fuel pressure should be 41-47 psi (2.9-3.3 kg/cm2 ). If fuel pressure is as specified, go to step 23). If fuel pressure is not as specified, go to next step. 14. Inspect fuel rail return/outlet passage for restriction. If restriction is present, go to step 24). If restriction is not present, go to step 20). 15. If fuel pressure is not present, go to next step. If fuel pressure is present, go to step 17). CAUTION: DO NOT allow fuel pressure to exceed 65 psi (4.5 kg/cm2 ).

16. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF . Connect Fuel Pressure Gauge Kit (J-29658-D). Using scan tool, pressurize fuel system. Bleed air out of fuel gauge. Wait for pressure to build up. Slowly pinch fuel return hose. Fuel pressure should be 41-47 psi (2.9-3.3 kg/cm2 ). If fuel pressure increases to greater than specification, go to step 20). If fuel pressure does not increase to greater than specification, go to step 7). 17. Check fuel system electrical circuits. See FUEL SYSTEM under NO-START DIAGNOSIS . If fuel Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

18.

19. 20. 21. 22. 23. 24.

pump circuit is faulty, go to step 24). If fuel pump circuit is okay, go to next step. Inspect fuel filter for obstruction, fuel supply line for restriction, fuel pump strainer for obstructions or fuel pump flex pipe for leaks. Repair or replace as necessary. After repairs, go to step 24). If problem was not found, go to step 21). Locate and repair vacuum leak to fuel pressure regulator. After repairs, system is okay. Replace fuel pressure regulator. After repairs, system is okay. Replace fuel sending unit. After repairs, system is okay. Locate and replace any leaking fuel injector(s). After repairs, system is okay. Locate and correct restriction in fuel return line. After repairs, system is okay. Repair problem as necessary. After repairs, system is okay.

BASIC IGNITION SYSTEM CHECKS NOTE:

To diagnose ignition system, see appropriate IGNITION SYSTEM test in NOSTART DIAGNOSIS .

IDLE SPEED & IGNITION TIMING Ensure idle speed and ignition timing are set to specifications. For specifications, see SPECIFICATIONS article. For adjustment procedures, see ADJUSTMENTS article.

ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK NOTE:

Use of Tech 1 scan tool is required to perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .

The OBD System Check determines:   

If Malfunction Indicator Light (MIL) works. If PCM/VCM is operating and can recognize a fault. If any Diagnostic Trouble Codes (DTCs) are stored.

After performing procedures in PRELIMINARY INSPECTION & ADJUSTMENTS, BASIC FUEL SYSTEM CHECKS and BASIC IGNITION SYSTEM CHECKS, this is the starting point for utilizing the self-diagnostic system for determining computer-related problems. After performing necessary tests as described in the OBD system circuit check, if no codes are indicated and driveability problems still exist, see the TESTS W/O CODES article and SCAN TOOL usage in the TESTS W/CODES article. 1. Turn ignition on with engine off. If Malfunction Indicator Light (MIL) illuminates, go to next step. If MIL does not illuminate, go to MIL INOPERATIVE. 2. Turn ignition off. Install Tech 1 scan tool and follow scan tool manufacturer's instructions to proceed with test. Turn ignition on. If scan tool displays PCM data, go to next step. If scan tool does not display PCM data, go to DLC DIAGNOSIS OR NO SCAN TOOL DATA . Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

3. Using scan tool, command MIL to turn off. If MIL turns off, go to next step. If MIL does not turn off, go to MIL ON STEADY. 4. Using scan tool, check if any DTC(s) are present. If DTC(s) are present, go to next step. If DTC(s) are not present, go to step 6). 5. Using scan tool, store FREEZE FRAME and FAILURE RECORDS data. Diagnose any stored DTC. See the TESTS W/CODES article. 6. Start engine. If engine starts and runs, go to next step. If engine does not start, or starts and dies, go to NO START DIAGNOSIS. 7. Turn ignition on with engine off. Check Engine Coolant Temperature (ECT) and TP sensors for proper operation. Start and warm engine to normal operating temperature. Check ECT sensor, MAP sensor, O2 sensors, and IAC valve for proper operation. Compare scan tool engine data with actual control system data values. If value is within limits, see the TESTS W/O CODES article. If value is not within limits, go to the SYSTEM/COMPONENT TESTS article. MALFUNCTION INDICATOR LIGHT (MIL) 1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step. 2. Turn ignition on with engine off. If Malfunction Indicator Light (MIL) illuminates, go to next step. If MIL does not illuminate, go to step 4). 3. Check for poor connections at battery feed circuit or ignition positive voltage 1 circuit. Repair as necessary. After repairs, go to step 22). If circuits are okay, go to step 5). 4. Attempt to start engine. If engine starts, go to step 6). If engine does not start, go to step 7). 5. Check for poor PCM ground connection on engine block or PCM connector ground terminals. Repair as necessary. After repairs, go to step 22). 6. Turn ignition off. Disconnect PCM connectors. Turn ignition on. Using a test light connected to ground, probe MIL control circuit. See the WIRING DIAGRAMS article. If MIL illuminates, go to step 8). If MIL does not illuminate, go to step 9). 7. Check ignition and battery feed fuses. If fuses are okay, go to step 10). If fuses are blown, go to step 11). 8. Check for poor battery feed, ignition positive voltage 1 or MIL control circuit connections. Repair as necessary. After repairs, go to step 22). If circuits are okay, go to step 12). 9. If test light illuminates, go to step 13). If test light does not illuminate, go to step 14). 10. Turn ignition off. Disconnect PCM connectors. Turn ignition on. Using a test light connected to ground, probe ignition positive voltage 2 circuit. See the WIRING DIAGRAMS article. If test light illuminates, go to step 15). If test light does not illuminate, go to step 16). 11. Check for short to ground in fuse circuit that was open. Repair as necessary and replace fuse. After repairs, go to step 22). 12. Replace PCM. Perform PCM relearn procedures. After repairs, go to step 22). 13. Repair short to voltage in MIL control circuit. After repairs, go to step 22). 14. Check for open or poor connection in MIL control circuit. See the WIRING DIAGRAMS article. Repair as necessary. After repairs, go to step 22). If circuit is okay, go to step 17). 15. Using a test light connected to ground, probe ignition positive voltage 1 circuit. See the WIRING Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

16. 17. 18. 19. 20. 21. 22.

DIAGRAMS article. If test light illuminates, go to step 18). If test light does not illuminate, go to step 19). Repair open in battery feed circuit. After repairs, go to step 22). Check for open in ignition feed circuit or fuse to MIL. See the WIRING DIAGRAMS article. Repair as necessary. After repairs, go to step 22). If circuit or fuse is okay, go to step 20). Check for poor connections at battery feed circuit or ignition positive voltage 1 circuit. Repair as necessary. After repairs, go to step 22). If circuits are okay, go to step 21). Repair open in ignition positive voltage 1 circuit. After repairs, go to step 22). Replace Instrument Panel Cluster (IPC). After IPC replacement, go to step 22). Check for poor PCM ground connection on engine block or PCM connector. Repair as necessary. After repairs, go to next step. If connection and connector are okay, go to step 12). Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to the TESTS W/CODES article. If DTC(s) are not present, system is okay.

MIL ON STEADY 1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step. 2. Turn ignition on with engine off. MIL should illuminate. If MIL does not illuminate, go to MALFUNCTION INDICATOR LIGHT (MIL) . If MIL illuminates, go to next step. 3. Install scan tool. Using scan tool, command MIL on and off. If MIL turns on and off when commanded, go to step 8). If MIL does not turn on and off when commanded, go to next step. 4. Turn ignition off. Disconnect PCM connectors. Turn ignition on. If MIL does not illuminate, go to step 7). If MIL illuminates, go to next step. 5. Check for short to ground in MIL control circuit. See the WIRING DIAGRAMS article. Repair as necessary. After repairs, go to step 8). If circuit is okay, go to next step. 6. Replace Instrument Panel Cluster (IPC). After IPC replacement, go to step 8). 7. Replace PCM. Perform PCM relearn procedures. After repairs, go to next step. 8. Using scan tool, clear DTC(s). Attempt to start engine. If engine starts and runs, go to next step. If engine does not start, or starts and dies, go to step 1). 9. Warm engine to operating temperature. Check for DTCs. If DTCs are present, go to the TESTS W/CODES article. If DTC(s) are not present, system is okay. DLC DIAGNOSIS OR NO SCAN TOOL DATA 1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step. 2. Turn ignition on with engine off. Install scan tool. If scan tool is equipped with external power source, ensure power source and ground are okay. If scan tool powers up, go to next step. If scan tool does not power up, go to step 5). 3. Using scan tool, attempt to communicate with other control modules. If scan tool communicates with other control modules, go to step 10). If scan tool does not communicate with other control modules, go to next step. Microsoft Saturday, August 29, 2009 11:40:03 AM

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1997 Chevrolet S10 Pickup F - BASIC TESTING - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - Basic Diagnostic Procedures - 2.2L

4. Turn ignition off. Disconnect PCM connectors. Turn ignition on. Using scan tool, attempt to communicate with other control modules. If scan tool communicates with other control modules, go to step 12). If scan tool does not communicate with other control modules, go to step 11). 5. Using a test light connected to ground, probe DLC battery feed circuit. See the WIRING DIAGRAMS article. If test light illuminates, go to next step. If test light does illuminate, go to step 7). 6. Using a test light connected to battery voltage, probe DLC ground circuits. See the WIRING DIAGRAMS article. If test light illuminates for both ground circuits, go to step 8). If test light does not illuminate for both ground circuits, go to step 9). 7. Repair open or short to ground in DLC battery feed circuit. After repairs, go to step 15). 8. Check DLC for proper terminal tension or excessive resistance. Repair as necessary. After repairs, go to step 15). If terminals are okay, go to step 14). 9. Repair open or poor connection(s) in DLC ground circuit(s). After repairs, go to step 15). 10. Check for open in class 2 serial data circuit between PCM and splice connection. Repair as necessary. After repairs, go to step 15). If circuit is okay, go to step 12). 11. Check for open or short in class 2 serial data circuit between PCM and DLC. Repair as necessary. After repairs, go to step 15). If circuit is okay, go to step 13). 12. Replace PCM. Perform PCM relearn procedures. After repairs, go to step 15). 13. Install scan tool on another vehicle equipped with class 2 serial data and check for proper operation. If scan tool operates properly, diagnose vehicle computer system. If scan tool does not operate properly, go to next step. 14. Scan tool is malfunctioning. Using scan tool operation manual, repair as necessary. After repairs, go to next step. 15. Using scan tool, clear DTC(s). Warm engine to operating temperature. Operate vehicle within conditions required to set DTC. If scan tool indicates diagnostic ran and passed, go to next step. If scan tool does not indicate diagnostic ran and passed, go to step 2). 16. Check if any additional DTC(s) are set. If additional DTC(s) are present, diagnose DTC(s). See the TESTS W/CODES article. If DTC(s) are not present, system is okay.

SUMMARY If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, no trouble codes (or only intermittent ones) were found while performing ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK and driveability problems exist, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.) or intermittent diagnostic procedures.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

ENGINE IDENTIFICATION VEHICLE IDENTIFICATION NUMBER (VIN) The VIN is stamped on a metal pad located near lower left corner of windshield. A "4" in the eighth character of VIN identifies 2.2L 4-cylinder engine. ENGINE BUILD DATE & ENGINE CODE The engine build date (month and day) and the engine code are stamped on left side of cylinder block, near cylinder head. See Fig. 1 . Engine code LN2 indicates 2.2L 4-cylinder engine. PARTIAL VIN A partial VIN (9 characters) is stamped on lower left side of cylinder block, at cylinder block-to-transmission flange. See Fig. 1 .

Fig. 1: Locating Engine Build Date, Engine Code & Partial VIN Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:33:52 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

ADJUSTMENTS VALVE CLEARANCE ADJUSTMENT Engine is equipped with non-adjustable hydraulic valve lifters.

TROUBLE SHOOTING NOTE:

To trouble shoot engine mechanical components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

FUEL PRESSURE RELEASE Loosen fuel tank filler cap to release tank vapor pressure (DO NOT tighten at this time). Remove fuel pump fuse. Start and run engine until engine stops. Engage starter for at least 3 seconds to ensure remaining fuel pressure is released. Disconnect negative battery cable. Reinstall fuel pump fuse. Some residual line pressure may exist. Cover fuel lines using shop towel before disconnecting. ENGINE NOTE:

Remove engine through top of engine compartment.

Removal & Installation

1. Release fuel system pressure. See FUEL PRESSURE RELEASE . Disconnect negative battery cable. Disconnect under hood light. Remove vacuum reservoir from hood. Disconnect windshield washer fluid line from hood. Remove outer cowl vent grilles. Remove hood. Raise vehicle. 2. Drain engine oil and coolant. Discharge A/C system using approved refrigerant recovery/recycling equipment (if equipped). Remove oxygen sensor. Disconnect exhaust at manifold and loosen hanger at converter. 3. Remove pencil braces from engine to transmission. Remove inspection cover. Remove starter motor. Remove long bolts at engine mount. Remove bell housing bolts. Lower vehicle. Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

4. Remove battery from vehicle and disconnect body ground. Remove fan shrouds and fan. Remove serpentine belt. Remove upper radiator hose. Remove A/C compressor (if equipped) and lay it aside. Remove lower radiator hose. 5. Remove radiator. Disconnect power steering lines from pump. Disconnect heater hoses from engine. Disconnect wiring harness from engine. Disconnect vacuum lines, throttle cable and fuel lines. 6. Support transmission. Install engine hoist. Raise engine slightly. Remove left engine mount. Remove engine from vehicle. To install, reverse removal procedure. INTAKE MANIFOLD Removal

1. Release fuel system pressure. See FUEL PRESSURE RELEASE . Disconnect negative battery cable. Remove air intake duct. Remove MAP sensor and EGR solenoid valve. Disconnect vacuum hoses, electrical connectors, and fuel lines from upper intake manifold. Remove bolts and upper intake manifold. 2. Disconnect wiring and fuel lines from lower intake manifold. Disconnect spark plug wires from DIS coil pack. Remove nuts, lower intake manifold, and gasket. Installation

To install, reverse removal procedure using NEW gaskets. Tighten nuts in sequence to specification. See TORQUE SPECIFICATIONS . See Fig. 2 and Fig. 3 . Fill cooling system.

Fig. 2: Lower Intake Manifold Nut Tightening Sequence Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 3: Upper Intake Manifold Nut Tightening Sequence Courtesy of GENERAL MOTORS CORP. EXHAUST MANIFOLD Removal

Disconnect negative battery cable. Remove air cleaner and duct work. Disconnect oxygen sensor electrical connector. Remove oil fill tube assembly. Disconnect exhaust pipe from exhaust manifold. Remove exhaust manifold nuts. Remove exhaust manifold and gasket. Installation Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

To install, reverse removal procedure using NEW gasket. Tighten nuts to specification. See TORQUE SPECIFICATIONS . CYLINDER HEAD Removal

1. Release fuel system pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION . Remove air intake duct. Drain cooling system. 2. Disconnect vacuum hoses, electrical connectors and control cables from throttle body. Remove coolant reservoir, serpentine drive belt and generator. 3. Remove power steering pump (leave hoses connected, and lay pump aside). Remove serpentine drive belt tensioner and spark plug wires. Disconnect canister purge hose, upper radiator hose and heater hoses from intake manifold. 4. Remove intake manifold bracket from power steering bracket. Disconnect fuel lines as necessary. Remove valve cover. See Fig. 4 . Loosen rocker arm nuts, rotate rocker arms to one side and remove push rods. 5. Remove spark plug wire bracket and engine lifting bracket. Disconnect exhaust pipe from exhaust manifold. Remove cylinder head bolts. Remove transmission fluid level indicator bracket (A/T). Remove cylinder head. Inspection

Inspect cylinder head for warpage at deck surface and manifold surfaces. DO NOT remove more than .010" (.25 mm) material from cylinder head deck surface. Installation

1. Ensure cylinder head bolt threads and cylinder block bolt hole threads are clean. Install NEW head gasket over dowel pins, and ensure all holes align with cylinder block. 2. Install cylinder head. Tighten cylinder head bolts to specification in proper sequence. See TORQUE SPECIFICATIONS . See Fig. 5 . To complete installation, reverse removal procedure. Fill cooling system.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 4: Exploded View Of Cylinder Head & Components (S10 Pickup) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 5: Cylinder Head Bolt Tightening Sequence Courtesy of GENERAL MOTORS CORP. FRONT COVER Removal

1. Disconnect negative battery cable. Remove oil pan. See OIL PAN . Remove serpentine drive belt. Remove power steering pump (leave hoses connected). Remove generator (leave wiring connected). Remove drive belt tensioner. Raise and support vehicle. 2. Remove right front wheel. Remove engine splash shield. Remove bolt from center of crankshaft pulley. Remove 3 crankshaft pulley bolts. Using a puller, remove crankshaft pulley hub. If replacing seal, pry seal from front cover with a large screwdriver (DO NOT distort front cover). Remove bolts and front cover. CAUTION: To prevent oil leakage, apply RTV sealant to keyway of crankshaft pulley hub before installing hub. Installation

1. Install front cover and NEW gasket. Tighten front cover bolts to specification. See TORQUE Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

SPECIFICATIONS . If seal was removed, apply engine oil to lip of NEW oil seal, then install using Seal Installer (J-35468). Apply RTV sealant to crankshaft pulley hub keyway. 2. Install crankshaft pulley hub using Hub Installer (J-29113), ensuring at least .24" (6.0 mm) of installer bolt thread is engaged into end of crankshaft. To complete installation, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS . FRONT COVER OIL SEAL Removal

Disconnect negative battery cable. Remove serpentine drive belt. Raise and support vehicle. Remove right front wheel. Remove engine splash shield. Remove bolt from center of crankshaft pulley. Remove 3 crankshaft pulley bolts. Using a puller, remove crankshaft pulley hub. Pry seal from front cover with a large screwdriver or seal puller. DO NOT distort front cover. CAUTION: To prevent oil leakage, apply RTV sealant to keyway of crankshaft pulley hub before installing hub. Installation

1. Apply engine oil to lip of NEW oil seal. Using Seal Install (J-35468), drive seal into front cover with seal lip toward engine. Ensure seal is fully seated. Apply RTV sealant to crankshaft pulley hub keyway. Position crankshaft pulley hub onto crankshaft. 2. Install crankshaft pulley hub using Hub Installer (J-29113), ensuring at least .24" (6.0 mm) of installer bolt thread is engaged into end of crankshaft. To complete installation, reverse removal procedure. Tighten nuts and bolts to specification. See TORQUE SPECIFICATION. TIMING CHAIN & SPROCKETS Removal

1. Remove front timing case cover. See FRONT TIMING COVER. Align timing marks on camshaft sprocket and crankshaft sprocket with tabs on chain tensioner. See Fig. 6 . 2. Remove timing chain tensioner upper bolt. Loosen but DO NOT remove timing chain tensioner Torx bolt. Remove camshaft sprocket bolt. Remove camshaft sprocket and timing chain. Using Sprocket Puller (J-22888-20A), remove crankshaft sprocket. Installation

1. Install crankshaft sprocket using Sprocket Installer (J-5590). Ensure crankshaft sprocket is fully seated against crankshaft. Compress chain tensioner spring, and install a cotter pin or nail in hole of chain tensioner. See Fig. 6 . 2. Install timing chain and camshaft sprocket, aligning sprocket marks on sprockets with tabs on chain tensioner. Ensure hole in camshaft sprocket aligns with camshaft dowel pin. Install camshaft sprocket bolt and tighten to specification. See TORQUE SPECIFICATIONS . Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

3. Install and tighten chain tensioner upper bolt. Tighten chain tensioner Torx bolt. Remove cotter pin from chain tensioner. Lubricate timing chain with oil. To complete installation, reverse removal procedure.

Fig. 6: Aligning Timing Marks & Compressing Chain Tensioner Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Courtesy of GENERAL MOTORS CORP. VALVE LIFTERS Removal

Remove cylinder head. See CYLINDER HEAD . Remove anti-rotation brackets. See Fig. 7 . Remove lifters (note location for reassembly reference). NOTE:

Verify use of oversize valve lifters. Oversize valve lifters are identified by a mark on cylinder block, near lifter bore. If installing new lifter, coat bottom of lifter with Camshaft Lubricant (1052365) before installation.

Installation

Install lifters in original locations. To complete installation, reverse removal procedure.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 7: Identifying Push Rod, Anti-Rotation Bracket & Lifter Courtesy of GENERAL MOTORS CORP. CAMSHAFT NOTE:

To replace camshaft, engine must be removed from vehicle.

Removal

Remove engine. See ENGINE . Remove Cylinder head, valve lifters front cover, timing chain and camshaft sprocket. Remove oil pump drive from right side of cylinder block. Remove camshaft thrust plate. Remove camshaft. If necessary , use Camshaft Bearing Remover/Installer (J-33049) to remove camshaft bearings. Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Inspection

Inspect camshaft journal diameter, lobe lift and oil clearance. Replace components if not within specification. See CAMSHAFT table under ENGINE SPECIFICATIONS. CAUTION: If installing new camshaft, Replace all lifters and add GM EP Lubricant (1051396) to engine oil. Verify use of oversize valve lifters. Oversize lifters are identified by mark on cylinder block, near lifter bore. Installation

Install camshaft bearings (if removed), ensuring oil holes are aligned. Coat camshaft journals and bearings with Lubricant (1051396). Install camshaft. Install camshaft thrust plate. To complete installation, reverse removal procedure. CRANKSHAFT REAR OIL SEAL Removal

Remove transmission or transaxle. Remove flexplate/flywheel. See TRANSMISSION REMOVAL & INSTALLATION - M/T article (M/T models) or TRANSMISSION REMOVAL & INSTALLATION - A/T (A/T models). Pry seal from housing, being careful not to damage sealing surface of crankshaft. Note direction of seal installation. Installation

1. Coat inner and outer seal surfaces with engine oil. Install seal on mandrel of Seal Installer (J-34686) until dust lip bottoms against tool collar. See Fig. 8 . Align seal installer dowel pin with alignment hole of crankshaft. Install seal installer on crankshaft. 2. Tighten seal installer bolts to 27-62 INCH lbs. (3-7 N.m). Tighten seal installer handle until collar is even with cylinder block. Remove seal installer. To complete installation, reverse removal procedure. Apply thread locking compound to flexplate/flywheel bolts.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 8: Installing Rear Crankshaft Seal Courtesy of GENERAL MOTORS CORP. WATER PUMP Removal & Installation

Disconnect negative battery cable. Drain cooling system. Loosen water pump pulley bolts. Remove serpentine drive belt. Remove generator and brackets (if necessary). Remove water pump pulley. Remove water pump gasket. To install, reverse removal procedure. Use NEW gasket. Fill cooling system. OIL PAN NOTE:

This procedure requires engine to be supported from top.

Removal

Remove engine from vehicle. See ENGINE. Installation

Apply a 1/8" (2 mm) bead of RTV sealant to ears of NEW oil pan rear seal. Install seal onto bottom of rear main bearing cap. Install oil pan. To complete installation, reverse removal procedure. Tighten oil pan bolts to Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

specification. See TORQUE SPECIFICATIONS . Fill crankcase.

OVERHAUL CYLINDER HEAD Gasket Surfaces

If warpage of head gasket surface or manifold surfaces exceeds specification, resurface or replace cylinder head as necessary. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT remove more than .101" (.25 mm) material from head gasket surface. Valve Springs

If valve spring free length, out-of-square, or pressure is not within specification, replace valve spring. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS . Valve Stem Oil Seals

If installing oversize valves, use oversize seals. Ensure seal is fully seated on guide. Intake and exhaust seals are different. Valve Guides

If oil clearance exceeds specification, ream valve guides for .005" (.13 mm) oversize valves. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT knurl valve guides. Valve Seats

If valve seat runout and width are not within specification, machine valve seat or replace cylinder head as necessary. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. Valves

If valve head margin is not within specification, replace valve. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS. Machine valve face if rough. Valve Seat Correction Angles

If seat contact is too close to margin, machine seat with a 30-degree stone. If seat contact is too close to stem, machine seat with a 45-degree stone. If seat is too narrow, widen is with a 45-degree stone. If seat is too wide, narrow it with a 60-degree stone. CYLINDER BLOCK ASSEMBLY CAUTION: Before disassembly, mark all parts for reassembly reference. Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Piston & Assembly

Mark piston in relation to connecting rod for reassembly reference. Install piston with arrow on top of piston toward front of engine. Fitting Pistons

Measure cylinder bore diameter at center of bore. Measure piston diameter at 90-degree angle to piston pin .4" (10 mm) above bottom of piston skirt. Determine piston clearance. If piston clearance is not within specification, machine cylinder bore and/or install oversize piston as necessary. See PISTON, PINS & RINGS table and CYLINDER BLOCK table under ENGINE SPECIFICATIONS. Piston Rings

Measure piston ring end gap and side clearance. If end gap and side clearance are not within specification, replace piston rings and/or piston as necessary. See POISONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Install piston rings with identification mark on ring land facing top of piston. Properly position ring end gaps around circumference of piston. See Fig. 9 . Rod Bearings

If rod bearing oil clearance is not within specification, machine crankshaft rod bearing journals and install undersize bearings. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS. Crankshaft & Main Bearings

If crankshaft main bearing oil clearance, out-of-round or taper is not within specification, machine crankshaft main bearing journals and install undersize bearings. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS . Thrust Bearing

Thrust bearing is part of main bearing No. 4. Pry crankshaft toward rear of engine. Measure clearance between thrust bearing face and crankshaft. If clearance is not within specification, replace thrust bearing and/or crankshaft. Deck Surface Warpage

If deck surface warpage exceeds specification, machine or replace cylinder block. DO NOT remove more than .010" (.25 mm) material from deck surface. Valve Lifter Bores

Oversize valve lifters are available to compensate for excessive clearance between lifter and bore. Oversize lifter is indicated on cylinder block, near lifter bore.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 9: Positioning Piston Ring End Gaps Courtesy of GENERAL MOTORS CORP.

ENGINE OILING ENGINE LUBRICATION SYSTEM A camshaft-driven, gear-type oil pump is mounted at bottom of cylinder block and is accessible with oil pan removed. Oil pump supplies pressurized oil to internal passages of cylinder block. Internal passages intersect with hydraulic valve lifter bosses where oil flows to main and camshaft bearings and lifters. See Fig. 10 . Crankcase Capacity

Engine oil capacity is about 4 qts. (3.8L) without oil filter change. When changing oil filter, add more oil if necessary. Oil Pressure

Normal oil pressure is 56 psi (3.9 kg/cm2 ) at 3000 RPM.

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 10: Cross-Sectional View Of Engine Oil Circuit (Typical) Courtesy of GENERAL MOTORS CORP. OIL PUMP Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

WARNING: Pressure regulator valve spring is under pressure. Use caution when removing retaining pit to prevent bodily injury. Removal & Disassembly

Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION . Remove bolt securing oil pump to rear main bearing cap. Remove oil pump and extension shaft. Remove extension shaft and retainer from oil pump. Disassemble oil pump. DO NOT remove pick-up tube unless loose or broken. Inspection

1. Replace extension shaft retainer if cracked. Inspect components for damage. Measure depth and diameter of gear housing. Measure gear diameter and gear length. Measure gear lash (clearance between tip of gear teeth of both gears). Measure gear side clearance (clearance between tip of gear tooth and housing). 2. Using straightedge and feeler gauge, measure gear end clearance (clearance between cover plate and gear). Determine clearance between pressure regulator valve and bore. If clearances are not within specification, replace components as necessary. See OIL PUMP SPECIFICATIONS table. CAUTION: Before installing gears, pack oil pump cavities with petroleum jelly to prime pump. Use only original equipment gaskets when assembling oil pump, as gasket thickness is critical. Pick-up tube must be replaced if removed. Reassembly & Installation

To reassemble, reverse disassembly procedure. If pickup tube was removed apply Sealant (1050026) to MEW tube before installing it into oil pump. Install pick-up tube using Tube Installer (J-8369). To keep extension shaft retainer from cracking, heat it in hot water before installing it onto oil pump. To install, reverse removal procedure. Tighten oil pump bolt to specification. See TORQUE SPECIFICATIONS . OIL PUMP SPECIFICATIONS Application Gear Diameter End Clearance Lash Length Side Clearance Gear Housing Depth Diameter Valve-To-Bore Clearance

In. (mm) 1.498-1.500 (38.05-38.10) .002-.007 (,05-.18) .004-.008 (.10-.20) 1.199-1.200 (30.45-30-48) .0015-.0040 (.038-.102) 1.195-1.198 (30.36-30.44) 1.503-1.506 (38.18-38.25) .0015-.0035 (.038-.089)

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Fig. 11: Tightening Engine Mounts (S10 Pickup) Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

TORQUE SPECIFICATIONS Application A/C Compressor Bracket-To-Engine Bolts Camshaft Sprocket Bolts Connecting Rod Nuts Crankshaft Pulley & Hub-To-Crankshaft Bolts Crankshaft Pulley-To-Hub Bolts

Ft. Lbs. (N.m) 67 (91) 96 (130) 38 (52) 77 (104) 37 (50)

Cylinder Head Bolts (1) Step 1 Head Bolts "A" Head Bolts "B" Step 2

46 (62) 43 (58) Additional 90 Degrees

Engine Mounts (2) Mount-To-Block Bolts Mount Through Bolts Exhaust Manifold Nuts Exhaust Pipe-To-Manifold Nuts

39 (53) 38 (51) 22 (30) 18 (24) 55 (75)

Flexplate/Flywheel-To-Crankshaft Bolts (3) Intake Manifold Lower Manifold-To-Cylinder Head Nuts (4) Upper Manifold-To-Lower Manifold Bolts Main Bearing Cap Bolts Oil Pump Bolts Oil Pump Drive Bolts Oxygen Sensor Rocker Arm Nuts Serpentine Bolt Tensioner Pulley Bolts Timing Chain Tensioner Bolts Water Pump Bolts Water Pump Inlet INCH Lbs. (N.m) Anti-Rotation Bracket Bolts Camshaft Thrust Plate Bolts Front Cover Bolts Oil Pan Nuts/Bolts Oil Pump Cover Bolts Valve Cover Bolts (1) Tighten in sequence. See Fig. 5 .

24 (33) 22 (30) 70 (95) 32 (43) 18 (24) 31 (42) 22 (30) 37 (50) 18 (24) 18 (24) 18 (24) 97 (11) 106 (12) 97 (11) 89 (10) 89 (10) 89 (10)

(2) See Fig. 11 . Microsoft Saturday, August 29, 2009 11:33:48 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

(3) Apply thread locking compound to bolts. (4) Tighten in sequence. See Fig. 2 .

ENGINE SPECIFICATIONS GENERAL SPECIFICATIONS GENERAL SPECIFICATIONS Application Displacement Bore Stroke Compression Ratio Fuel System Horsepower @ RPM Torque Ft. Lbs. @ RPM

Specification 134 Cu. In. (2.2L) 3.50" (89.0 mm) 3.46" (88.0 mm) 9.0:1 MFI 120 @ 5200 130 @ 4000

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS Application Crankshaft End Play Main Bearings Journal Diameter Journal Out-Of-Round Journal Taper Oil Clearance Connecting Rod Bearings Journal Diameter

In. (mm) .002-.007 (.05-.18) 2.4945-2.4954 (63.36063.384) .0002 (.005) .0002 (.005) .0006-.0019 (.015-.047) 1.9983-1.9994 (50.75850.784) .0002 (.005) .0002 (.005) .0010-.0031 (.025-.079)

Journal Out-Of-Round Journal Taper Oil Clearance CONNECTING RODS CONNECTING RODS Application Maximum Bend

In. (mm) (1) (1)

Maximum Twist Microsoft Saturday, August 29, 2009 11:33:49 AM

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Side Play (1) Replace rod if any bend or twist exists.

.004-.015 (.10-.38)

PISTONS, PINS & RINGS PISTONS, PINS & RINGS Application Pistons Clearance Pins Diameter Piston Fit Rod Fit Rings No. 1 & 2 End Gap Side Clearance No. 3 (Oil) End Gap Side Clearance

In. (mm) .0006-.0018 (.015-.045) .8000-.8002 (20.320-20.325) .0004-.0009 (.010-.022) .0010-.0017 (.025-.045)

.010-.020 (.25-.50) .002-.003 (.05-.08) .010-.050 (.25-1.27) .002-.008 (.05-.21)

CYLINDER BLOCK CYLINDER BLOCK Application Cylinder Bore Standard Diameter

In. (mm) 3.5036-3.5043 (88.99189.009) .0005 (.013) .0005 (.013)

Maximum Taper Maximum Out-Of-Round Maximum Deck Warpage

(1)

(1) If more than .010" (.25 mm) material must be removed from original surface of deck, replace

cylinder block. VALVES & VALVE SPRINGS VALVES & VALVE SPRINGS Application Valves Face Angle Head Margin (Minimum)

Specification 45° .031" (.80 mm)

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Face Runout (Maximum) Valve Springs Free Length Out-Of-Square

.0012" (.030 mm) 1.94" (49.5 mm) .63" (1.6 mm) Lbs. @ In. (kg @ mm)

Pressure (Minimum) Valve Closed Valve Open

75 @ 1.71 (34 @ 43.4) 220 @ 1.28 (100 @ 32.5)

CYLINDER HEAD CYLINDER HEAD Application Maximum Warpage

Specification (1) .004" (.10 mm)

Valve Seats Intake Valve Seat Angle Seat Width Seat Runout (Maximum) Exhaust Valve Seat Angle Seat Width Seat Runout (Maximum) Valve Guides Intake Valve Stem-To-Guide Oil Clearance

46° .049-.059" (1.25-1.50 mm) .002" (.05 mm) 46° .063-.075" (1.60-1.91 mm) .002" (.05 mm)

.0010-.0027" (.025-.069 mm)

Exhaust Valve Stem-To-Guide Oil Clearance

.0014-.0032" (.035-.081 mm) (1) If more than .010" (.25 mm) material must be removed from original surface of cylinder head, replace cylinder head. CAMSHAFT CAMSHAFT Application Journal Diameter Lobe Lift

In. (mm) 1.868-1.8693 (47.45-47.48)

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1997 Chevrolet S10 Pickup 2.2L 4-CYL - VIN [4] 1996-97 ENGINES General Motors Corp. 2.2L 4-Cylinder VIN [4]

Intake Exhaust Oil Clearance

.2878 (7.309) .2877 (7.307) .0010-.0039 (.026-.101)

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

MODEL IDENTIFICATION Vehicle model is identified by fifth character of Vehicle Identification Number (VIN). VIN is stamped on metal pad on top of left end of instrument panel, near windshield.

INTRODUCTION This article contains removal, overhaul and installation procedures (when given by manufacturer). If component removal and installation is primarily an unbolt and bolt-on procedure, only a torque specification may be furnished.

COMPUTERIZED ENGINE CONTROLS POWERTRAIN CONTROL MODULE (PCM) NOTE:

All vehicles are equipped with either an Engine Control Module (ECM), Powertrain Control Module (PCM) or Vehicle Control Module (VCM) for engine control. Unless specifically stated, references to PCM also apply to ECM and VCM equipped vehicles. Some vehicles equipped with an electronicallycontrolled transmission also use a Transmission Control Module (TCM) for transmission control. CAUTION: Electronic components used in control systems are designed to carry very low voltages. As little as a 30-volt charge created by static electricity can cause a total or degrading failure in PCM or other electronic components containing integrated circuits. Before servicing PCM, technician must ground himself and work area to discharge static electricity. DO NOT remove part from packaging until ready to install. Ground any static-proof package before opening. DO NOT touch electrical terminals of components unless properly grounded. DO NOT lay electrical components on car seat, carpeting or dashboard. Use electrostatic protection mat and ground strap whenever possible.

NOTE:

Before replacing PCM, carefully inspect all wiring and control components. Failure to test for short circuits may result in repeated PCM failure due to shorts and Quad-Driver failure. To prevent internal damage to PCM, ensure ignition switch is in OFF position when connecting or disconnecting PCM connectors or any electrical components.

NOTE:

If the diagnostic procedures call for the PCM to be replaced, the PCM should be checked first to see if it is the correct part. DTC P0601 indicates the EEPROM

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

programming has malfunctioned. When DTC P0601 is obtained, re-program the EEPROM. Removal

PCM is located in right corner of engine compartment. Ensure ignition switch is in OFF position. The ignition should be OFF for at least 10 seconds before disconnecting power to the PCM so the IAC valve has time to move to the engine OFF position. Disconnect negative battery cable. Move the PCM retention bar and retainer away from the PCM. Unplug harness connectors from PCM. Remove PCM from vehicle.

Fig. 1: Locating PCM Retainer And PCM Courtesy of GENERAL MOTORS CORP. NOTE:

After installation of a NEW PCM, Malfunction Indicator Light (MIL) will remain on until PCM is programmed.

Installation

Install PCM into vehicle. Connect harness connectors to PCM. Reconnect negative battery cable. Slide the PCM Microsoft Saturday, August 29, 2009 11:40:48 AM

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

retainer into the PCM bracket slots. If NEW PCM has been installed, PCM MUST BE programmed and the crankshaft position system variation procedure must be performed.. For PCM programming, See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. For crankshaft position system variation learn, see Crankshaft Position System Variation Learn. ELECTRICALLY ERASABLE PROGRAMMABLE READ-ONLY MEMORY (EEPROM) EEPROM is a permanent memory that is part of PCM. EEPROM cannot be replaced. EEPROM contains program and calibration information that PCM uses to control powertrain. If PCM is replaced, ensure that NEW PCM software/calibration is correct and most recent version for vehicle. EEPROM must be programmed when NEW PCM is installed. Program EEPROM using latest software for that specific vehicle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION.

IGNITION SYSTEM KNOCK SENSOR (KS) MODULE NOTE:

Knock sensor module is an integral part of PCM.

CAMSHAFT POSITION (CMP) SENSOR Removal & Installation

On engines with distributorless ignition, CMP sensor is located in the engine block adjacent to cam. See Fig. 2. CAUTION: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist. 1. 2. 3. 4. 5. 6.

Raise the vehicle. Remove the RH tire assembly. Remove the Camshaft Position (CMP) sensor electrical connector. Remove the CMP sensor Install the Camshaft Position (CMP) sensor. Tighten the CMP sensor bolt to 10 Nm (7.5 lb in). To complete installation, reverse removal procedure.

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 2: Locating CMP Sensor Courtesy of GENERAL MOTORS CORP. CRANKSHAFT POSITION (CKP) SENSOR Removal & Installation (24X Sensor)

Disconnect CKP sensor harness connector. Remove CKP sensor retaining bolt. Remove CKP sensor. See Fig. 3. To install, reverse removal procedure.

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 3: Locating CKP Sensor Courtesy of GENERAL MOTORS CORP. Crankshaft Position System Variation Learn

IMPORTANT: A Crankshaft Position System Variation Learning Procedure must be performed any time a change is made to the crankshaft sensor to crankshaft relationship. Changing the crank sensor to crankshaft relationship will not allow the PCM to detect misfire at all speeds and loads accurately. Resulting in a possible false misfire DTC being set. Removing a part for inspection and then reinstalling the same part is considered a disturbance. A false DTC P0300 could be set if this procedure is not performed. The learn procedure is required after the following service procedures have been performed, regardless of whether or not DTC P1336 is set:     

PCM replacement. Engine replacement. Crankshaft replacement. Crankshaft position sensor replacement. Any engine repair(s) which disturbs the crankshaft/harmonic balancer to the crankshaft position sensor relationship CAUTION: Before performing the Crankshaft Position System Variation Learning

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Procedure always set the vehicle parking brake and block the drive wheels in order to prevent personal injury. Release the throttle immediately when the engine starts to decelerate in order to eliminate over revving the engine. Once the learn procedure is completed, the control module will return engine control to the operator and the engine will respond to the throttle position. IMPORTANT: The battery must be fully charged and in good condition. The scan tool connection at the DLC is clean and tight before starting the Crankshaft Position System Variation Learning Procedure. 1. 2. 3. 4. 5. 6. 7.

Close the hood. Block the drive wheels and set the vehicle parking brake. Put vehicle in Park or Neutral. Turn all the accessories OFF. Install a scan tool. Run the engine until it is at normal operating temperature 85°C (185°F). With the engine still running, enable the Crankshaft Position System Variation Learning Procedure with the scan tool. 8. Press and hold the brake pedal firmly and raise the engine speed to the specified value, RELEASING the throttle as soon as the engine cuts out. 9. Verify with the scan tool that the crankshaft variation has been learned.

Perform this procedure up to 10 times. If the PCM will not learn the variation, a DTC P1336 should be set. For 1997, refer to DTC P1336 - CKP SYSTEM VARIATION NOT LEARNED . For 1998, refer to DTC P1336 - CKP SYSTEM VARIATION NOT LEARNED . IGNITION COIL AND IGNITION COIL MODULE REPLACEMENT Removal Procedure

1. Remove the spark plug wires from the ignition control module assembly. The ignition coils and the spark plug wires are numbered in order to aid assembly.

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 4: Removing/Installing Spark Plug Wires Courtesy of GENERAL MOTORS CORP. 2. Disconnect the electrical connector and the vacuum hoses from the purge solenoid valve

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 5: Removing/Installing Purge Solenoid Valve Courtesy of GENERAL MOTORS CORP. 3. Remove the nut and the purge solenoid valve. 4. Remove the two bolts and one stud retaining the ignition control module assembly.

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 6: Removing/Installing Ignition Control Module Assembly Courtesy of GENERAL MOTORS CORP. 5. Remove the ignition control module assembly Installation Procedure

1. Install the ignition control module assembly to the engine with one bolt. NOTE:

Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

parts and systems.

Fig. 7: Removing/Installing Ignition Control Module Assembly Courtesy of GENERAL MOTORS CORP. 2. Install the remaining bolt and the stud. Tighten the bolts and the stud to 27 Nm (20 lb ft).

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 8: Removing/Installing Purge Solenoid Valve Courtesy of GENERAL MOTORS CORP. 3. Install the purge solenoid valve and the nut. Tighten the nut to 27 Nm (20 lb ft). 4. Connect the electrical connector and the vacuum hoses to the purge solenoid valve.

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Fig. 9: Removing/Installing Spark Plug Wires Courtesy of GENERAL MOTORS CORP. 5. Install the spark plug wires to the ignition control module assembly. The ignition coils and the spark plug wires are numbered in order to aid assembly. KNOCK SENSOR (KS) NOTE:

Cooling system may need draining prior to removing knock sensor.

Removal & Installation

CAUTION: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components Knock sensor is located on side of engine block. See Fig. 10. Disconnect negative battery cable. Raise vehicle. Microsoft Saturday, August 29, 2009 11:40:48 AM

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Disconnect wiring harness connector from knock sensor. Remove knock sensor. To install, reverse removal procedure. Install sealant to sensor threads prior to installation. Tighten knock sensor to 14 ft. lbs. (19 N.m). Install harness connector. Lower vehicle. reconnect negative battery cable.

Fig. 10: Locating Knock Sensor Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:40:48 AM

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

FUEL SYSTEM FUEL SYSTEM PRESSURE RELIEF 1. Disconnect negative battery cable. Loosen fuel filler cap to relieve fuel tank pressure. Install Fuel Pressure Gauge (J-34730-1) to fuel pressure connection. 2. Wrap shop towel around pressure connection when installing fuel pressure gauge to absorb fuel leakage. Place gauge bleed hose into suitable container. Open bleed valve to bleed fuel pressure. FUEL PUMP NOTE:

When installing sending unit, DO NOT fold or twist strainer. This will restrict fuel flow.

Removal & Installation

1. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELIEF under FUEL SYSTEM. Disconnect negative battery cable. Raise vehicle and remove fuel tank. Using Sending Unit Remover (J36608 or J-24187), remove sending unit and pump by turning cam lock counterclockwise. 2. Remove fuel pump from sending unit by pulling pump up into attaching hose while pulling outward from the bottom support. DO NOT damage rubber insulator or strainer. To install, reverse removal procedure. FUEL RAIL & INJECTORS Removal

1. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF under FUEL SYSTEM. Disconnect negative battery cable. Label fuel injector connectors for installation reference. 2. Disconnect fuel injector harness connectors. Disconnect fuel feed line at fuel rail. Disconnect fuel return line at pressure regulator. Remove fuel pressure regulator. Remove fuel rail retaining bolts. Remove fuel rail and injectors as an assembly. Disassemble as necessary. Installation

To install, reverse removal procedure. Replace and lubricate injector "O" rings with clean engine oil. Tighten bolts to specification. See TORQUE SPECIFICATIONS. IDLE AIR CONTROL (IAC) VALVE Removal

Disconnect IAC valve harness connector. Remove IAC valve retaining screws and remove IAC valve and "O" ring from throttle body. CAUTION: DO NOT manually extend or retract pintle if IAC valve has been in service. Damage to worm gear will result. Microsoft Saturday, August 29, 2009 11:40:48 AM

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

NOTE:

Before installation, clean "O" ring sealing surface, pintle seat and air passage. If air passage has heavy deposits, remove throttle body for complete cleaning.

Installation

1. Inspect "O" ring for damage. Replace if necessary. If reusing IAC valve, DO NOT push or pull on pintle. Threads on worm gear will be damaged. 2. If replacing IAC valve, measure distance between tip of new IAC valve pintle and mounting flange. Distance should not exceed 1 1/8" (28 mm). If distance is more than specified, use finger pressure to slowly retract pintle. Lubricate "O" ring with clean engine oil. 3. Apply thread locking compound (Loctite 262) to IAC valve retaining screw threads. Install IAC valve to throttle body. Tighten IAC valve retaining screws to 27 INCH lbs. (3 N.m). Connect IAC valve harness connector. 4. To reset IAC valve pintle position, turn ignition on for 5 seconds. Turn ignition off for 10 seconds. Start engine and check for proper idle operation. Repeat IAC valve resetting procedure if proper idle operation cannot be obtained. 5. Start engine and allow it to reach normal operating temperature. Drive vehicle. It may be necessary to reset idle speed. To reset, disconnect negative battery cable for 10 seconds and reconnect. Cycle ignition on with engine off for 5 seconds. Turn ignition off for 10 seconds and restart vehicle. Proper idle will be initialized. THROTTLE BODY Removal & Installation

1. Disconnect negative battery cable. Remove air cleaner resonator from throttle body. Disconnect IAC and TP sensor harness connectors. Disconnect vacuum hose from throttle body. 2. Disconnect control cables from throttle body. Remove accelerator cable bracket. Remove throttle body attaching bolts. Remove throttle body and gasket. To install, reverse removal procedure. THROTTLE POSITION (TP) SENSOR Removal & Installation

1. Remove air cleaner assembly (if necessary). Disconnect harness connector from TP sensor. Remove attaching screws, lock washers, retainers, and TP sensor. 2. To install, reverse removal procedure. Adjust TP sensor to specification. See ADJUSTMENTS - 2.2L article. When replacing a TP sensor, ensure correct part number is used. Use Loctite on TP sensor attaching screws. OXYGEN SENSOR CAUTION: Oxygen sensor is equipped with a permanent pigtail which must be protected to prevent damage when removing sensor. Microsoft Saturday, August 29, 2009 11:40:48 AM

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1997 Chevrolet S10 Pickup 1997-98 ENGINE PERFORMANCE Removal, Overhaul & Installation 2.2L

Removal

1. Oxygen sensor is mounted in the exhaust pipe below exhaust manifold. Ensure sensor is free of contaminants. DO NOT use cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Excessive removal force may damage threads in exhaust manifold or pipe. 2. Disconnect negative battery cable. Disconnect harness connector from oxygen sensor. Carefully remove oxygen sensor from exhaust pipe. CAUTION: Correct torque of oxygen sensor is critical to prevent crushing glass beads in graphite anti-seize compound. Crushing glass beads will cause sensor to seize in exhaust manifold. This may require replacement of exhaust manifold upon next removal. Installation

1. Whenever oxygen sensor is removed, coat threads with anti-seize compound before reinstalling. New oxygen sensors already have this compound applied to threads. 2. Install oxygen sensor in exhaust pipe and tighten sensor to 30 ft. lbs. (41 N.m). Reconnect harness connector to oxygen sensor. Reconnect negative battery cable.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application ECT Sensor EGR Valve Fuel Line Nut Fuel Rail Retaining Bolts Fuel Tank Strap Nuts Knock Sensor Oxygen Sensor Throttle Body-To-Manifold Bolt

Ft. Lbs. (N.m) 17 (23) 22 (30) 20 (27) 18 (24) 33 (45) 14 (19) 30 (41) (1)

INCH Lbs. (N.m) 71 (8)

Crankshaft Position Sensor Bolt Idle Air Control Valve Screws

27 (2) 27 (2)

TP Sensor Bolt (1) Tighten bolts to 89 INCH lbs. (10 N.m). (2) Tighten bolts to 11 ft. lbs. (15 N.m).

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1997 Chevrolet S10 Pickup D - ADJUSTMENTS - 4.3L 1997 ENGINE PERFORMANCE General Motors - On-Vehicle Adjustments - 4.3L

D - ADJUSTMENTS - 4.3L 1997 ENGINE PERFORMANCE General Motors - On-Vehicle Adjustments - 4.3L

ENGINE MECHANICAL Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.

VALVE CLEARANCE NOTE:

All models are equipped with hydraulic lifters. Adjustments are not required.

IGNITION TIMING NOTE:

Ignition timing is controlled by control module and is not adjustable.

IDLE SPEED & MIXTURE NOTE:

NOTE:

Controlled idle speed and IAC count can be checked using scan tool. See CONTROLLED IDLE SPEED & IAC COUNT table.

CONTROLLED IDLE SPEED CHECK 1. Ensure no trouble code(s) are present, IAC system is okay, and ignition timing is correct. Block drive wheels. Apply parking brake. Connect Tech 1 scan tool to Data Link Connector (DLC). Put scan tool into OPEN mode. 2. Start engine and bring to normal operating temperature. Check for correct state of transmission range switch on scan tool. Check if idle speed and IAC valve pintle position (counts) are as specified. See CONTROLLED IDLE SPEED & IAC COUNT table. 3. If idle speed is not within specification, refer to the TESTS W/O CODES - 4.3L article. CONTROLLED IDLE SPEED & IAC COUNT Application Under 8500 GVW

Idle RPM

(1) IAC Counts

Auto. Trans. (2)

565-615

50-30

Man. Trans. (3)

525-575

50-30

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1997 Chevrolet S10 Pickup D - ADJUSTMENTS - 4.3L 1997 ENGINE PERFORMANCE General Motors - On-Vehicle Adjustments - 4.3L

Over 8500 GVW Auto. Trans. (2)

625-675

50-30

675-725 50-30 Man. Trans. (3) (1) Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. (2) Automatic transmission in Drive. (3) Manual transmission in Neutral. Tech 1 scan tool will display "RDL" with transmission in Neutral.

THROTTLE POSITION (TP) SENSOR TP sensor output voltage should be .85 volt or less at idle (closed throttle) and is not adjustable.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

1996-97 ENGINES 4.3L V6 - Trucks

ENGINE IDENTIFICATION NOTE:

For repair procedures not covered in this article, see ENGINE OVERHAUL PROCEDURES article in GENERAL INFORMATION.

Engine is identified by eighth character of Vehicle Identification Number (VIN). VIN is stamped on a metal tag on top left end of instrument panel, near windshield. See ENGINE IDENTIFICATION CODES table. Engine can also be identified by engine identification (ID) number. Number is stamped on front of cylinder block, immediately forward of right cylinder head or on left side of cylinder block, on engine-to-transmission mating flange. ENGINE IDENTIFICATION CODES Engine CSI CSI (1) Eighth character of VIN.

(1) VIN Code

W X

Engine ID L35 LB4

ADJUSTMENTS VALVE CLEARANCE ADJUSTMENT NOTE:

Although valve clearance adjustment is not usually required (engine uses hydraulic valve lifters), perform the following procedure after servicing valve train.

Engine uses screw-in rocker arm studs with a shoulder. Tighten rocker arm nuts to specification. See TORQUE SPECIFICATIONS table. SHIFT CABLE ADJUSTMENT NOTE:

When installing shift cable, DO NOT pull shift lever ball stud forward of transmission shift lever ball stud.

Express, "C" & "K" Pickup, Savana, Sierra & Tahoe

1. Ensure transmission shift lever is in mechanical park position. Rotate control lever clockwise until it reaches it's final stop position. Apply parking brake. Raise and support vehicle. 2. Slide Black retaining clip forward on shift cable end far enough to allow White lock button to be pushed out. Push White lock button on shift cable end out far enough to free metal core adjust body inside cable Microsoft Saturday, August 29, 2009 11:34:28 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

end. DO NOT push White lock button completely out. 3. Inspect metal core adjust body on shift cable end for dirt or debris that may restrict its travel. If travel of metal core adjust body remains restricted, shift cable assembly must be replaced. Lower vehicle. Ensure parking brake is applied. 4. Turn ignition switch to ON position. Move transmission shift lever from Park to One and back to Park position 10 times. Place shift lever to Park. Turn ignition switch to OFF position. Raise and support vehicle. Ensure transmission control lever is in mechanical park position. 5. Rotate control lever clockwise until it reaches it's final stop position. Push White lock button in to secure core adjuster body inside shift cable end. Slide Black retainer clip rearward over shift cable end until it covers White lock button and locks in place over shift cable end. Ensure parking brake is applied. Lower vehicle. Astro & Safari

1. Ensure shift cable is not restricted. Place steering column shift lever into Neutral. Position shift cable to assume a natural routing. Shift cable must be free to move .80" (20 mm) during adjustment. 2. Pull cable end completely forward and release it. When cable is pulled completely forward and released, adjustment spring will position cable to its most rearward position. Connect end of shift cable to transmission shift lever stud ball.

TROUBLE SHOOTING NOTE:

To trouble shoot mechanical engine components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

REMOVAL & INSTALLATION WARNING: On vehicles equipped with air bag restraint system, see appropriate AIR BAG RESTRAINT SYSTEM article before servicing steering wheel or column. Use extreme caution to avoid personal injury and vehicle damage. CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. NOTE:

For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

FUEL PRESSURE RELEASE Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Disconnect battery terminals. Loosen fuel tank cap to relieve tank pressure. Connect one end of fuel gauge hose to pressure relief fitting at rear of intake manifold. Place other end of hose in a container. Open relief valve to release pressure. COOLING SYSTEM BLEEDING 1. Fill radiator to base of filler neck. Start engine. Place A/C-heater control in any position except MAX. Select highest temperature setting. Idle engine until lower radiator hose is hot. 2. Increase engine speed to 3000 RPM and then back to idle. Do this 5 times to expel any air trapped in system. Fill radiator as necessary. Install radiator cap. Allow engine to cool. Fill coolant recovery reservoir as necessary. 3. Crush and add 2 Coolant Sealant Pellets (GM P/N 3634621) or equivalent to radiator (if reservoir is not pressurized) or coolant reservoir (if reservoir is pressurized). POWER STEERING BLEEDING NOTE:

If air was introduced into hydraulic system during servicing, bleed system. Aerated fluid, which appears Light Tan in color, results in poor steering performance and will cause pump damage.

1. Turn ignition off. Raise and support vehicle with front wheels off ground. Using steering wheel, turn wheels fully to left. Add power steering fluid to FULL COLD mark on dipstick. Turn wheels from side to side at least 20 times, but DO NOT touch steering stops. Add fluid as necessary to maintain level at FULL COLD mark. 2. Start engine. With engine idling, check fluid level. Add fluid as necessary to bring fluid level to FULL COLD mark. Return wheels to center position. Lower vehicle. Continue to run engine for 2 to 3 minutes to raise temperature of fluid and eliminate trapped air. Turn steering wheel in both directions. 3. Road test vehicle. Check for leaks. Ensure fluid level is at FULL HOT mark when fluid is stabilized at operating temperature. ENGINE CAUTION: Minimal clearance exists between oil pump pick-up tube and bottom of oil pan. DO NOT place jack under oil pan, crankshaft pulley or any sheet metal when lifting engine. WARNING: Provide addition support for opposite end from which components are being removed. When removing major components of vehicle, vehicle frame should be chained to hoist pads at same end as removed components to prevent tip-off. Failure to follow these precautionary measures could result in vehicle damage or serious personal injury. NOTE:

Flush out oil and engine cooling system when installing new engine.

Removal (Astro & Safari) Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

1. On this vehicle, engine must be removed out of bottom of vehicle. Release fuel system pressure. See FUEL PRESSURE RELEASE . Remove battery. Remove air filter assembly and if equipped, disconnect cruise control cable from throttle body. Disconnect cruise control stepper motor electrical connector. Drain cooling system. Raise and support vehicle. 2. Remove drive shaft. Disconnect transfer case vent hose. Disconnect exhaust pipes from manifolds and behind catalytic converter. Remove park brake bracket from frame. Disconnect rear brake line from metering proportioning valve (combination valve). Remove flywheel cover, 3 torque converter bolts (A/T), starter and oil filter. Disconnect shift linkage. Disconnect engine wiring harness from transmission and frame. 3. Disconnect fuel lines from sub-frame. Disconnect transmission fluid lines and engine oil cooler lines from radiator. Remove lower fan shroud bolts. Disconnect power steering cooler from front air deflector. Disconnect air bag sensor connector. Remove motor mount through-bolts. Lower vehicle. Remove front bumper. 4. Remove headlight bezels and grille. Remove lower radiator close-out panel, radiator support braces and radiator cross brace. Remove hood latch mechanism. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove upper fan shroud and radiator. 5. Remove radiator filler panels. Remove engine cover. Disconnect A/C hose from accumulator and condenser. Remove A/C compressor and bracket. Remove power steering pump. Disconnect master cylinder and tie to oil fill tube. Disconnect steering shaft. Disconnect wheel housing splash shields. If equipped, disconnect rear A/C lines at rear crossmember. 6. Disconnect vacuum hoses as necessary. Disconnect fuse box and wiring harness from bulkhead connector, and all related electrical connectors. Lay harness on engine. Remove right kick panel. Remove CPI or TBI unit from intake manifold. Push connector and harness through firewall. Remove distributor cap and A/C accumulator. Disconnect fuel line from injection unit. Pull fuel lines through crossmember and lay lines on transmission. Remove fuel tank electrical connector. 7. Remove transmission dipstick tube (A/T). Disconnect heater hose from heater core. Remove horn. Attach side lift hoist. Attach Body Protection Hoist Adapter Set (J41602), Twin Post Hoist Frame Support (J41617), and Universal Lift Bracket (J41427). Support transmission. On 4WD, disconnect transfer case to engine block support brace. Remove 9 bellhousing bolts. Lower engine from vehicle. Installation

1. Place engine in position on sub-frame. Install engine mount through bolts. Torque to specification. See TORQUE SPECIFICATIONS . Remove engine lift Adapter (J-41427). 2. Connect transmission to engine, torque to specification. See TORQUE SPECIFICATIONS . Install exhaust "Y" pipe to engine. On 4WD models, install transfer case support brace. Route and connect all fuel lines, hoses and transmission wiring harness. Connect steering shaft and wheel housing splash shields. 3. Install distributor cap. Connect heater hose from coolant pump. Connect harness at knock sensor module. Connect wiring harness at bulkhead. Install CPI or TBI unit to intake manifold. Install A/C compressor. 4. Lower vehicle into position for engine/sub-frame installation. Install sub-frame bolts and tighten in sequence. See Fig. 1 . Connect engine electrical harness. Route and install remaining accessory, bulkhead and fuse box wiring. Secure fuse box. Connect wheel housing splash shields to frame. Install steering shaft and torque to specification. See TORQUE SPECIFICATIONS . Install power steering pump bracket and pump. Connect A/C compressor hose assembly. Install cruise control servo and bracket. Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

5. Connect power steering pump. Connect hydraulic lines at gear-box, pump, hydro boost and reservoir. Install serpentine belt. Install/connect A/C accumulator and hoses. Install radiator. Install upper radiator hoses and cooler lines. Connect heater hoses. Install all vacuum hoses. 6. Install fan and fan clutch assembly. Install fan shroud and radiator filler panels. Install grille and headlamp bezels. 7. Install master cylinder and connect all fittings disconnected previously. Install hood latch and radiator braces. Install transmission and engine filler tubes. Install cruise control stepper motor cable, wiring and accelerator cable. Install plug wires. 8. Install air cleaner and ducts. Connect fuel lines at intake manifold. Install fuel line bracket and connect fuel lines at frame. Raise and support vehicle with safety stands. 9. Connect lower engine oil cooler line to radiator. Install power steering cooler and lines. Install lower transmission oil cooler line and lower radiator hose to radiator. Install front bumper. Connect drive shaft and transmission linkage. Torque all fasteners to specification. See TORQUE SPECIFICATIONS . Connect all fuel hoses. Install air bag sensor wiring. Install starter. Connect remaining wiring at engine and sub-frame. 10. Install torque converter bolts and cover. See TORQUE SPECIFICATIONS . Connect exhaust pipes and lower vehicle. Install oil filter and oil. Ensure oil level is correct. See Crankcase Capacity . Ensure transmission fluid level is correct. Fill and bleed power steering system. See POWER STEERING BLEEDING . Install air filter assembly. Install battery and negative battery cable. Install engine cover. Install right kick panel. 11. Install battery. Fill and bleed brake system. Install coolant as needed. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. See appropriate article in REFRIGERANT RECOVERY/RECYCLING in A/C GENERAL SERVICING. 12. Check all components for leaks, proper fluid levels and proper operation.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 1: Tightening sub-frame mounting bolts in sequence (Astro & Safari). Courtesy of GENERAL MOTORS CORP. Removal (Pickup, Sierra, & Tahoe)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE . Remove hood. Remove air cleaner, accessory drive belt, fan and water pump pulley. 2. Drain cooling system. Remove fan shroud and radiator. Disconnect heater hoses from engine. Disconnect fuel lines, electrical connectors, vacuum hoses, coolant hoses and control cables as necessary. Discharge Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C compressor and power steering pump with hoses attached and position aside (if equipped). 3. Mark and remove distributor. Raise and support vehicle. Drain crankcase. Disconnect exhaust pipes from manifolds. Disconnect strut rods. Remove flywheel cover. Remove starter. Remove torque converter bolts (A/T). Lower vehicle. 4. Support transmission. Attach engine hoist. Remove bellhousing bolts. Remove front engine mount-toframe bolts. Remove engine. Installation

1. Release fuel system pressure. See FUEL PRESSURE RELEASE . Drain crankcase and cooling system. Remove engine cover and floor panel sections. 2. Remove air cleaner, duct and exhaust heat stove pipe. Remove distributor cap and position aside. Disconnect all engine harness electrical connectors and position aside. Disconnect fuel lines from injection unit. Remove fuel line clamps from transmission and position fuel lines aside. Disconnect electrical connectors, vacuum hoses, coolant hoses and control cables as necessary. 3. Disconnect ground strap from rear end of left cylinder head. Disconnect all transmission harness electrical connectors and position harness aside. Remove transmission shifter (if necessary). Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C compressor. Remove upper radiator hose, all accessory drive belts, fan, fan pulley, fan shroud, lower radiator hose and radiator. 4. Remove engine oil filler tube. Remove clutch adjuster rod, return spring and pivot arm assembly (M/T). Disconnect exhaust pipes from manifolds. Disconnect battery cable from clamp on cylinder block. Disconnect drive shaft from transmission. Remove transmission mount. 5. Disconnect oil cooler lines from oil filter adapter and oil cooler line clamps from engine. Remove torque converter bolts. Attach engine hoist. Remove engine mount through-bolts. Remove engine. Installation

NOTE:

Notice: If the engine is damaged internally and a new engine assembly is installed in the vehicle, ensure that all foreign material is flushed out of the cooling system. You must also flush out the oil cooler system. Failure to rid the

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

oil cooler system of debris can result in engine damage. NOTE: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

22. 23. 24. 25.

Tool Required: J-41427 Universal Lift Bracket.

Release fuel system pressure. See FUEL PRESSURE RELEASE . Raise the vehicle. Remove the underbody shield. Remove the braces from the engine to the transmission. Disconnect the exhaust pipe from the exhaust manifolds. Disconnect the slave cylinder or hydraulic line if the cylinder is mounted inside the bellhousing. Disconnect the fuel line clamp at the bellhousing. Remove the starter. Disconnect the torque convertor bolts from the flywheel. Disconnect the front propeller shaft (4WD only). Remove the oil filter. Remove the transmission to engine bolts.  Remove all the transmission to engine bolts except for the upper left bolt.  For an automatic transmission refer to Transmission Replacement in Automatic Transmission.  For a manual transmission refer to Transmission Replacement in Manual Transmission. Remove the front engine mount through bolts. See Fig. 2 . Remove the rear engine mount crossbar nut and washer. See Fig. 3 . Lower the vehicle. Remove the battery ground cable at the engine. Remove the water pump pulley. Remove the air conditioning compressor and bracket. Remove the radiator. Disconnect the power steering hoses from the power steering gear and cap them. Disconnect the heater hoses from the engine. Disconnect the following items:  The wiring harnesses  The vacuum lines  The throttle cable  The fuel lines Remove the distributor. Support the transmission with a jack and remove the final transmission to engine bolt. Install J-41427 to the right rear and the left front of the intake manifold. Tighten Retaining bolts to 15 N.m (11 lb. ft.). see Fig. 4 . Use an engine lifting device and remove the engine from the vehicle.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 2: Removing & Installing Engine Mount Through Bolt

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 3: Removing & Installing Crossbar Mount

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 4: Installing J-41427 To Intake Manifold Installation

1. Install the engine into the vehicle. 2. Install the left upper transmission to engine bolt. 3. Install the front engine mount through bolts and nuts:  Tighten the bolts to 66 N.m (49 lb ft).  Tighten the nuts to 56 N.m (41 lb ft). 4. Remove the universal lift brackets and install the intake manifold bolts. 5. Install the distributor. 6. Install the following items: Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

The wiring harnesses  The vacuum lines  The throttle cable  The fuel lines Connect the heater hoses to the engine. Install the power steering hoses. Install the radiator. Install the air conditioning compressor and bracket. Install the water pump pulley. Raise the vehicle. Install the battery ground cable at the engine. Install the remaining transmission to engine bolts.  For an automatic transmission refer to Transmission Replacement in Automatic Transmission.  For a manual transmission refer to Transmission Replacement in Manual Transmission. Install the rear engine mount crossbar nut and washer. Tighten the nut to 45 N.m (33 lb ft). Install the oil filter. Connect the torque convertor bolts to the flywheel. Install the front propeller shaft (4WD only). Install the starter. Connect the fuel line clamp at the bellhousing. Connect the slave cylinder or hydraulic line if the cylinder is mounted inside the bellhousing. Connect the exhaust pipe to the exhaust manifolds. Install the braces from the engine to the transmission. Install the underbody shield. Lower the vehicle. Fill the crankcase with oil. Connect the negative battery cable. 

7. 8. 9. 10. 11. 12. 13. 14.

15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27.

Fill cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table. Removal (Express & Savana)

1. Release fuel system pressure. See FUEL PRESSURE RELEASE . Drain cooling system. Remove engine cover and air cleaner. Remove power steering fluid reservoir. 2. Remove upper fan shroud, fan, fan pulley, radiator and lower fan shroud. Remove engine coolant reservoir. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C condenser. Remove A/C compressor and brace. Remove generator and bracket. Remove 2 ground straps. Remove cruise control servo (if equipped). Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

3. Disconnect fuel lines, electrical connectors, vacuum hoses, coolant hoses and control cables as necessary. Remove injection unit. Remove distributor cap with wires attached. Remove diverter valve assembly and pipe. 4. Remove ignition coil and manifold absolute pressure sensor. Remove upper half of engine oil dipstick tube. Remove engine oil filler tube. Remove headlight bezels, grille and upper radiator support (sheet metal cross panel support). Remove front bumper. Remove intake manifold. See INTAKE MANIFOLD . 5. Raise and support vehicle. Drain crankcase. Disconnect exhaust pipes from manifolds. Remove strut rods. Remove flywheel cover. Disconnect oil cooler lines from engine. Remove transmission shift cable. Remove starter, torque converter bolts (A/T) and engine mount through-bolts. 6. Lower vehicle. Attach engine hoist. Remove bellhousing bolts. Support transmission. Remove engine. Installation

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary, adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table. INTAKE MANIFOLD (UPPER) CAUTION: Always apply a few drops of clean engine oil to male fuel pipe ends before connecting fuel pipe fittings in order to reduce risk of fire and personal injury. This will also prevent a possible fuel leak. During normal operation, the "O" rings located in the female connector will swell, and may prevent proper reconnecting if not lubricated. NOTE:

Manufacturer does not provide a torque sequence for upper intake manifold.

Removal

1. Remove negative battery terminal. Release fuel system pressure. See FUEL PRESSURE RELEASE . Remove air filter assembly and intake duct. 2. Remove wiring harness connectors and brackets and move to the side. Remove throttle and cruise control (if equipped) cable. Remove fuel lines and bracket at rear of lower intake manifold. 3. Remove brake booster vacuum hose and PCV hose at upper intake manifold. Remove ignition coil and bracket. Remove purge solenoid and bracket. 4. Remove upper intake manifold bolts and studs. Mark location of all studs for proper assembly. Remove upper intake manifold. See Fig. 5 . Clean old pieces of gasket from all gasket surfaces. Inspect manifold for cracks, broken flanges, and damage to gasket surface.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 5: Exploded View Of Intake Manifold Assembly (VIN W) Courtesy of GENERAL MOTORS CORP. Installation

1. Install upper intake manifold gasket. See Fig. 6 . Install upper intake manifold. DO NOT pinch injector lines between upper and lower intake manifolds. Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

NOTE:

Tighten upper intake manifold bolts to specification in a criss-cross pattern. Manufacturer does not provide a specific torque sequence.

2. Install the 2 corner studs first in order to help align the two halves. Install upper intake manifold bolts. Tighten first to 44 INCH lbs. (5 N.m) and then tighten to 89 INCH lbs. (10 N.m). 3. Install the purge solenoid and bracket. Install the ignition coil and bracket. Install the PCV hose at the upper intake manifold. Install the fuel lines and bracket at the rear of the lower intake manifold. 4. Install the throttle linkage and cruise control cable (if equipped). Install the wiring harness connectors and brackets. 5. Install the air filter assembly and intake duct. Connect the negative battery cable.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 6: Installing Upper Intake Manifold Gasket (VIN W) Courtesy of GENERAL MOTORS CORP. INTAKE MANIFOLD (LOWER) Removal

NOTE:

Removing upper intake manifold is not necessary when removing lower intake manifold, they are removed as an assembly.

1. Remove distributor cap. Mark distributor rotor in relation to distributor housing. Mark base of distributor Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

2. 3. 4. 5. 6. 7.

housing in relation to intake manifold. Remove distributor. Drain cooling system. Disconnect upper radiator hose at thermostat housing. Disconnect water pump bypass hose and heater hose at intake manifold. Remove EGR valve. Disconnect fuel lines at rear of lower intake manifold. Disconnect wiring harness. Disconnect throttle cable and cruise control cable (if equipped). Unbolt throttle cable bracket from intake manifold. Move throttle cable bracket aside, with cables attached. Unbolt transmission dipstick tube and remove/move aside as necessary. Remove PCV valve and disconnect vacuum hoses as necessary. Remove serpentine belt. Unbolt A/C compressor/accessory bracketry and move aside as necessary to allow removal of intake manifold. Remove lower intake manifold bolts, lower intake manifold and gaskets.

Installation

1. Apply a 3/16" (5 mm) bead of RTV (GM P/N 1052289) or equivalent to 4 sealing corners of block. Extend bead 1/2" (13 mm) up each cylinder head. See Fig. 7 . 2. Apply Loctite(R) 242 (GM P/N 12345382) or equivalent to lower intake manifold bolt threads. Tighten bolts in sequence to specification. See Fig. 8 . See TORQUE SPECIFICATIONS table. CAUTION: Always use NEW "O" rings when reconnecting fuel lines at rear of engine. 3. To complete installation, reverse removal procedure. Fill and bleed cooling system. See COOLING SYSTEM BLEEDING .

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 7: Applying RTV Sealant Before Installing Intake Manifold Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 8: Lower Intake Manifold Bolt Tightening Sequence Courtesy of GENERAL MOTORS CORP. EXHAUST MANIFOLD Removal

Remove engine cover or floor panel. Remove negative battery cable. Remove oil level indicator tube and EGR inlet pipe. Remove spark plugs and spark pug heat shields. Remove exhaust pipe at manifold. Remove exhaust manifold bolts and exhaust manifold. Installation

Install manifold. Tighten bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. CYLINDER HEAD Removal

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Remove negative battery cable. Remove engine cover or floor panel. Remove intake manifold. See appropriate INTAKE MANIFOLD . Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C compressor and bracket (if equipped). Remove generator and brackets. Remove spark plugs. Installation

1. Clean gasket surfaces, bolt threads and bolt holes. If using steel head gasket, thinly coat both sides of gasket with sealant. DO NOT apply sealant to composite (steel/asbestos) head gaskets. Position head gasket on cylinder block. Ensure all holes align. Coat head bolt threads with GM Sealant (1052080). 2. Install cylinder head with bolts finger-tight. Tighten head bolts in sequence to specification. See Fig. 9 . See TORQUE SPECIFICATIONS table. Lubricate valve tip, rocker arm pivot and push rod socket with Molykote. 3. To complete installation, reverse removal procedure. Adjust valves. See VALVE CLEARANCE ADJUSTMENT under ADJUSTMENTS.

Fig. 9: Cylinder Head Bolt Tightening Sequence Courtesy of GENERAL MOTORS CORP. ROCKER ARMS & PUSHRODS Removal

Remove negative battery cable. On Commercial Van, remove engine cover of floor panel. Remove PCV valve and tube. Remove EGR inlet tube. Remove purge solenoid and spark plug wires. Remove valve cover. Remove Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

rocker arm bolts. If pushrods are to be replaced only, back off valve rocker arm bolts until valve rocker arm can be swung away from pushrod and remove pushrod. Installation

Coat bearing surfaces with High Viscosity Oil/Zinc (GM P/N 12345501). Valve cover gaskets are reusable. Replace gaskets only if damaged. Tighten to specification. See TORQUE SPECIFICATIONS table. To install remaining components, reverse removal procedure. FRONT COVER OIL SEAL Removal

1. Coat crankshaft front cover oil seal lips with clean engine oil. Using Seal Installer (J-35468), install NEW seal in front cover with seal lip facing engine. Apply RTV sealant to Woodruff keyway in crankshaft balancer. 2. Using Damper Puller/Installer (J-23523-F), install crankshaft balancer. Tighten fasteners to specification. See TORQUE SPECIFICATIONS table. To install remaining components, reverse removal procedure. FRONT COVER Removal

NOTE:

DO NOT reinstall original composite front cover. Always install a NEW front cover. Reinstalling original front cover can lead to oil leaks.

1. Remove negative battery cable. If equipped, remove engine cover or floor pan. Remove upper fan shroud. Remove engine cooling fan. Remove accessory drive belt(s) and water pump pulley. 2. Raise and support vehicle. Remove lower fan shroud. Remove crankshaft balancer bolt. Remove crankshaft pulley bolts and crankshaft pulley. 3. Using Damper Puller/Installer (J-23523-F), remove crankshaft balancer. Remove water pump. See WATER PUMP . 4. Disconnect Crankshaft Position (CKP) sensor harness connector. Remove CKP sensor bolt and CKP sensor. Loosen or remove oil pan as necessary for removal of front cover. 5. Remove front cover bolts, front cover and gasket. Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Installation

1. Install NEW front cover and gasket. Tighten front cover bolts to specification. See TORQUE SPECIFICATIONS . CAUTION: Ensure CKP sensor is fully seated and held stationary in bore of front cover upon installation. A CKP sensor that is not fully seated may result in erratic engine operation. 2. Install CKP sensor. Tighten CKP sensor holddown bolt to specification. See TORQUE SPECIFICATIONS . 3. Apply RTV sealant to Woodruff keyway in crankshaft damper. Install crankshaft damper using Damper Puller/Installer (J-23523-F). Tighten fasteners to specification. See TORQUE SPECIFICATIONS . To complete installation, reverse removal procedure. TIMING CHAIN & SPROCKETS Removal

1. Remove front cover. See FRONT COVER . 2. Remove CKP sensor reluctor ring. See Fig. 10 . Rotate crankshaft until timing marks on camshaft and crankshaft sprockets are aligned. See Fig. 11 . Remove camshaft sprocket and timing chain. To remove crankshaft sprocket, use Sprocket Puller (J-5825-A).

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 10: Removing/Installing CKP Sensor Reluctor Ring Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 11: Aligning Timing Marks Courtesy of GENERAL MOTORS CORP. Installation

1. Install Woodruff key in crankshaft (if removed). Using Crankshaft Sprocket Installer (J-5590), install crankshaft sprocket. Install camshaft sprocket and timing chain. Ensure timing marks on sprockets are aligned. See Fig. 11 . 2. Balance shaft drive gear, driven gear and gear bolt are serviced as a set. Install and tighten camshaft sprocket bolts to specification. See TORQUE SPECIFICATIONS . CAUTION: Failure to properly align CKP sensor reluctor ring may result in component damage and could affect system performance. CKP sensor reluctor ring is shaped like a dish. Dished side of CKP reluctor ring must face engine front cover. Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

NOTE:

DO NOT reinstall original composite front cover. Always install a NEW front cover. Reinstalling original front cover can lead to oil leaks.

3. Install and align CKP sensor reluctor ring. See Fig. 10 . Install NEW front cover and gasket. Tighten front cover bolts to specification. CAUTION: Ensure CKP sensor is fully seated and held stationary in bore of front cover upon installation. A CKP sensor that is not fully seated may result in erratic engine operation. 4. Install CKP sensor. Tighten CKP sensor holddown bolt to specification. See TORQUE SPECIFICATIONS . 5. Apply RTV sealant to Woodruff keyway in crankshaft damper. Using Damper Puller/Installer (J-23523F), install crankshaft balancer. Tighten fasteners to specification. See TORQUE SPECIFICATIONS . To complete installation, reverse removal procedure. ROCKER ARM STUDS Removal & Installation

CAUTION: On models equipped with press in rocker arm studs, ream stud bore before installing oversize rocker arm stud, or cylinder head may be damaged. Unscrew rocker arm stud from cylinder head. To install, insert NEW rocker arm stud. Tighten to 35 ft. lbs. (47 N.m). VALVE LIFTERS Removal

Remove upper and lower intake manifold. See INTAKE MANIFOLD (UPPER) and INTAKE MANIFOLD (LOWER) . Remove valve covers. Remove push rods. See ROCKER ARMS & PUSH RODS . Remove stuck valve lifter using Valve Lifter Remover (J-9290-01). Installation

Coat lifter base or roller (if equipped) and body with High Viscosity Oil/Zinc (12345501) or equivalent. Install lifters in original location. To complete installation, reverse removal procedure. Replace oil and filter, and add High Viscosity Oil/Zinc (GM P/N 12345501) or equivalent. CAMSHAFT Removal

Remove front cover. See FRONT COVER . Remove timing chain and sprockets. See TIMING CHAIN & Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

SPROCKETS . Install three 5/16" X 18 bolts (4-5 inches long) into camshaft threaded holes. Use bolts to remove and install camshaft. Installation

Coat camshaft lobes and bearing journals with High Viscosity Oil/Zinc (12345501). Ensure bearing oil holes align with oil holes in block. On engines where oil holes are difficult to see, use a piece of 3/32" rod to check alignment. Install outer camshaft bearing first. Install camshaft. To complete installation, reverse removal procedure. BALANCE SHAFT (IF EQUIPPED) Removal

1. Remove radiator. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C condenser (if equipped) and grille. Remove valve lifters. See VALVE LIFTERS . 2. Remove timing chain and camshaft sprocket. See TIMING CHAIN & SPROCKETS . Remove balance shaft gears. Remove balance shaft retainer plate. NOTE:

Front bearing is removed with balance shaft. Replace front bearing and balance shaft as a set only. Replace balance shaft timing gears as a set only.

3. Remove intake manifold. See INTAKE MANIFOLD . Using a soft-faced hammer, tap balance shaft out toward front of engine. Installation

1. Apply oil to balance shaft bearings. Using Installers (J-36996 and J-8092), install balance shaft in block. See Fig. 12 . Install lifter retainer (if equipped). Ensure balance shaft turns. 2. Install thrust plate. Install balance shaft gears. Ensure timing marks on balance shaft gears are aligned. See Fig. 13 . Install balance shaft timing gear bolt. Tighten bolt to 15 ft. lbs. (20 N.m), then tighten bolt an additional 35 degrees. To complete installation, reverse removal procedure.

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Fig. 12: Installing Balance Shaft Courtesy of GENERAL MOTORS CORP.

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Fig. 13: Aligning Timing Marks For Balance Shaft Gears Courtesy of GENERAL MOTORS CORP. REAR CRANKSHAFT OIL SEAL Removal

Remove transmission, clutch (M/T) and flywheel. See appropriate TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING. Pry seal from housing. Installation Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

1. Lubricate inner and outer diameter of seal with engine oil. Place seal on Seal Installer (J-35621). Position seal against crankshaft as indicated in illustration. See Fig. 14 . 2. Thread attaching screws into crankshaft flange and tighten with screwdriver. This squares seal with crankshaft. Rotate seal installer handle until it bottoms. Remove seal installer. Install flywheel, clutch (M/T) and transmission.

Fig. 14: Installation Position Of Rear Crankshaft Oil Seal. Courtesy of GENERAL MOTORS CORP. WATER PUMP NOTE:

DO NOT immerse water pump in solvent. Solvent may cause premature bearing failure.

Removal

Disconnect battery. Drain cooling system. Remove all drive belts, coolant hoses and mounting brackets attached to water pump. If necessary, remove fan shroud. Remove fan and pulley. Remove water pump and gaskets. Installation

Install water pump with NEW gaskets. Tighten water pump bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

OIL PAN CAUTION: Minimal clearance exists between oil pump pick-up tube and bottom of oil pan. DO NOT place jack under oil pan, crankshaft pulley or any sheet metal when lifting engine. Removal (Except "S" & "T" Series)

1. Disconnect battery. Raise and support vehicle. Drain crankcase. Remove exhaust crossover pipe, strut rods, strut rod brackets and flywheel cover. 2. Remove starter. Remove or disconnect engine oil cooler lines and/or transmission fluid lines as necessary. Remove oil pan bolts, oil pan and gasket. Removal ("S" Series Pickup, Jimmy & Sonoma 2WD)

Raise and support vehicle. Drain crankcase. Remove engine. See ENGINE . Remove oil pan bolts, oil pan and gasket. Removal ("T" Series Pickup, Jimmy & Sonoma 4WD)

1. Disconnect battery. Remove engine oil dipstick and accessory drive belt splash shield. Raise and support vehicle. Drain crankcase. Remove front axle shield and transfer case shield. Remove brake line clips from crossmember. 2. Remove second crossmember. Remove converter hanger bolts and exhaust pipe clamp from converter. Disconnect exhaust pipes from manifolds. Slide exhaust pipe rearward. Disconnect front drive shaft from differential. 3. Remove flywheel cover. Remove starter motor. Remove idler arm-to-frame bolts. Remove differential housing mounting bolts from bracket (right side) and frame (left side). 4. Move differential housing forward. Remove front engine mount through-bolts. Raise and support engine. Remove oil pan bolts, oil pan and gasket. Installation

NOTE:

If transmission and oil pans are removed at same time, transmission pan must be installed before oil pan.

1. Apply RTV sealant to front cover-to-cylinder block junction and rear main bearing-to-cylinder block junction. 2. Using feeler gauge check clearance between 3 oil pan-to-transmission contact points. If clearance exceeds .0100" (.025 mm) at any of 3 points, repeat installation steps until clearance is within specification. See Fig. 15 . Install oil pan. Tighten oil pan bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Fill crankcase.

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Fig. 15: Oil Pan Bolt Tightening Sequence. Courtesy of GENERAL MOTORS CORP.

OVERHAUL CYLINDER HEAD Valve Springs

1. Measure valve spring free length, installed height and pressure (tension). Replace valve spring if measurement is not within specification. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS. 2. Measure installed height between cylinder head spring seat (or top of shim, if shimmed) and top of spring shield. If installed height exceeds specification, install shims as necessary to bring installed height to specification. Valve Stem Oil Seals Microsoft Saturday, August 29, 2009 11:34:24 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

1. Intake valve uses upper "O" ring seal and lower umbrella seal; exhaust valve uses upper "O" ring seal. 2. When installing umbrella seal, seat seal against valve guide boss on cylinder head. If equipped, coat upper "O" ring seal with engine oil before installation and ensure seal is not twisted when installed. A gap of .040-.080" (1-2 mm) must exist between edge of oil seal and valve guide. See Fig. 16 . Valve Guides

Valve guides are part of cylinder head (not replaceable). Measure valve guide oil clearance. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. If not within specification, ream valve guide and install valves with oversize stems. Valves

Replace valve if margin is less than .031" (.8 mm).

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Fig. 16: Installation Of Valve Stem Oil Seal Courtesy of GENERAL MOTORS CORP. VALVE TRAIN Rocker Arm Assembly

Clean push rods, rocker arms, balls and nuts with solvent and blow dry. Inspect rocker arms and balls at mating surface. Surface should be smooth and free of damage. Inspect push rods for bends or wear. Ensure oil passages are clear. CYLINDER BLOCK ASSEMBLY Piston & Rod Assembly

1. Mark piston in relation to cylinder bore before removal. Piston pin is press-fit in connecting rod. Mark piston in relation to connecting rod before separating components. 2. Replace piston and piston pin as matched set. Install piston in bore with notch on top of piston toward front of engine. Fitting Pistons

1. Measure piston diameter at 90-degree angle to piston pin, on piston pin center line. Measure cylinder bore diameter 2 1/2" below cylinder block deck. Determine piston clearance. 2. If piston clearance is not within specification, replace piston and/or machine cylinder bore as necessary. See CYLINDER BLOCK and PISTONS, PINS & RINGS tables under ENGINE SPECIFICATIONS. Piston Rings

Measure piston ring end gap and side clearance. If measurement is not within specification, replace piston and/or rings as necessary. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Install rings with mark on ring facing upward. Position ring end gaps around circumference of piston as shown. See Fig. 17 .

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Fig. 17: Positioning Piston Ring End Gaps Courtesy of GENERAL MOTORS CORP. Rod Bearings

1. Measure rod bearing journal out-of-round, taper and oil clearance. If measurement is not within specification, replace rod bearings and/or machine crankshaft. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS. 2. Ensure rod side play is within specification. See CONNECTING RODS table under ENGINE SPECIFICATIONS. Crankshaft & Main Bearings

1. Mark bearing caps for reassembly. Measure journal diameter, out-of-round, taper and oil clearance. If measurement is not within specification, replace main bearings and/or machine crankshaft. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS. 2. Align thrust bearing surfaces, and measure crankshaft end play. See THRUST BEARING . Main bearing caps are press fit. Using Tool (J-6125-B and J-41348), carefully remove caps for service. Install main bearings and main caps. Tap bearing caps into cylinder block cavity using a brass, lead, or leather mallet before installing attaching bolts. 3. DO NOT use cap bolts to pull crankshaft bearing caps into seats. Tighten NEW main cap bolts evenly. Thrust Bearing Microsoft Saturday, August 29, 2009 11:34:25 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

CAUTION: On some 4.3L engines, the distance between rear main bearing thrust faces is .008" (.20 mm) wider than standard (identified by .008" stamped on crankshaft rear counterweight). When replacing rear main bearings on these engines, use only .008" (.20 mm) wider bearings. 1. Install main bearing caps (except rear), and tighten cap bolts to specification. See TORQUE SPECIFICATIONS table. Install rear main bearing cap and tighten cap bolts to 10 ft. lbs. (14 N.m). 2. Tap crankshaft rearward then forward to align thrust surfaces. Tighten rear main bearing cap bolts to specification. Measure crankshaft end play at forward thrust surface of rear main bearing cap. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS . Cylinder Block

Measure cylinder bore out-of-round and taper. If measurement is not within specification, machine cylinder bore and/or replace piston. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS. Finish bore with a 45-65 degree cross-hatch pattern.

ENGINE OILING ENGINE LUBRICATION SYSTEM Gear-type oil pump delivers full pressure lubrication through full-flow oil filter to main oil gallery. Main oil gallery feeds crankshaft and camshaft bearings through drilled passages in block. Valve lifter oil gallery feeds valve lifters. From lifters, oil is routed through hollow push rods to upper valve train components. Timing chain and sprockets are lubricated by oil drainage from No. 1 camshaft bearing. Pistons and piston pins are lubricated by oil splash. Non-adjustable oil pressure regulator is located in oil pump body. Crankcase Capacity

Crankcase capacity is 4.5 qts (4.26L), including oil filter. Oil Pressure

Measure oil pressure with engine at operating temperature and specified RPM. See OIL PRESSURE SPECIFICATIONS table. OIL PRESSURE SPECIFICATIONS (1) psi (kg/cm2 ) 6 (0.4) 18 (1.3) 24 (1.7)

Application 1000 RPM 2000 RPM 4000 RPM Microsoft Saturday, August 29, 2009 11:34:25 AM

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

(1) Minimum specification.

OIL PUMP Removal & Disassembly

NOTE:

Pick-up tube is serviceable; however, unless tube is damaged, DO NOT remove tube from pump body.

1. Remove oil pan. See OIL PAN under REMOVAL & INSTALLATION. Remove oil pump bolt. Remove pump and extension shaft. If necessary, remove pick-up tube. 2. Remove pump cover. Mark relationship between gears at a meshing point for reassembly. Remove gears. Remove pressure regulator valve retaining pin. Remove pressure regulator valve and spring. Remove oil pump-to-rear crankshaft bearing cap bolt. Remove oil pump, retainer and driveshaft from rear crankshaft bearing cap. Inspection

Inspect pump body and cover for cracks or excessive wear. Inspect pump gears for damage or wear. Check drive gear shaft for looseness in pump body. Check pressure regulator valve for fit in bore. Replace entire pump assembly if damaged. Inspect inlet tube and screen assembly for damage. Reassembly & Installation

1. Install pump gears into pump body with marked gear teeth indexed. If pick-up tube was removed, apply sealant to tube end. Tap tube end into pump using plastic hammer. Reassemble remaining components in reverse order of disassembly. 2. Prime oil pump with engine oil. Install pump and extension shaft, ensuring slot on top of extension shaft engages with drive tang on end of distributor shaft. Tighten oil pump bolt to specification. See TORQUE SPECIFICATIONS table. Install oil pan.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Balance Shaft Gear Bolt Step 1 Step 2 Bellhousing Bolt Camshaft Sprocket Bolt Connecting Rod Cap Nut Step 1 Step 2 Crankshaft Damper Bolt

Ft. Lbs. (N.m) 15 (20) Additional 35 Degrees 32 (44) 18 (25) 20 (27) Additional 70 Degrees 74 (100)

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

Crankshaft Oil Deflector Bolt/Nut

27 (36)

Cylinder Head Bolt (1) Step 1 Step 2 Short Bolts (No. 2, 3, 6, 7, 10, 11) Medium Bolts (No. 12, 13) Long Bolts (No. 1, 4, 5, 8, 9) Exhaust Manifold Bolt Step 1 Step 2 Flywheel Bolt Main Bearing Cap Bolt Oil Filter Adapter Bolt Oil Pan Nut/Bolt Oil Pump Bolt Rear Crankshaft Oil Seal Retainer Bolt Rocker Arm With Press-In Studs Rocker Stud Rocker Nut With Screw-In Studs Rocker Stud Rocker Nut Valve Lifter Retainer Bolt Water Pump Bolt

22 (30) Additional 55 Degrees Additional 65 Degrees Additional 75 Degrees 11 (15) 22 (30) 74 (100) 78 (106) 16 (22) 18 (25) 66 (90) 11 (15)

35 (47) 18 (25) 35 (47) 19 (26) 12 (16) 33 (45) INCH Lbs. (N.m) 106 (12) 106 (12) 80 (9) 106 (12)

Balance Shaft Retainer Plate Bolts Camshaft Retainer Bolt Crankshaft Position Sensor Holddown Bolt Front Cover Bolt Intake Manifold Upper Step 1 Step 2 Lower Step 1 Step 2 Step 3 Oil Pump Cover Bolt Valve Cover Bolt

44 (5) 89 (10) 27 (3) 106 (12) 133 (15) 106 (12) 89 (10)

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

(1) Apply GM Sealant (1052080) to head bolt threads. Tighten bolts in sequence. See Fig. 9 .

ENGINE SPECIFICATIONS GENERAL SPECIFICATIONS Application Displacement Bore Stroke Compression Ratio Fuel System VIN W VIN X Horsepower @ RPM 2WD VIN W VIN X 4WD VIN W VIN X Torque Ft. Lbs. @ RPM 2WD VIN W VIN X 4WD VIN W VIN X

Specification 262 Cu. In. 4.00" (101.6 mm) 3.48" (88.4 mm) 9.2:1 CSI CSI

180 @ 4400 175 @ 4400 190 @ 4400 180 @ 4400

245 @ 2800 240 @ 2800 250 @ 2800 240 @ 2800

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS Application Crankshaft End Play Main Bearings Journal Diameter No. 1 No. 2 & 3 No. 4 Journal Out-Of-Round Journal Taper (Maximum) Oil Clearance Standard

In. (mm) .002-.008 (.05-.20)

2.4488-2.4495 (62.199-62.217) 2.4485-2.4494 (62.191-62.215) 2.4480-2.4489 (62.179-62.203) .0002-.001 (.005-.03) .0003 (.008)

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

No. 1 No. 2, 3 & 4 Connecting Rod Bearings Journal Diameter Journal Out-Of-Round Service Limit Journal Taper Service Limit Oil Clearance Service Limit Side Clearance

.0008-.0020 (.020-.051) .0009-.0024 (.023-.061) 2.2487-2.2497 (57.117-57.142) .0002 (.005) .001 (.03) .0003 (.008) .001 (.03) .0013-.0035 (.033-.089) .001-.0030 (.03-.076) .006-.017 (.15-.43)

CONNECTING RODS Application Side Play

In. (mm) .015-.046 (.38-1.17)

PISTONS, PINS & RINGS Application Pistons Clearance Pins Diameter Piston Fit Rod Fit

In. (mm) .0007-.0020 (.018-.051) .9270-.9271 (23.545-23.548) .0002-.0007 (.005-.018) .0013-.0019 (.033-.048) Interference

Rings No. 1 End Gap Side Clearance No. 2 End Gap Side Clearance No. 3 (Oil) End Gap Side Clearance

.010-.016 (.25-.41) .001-.003 (.03-.08) .018-.026 (.46-.66) .001-.003 (.03-.08) .015-.055 (.38-1.40) .002-.007 (.05-.18)

CYLINDER BLOCK Application Cylinder Bore Diameter

In. (mm) 4.0007-4.0017 (101.618101.643)

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

(1) .0005 (.013) (2) .001 (.03)

Maximum Taper Maximum Out-Of-Round (1) Specification is for thrust side. Relief side is .001" (.03 mm). (2) Production specification is given. Maximum service specification is .002" (.05 mm).

VALVES & VALVE SPRINGS Application Valves Face Angle Minimum Margin Valve Springs Free Length Installed Height

Specification 45° .031" (.79 mm) 2.02" (51.3 mm) 1.69-1.71" (42.9-43.4 mm) Lbs. @ In. (Kg @ mm)

Pressure Valve Closed Valve Open

76-84 @ 1.70 (34-38 @ 43.2) 187-203 @ 1.27 (85-92 @ 32.3)

CYLINDER HEAD Application Valve Seats Intake Valve Seat Angle Seat Width Maximum Seat Runout Exhaust Valve Seat Angle Seat Width Maximum Seat Runout Valve Guide Oil Clearance Warpage

Specification

46° .035-.060" (.88-1.52 mm) .002" (.05 mm) 46° .062-.093" (1.58-2.36 mm) .002" (.05 mm) .001-.003" (.03-.07 mm) .004" (.10 mm)

CAMSHAFT Application End Play Journal Diameter Lobe Lift Intake Exhaust

In. (mm) .001-.009 (.03-.23) 1.8682-1.8692 (47.452-47.478) .286-.290 (.0726-.0736) .292-.296 (.0741-.0751)

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1997 Chevrolet S10 Pickup 1996-97 ENGINES 4.3L V6 - Trucks

BALANCE SHAFT Application Journal Diameter Front Journal

In. (mm) 2.1648-2.1654 (54.98655.001) 1.4994-1.5000 (38.08538.100) .001-.004 (.03-.10)

Rear Journal Oil Clearance (Rear Journal)

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

INTRODUCTION This article contains removal, overhaul and installation procedures (when information was available at time of publication). If component removal and installation is primarily an unbolt and bolt-on procedure, only a torque specification may be furnished.

AIR INDUCTION SYSTEMS THROTTLE BODY (CSI) Removal & Installation

1. Disconnect negative battery cable. Remove air inlet duct fastener and duct. Disconnect IAC valve and TP sensor electrical connectors. Disconnect throttle and cruise control cables. 2. Remove accelerator cable bracket bolts and bracket. Remove wiring harness fastener nut and throttle body fasteners. Remove throttle body assembly. Remove flange gasket and discard. 3. Clean gasket surface on intake manifold and throttle body. Install NEW flange gasket. Install throttle body. Tighten throttle body fasteners to specification. See TORQUE SPECIFICATIONS . To complete installation, reverse removal procedure. Ensure throttle and cruise control linkages do not hold throttle open. UPPER INTAKE MANIFOLD ASSEMBLY (CSI) Removal

1. Disconnect negative battery cable. Remove air inlet fastener and duct. Disconnect injector electrical connector. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF under FUEL SYSTEM. 2. Disconnect throttle and cruise control cables from throttle lever cam and bracket. Disconnect power brake and crankcase ventilation valve vacuum hoses at upper manifold and valve cover. Disconnect electrical harness connectors from TP sensor, IAC valve and MAP sensor. 3. Disconnect No. 1 plug wire from distributor cap. Remove fuel pipe clip retaining bolt. Remove injector fuel inlet and outlet pipe retainer and nuts. Remove upper manifold assembly, attaching bolts and rear mounting nuts (position canister purge solenoid bracket to one side).

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

Fig. 1: Upper Intake Manifold Assembly Courtesy of GENERAL MOTORS CORP. Disassembly

1. When cleaning or replacing upper manifold assembly, remove throttle cable bracket attaching bolts and Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

bracket, throttle body assembly, MAP sensor, crankcase ventilation valve, purge solenoid and power brake booster vacuum pipe fitting. CAUTION: DO NOT soak upper manifold assembly in an immersion type cleaner or any cleaner containing MEK. 2. Upper manifold assembly contains TP sensor, IAC valve and internal throttle shaft sealed ball bearings. These components MUST NOT be subjected to strong solvent or cleaner bath. Clean throttle bore and valve deposits with carburetor cleaner and a shop towel. Use care when cleaning gasket surfaces. Sharp tools may damage sealing surfaces. Installation

To install, reverse removal procedure. Tighten upper intake manifold assembly fasteners to specification using a criss-cross pattern. See TORQUE SPECIFICATIONS .

COMPUTERIZED ENGINE CONTROLS POWERTRAIN CONTROL MODULE (PCM) CAUTION: All vehicles are equipped with either an Engine Control Module (ECM), Powertrain Control Module (PCM) or Vehicle Control Module (VCM) for engine control. Unless specifically stated, references to PCM also apply to ECM and VCM equipped vehicles. Some vehicles equipped with an electronically controlled transmission also use a Transmission Control Module (TCM) for transmission control. Electronic components used in control systems are designed to carry very low voltages. As little as a 30volt charge created by static electricity can cause a total or degrading failure in PCM or other electronic components containing integrated circuits. Before servicing PCM, technician must ground himself/herself and work area to discharge static electricity. CAUTION: DO NOT remove part from packaging until ready to install. Ground any static-proof package before opening. DO NOT touch electrical terminals of components unless properly grounded. DO NOT lay electrical components on car seat, carpeting or dashboard. Use electrostatic protection mat and ground strap whenever possible. NOTE:

NOTE:

When replacing defective PCM, remove knock sensor module from defective

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

PCM. New PCM does not come equipped with knock sensor module. Install knock sensor module into new PCM. Removal

Ensure ignition switch is in OFF position. Disconnect negative battery cable. Unplug electrical connectors from PCM. Remove PCM from vehicle. Remove access cover and remove knock sensor module from PCM. Installation

Install knock sensor module in NEW PCM. Install access cover. Install PCM into vehicle. Connect electrical connectors to PCM. Reconnect negative battery cable. ELECTRICALLY ERASABLE PROGRAMMABLE READ-ONLY MEMORY Electrically Erasable Programmable Read-Only Memory (EEPROM) is a permanent memory that is part of PCM. EEPROM cannot be replaced. EEPROM contains program and calibration information that PCM uses to control powertrain. If PCM is replaced, ensure that NEW PCM software/calibration is correct and most recent version for vehicle. EEPROM must be programmed when new PCM is installed. Program EEPROM using latest software for that specific vehicle. KNOCK SENSOR MODULE Removal & Installation

1. Knock Sensor (KS) module is located in PCM. Disconnect negative battery cable. Remove PCM from vehicle. See POWERTRAIN CONTROL MODULE (PCM) . Position PCM with access cover up. Remove access cover from PCM. 2. Using thumb and forefinger, squeeze both ends of knock sensor module inward and pull module up from access hole. To install, reverse removal procedure. Ensure module latches into holder in PCM. NOTE:

If PCM is replaced, KS module must be transferred from original to replacement PCM.

SENSORS & SWITCHES CAMSHAFT POSITION SENSOR Removal & Installation

1. Disconnect negative battery cable. Reference mark spark plug wires at distributor cap. Disconnect spark plug wires and ignition coil wire at distributor cap. 2. Disconnect Camshaft Position (CMP) sensor electrical connector at distributor. Remove distributor cap retaining screws and distributor cap. 3. Remove rotor retaining screws and rotor. Align the square slot in the reluctor wheel with the CMP sensor. Remove CMP sensor retaining screws. Remove CMP sensor. See Fig. 2 . Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

NOTE:

DO NOT use the old distributor cap screws, CMP sensor screws, or rotor screws. Use replacement screws that have been coated with a thread locking compound.

4. Insert the CMP sensor through the reluctor wheel slot. Install NEW CMP sensor retaining screws coated with a thread locking compound. Tighten CMP sensor retaining screws to specification. See TORQUE SPECIFICATIONS . 5. To complete installation, reverse removal procedure. Tighten fasteners to specification. See TORQUE SPECIFICATIONS .

Fig. 2: Locating Camshaft Position Sensor Courtesy of GENERAL MOTORS CORP. CRANKSHAFT POSITION SENSOR Removal

Crankshaft Position (CKP) sensor is a magnetic sensor and is located behind the crankshaft pulley, mounted near front of crankshaft. Disconnect CKP sensor electrical connector. Remove CKP sensor mounting bolt. See Fig. 3 . Remove CKP sensor. Installation

NOTE:

Make certain that the Crankshaft Position (CKP) sensor mounting surfaces

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

are clean and free of burrs before installing the CKP sensor. 1. Inspect the Crankshaft Position (CKP) sensor "O" ring for wear, cracks or leakage. Replace if necessary. Lubricate the "O" ring with clean engine oil before installation. NOTE:

When installing or removing a CKP sensor, ensure the sensor is fully seated and held stationary in the front cover before tightening the holddown bolt into the front cover. A sensor which is not seated may result in erratic operation and lead to the setting of false trouble codes.

2. Tighten CKP sensor hold-down bolt to specification. See TORQUE SPECIFICATIONS . Connect CKP sensor electrical connector. 3. Perform Crankshaft Position (CKP) Variation Learn procedure using scan tool. See CRANKSHAFT POSITION (CKP) SENSOR VARIATION LEARN PROCEDURE (4.3L, 5.0L, 5.7L & 7.4L) in COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION.

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

Fig. 3: Locating Crankshaft Position Sensor Courtesy of GENERAL MOTORS CORP. KNOCK SENSOR NOTE:

Cooling system may need draining prior to removing knock sensor.

Removal & Installation

Knock sensor is located on side of engine block. See Fig. 4 . Disconnect negative battery cable. Disconnect wiring harness connector from knock sensor. Remove knock sensor. To install, reverse removal procedure. Install sealant to sensor threads prior to installation. Tighten knock sensor to 14 ft. lbs. (19 N.m). Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

Fig. 4: Locating Knock Sensor Courtesy of GENERAL MOTORS CORP. OXYGEN SENSOR CAUTION: Oxygen sensor is equipped with a permanent pigtail, which must be protected to prevent damage when removing sensor. Removal

1. Oxygen sensor is mounted in exhaust manifold/pipe. Ensure sensor is free of contaminants. DO NOT use Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Excessive removal force may damage threads in exhaust manifold or pipe. 2. Disconnect negative battery cable. Disconnect electrical connector from oxygen sensor. Carefully remove oxygen sensor. CAUTION: Correct torque of oxygen sensor is critical to prevent crushing glass beads in graphite anti-seize compound. Crushing glass beads will cause sensor to seize in exhaust manifold/pipe. This may require replacement of exhaust manifold/pipe upon next removal. Installation

1. Whenever oxygen sensor is removed, coat threads with anti-seize compound before reinstalling. New oxygen sensors already have this compound applied to threads. 2. Install oxygen sensor in exhaust manifold/pipe and tighten sensor to 30 ft. lbs. (41 N.m). Reconnect electrical connector to oxygen sensor. Reconnect negative battery cable. THROTTLE POSITION (TP) SENSOR Removal & Installation

1. Remove air cleaner assembly. Disconnect electrical connector from TP sensor. Remove attaching screws, lock washers, retainers, and TP sensor. 2. To install, reverse removal procedure. Adjust TP sensor to specification. See the ADJUSTMENTS 4.3L article. When replacing a TP sensor, ensure correct part number is used. Use Loctite on TP sensor attaching screws.

MOTORS, RELAYS & SOLENOIDS IDLE AIR CONTROL VALVE Removal

Disconnect Idle Air Control (IAC) valve harness connector. Remove IAC valve retaining screws and remove IAC valve. CAUTION: DO NOT manually extend or retract pintle if IAC valve has been in service. Damage to worm gear will result. Installation

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

slowly retract pintle. Lubricate "O" ring with clean engine oil. 3. Apply thread locking compound (Loctite 262) to IAC valve retaining screw threads. Install IAC valve. Tighten IAC valve retaining screws to 27 INCH lbs. (3 N.m). Connect IAC valve harness connector. 4. To reset IAC valve pintle position, turn ignition on for 5 seconds. Turn ignition off for 10 seconds. Start engine and check for proper idle operation. Repeat IAC valve resetting procedure if proper idle operation cannot be obtained.

1. Disconnect negative battery cable. Relieve fuel system pressure. Remove upper intake manifold assembly and throttle body. See UPPER INTAKE MANIFOLD ASSEMBLY (CSI) under AIR INDUCTION SYSTEMS. NOTE:

When disconnecting poppet nozzles, note installation sequence.

2. Disconnect fuel meter body electrical connector. Remove fuel feed and return hoses from fuel pipes. Squeeze poppet nozzle locking tabs together while lifting nozzle out of the casting socket. Remove fuel meter body from bracket by releasing lock tabs on bracket.

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

Fig. 5: Fuel Meter Body Assembly Courtesy of GENERAL MOTORS CORP. Installation

1. Install fuel meter body on intake manifold. Tighten fuel meter attachment bolts to 88 INCH lbs. (10 N.m). Push fuel meter body into bracket. Ensure tabs are locked into place. CAUTION: To reduce risk of fire, ensure that poppet nozzles are firmly seated and locked in their sockets. Unlocked poppet nozzles can become loose which can result in fuel leaks. NOTE:

Fuel meter body assemblies are numbered indicating nozzle order.

2. Push poppet nozzles into casting sockets. Inspect poppet nozzles to ensure they are firmly seated and locked. Connect fuel meter body electrical connector. 3. Install new O-rings on fuel feed and return pipes. Install fuel feed and return hoses on engine fuel pipes. Tighten fuel pipe nuts to 22 ft. lbs. (30 N.m). Connect negative battery cable. Turn ignition ON for 2 seconds. Ignition OFF for 10 seconds. Turn ignition ON. Check for fuel leaks and correct as necessary. 4. Install upper intake manifold assembly. See UPPER INTAKE MANIFOLD ASSEMBLY (CSI) under Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

AIR INDUCTION SYSTEMS. Install fuel filler cap. FUEL PRESSURE REGULATOR Removal & Installation

1. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELIEF . Disconnect negative battery cable. Remove ignition coil. 2. Remove upper intake manifold plenum. See UPPER INTAKE MANIFOLD ASSEMBLY (CSI) under AIR INDUCTION SYSTEMS. 3. Disconnect vacuum line to fuel pressure regulator. Remove snap ring from fuel pressure regulator housing. Place a towel under fuel pressure regulator to catch any fuel. 4. Twist fuel pressure regulator back and forth while pulling from fuel rail socket. Remove fuel pressure regulator. Remove and discard fuel pressure regulator "O" rings. 5. Install fuel pressure regulator using NEW "O" rings, lubricated with clean engine oil. Ensure fuel pressure regulator vacuum tube is pointing down. To complete installation, reverse removal procedure. Tighten fasteners to specification. See TORQUE SPECIFICATIONS . FUEL PUMP NOTE:

When installing sending unit, DO NOT fold or twist strainer. This will restrict fuel flow.

Removal & Installation

1. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELIEF . Disconnect negative battery cable. Raise vehicle and remove fuel tank. Using Sending Unit Remover (J-36608 or J-24187), remove sending unit and pump by turning cam lock counterclockwise. 2. Remove fuel pump from sending unit by pulling pump up into attaching hose while pulling outward from the bottom support. DO NOT damage rubber insulator or strainer. To install, reverse removal procedure. Tighten fasteners to specification. See TORQUE SPECIFICATIONS .

IGNITION SYSTEM CAMSHAFT POSITION SENSOR See CAMSHAFT POSITION SENSOR under SENSORS & SWITCHES. CRANKSHAFT POSITION SENSOR See CRANKSHAFT POSITION SENSOR under SENSORS & SWITCHES. DISTRIBUTOR WARNING: Procedure A may be used for distributor installation if crankshaft has not Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

been rotated from original position when distributor was removed. If intake manifold, cylinder head, crankshaft, camshaft, timing gear, or complete engine was removed or replaced, Procedure B must be followed. If DTC P1345 is present, distributor may be installed incorrectly, and must be reinstalled with Procedure B. Removal

1. Ignition OFF. Remove spark plug and coil leads from distributor cap. Disconnect hall-effect switch connector from base of distributor. Remove distributor cap. 2. With a grease pencil, mark rotor position on distributor body, and label "#1". Remove distributor clamp hold-down bolt. Slowly remove distributor. Rotor will turn 42° counter-clockwise as distributor is removed. Mark new rotor position on distributor body with a grease pencil as "#2". NOTE:

If distributor is being replaced, transfer grease pencil marks from original distributor to new distributor.

Installation (Procedure A)

1. Align rotor to "#2" mark on distributor body. Guide distributor into place noting alignment of mounting hole in distributor hold down base with hole in intake manifold. 2. Rotor will rotate 42° clockwise as distributor is installed. If rotor does not align with "#1" mark, remove distributor and reinstall using INSTALLATION (PROCEDURE B). Remaining installation is reverse of removal. NOTE:

If DTC P1345 is present, distributor may be installed incorrectly, and must be reinstalled with Procedure B.

Installation (Procedure B)

1. Rotate engine until cylinder 1 is at TDC of compression stroke. Align indent hole of distributor gear with white alignment line on lower part of distributor shaft housing. Rotor should point to distributor cap hold down hole nearest to flat side of distributor body. 2. Using a long screwdriver, align oil pump drive shaft with drive tab of distributor. Slowly install distributor, ensuring that spark plug towers are perpendicular to center line of engine. 3. When fully seated, rotor should be aligned with pointer cast into distributor body (pointer is marked with a "6" to indicate distributor is for 6-cylinder engine). If rotor is not aligned within a few degrees of pointer, remove distributor and return to step 1). Remaining installation is reverse of removal. NOTE:

If DTC P1345 is present, distributor may be installed incorrectly, and must be reinstalled with Procedure B.

KNOCK SENSOR See KNOCK SENSOR under SENSORS & SWITCHES. Microsoft Saturday, August 29, 2009 11:41:21 AM

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1997 Chevrolet S10 Pickup N - REMOVE/INSTALL/OVERHAUL - 4.3L 1997 ENGINE PERFORMANCE General Motors - Removal, Overhaul & Installation - 4.3L

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Distributor Clamp Bolt Fuel Line Nut Fuel Tank Strap Nuts Idle Air Control Valve (Threaded) Oxygen Sensor Throttle Body-To-Upper Intake Manifold Fasteners

Ft. Lbs. (N.m) 20 (27) 17 (23) 33 (45) 13 (18) 30 (41) 18 (24) INCH Lbs. (N.m) 14-25 (1.6-2.8) 71 (8) 21 (2.5) 17 (2) 88 (10) 27 (3) 106 (12)

Camshaft Position Sensor Retaining Screws Crankshaft Position Sensor Bolt Distributor Cap Retaining Screws Distributor Rotor Retaining Screws Fuel Meter Body Fasteners Idle Air Control Valve Screws (Flange Mounted) Ignition Coil Studs Upper Intake Manifold Fasteners (1) Step 1 Step 2 (1) Tighten fasteners to specification in a criss-cross pattern.

44 (5) 89 (10)

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1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

INTRODUCTION Most engine control problems are the result of mechanical breakdowns, poor electrical connections or damaged vacuum hoses. Before considering the computer system as a possible cause of problems, perform checks and inspections covered in the BASIC TESTING - 4.3L article. Failure to do so may result in lost diagnostic time. If no faults found performing procedures in the BASIC TESTING - 4.3L article, proceed with DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If no fault codes are present and driveability problems exist, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.). If only intermittent codes are present, see INTERMITTENTS in the TESTS W/O CODES article.

SELF-DIAGNOSTIC SYSTEM NOTE:

For On-Board Diagnostic System Check see the BASIC TESTING - 4.3L article.

NOTE:

Powertrain Control Module (PCM) may also be referred to as Vehicle Control Module (VCM) in some diagnostic text and illustrations. Terms may be used interchangeably.

PCM/VCM is equipped with a self-diagnostic system, which detects system failures or abnormalities. When a malfunction occurs, PCM/VCM will store a Diagnostic Trouble Code (DTC) and, in most cases, illuminate the Malfunction Indicator Light (MIL) located on instrument cluster. Malfunctions are recorded as hard failures or as intermittent failures. There are 4 types of DTC category:    

Type "A" - Emissions related, turns on MIL the first time DTC sets. Type "B" - Emissions related, turns on MIL if fault is active for 2 consecutive driving cycles. Type "C" - Non-emissions related, does not turn on MIL, but will turn on SERVICE light. Type "D" - Non-emissions related, does not turn on MIL or SERVICE light.

HARD FAILURES Most hard failures cause MIL to illuminate and remain on until malfunction is repaired. If MIL comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined. See DIAGNOSTIC PROCEDURE . If a sensor fails, PCM/VCM will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but it will most likely display degraded driveability. INTERMITTENT FAILURES Microsoft Saturday, August 29, 2009 11:39:18 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Intermittent failures cause MIL to flicker or glow and go out about 10 seconds after intermittent fault goes away. Corresponding DTC, however, will be retained in PCM/VCM memory. If related fault does not reoccur within 50 engine starts, trouble code will be erased from control module memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in the TESTS W/O CODES article. NOTE:

OBD II vehicles have options available in the scan tool DTC mode to display enhanced information available. However, to fully utilize information and procedures requires the use of a Tech 1 or 2 scan tool. See scan tool operator's manual for additional information.

The following are Tech 1 or 2 scan tool sub-menus in the DTC INFO and SPECIFIC DTC modes: DTC INFO MODE Used to search for a specific type of stored DTC information. There are 7 choices in this mode. Technician may be instructed to test DTC(s) in a certain manner. Follow the affected DTC test procedures. To get complete description of any status, hit ENTER key before pressing the desired F-key. DTC STATUS This selection will display any DTC(s) that have not run during the current ignition cycle or have reported a test failure during this ignition up to a maximum of 33 DTCs. DTC test which run and passed will cause that affected DTC to be removed from scan tool screen. FAIL THIS IGN. This selection will display all DTCs that have failed during the present ignition cycle. HISTORY This selection will display only DTC(s) that are stored in the control module's history memory. It will not type "B" DTCs. It will display all type "A" and type "B" DTCs that have the MIL illuminated and have failed within the last 40 warm-up cycles. It will also display type "C" DTCs that have failed within the 40 warm-up cycles. LAST TEST FAIL This selection will display only DTCs that have failed the last time the test ran. The last test may have ran during the previous ignition cycle, if a type "A" or "B" DTC is displayed. For type "C" DTCs, the last failure must have occurred during the current ignition cycle to be displayed as LAST TEST FAIL. MIL REQUEST This selection will display only DTCs that are requesting the MIL. Type "C" DTCs cannot be displayed using this option. This selection will report type "B" DTCs only after the MIL has been requested. NOT RUN SCC Microsoft Saturday, August 29, 2009 11:39:10 AM

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Not Run Since Code Clear option will display up to 33 DTCs that have not run since DTCs were last cleared. Since any displayed DTCs have not run, their condition (passing or failing) is unknown. TEST FAIL SCC Test Fail Since Code Clear selection will display all active and history DTCs that have reported a test failure since the last time DTCs were cleared. DTCs that last failed over 40 warm-up cycles before this option is selected will not be displayed. FAILED SINCE CLEAR This message indicates the DTC has failed at least once within the last 40 warm-up cycles since the last time DTCs were cleared. NOT RUN SINCE CL. Not Run Since Cleared message indicates that the selected diagnostic test has not run since the last time DTCs were cleared. Therefore, the diagnostic test status (passed or failed) is unknown. After DTCs are cleared, this message will continue to be displayed until the diagnostic test runs. NOT RUN THIS IGN. Not Run This Ignition message indicates the selected diagnostic test has not run this ignition cycle. TEST RAN AND PASSED This message indicates the selected diagnostic test has:    

Passed the last test. Ran and passed during this ignition cycle. Ran and passed since DTCs were last cleared. Test has not failed since DTCs were last cleared.

If this message is displayed, repair is done. If FAILED THIS IGN. message is displayed, repair is incomplete and further diagnosis is required. DIAGNOSTIC PROCEDURE Diagnosis of computerized engine control system should be performed in following order: 1. Ensure all engine systems not related to computer system are operating properly. DO NOT proceed with testing unless all other problems have been repaired. ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK must be performed before using specific DTC testing procedure. See the BASIC TESTING 4.3L article. 2. If DTC(s) were displayed, determine whether codes are hard or intermittent trouble codes. Hard codes will cause MIL to illuminate continuously while engine is running. See HARD OR INTERMITTENT Microsoft Saturday, August 29, 2009 11:39:10 AM

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TROUBLE CODE DETERMINATION . For diagnosing hard codes, proceed to appropriate DTC test. For diagnosing intermittent codes, proceed to INTERMITTENTS in the TESTS W/O CODES article. 3. If no DTCs are present and a driveability problem exists, refer to SYMPTOMS in the TESTS W/O CODES article. Doing so will help identify proper system or component to check in the SYSTEM/COMPONENT TESTS article. 4. After necessary repairs are made, clear DTCs, verify vehicle will enter "closed loop" operation and ensure DTC does not reset. READING TROUBLE CODES NOTE:

Use of Tech 1 or 2 scan tool is required to retrieve DTCs. Refer to user reference manuals supplied with scan tool.

HARD OR INTERMITTENT TROUBLE CODE DETERMINATION During any diagnostic procedure, determine if DTC(s) are hard failure codes or intermittent failure codes. Diagnostic procedures will not always help analyze intermittent codes. To determine hard codes and intermittent codes: 1. Enter diagnostic mode. Read and record all stored DTCs. Exit diagnostic mode, and clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTC) . 2. Apply parking brake, and place transmission in Neutral or Park. Block drive wheels, and start engine. MIL should go out. Operate warm engine at specified RPM for 2 minutes and note MIL. 3. If MIL illuminates, enter diagnostic mode. Read and record DTCs. This will reveal hard failure codes. Oxygen sensor related codes may require a road test to reset hard failure after DTCs were cleared. 4. If MIL does not illuminate, all stored DTCs were intermittent failures, except as noted above. NOTE:

DTCs will be recorded at various operating times. Some codes require operation of that sensor or switch for 5 seconds; others require operation for 5 minutes or longer at normal operating temperature, vehicle speed and load. Therefore, some DTCs may not set in a service bay operational mode and may require road testing vehicle in order to duplicate conditions under which code will set.

CLEARING DIAGNOSTIC TROUBLE CODES (DTC) To clear DTCs from memory, either to determine if malfunction will occur again or after making necessary repairs, disconnect power supply to ECM/PCM/VCM for at least 30 seconds or clear codes using a scan tool. ECM/PCM/VCM LOCATION On most models, ECM/PCM/VCM is located behind right or left side of dash, behind right or left kick panel, or on left or right side of engine compartment. For more precise location, see COMPONENT LOCATIONS in the SYSTEM/COMPONENT TESTS article. Microsoft Saturday, August 29, 2009 11:39:10 AM

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DIAGNOSTIC MATERIALS Diagnostic Aids

Diagnostic aids are additional tips used to help diagnose trouble codes when inspected circuit is okay. Diagnostic aids may help lead to a definitive solution to trouble code problem. SPECIAL TOOLS (DIAGNOSTIC) NOTE:

A scan tool plugged into DLC is used to read DTCs and check voltages in system on serial data line. A scan tool is REQUIRED to retrieve vehicle information.

Computerized engine control system is most easily diagnosed using scan tool; however, other tools may aid in diagnosing problems. These tools are a tachometer, test light, ohmmeter, digital voltmeter with a 10-megohm input impedance (minimum), vacuum pump, vacuum gauge, fuel injector test lights and 6 jumper wires 6" long (one wire with female connectors at both ends, one wire with male connectors at both ends and 4 wires with male and female connectors at opposite ends). A test light, rather than a voltmeter, must be used when indicated by a diagnostic test. In addition, special jumper harnesses or testers may be required by manufacturer to facilitate diagnosis. SCAN TOOL USAGE NOTE:

Before connecting scan tool to vehicle, diagnostic system should be checked to determine if system is operating properly and if information received will be accurate. This is done by performing ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK located in the BASIC TESTING - 4.3L article. If vehicle does not pass OBD system check, information received may be invalid.

Scan tool is a specialized tester which, when plugged into DLC, can be used to diagnose on-board computer control systems by providing instant access to circuit voltage information without need to crawl under dash or hood to backprobe sensors and connectors. Scan tool cuts down diagnostic time dramatically by furnishing input data (voltage signals) which can be compared to specification parameters. See SCAN DATA . They may also furnish information on output device (solenoids and motors) status. However, status parameters only indicate output signals have been sent to devices by PCM/VCM; they do not indicate whether devices have responded properly to signal. Verify proper response at output device using a voltmeter or test light. A problem may exist even if DTCs are not present. About 80 percent of driveability problems occur without DTCs. Sensors that are out of calibration will not set a DTC but will cause driveability problems. Using a scan tool is the easiest method of checking sensor specifications and other data parameters. Scan tool is also useful in finding intermittent wiring problems by wiggling wiring harnesses and connections (key on, engine off) while observing data parameters. See SCAN DATA. Microsoft Saturday, August 29, 2009 11:39:10 AM

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NOTE:

If erroneous voltage signals are suspected, verify tester information using a digital voltmeter and wiring schematic. If non-existent codes are displayed, DO NOT use scan tool for diagnosis. Contact tester manufacturer for additional information.

SCAN DATA NOTE:

For scan data values, refer to scan tool manufacturer owner's manual or compare values with a known good component or vehicle.

DTC DEFINITIONS TROUBLE CODE DEFINITIONS TROUBLE CODE DEFINITIONS Code No. P0101 P0102 P0103 P0106 P0107 P0108 P0112 P0113 P0117 P0118 P0121 P0122 P0123 P0125 P0131 P0132 P0133 P0134 P0135 P0137 P0138 P0140 P0141 P0143 P0144 P0146

Circuit Affected MAF System Performance MAF Sensor Circuit Low Frequency MAF Sensor Circuit High Frequency MAP Sensor System Performance MAP Sesnor Circuit Low Voltage MAP Sensor Circuit High Voltage IAT Sensor Circuit Low Voltage IAT Sensor Circuit High Voltage ECT Sensor Circuit Low Voltage ECT Sensor Circuit High Voltage TP Sensor System Performance TP Sensor Circuit Low Voltage TP Sensor Circuit High Voltage ECT Excessive Time To Reach Closed Loop HO2S Circuit Low Voltage-Bank 1, Sensor 1 HO2S Circuit High Voltage-Bank 1, Sensor 1 HO2S Slow Response-Bank 1, Sensor 1 HO2S Insufficient Activity-Bank 1, Sensor 1 HO2S Heater Circuit-Bank 1, Sensor 1 HO2S Circuit Low Voltage-Bank 1, Sensor 2 HO2S Circuit High Voltage Bank 1, Sensor 2 HO2S Insufficient Activity-Bank 1, Sensor 2 HO2S Heater Circuit-Bank 1, Sensor 2 HO2S Circuit Low Voltage-Bank 1, Sensor 3 HO2S Circuit High Voltage-Bank 1, Sensor 3 HO2S Insufficient Activity-Bank 1, Sensor 3

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P0147 P0151 P0152 P0153 P0154 P0155 P0171 P0172 P0174 P0175 P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0327 P0336 P0337 P0338 P0339 P0340 P0341 P0401 P0420 P0461 P0462 P0463 P0500 P0506 P0507 P0704 P1106 P1107 P1111 P1112 P1114 P1115 P1121 P1122

HO2S Heater Circuit-Bank 1, Sensor 3 HO2S Circuit Low Voltage-Bank 2, Sensor 1 HO2S Circuit High Voltage-Bank 2, Sensor 1 HO2S Slow Response-Bank 2, Sensor 1 HO2S Insufficient Activity-Bank 2, Sensor 1 HO2S Heater Circuit-Bank 2, Sensor 1 Fuel Trim System Lean-Bank 1 Fuel Trim System Rich-Bank 1 Fuel Trim System Lean-Bank 2 Fuel Trim System Rich-Bank 2 Engine Misfire Detected Cyl. No. 1 Misfire Detected Cyl. No. 2 Misfire Detected Cyl. No. 3 Misfire Detected Cyl. No. 4 Misfire Detected Cyl. No. 5 Misfire Detected Cyl. No. 6 Misfire Detected Knock Sensor Low Voltage CKP Sensor Circuit Performance CKP Sensor Circuit Low Frequency CKP Sensor Circuit High Frequency CKP Sensor Circuit Intermittent CKP Sensor Circuit CMP Sensor Circuit Performance EGR System Performance TWC System Low Efficiency-Bank 1 Fuel Level Sensor Circuit Malfunction Fuel Level Sensor Circuit Low Voltage Fuel Level Sensor Circuit High Voltage Vehicle Speed Sensor Circuit Idle RPM Low (IAC Responding) Idle RPM High (IAC Responding) Clutch Switch Circuit MAP Sensor Circuit Intermittentl High Voltage MAP Sensor Circuit Intermittentl Low Voltage IAT Sensor Circuit Intermittent High Voltage IAT Sensor Circuit Intermittent Low Voltage ECT Sensor Circuit Intermittent Low Voltage ECT Sensor Circuit Intermittent High Voltage TP Sensor Voltage Intermittentl High TP Sensor Voltage Intermittentl Low

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

HO2S Insufficient Switching-Bank 1, Sensor 1 HO2S Transition Time Ratio-Bank 1, Sensor 1 HO2S Insufficient Switching-Bank 2, Sensor 1 HO2S Transition Time Ratio-Bank 2, Sensor 1 CKP/CMP Sesnor Correlation IC Circuit High Voltage IC Circuit Low Voltage EBCM DTC Detected Rough Road Data Unusable Misfire Detected-No EBCM/PCM/VCM Serial Data EVAP System Flow During Non-Purge IAC System-Low RPM IAC System-High RPM

P1134 P1153 P1154 P1345 P1351 P1361 P1380 P1381 P1441 P1508 P1509

SUMMARY If no hard fault codes are present, driveability symptoms exist or intermittent DTC(s) exist, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

CONNECTOR IDENTIFICATION NOTE:

For additional connector and terminal identification, see CONNECTOR IDENTIFICATION - S/T SERIES article.

VCM CONNECTORS C1

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 1: VCM 32-Pin Connector C1 (Blue) - With M/T Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 2: VCM 32-Pin Connector C1 (Blue) - With A/T Courtesy of GENERAL MOTORS CORP. C2

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 3: VCM 32-Pin Connector C2 (Red) - With M/T, Without A/C Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 4: VCM 32-Pin Connector C2 (Red) - With M/T, With A/C Courtesy of GENERAL MOTORS CORP.

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Fig. 5: VCM 32-Pin Connector C2 (Red) - With A/T, Without A/C Courtesy of GENERAL MOTORS CORP.

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Fig. 6: VCM 32-Pin Connector C2 (Red) - With A/T, With A/C Courtesy of GENERAL MOTORS CORP. C3 Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 7: VCM 32-Pin Connector C3 (Clear) - With M/T, Without A/C Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 8: VCM 32-Pin Connector C3 (Clear) - With M/T, With A/C Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 9: VCM 32-Pin Connector C3 (Clear) - With A/T, Without A/C Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 10: VCM 32-Pin Connector C3 (Clear) - With A/T, With A/C Courtesy of GENERAL MOTORS CORP. C4

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 11: VCM 32-Pin Connector C4 (Natural) Courtesy of GENERAL MOTORS CORP. C5

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Fig. 12: VCM 32-Pin Connector C5 (Black) Courtesy of GENERAL MOTORS CORP.

DIAGNOSTIC TROUBLE CODES NOTE:

Before clearing DTCs, perform On-Board Diagnostic (OBD) System Check. See the BASIC TESTING - 4.3L article. Record FREEZE FRAME and FAILURE

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RECORDS for reference during testing. Data will be erased when DTCs are cleared. If PCM/VCM is replaced, NEW PCM/VCM must be programmed using special manufacturer's equipment. DTC P0101 - MAF SENSOR SYSTEM PERFORMANCE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Mass Airflow (MAF) sensor measures amount of air entering engine during a given time. VCM uses MAF sensor information for fuel delivery calculations. MAF sensor readings during acceleration are much higher than those during deceleration or idle. VCM calculates what MAF sensor reading should be received from sensor under certain conditions using engine speed (RPM), throttle position, and altitude parameters. When these test conditions are met, VCM will compare its calculated MAF value to actual value received from sensor. Conditions required to test for DTC are:     

Vehicle driven at a steady speed. No MAP or TP sensor DTCs are set. No EVAP system DTCs are set. EGR DTC P0401 not set. MAF sensor DTC P0102 or P0103 not set.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on, with engine off. Using scan tool, read and record FAIL RECORD data. Operate vehicle within conditions noted in FAIL RECORD data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0101, go to next step. If DTC P0101 is not displayed, see DIAGNOSTIC AIDS. 3. Check for throttle body inlet screen blockage. Check for vacuum leaks at intake manifold, throttle body or EGR valve flange and pipes. Check for crankcase valve faulty, missing or incorrectly installed. Repair faulty conditions as necessary and go to step 17). If no faulty conditions exist, go to next step. 4. Turn ignition on, throttle closed. Using scan tool, read TP ANGLE value. If scan tool displays about zero percent, go to next step. If scan tool does not display zero percent, go to DTC P0121 . 5. Turn ignition off. Disconnect MAF sensor harness connector. Turn ignition on, engine off. Using a DVOM, check voltage between MAF sensor harness connector signal circuit and chassis ground. If voltage is about 5 volts, go next step. If voltage is not as specified, go to step 7). 6. Connect a test light between MAF sensor harness connector ignition feed and ground circuits. If test light Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

7. 8.

9. 10. 11. 12. 13. 14. 15. 16. 17.

18.

illuminates, go to step 10). If test light does not illuminate, go to step 9). If voltage is less than 4.5 volts, go to step 11). If voltage is 4.5 volts or greater, go to next step. Turn ignition off. Disconnect VCM connectors. Turn ignition on, engine off. Check voltage between VCM harness connector MAF signal circuit and chassis ground. If voltage reading is about zero volts, go to step 16). If voltage is not as specified, go to step 14), Connect test light between MAF sensor harness connector ignition feed circuit and chassis ground. If test light illuminates, go to step 12). If test light does not illuminate, go to step 13). Check for faulty connection at MAF sensor. Repair connection as necessary and go to step 17). If connection is okay, go to step 15). Check MAF sensor signal circuit between VCM and MAF sensor for open or short to ground. Repair signal circuit as necessary and go to step 17). If signal circuit is okay, go to step 16). Locate and repair open in the MAF sensor ground circuit. After repairs, go to step 17). Locate and repair open MAF sensor ignition feed circuit. After repairs, go to step 17). Locate and repair short to voltage in MAF sensor signal circuit. After repairs, go to step 17). Replace MAF sensor. After replacing sensor, go to step 17). Replace VCM. Program replacement VCM using required equipment. After replacement, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0101. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, read and record REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for stuck or faulty Throttle Position (TP) sensor. Using scan tool, read TP ANGLE value with throttle closed. If value is not zero percent, check for and repair the following condition(s):   

Throttle plate sticking or excessive deposits on throttle plate or throttle bore. TP sensor signal circuit shorted to voltage. Faulty connection or high resistance in TP sensor ground circuit.

If none of the listed conditions exist and TP ANGLE value is not zero percent, replace TP sensor. Check for faulty connections or damaged harness. Ensure harness is not routed too close to high-voltage wires, such as spark plug cables. If connections and harness appear okay, observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for plugged intake air duct or dirty air filter. A wide-open throttle acceleration from a stop should cause MAF reading on scan tool to increase from about 5-7 grams at idle to about 100 grams or greater at time of 1-2 shift. If not, check for restriction. Check for a skewed MAP sensor, which can cause Barometric (BARO) pressure reading to be incorrectly calculated. This condition may also cause high Idle Air Control (IAC) counts. If IAC counts are high, replace Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

MAP sensor. Check for vacuum leaks at following locations:       

Air inlet duct between MAF sensor and throttle body. "O" rings at fuel meter body. Oil cap and dipstick tube. Purge solenoid. MAP sensor. Brake booster. Intake manifold, crankcase, throttle body and EGR gaskets.

DTC P0102 - MAF SENSOR CIRCUIT LOW FREQUENCY NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine running. Engine run time greater than .4 second. System voltage is at least 8 volts. Conditions must be present for a period of greater than zero seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. After performing OBD system check, go to next step. 2. Start engine. With engine at idle, use scan tool to read MAF value. If MAF value is less than 2 grams per second, go to step 4). If value is 2 grams per second or greater, go to next step. 3. Turn engine off. Turn ignition on, engine off. Using scan tool, read and record FAIL RECORDS data. Operate vehicle within conditions noted in FAIL RECORD data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0102 FAILED THIS IGN, go to next step. If DTC P0102 FAILED THIS IGN Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

6. 7. 8. 9. 10. 11. 12. 13. 14.

15.

is not displayed, see DIAGNOSTIC AIDS. Check for MAF sensor inlet screen blockage. Check for vacuum leaks at intake manifold, throttle body or EGR valve flange and pipes. Check for crankcase valve faulty, missing or incorrectly installed. Repair faulty conditions as necessary. After repairs, go to step 14). If no faulty conditions exist, go to next step. Turn ignition off. Disconnect MAF sensor harness connector. Turn ignition on, engine off. Using a DVOM, check voltage between MAF sensor harness connector signal circuit and chassis ground. If voltage is about 5 volts, go next step. If voltage is not about 5 volts, go to step 9). Connect a test light between MAF sensor harness connector ignition feed and ground circuits. If test light illuminates, go to step 8). If test light does not illuminate, go to next step. Connect test light between MAF sensor harness connector ignition feed circuit and battery ground. If test light illuminates, go to step 10). If test light does not illuminate, go to step 11). Check for faulty connection at MAF sensor. Repair connection as necessary. After repairs, go to step 14). If connection is okay, go to step 12). Check MAF sensor signal circuit between VCM and MAF sensor for open or short. Repair signal circuit as necessary. After repairs, go to step 14). If signal circuit is okay, go to step 13). Locate and repair open in the MAF sensor ground circuit. After repairs, go to step 14). Locate and repair open MAF sensor ignition feed circuit. After repairs, go to step 14). Replace MAF sensor. After replacing sensor, go to step 14). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0102. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections or damaged harness. Ensure harness is not routed too close to high-voltage wires, such as spark plug cables. If connections and harness appear okay, observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for vacuum leaks at following locations:       

Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

DTC P0103 - MAF SENSOR CIRCUIT HIGH FREQUENCY NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine running. Engine run time is at least .4 second. System voltage is at least 8 volts. MAF sensor is at least 10400 Hz. Conditions must be present for a period greater than zero seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine. With engine at idle, use scan tool to read MAF value. If MAF value is greater than 20 grams per second, go to step 4). If value is less than specified, go to next step. 3. Turn engine off. Turn ignition on, engine off. Using scan tool, read and record FAIL RECORDS data. Operate vehicle within conditions noted in FAIL RECORD data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0103 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0103 FAILED THIS IGN, see DIAGNOSTIC AIDS. 4. Turn ignition off. Disconnect MAF sensor harness connector. Turn engine on and allow it to idle. Using scan tool, read MAF value. If value is about zero grams per second, go to next step. If value is not as specified, go to step 7). 5. Check for faulty connection at MAF sensor. Repair as necessary. After repairs, go to step 10). If connection is okay, go to next step. 6. Replace MAF sensor. After replacing sensor, go to step 10). 7. Ensure MAF sensor harness is not routed too close to high-voltage wires, such as spark plug cables, ignition coils or other high-voltage components. Reroute harness if necessary and go to step 10). If harness routing is okay, go to next step. 8. Check MAF sensor signal circuit connection at VCM. Repair as necessary. After repairs, go to step 10). If Microsoft Saturday, August 29, 2009 11:39:10 AM

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connection is okay, go to next step. 9. Replace VCM. Program replacement PCM using required equipment. After replacing VCM, go to next step. 10. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0103. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 11. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

DTC P0106 - MAP SENSOR SYSTEM PERFORMANCE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum). A 5-volt reference is applied to sensor. A variable resistor moves in relation to manifold pressure and a voltage signal is returned to VCM through MAP signal circuit. Voltage signal varies from 1.0-1.5 volts at closed throttle (high vacuum) to 4.0-4.5 volts at wide open throttle (low vacuum). A change in throttle position and engine speed should precede change in MAP. If change does not occur, MAP malfunction is present. VCM utilizes MAP signal and throttle position to determine fuel delivery. Conditions for setting DTC are:   

No TP sensor related DTCs. Engine running. Engine speed changes less than 100 RPM.

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

       

TP angle changes less than 1.95 percent. EGR flow changes less than 10 percent. Idle air changes less than 100 counts. No change in brake switch status. No change in clutch status (M/T). No change in A/C status. No change in power steering switch status. Conditions have stabilized for a period of 0.5 second.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on, engine off. Using scan tool, read MAP sensor voltage. Voltage should be 4.0-4.5 volts. If voltage varies 0.4 volt or greater from specification, go to next step. If voltage does not vary 0.4 volt or greater, go to step 6). 3. Disconnect and plug MAP sensor vacuum source. Connect a vacuum gauge to MAP sensor. Start engine. Using scan tool, read and record MAP sensor voltage. Observe and record MAP sensor voltage while applying 10 in. Hg If difference between first and second reading is 1.5 volts or greater, see DIAGNOSTIC AIDS. If difference is less than 1.5 volts, go to next step. 4. Check for faulty connection at MAF sensor. If faulty connection is found, go to next step. If connection is okay, go to step 6). 5. Repair connection as necessary. After repairs, go to step 7). 6. Replace MAP sensor. After replacing sensor, go to next step. 7. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0106. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 8. Using scan tool, select Read and Record INFO in REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check MAP sensor vacuum source for leaks, restrictions or faulty connections. DTC P0107 - MAP SENSOR CIRCUIT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Manifold Absolute Pressure (MAP) sensor measures changes in intake manifold pressure (vacuum). A low voltage signal, 1.0-1.5 volts, is sent to VCM on signal circuit at closed throttle (high vacuum). A high voltage signal, 4.0-4.5 volts is sent at wide open throttle (low vacuum). Conditions required to set DTC are:     

No TP sensor related DTCs. Engine running. TP sensor is at least zero percent when engine speed is not greater than 1000 RPM. TP sensor is at least 10.1 percent when engine speed is greater than 1000 RPM. MAP voltage greater than 4.9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start and warm engine to normal operating temperature. Allow engine to idle. Using scan tool, read MAP sensor voltage. If voltage is less than 0.5 volt, go to next step. If voltage is not less than 0.5 volt, go to step 5). 3. Turn ignition off. Disconnect MAP sensor harness connector. Connect a jumper wire between MAP sensor harness connector 5-volt reference circuit and signal circuit. Turn ignition on. If voltage is greater than 4.7 volts, go to step 6). If voltage is not greater than 4.7 volts, go to next step. 4. Turn ignition off. Remove jumper wire. Connect a test light between MAP sensor harness connector signal circuit and battery voltage. Turn ignition on. If voltage is greater than 4.7 volts, go to step 9). If voltage is not greater than 4.7 volts, go to step 7). 5. DTC P0107 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check for faulty connection at MAP. If faulty connection is found, go to step 12). If connection is okay, go to step 11). 7. Check for open MAP sensor signal circuit. If open signal circuit is found, go to step 12). If no open signal circuit is found, go to next step. 8. Check MAP sensor signal circuit for short to ground. If short to ground in signal circuit is found, go to step 12). If no short to ground in signal circuit is found, go to step 13). 9. Check for open MAP sensor 5-volt reference circuit. If open 5-volt reference circuit is found, go to step 12). If no open 5-volt reference circuit is found, go to next step. 10. Check MAP sensor 5-volt reference circuit for short to ground. If short to ground in 5-volt reference circuit is found, go to step 12). If no short to ground in 5-volt reference circuit is found, go to step 13). 11. Replace MAP sensor. After replacing sensor, go to step 14). 12. Repair circuit as necessary. After repairs, go to step 14). 13. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating Microsoft Saturday, August 29, 2009 11:39:10 AM

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temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0107. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check MAP sensor signal and 5-volt reference circuits for intermittent open condition. With ignition on and engine off, MAP signal is equal to atmospheric pressure with signal voltage high. This information is used by VCM as an indication of altitude. Comparison of this reading with a known-good vehicle with same sensor is a way to check accuracy of suspect sensor. Reading should be within 0.4 volt. Disconnect sensor from bracket and twist sensor by hand to check for intermittents. Output changes greater than 0.1 volt indicate a faulty sensor connection. DTC P0108 - MAP SENSOR CIRCUIT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Manifold Absolute Pressure (MAP) sensor measures changes in intake manifold pressure (vacuum). A low voltage signal, 1.0-1.5 volts, is sent to VCM on signal circuit at closed throttle (high vacuum). A high voltage signal, 4.0-4.5 volts, is sent at wide open throttle (low vacuum). Conditions for setting DTC:    

No TP sensor related DTCs are set. TP angle is not greater than 96.8 percent when engine speed is not greater than 1000 RPM. TP angle is not greater than 89.8 percent when engine speed is greater than 1000 RPM. MAP is greater than or equal to 4.9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Correct any engine idle or vacuum problems before proceeding. Turn engine on and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is less than 4 volts, go to next step. If voltage is not less than 4 volts, go to step 4). 3. Turn ignition off. Disconnect MAP sensor harness connector. Turn ignition on. If voltage is less than one volt, go to step 5). If voltage is not less than one volt, go to step 9). 4. DTC P0108 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, go to DIAGNOSTIC AIDS. Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

5. Using a DVOM connected to ground, probe 5-volt reference circuit at MAP sensor harness connector. If voltage reading is greater than 5.2 volts, go to step 10). If voltage reading is not greater than 5.2 volts, go to next step. 6. Using a test light connected battery voltage, probe MAP sensor ground circuit at MAP sensor harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 14). 7. Check MAP sensor vacuum source for restriction. If restriction is found, go to step 15). If no restriction is found, go to next step. 8. Replace MAP sensor. After replacing sensor, go to step 19). 9. Check for short to voltage in MAP sensor signal circuit. Repair as necessary. After repairs, go to step 15). If circuit is okay, go to step 18). 10. Turn ignition off. Disconnect VCM White harness connector. Turn ignition on. Using DVOM connected to ground, check voltage on 5-volt reference circuit at VCM harness connector. If voltage reading is greater than 5.2 volts, go to next step. If voltage reading is not greater than 5.2 volts, go to step 13). 11. Disconnect EGR harness connector. Check voltage on 5-volt reference circuit at VCM harness connector. If voltage reading is greater than 5.2 volts, go to next step. If voltage reading not greater than 5.2 volts, go to step 16). 12. Repair short to voltage on 5-volt reference circuit. After repairs, go to step 19). 13. Using DVOM connected to ground, check voltage on VCM harness connector terminal GR12. If voltage reading is greater than 5.2 volts, go to step 17). If voltage reading is not greater than 5.2 volts, go to step 18). 14. Repair sensor ground circuit. After repairs, go to step 19). 15. Repair as necessary. After repairs, go to step 19). 16. Replace EGR valve. After replacing EGR valve, go to step 19). 17. Repair short to ground on 5-volt reference circuit. After repairs, go to step 19). 18. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 19. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0108. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 20. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check MAP sensor signal and 5-volt reference circuits for intermittent open condition. With ignition on and engine off, MAP signal is equal to atmospheric pressure with signal voltage high. This information is used by VCM as an indication of altitude. Comparison of this reading with a known-good vehicle with same sensor is a way to check accuracy of suspect sensor. Readings should be within 0.4 volt of each other. Disconnect sensor from bracket and twist sensor by hand to check for intermittents. Output changes greater than 0.1 volt indicate a faulty sensor connection. Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

DTC P0112 - IAT SENSOR CIRCUIT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Intake Air Temperature (IAT) sensor is a thermistor that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. High temperature will result in a low signal voltage. DTC will set when VCM sees an IAT sensor voltage of less than 0.82 volt for 10 seconds after engine runs for 100 seconds. Conditions required to test for DTC are:  

Vehicle driven at 2 MPH or greater. No VSS DTCs are set.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Using scan tool, read IAT sensor voltage. If voltage is less than 0.82 volt, go to next step. If voltage is not less than 0.82 volt, go to step 5). 3. Turn engine off. Turn ignition on. Disconnect IAT sensor harness connector. If voltage is greater than 4 volts, go to step 7). If voltage is not greater than 4 volts, go to next step. 4. Turn ignition off. Using DVOM, check resistance across IAT sensor harness connector. If resistance is infinite, go to step 8). If resistance is not infinite, go to step 6). 5. DTC P0112 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Repair short to ground in IAT sensor signal circuit. After repairs, go to step 9). 7. Replace IAT sensor. After replacing sensor, go to step 9). 8. Replace VCM. Program replacement VCM using required equipment. After replacing and reprogramming VCM, go to next step. 9. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0112. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

If DTC P1112 is also set, problem is intermittent. Check for short to ground in IAT sensor harness connector signal circuit. Observe scan tool while moving all related harness and connectors. A change in scan tool display Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

indicates fault location. See IAT TEMPERATURE-TO-RESISTANCE VALUES . IAT TEMPERATURE-TO-RESISTANCE VALUES Temperature °F (°C) 212 (100) 194 (90) 158 (70) 122 (50) 104 (40) 86 (30) 68 (20) 50 (10)

Ohms 177 241 467 973 1459 2238 3520 5670

DTC P0113 - IAT SENSOR CIRCUIT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Intake Air Temperature (IAT) sensor is a thermistor that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. Low temperature will result in a high signal voltage. DTC will set when VCM sees an IAT sensor voltage of greater than 5 volts. Conditions required to set DTC are:        

No ECT sensor related DTCs. No VSS DTCs are set. No MAF sensor related DTCs. Vehicle speed is less than 2 MPH. MAF value is less than 250 grams per second. ECT is greater than 84.7°F (29.3°C). Engine run time is greater than 100 seconds. IAT voltage is greater than 4.9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow to idle. Using scan tool, read IAT sensor voltage. If voltage is greater than 4.9 volts, go to next step. If voltage is not greater than 4.9 volts, go to step 6). 3. Turn engine off. Turn ignition on. Disconnect IAT sensor harness connector. Connect a jumper wire Microsoft Saturday, August 29, 2009 11:39:10 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

14.

across IAT sensor harness connector. If voltage is less than 0.82 volt, go to step 7). If voltage is not less than 0.82 volt, go to next step. Connect jumper wire between IAT sensor harness connector signal circuit and chassis ground. If voltage is less than 0.82 volt, go to step 8). If voltage is not less than 0.82 volt, go to next step. If DTC P0123 is also set, go to DTC P0123 . If DTC is not set, go to step 9). DTC P0113 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. Inspect VCM and IAT sensor for proper connection. If a problem is found, go to step 10). If connections are okay, go to step 11). Check IAT sensor harness connector ground circuit for open between VCM and IAT sensor. If open is found, go to step 10). If open is not found, go to step 12). Check IAT sensor harness connector signal circuit for open between VCM and IAT sensor. If open is found, go to next step. If open is not found, go to step 12). Repair circuit as necessary. After repairs, go to step 13). Replace IAT sensor. After replacing sensor, go to step 13). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0113. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine Coolant Temperature (ECT) sensor is a thermistor that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. High temperature will result in a low signal voltage. DTC will set when VCM sees an ECT sensor voltage of less than 0.82 volt for 10 seconds after engine runs for 100 seconds. Condition for setting DTC: Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

 

Engine run time is greater than 5 seconds. Signal voltage is less than .25 volt for 5 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Using scan tool, read ECT sensor voltage. If voltage is less than 0.82 volt, go to next step. If voltage is not less than 0.82 volt, go to step 5). 3. Turn engine off. Turn ignition on. Disconnect ECT sensor harness connector. If voltage is greater than 4 volts, go to step 7). If voltage is not greater than 4 volts, go to next step. 4. Turn ignition off. Using DVOM, check resistance across ECT sensor harness connector. If resistance is infinite, go to step 8). If resistance is not infinite, go to step 6). 5. DTC P0117 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Repair short to ground in ECT sensor signal circuit. After repairs, go to step 9). 7. Replace ECT sensor. After replacing sensor, go to step 9). 8. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 9. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0117. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for short to ground in ECT sensor harness connector 5-volt reference circuit. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for skewed ECT sensor. See ECT TEMPERATURE-TO-RESISTANCE VALUES . ECT TEMPERATURE-TO-RESISTANCE VALUES Temperature °F (°C) 212 (100) 194 (90) 158 (70) 122 (50) 104 (40) 86 (30) 68 (20)

Ohms 177 241 467 973 1459 2238 3520

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50 (10)

5670

DTC P0118 - ECT SENSOR CIRCUIT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine Coolant Temperature (ECT) sensor is a thermistor that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. Low temperature will result in a high signal voltage. DTC will set when VCM sees an ECT sensor voltage of greater than 5 volts. Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to idle. Using scan tool, read ECT sensor voltage. If voltage is greater than 4.9 volts, go to next step. If voltage is not greater than 4.9 volts, go to step 5). 3. Turn engine off. Turn ignition on. Disconnect ECT sensor harness connector. Connect a jumper wire across ECT sensor harness connector. If voltage is less than 0.82 volt, go to step 6). If voltage is not less than 0.82 volt, go to next step. 4. Connect jumper wire between ECT sensor harness connector signal circuit and chassis ground. If voltage is less than 0.82 volt, go to step 7). If voltage is not less than 0.82 volt, go to step 8). 5. DTC P0118 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, go to DIAGNOSTIC AIDS. 6. Inspect VCM and ECT sensor for proper connection. If a problem is found, go to step 10). If connections are okay, go to step 11). 7. Check ECT sensor harness connector ground circuit for open between VCM and ECT sensor. If open is found, go to step 10). If open is not found, go to step 12). 8. If DTC P0123 is also set, go to DTC P0123. If DTC is not set, go to next step. 9. Check ECT sensor harness connector signal circuit for open between VCM and ECT sensor. If open is found, go to next step. If open is not found, go to step 12). 10. Repair circuit as necessary. After repairs, go to step 13). 11. Replace ECT sensor. After replacing sensor, go to step 13). 12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0118. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are Microsoft Saturday, August 29, 2009 11:39:11 AM

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displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or open in 5-volt reference and ground circuits. Check for skewed ECT sensor. See ECT TEMPERATURE-TO-RESISTANCE VALUES . DTC P0121 - TP SENSOR SYSTEM PERFORMANCE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Throttle Position (TP) sensor measures amount of throttle opening. VCM uses TP sensor information for fuel delivery calculations. TP sensor readings during acceleration are much higher than those during deceleration or idle. TP sensor signal is one of the most important inputs used by the VCM for fuel control and for most of the VCM control inputs. Conditions required for setting DTC:      

No MAP related DTCs are present. No TP related DTCs are present. No IAT related DTCs are present. Engine is running. BARO is not at calculated default. Change in TP is less than 1.9 percent.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on, engine off. Using scan tool, read TP ANGLE value. If value is greater than 2 percent, go to step 4). If value is not greater than 2 percent, go to next step. 3. Observe scan tool while moving throttle from closed to wide open, and closed again. If TP ANGLE value is greater than 2 percent, go to next step. If value is 2 percent or less, go to step 5). 4. Disconnect TP sensor harness connector. If TP ANGLE value is zero percent, go to step 6). If value is not zero percent, go to step 9). 5. DTC P0121 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, go to DIAGNOSTIC AIDS. 6. Check for faulty connection at TP sensor. Repair connection as necessary. After repairs, go to next step. Microsoft Saturday, August 29, 2009 11:39:11 AM

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7. 8. 9. 10.

11.

If connection is okay, go to step 8). Repair circuit as necessary. After repairs, go to step 10). Replace TP sensor. After replacing sensor, go to step 10). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0121. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for and repair the following condition(s):   

Throttle plate sticking or excessive deposits on throttle plate or throttle bore. Check TP sensor harness connector terminals for damage. A steady throttle movement from a stop should cause TP ANGLE value reading on scan tool to increase smoothly as throttle is opened.

DTC P0122 - TP SENSOR CIRCUIT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine running. TP sensor voltage less than .25 volt.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. With throttle closed, use scan tool to read TP signal voltage. If voltage is less than 0.15 volt, go to next step. If voltage is not less than 0.15 volt, go to step 5). Microsoft Saturday, August 29, 2009 11:39:11 AM

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3. Disconnect TP sensor harness connector. Connect a jumper wire between TP sensor harness connector sensor signal and 5-volt reference circuits. If voltage is greater than 4 volts, go to step 13). If voltage is not greater than 4 volts, go to next step. 4. Connect a test light between TP sensor harness connector signal circuit and battery voltage. If scan tool reading is greater than 4 volts, go to step 6). If scan tool reading is not greater than 4 volts, go to step 8). 5. DTC P0122 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check for open in TP sensor harness connector 5-volt reference circuit. If circuit is open, go to step 11). If circuit is okay, go to next step. 7. Check for short to ground in TP sensor harness connector 5-volt reference circuit. If circuit is shorted, go to step 11). If circuit is okay, go to step 10). 8. Check for open in TP sensor harness connector signal circuit. If circuit is open, go to step 11). If circuit is okay, go to next step. 9. Check for short to ground in TP sensor harness connector signal circuit. If circuit is shorted, go to step 11). If circuit is okay, go to next step. 10. Check for faulty connection at VCM. If faulty connection is found, go to next step. If connection is okay, go to step 13). 11. Repair circuit as necessary. After repairs, go to step 14). 12. Replace TP sensor. After replacing sensor, go to step 14). 13. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0122. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for and repair the following condition(s):  



Throttle plate sticking or excessive deposits on throttle plate or throttle bore. Check TP sensor harness connector 5-volt reference circuit for open or short to ground, and repair as necessary. TP signal voltage reading on scan tool should be less than 1.25 volt with throttle closed, and greater than 4.5 volts at wide open throttle.

DTC P0123 - TP SENSOR CIRCUIT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

Engine running. TP sensor signal voltage is greater than 4.7 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. With throttle closed, use scan tool to read TP signal voltage. If voltage is greater than 4.8 volts, go to next step. If voltage is not greater than 4.8 volts, go to step 4). 3. Turn ignition off. Disconnect TP sensor harness connector. Turn ignition on. Using scan tool check TP sensor voltage reading. If voltage reading is less than 0.2 volt, go to step 5). If voltage is not less than 0.2 volt, go to step 8). 4. DTC P0123 is intermittent. If no additional DTC(s) are present, see DIAGNOSTIC AIDS. If other DTC (s) are present, diagnose affected DTC(s). 5. Using DVOM connected to ground, probe 5-volt reference circuit at TP sensor harness connector. If voltage reading is greater than 5.2 volts, go to step 9). If voltage reading is not greater than 5.2 volts, go to next step. 6. Using a test light connected to battery voltage, probe TP sensor ground circuit at TP sensor harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 13). 7. Replace TP sensor. After replacing sensor, go to step 18). 8. Check for short to voltage on TP sensor signal circuit. Repair as necessary. After repairs, go to step 14). If circuit is okay, go to step 17). 9. Turn ignition off. Disconnect VCM White harness connector. Turn ignition on. Using DVOM connected to ground, check voltage on the 5-volt reference circuit at the VCM harness connector. If voltage reading is greater than 5.2 volts, go to step 12). If voltage reading is not greater than 5.2 volts, go to next step. 10. Check voltage between ground and 5-volt reference circuit at VCM harness connector. If voltage reading is greater than 5.2 volts, go to next step. If voltage reading is not greater than 5.2 volts, go to step 17). 11. Disconnect EGR harness connector. Check voltage on 5-volt reference circuit at VCM harness connector. If voltage reading is greater than 5.2 volts, go to step 16). If voltage reading is not greater than 5.2 volts, go to step 15). 12. Repair short to voltage on the 5-volt reference circuit. After repairs, go to step 18). 13. Check for open in sensor ground circuit. If circuit is open, go to next step. If circuit is okay, go to step 17). 14. Repair as necessary. After repairs, go to step 18). Microsoft Saturday, August 29, 2009 11:39:11 AM

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15. Replace EGR valve. After replacing EGR, go to step 18). 16. Repair short to voltage on 5-volt reference circuit. After repairs, go to step 18). 17. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 18. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0123. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 19. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for and repair the following condition(s):   

Throttle plate sticking or excessive deposits on throttle plate or throttle bore. Check TP sensor harness connector ground circuit for open, and signal circuit for short to ground. TP sensor signal voltage should be less than 1.25 volt with throttle closed, and greater than 4.5 volts at wide open throttle.

DTC P0125 - ECT EXCESSIVE TIME TO REACH CLOSED LOOP NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

While engine is warming, VCM reads Engine Coolant Temperature (ECT) sensor to determine how long it takes coolant to reach temperature required for closed loop operation. VCM compares actual time required to a predetermined time. Conditions required to set DTC are:     

Engine running. No ECT or IAT DTCs are set. Vehicle speed greater than one MPH. ECT and IAT greater than 15.8°F (-9°C). Start-up ECT is greater than 15.8°F (-9°C).

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Allow engine to cool completely. Turn ignition on. Using scan tool, compare ECT and IAT values. If values are close, go to next step. If values are not close, go to DTC P0117 . Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

3. Check coolant level. If coolant level is low, diagnose cooling system. If coolant level is okay, go to next step. 4. While reading scan tool, start and warm engine to normal operating temperature. If ECT value rises steadily to greater than 95°F (35°C) within 9 minutes, see DIAGNOSTIC AIDS. If ECT value does not rise as specified, go to next step. 5. Compare actual coolant temperature with scan tool ECT value. If temperatures are close, repair cooling system as necessary. If temperatures are not close, go to next step. 6. Replace ECT sensor. After replacing sensor, go to next step. 7. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0125. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 8. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Ensure thermostat is operating properly. Check for faulty connections or damaged harness. If connections and harness appear okay, observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for skewed ECT sensor. See ECT TEMPERATURE-TO-RESISTANCE VALUES . DTC P0131 - HO2S CIRCUIT LOW VOLTAGE SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. VCM reads and stores sensor voltage information and evaluates the voltage samples to determine amount of time sensor voltage is out of range. If HO2S voltage is out of predetermined range, DTC will set. Conditions required to test for DTC are:     

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 1, SENSOR 1 voltage. If voltage is less than 0.086 volt, go to next step. If voltage is not less than 0.086 volt, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector ground circuit and chassis ground. Turn ignition on, engine off. If voltage is 0.35-0.55 volt, go to step 7). If voltage is not as specified, go to step 5). 4. DTC P0131 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Check HO2S sensor harness connector signal circuit for short to ground. If short is found, go to next step. If circuit is okay, go to step 8). 6. Repair circuit as necessary. After repairs, go to step 9). 7. See DIAGNOSTIC AIDS. 8. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 9. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0131. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Using scan tool, observe LT FUEL TRIM values at different RPM. If conditions to set DTC 1031 exist, value should be about 158 or greater. Check for an intermittent short to ground in HO2S signal circuit. Never solder HO2S wires. Check for fuel contamination. Check for proper fuel pressure. Check for exhaust leaks. DTC P0132 - HO2S CIRCUIT HIGH VOLTAGE BANK 1, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

    

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 1, SENSOR 1 voltage. If voltage is greater than 0.976 volt, go to next step. If voltage is not greater than 0.976 volt, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. If voltage is less than 0.2 volt, go to step 5). If voltage is not less than 0.2 volt, go to step 6). 4. DTC P0132 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. See DIAGNOSTIC AIDS. 6. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 7. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0132. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 8. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for proper fuel pressure. Check for proper fuel injector operation. Check EVAP canister for fuel saturation. Check for leaking fuel pressure regulator diaphragm. Check for proper TP sensor operation. Check HO2S for silicon contamination (powdery white deposit). Using scan tool, check HO2S voltage. Voltage should be greater than one volt. Check HO2S voltage with connector disconnected. If voltage goes from greater than one volt to about 0.45 volt, replace HO2S. Never solder HO2S wires. DTC P0133 - HO2S SLOW RESPONSE BANK 1, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls are active. System voltage measures at least 9 volts. HO2S average transition time from lean-to-rich and rich-to -lean is greater than 100 milliseconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other HO2S DTCs are set, diagnose affected DTCs. If no other HO2S DTCs are set, go to next step. 3. Using scan tool, read MAP sensor voltage, with engine idling. If voltage is greater than 4 volts, see DTC P0108 . If voltage is not greater than 4 volts, go to next step. 4. Visually inspect exhaust system for leaks near HO2S. If leaks are found, go to step 8). If no leaks are found, go to next step. 5. Visually inspect HO2S for secure installation. If HO2S is not securely installed, go to step 8). If HO2S is securely installed, go to next step. 6. Ensure HO2S connector and harness are not contacting engine or exhaust system. If connector or harness are contacting engine or exhaust system, go to step 8). If connector and harness are okay, go to next step. 7. Check HO2S for silicon (powdery white) deposit, engine oil or coolant contamination. If contamination exists, go to step 9). If no contamination exists, see DIAGNOSTIC AIDS. 8. Repair as necessary. After repairs, go to step 11). 9. Repair source of contamination. After repairs, go to step 11). 10. Replace HO2S. After replacing sensor, go to next step. 11. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0133. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 12. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

Check HO2S Heater operation. Never solder HO2S wires. DTC P0134 - HO2S INSUFFICIENT ACTIVITY BANK 1, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts. Engine run time is at least 2 minutes. HO2S voltage is greater than .299 volts but less than .598 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to greater than 1200 RPM for 2 minutes. Using scan tool, read LOOP MODE. If scan tool displays CLOSED LOOP, go to step 5). If scan tool does not display CLOSED LOOP, go to next step. 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. If voltage is less than 0.2 volt, go to step 7). If voltage is less than 0.2 volt, go to next step. 4. Remove jumper wire. Turn ignition off. Reconnect HO2S connector. Disconnect Blue VCM connector. Connect a test light between Blue VCM harness connector signal circuit and battery voltage. If test light illuminates, go to step 6). If test light does not illuminate, go to step 9). 5. DTC P0134 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check HO2S harness connector signal circuit for open. If open is found, go to step 11). If no open is found, go to step 8). 7. Check HO2S for faulty connection. If faulty connection is found, go to step 11). If connection is okay, go Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

8. 9. 10. 11. 12. 13.

14.

to step 10). Check VCM for faulty connection. If faulty connection is found, go to step 11). If faulty connection is not found, go to step 12). Repair open ground circuit. After repairs, go to step 13). Replace HO2S. After replacing sensor, go to step 13). Repair circuit as necessary. After repairs, go to step 13). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0134. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections or damaged harness. Check for faulty HO2S heater. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P0135 - HO2S HEATER CIRCUIT BANK 1, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. When ignition is turned on, battery voltage is supplied to HO2S heater to provide for faster sensor warm-up, thus allowing sensor to become active in a shorter period of time. VCM reads amount of time necessary for sensor to become active after startup. Conditions required to set DTC are:     

MAF less than 27 grams per second. Engine running greater than 2 seconds. ECT and IAT less than 89.6°F (32°C). Difference between ECT and IAT no greater than 41°F (5°C). Elapsed time HO2S bias voltage is greater than predetermined value.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. NOTE:

If engine has been operating, allow engine to cool for about 1 hour before proceeding with tests.

2. Turn ignition off. Turn ignition, engine off. Using scan tool, read HO2S voltage. If voltage gradually decreases 0.15 volt, go to step 5). If voltage does not decrease as indicated, go to next step. 3. Disconnect HO2S harness connector. Connect a test light between chassis ground and ignition feed circuit at HO2S. If test light illuminates, go to next step. If test light does not illuminate, go to step 6). 4. Connect test light between ignition feed and heater ground circuits at HO2S harness connector. If test light illuminates, go to step 7). If test light does not illuminate, go to step 8). 5. DTC P0135 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check HO2S (bank 1 sensor 1) fuse. If fuse is open, go to step 14. If fuse is okay, go to step 9). 7. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 15). 8. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 10). 9. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 11). 10. Repair open HO2S ground circuit. After repairs, go to step 16). 11. Check for open HO2S harness connector ignition feed circuit. After repairs, go to step 13). 12. Repair faulty connection. After repairs, go to step 16). 13. Repair open HO2S ignition feed circuit. After repairs, go to step 16). 14. Repair short to ground in HO2S ignition feed circuit, replace fuse and go to step 16) 15. Replace HO2S. After replacing sensor, go to next step. 16. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0135. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 17. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. Never solder HO2S wires. DTC P0137 - HO2S CIRCUIT LOW VOLTAGE BANK 1, SENSOR 2 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device control active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 2, SENSOR 1 voltage. If voltage is less than 0.086 volt, go to next step. If voltage is not less than 0.086 volt, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector ground circuit and chassis ground. Turn ignition on, engine off. If voltage is 0.35-0.55 volt, go to step 7). If voltage is not as specified, go to step 5). 4. DTC P0137 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Check HO2S sensor harness connector signal circuit for short to ground. If short is found, go to next step. If circuit is okay, go to step 8). 6. Repair circuit as necessary. After repairs, go to step 9). 7. See DIAGNOSTIC AIDS. 8. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 9. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0137. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids Microsoft Saturday, August 29, 2009 11:39:11 AM

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Using scan tool, observe LT FUEL TRIM values at different RPM. If conditions to set DTC P0137 exist, value should be about 158 or greater. Check for an intermittent short to ground in HO2S signal circuit. Never solder HO2S wires. Check for fuel contamination. Check for proper fuel pressure. Check for exhaust leaks. DTC P0138 - HO2S CIRCUIT HIGH VOLTAGE BANK 1, SENSOR 2 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 1, SENSOR 2 voltage. If voltage is greater than 976 mV, go to next step. If voltage is not greater 976 mV, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. If voltage is less than 0.2 volt, go to step 5). If voltage is not less than 0.2 volt, go to step 6). 4. DTC P0138 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Go to DIAGNOSTIC AIDS. 6. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 7. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0138. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Microsoft Saturday, August 29, 2009 11:39:11 AM

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8. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for proper fuel pressure. Check for proper fuel injector operation. Check EVAP canister for fuel saturation. Check for leaking fuel pressure regulator diaphragm. Check for proper TP sensor operation. Check HO2S for silicone contamination (powdery white deposit). Using scan tool, check HO2S voltage. Voltage should be greater than one volt. Check HO2S voltage with connector disconnected. If voltage goes from greater than one volt to about 0.45 volt, replace HO2S. Never solder HO2S wires. DTC P0140 - HO2S INSUFFICIENT ACTIVITY BANK 1, SENSOR 2 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts. Engine run time at least 2 minutes. HO2S voltage is greater than .299 volt, but less than .598 volt.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to greater than 1200 RPM for 2 minutes. Using scan tool, read LOOP MODE. If scan tool displays CLOSED LOOP, go to step 5). If scan tool does not display CLOSED LOOP, go to next step. 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. Read HO2S BANK 1 SENSOR GROUND voltage. If voltage is less than 0.2 volt, go to step 7). If voltage is 0.2 volt or greater, Microsoft Saturday, August 29, 2009 11:39:11 AM

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5. 6. 7. 8. 9. 10. 11. 12. 13.

14.

go to next step. Remove jumper wire. Turn ignition off. Reconnect HO2S connector. Disconnect Blue VCM connector. Connect a test light between Blue VCM harness connector signal circuit and battery voltage. If test light illuminates, go to step 6). If test light does not illuminate, go to step 9). DTC P0140 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. Check HO2S harness connector signal circuit for open. If open is found, go to step 11). If no open is found, go to step 8). Check HO2S for faulty connection. If faulty connection is found, go to step 11). If connection is okay, go to step 10). Check VCM for faulty connection. If faulty connection is found, go to step 11). If faulty connection is not found, go to step 12). Repair open ground circuit. After repairs, go to step 13). Replace HO2S. After replacing sensor, go to step 13). Repair circuit as necessary. After repairs, go to step 13). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0140. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. When ignition is turned on, battery voltage is supplied to HO2S heater to provide for faster sensor warm-up, thus allowing sensor to become active in a shorter period of time. VCM reads amount of time necessary for sensor to become active after startup. Conditions required to set DTC are: Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

    

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. NOTE:

If engine has been operating, allow engine to cool for about one hour before proceeding with tests.

2. Turn ignition off. Turn ignition, engine off. Using scan tool, read HO2S BANK 1, SENSOR 2 voltage. If voltage gradually decreases 0.3 volt, go to step 5). If voltage does not decrease, go to next step. 3. Disconnect HO2S harness connector. Connect test light to chassis ground and probe ignition feed circuit at HO2S harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 6). 4. Connect test light between ignition feed and heater ground circuits at HO2S harness connector. If test light illuminates, go to step 7). If test light does not illuminate, go to step 8). 5. DTC P0141 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check HO2S (bank 1 sensor 2) fuse. If fuse is open, go to step 14). If fuse is okay, go to step 9). 7. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 15). 8. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 10). 9. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 11). 10. Repair open HO2S ground circuit. After repairs, go to step 16). 11. Check for open HO2S harness connector ignition feed circuit. After repairs, go to step 13). 12. Repair faulty connection. After repairs, go to step 16). 13. Repair open HO2S ignition feed circuit. After repairs, go to step 16). 14. Repair short to ground in HO2S ignition feed circuit. After repairs, go to step 16) 15. Replace HO2S. After replacing sensor, go to next step. 16. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0141. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 17. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. Never solder HO2S wires. DTC P0143 - HO2S CIRCUIT LOW VOLTAGE BANK 1, SENSOR 3 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 1, SENSOR 3 voltage. If voltage is less than 0.26 volt, go to next step. If voltage is not less than 0.26 volt, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector ground circuit and chassis ground. Turn ignition on, engine off. If voltage is 0.35-0.55 volt, see DIAGNOSTIC AIDS. If voltage is not as specified, go to step 5). 4. DTC P0143 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Check HO2S sensor harness connector signal circuit for short to ground. If circuit is shorted, go to next step. If circuit is okay, go to step 7). 6. Repair circuit as necessary. After repairs, go to step 8). 7. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

8. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0143. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 9. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Using scan tool, observe LT FUEL TRIM values at different RPM. If conditions to set DTC 1043 exist, value should be about 158 or greater. Check for an intermittent short to ground in HO2S signal circuit. Never solder HO2S wires. Check for fuel contamination. Check for proper fuel pressure. Check for exhaust leaks. DTC P0144 - HO2S CIRCUIT HIGH VOLTAGE BANK 1, SENSOR 3 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 1, SENSOR 3 voltage. If voltage is greater than 0.976 volt, go to next step. If voltage is not greater than 0.976, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. If voltage is less than 0.2 volt, see DIAGNOSTIC AIDS. If voltage is not less than 0.2 volt, go to step 5). Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

4. DTC P0144 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 6. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0144. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 7. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for proper fuel pressure. Check for proper fuel injector operation. Check EVAP canister for fuel saturation. Check for leaking fuel pressure regulator diaphragm. Check for proper TP sensor operation. Check HO2S for silicone contamination (powdery white deposit). Using scan tool, check HO2S voltage. Voltage should be greater than one volt. Check HO2S voltage with connector disconnected. If voltage goes from greater than one volt to about 0.45 volt, replace HO2S. Never solder HO2S wires. DTC P0146 - HO2S INSUFFICIENT ACTIVITY BANK 1, SENSOR 3 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts. HO2S voltage is greater than .351 volts, but less than .473 volts.

Diagnostic Procedures

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2. If any other DTCs are set, diagnose affected DTC. If no other DTCs are set, go to next step. 3. Start engine and allow it idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, see DTC P0108 . If voltage is not greater than 4 volts, go to next step. 4. Visually inspect exhaust system near HO2S (bank 1 sensor 1) for leaks. If leaks are found, go to step 8). If no leaks are found, go to next step. 5. Check if HO2S (bank 1 sensor 3) is installed securely. If HO2S is not installed securely, go to Step 8). If HO2S is installed securely, go to next step. 6. Ensure HO2S connector and harness are not contacting engine or exhaust system. If connector or harness are contacting engine or exhaust system, go to step 8). If connector and harness are okay, go to next step. 7. Check HO2S for silicone (powdery white) deposit, engine oil or coolant contamination. If contamination exists, go to step 9). If no contamination exists, see DIAGNOSTIC AIDS. 8. Repair as necessary. After repairs, go to step 11). 9. Repair source of contamination. After repairs, go to step 11). 10. Replace HO2S. After replacing sensor, go to next step. 11. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0146. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 12. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check HO2S Heater operation. Never solder HO2S wires. DTC P0147 - HO2S HEATER CIRCUIT BANK 1, SENSOR 3 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. When ignition is turned on, battery voltage is supplied to HO2S heater to provide for faster sensor warm-up, thus allowing sensor to become active in a shorter period of time. VCM reads amount of time necessary for sensor to become active after startup. Conditions required to set DTC are:   

MAF less than 27 grams per second. Engine running greater than 2 seconds. ECT and IAT less than 89.6°F (32°C).

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 

Difference between ECT and IAT no greater than 41°F (5°C). Elapsed time HO2S bias voltage is greater than predetermined value.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. NOTE:

If engine has been operating, allow engine to cool for about one hour before proceeding with tests.

2. Turn ignition off. Turn ignition, engine off. Using scan tool, read HO2S voltage. If voltage gradually decreases 0.15 volt, go to step 5). If voltage does not decrease, go to next step. 3. Disconnect HO2S harness connector. Connect a test light between chassis ground and ignition feed circuit at HO2S. If test light illuminates, go to next step. If test light does not illuminate, go to step 6). 4. Connect test light between ignition feed and heater ground circuits at HO2S harness connector. If test light illuminates, go to step 7). If test light does not illuminate, go to step 8). 5. DTC P0147 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check HO2S (bank 1 sensor 3) fuse. If fuse is open, go to step 14). If fuse is okay, go to step 9). 7. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 15). 8. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 10). 9. Check HO2S for faulty connection. If faulty connection is found, go to step 12). If connection is okay, go to step 11). 10. Repair open HO2S ground circuit. After repairs, go to step 16). 11. Check for open HO2S harness connector ignition feed circuit. After repairs, go to step 13). 12. Repair faulty connection. After repairs, go to step 16). 13. Repair open HO2S ignition feed circuit. After repairs, go to step 16). 14. Repair short to ground in HO2S ignition feed circuit. After repairs, go to step 16) 15. Replace HO2S. After replacing sensor, go to next step. 16. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0147. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 17. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. Never solder HO2S wires. Microsoft Saturday, August 29, 2009 11:39:11 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

DTC P0151 - HO2S CIRCUIT LOW VOLTAGE BANK 2, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 2, SENSOR 1 voltage. If voltage is less than 0.086 volt, go to next step. If voltage is not less than 0.086 volt, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector ground circuit and chassis ground. Turn ignition on, engine off. If voltage is 0.35-0.55 volt, go to Step 7). If voltage is not as specified, go to step 5). 4. DTC P0151 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Check HO2S sensor harness connector signal circuit for short to ground. If circuit is shorted, go to next step. If circuit is okay, go to step 8). 6. Repair circuit as necessary. After repairs, go to step 9). 7. Go to DIAGNOSTIC AIDS. 8. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 9. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0151. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Microsoft Saturday, August 29, 2009 11:39:11 AM

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10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Using scan tool, observe LT FUEL TRIM values at different RPM. If conditions to set DTC 1051 exist, value should be about 158 or more. Check for an intermittent short to ground in HO2S signal circuit. Never solder HO2S wires. Check for fuel contamination. Check for proper fuel pressure. Check for exhaust leaks. DTC P0152 - HO2S CIRCUIT HIGH VOLTAGE BANK 2, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. System voltage measures at least 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine and allow it to reach operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to 1200 RPM. Using scan tool, read HO2S BANK 2, SENSOR 1 voltage. If voltage is greater than 0.976 volt, go to next step. If voltage is not greater than 0.976 volt, go to step 4). 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. If voltage is less than 0.2 volt, go to step 5). If voltage is not less than 0.2 volt, go to step 6). 4. DTC P0152 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 5. Go to DIAGNOSTIC AIDS. Microsoft Saturday, August 29, 2009 11:39:11 AM

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6. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 7. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0152. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 8. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for proper fuel pressure. Check for proper fuel injector operation. Check EVAP canister for fuel saturation. Check for leaking fuel pressure regulator diaphragm. Check for proper TP sensor operation. Check HO2S for silicone contamination (powdery white deposit). Using scan tool, check HO2S voltage. Voltage should be more than one volt. Check HO2S voltage with connector disconnected. If voltage goes from more than one volt to about 0.45 volt, replace HO2S. Never solder HO2S wires. DTC P0153 - HO2S SLOW RESPONSE BANK 2, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EVAP system DTC set. No other DTC tests in progress. No device controls active. HO2S average transition tome from lean-to-rich or rich-to -lean is greater than 100 milliseconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other HO2S DTCs are set, diagnose affected DTCs. If no other HO2S DTCs are set, go to next step. 3. Using scan tool, read MAP sensor voltage, with engine idling. If voltage is greater than 4 volts, see DTC Microsoft Saturday, August 29, 2009 11:39:11 AM

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4. 5. 6. 7. 8. 9. 10. 11.

12.

P0108 . If voltage is not greater than 4 volts, go to next step. Visually inspect exhaust system for leaks near HO2S. If leaks are found, go to step 8). If no leaks are found, go to next step. Visually inspect HO2S for secure installation. If HO2S is not securely installed, go to step 8). If HO2S is securely installed, go to next step. Ensure HO2S connector and harness are not contacting engine or exhaust system. If connector or harness are contacting engine or exhaust system, go to step 8). If connector and harness are okay, go to next step. Check HO2S for silicone (powdery white) deposit, engine oil or coolant contamination. If contamination exists, go to step 9). If no contamination exists, see DIAGNOSTIC AIDS. Repair as necessary. After repairs, go to step 11). Repair source of contamination. After repairs, go to step 11). Replace HO2S. After replacing sensor, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0153. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check HO2S Heater operation. Never solder HO2S wires. DTC P0154 - HO2S INSUFFICIENT ACTIVITY BANK 2, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, IAT, MAF, MAP or TP sensor DTCs set. No EGR and EVAP system DTC set. No other DTC tests in progress. No device controls active. Engine running at least 2 minutes. HO2S voltage is greater than 299 mV, but less than 598 mV.

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Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start and warm engine to normal operating temperature. Place gear selector in Park or Neutral, and apply parking brake. Increase engine speed to greater than 1200 RPM for 2 minutes. Using scan tool, read LOOP MODE. If scan tool displays CLOSED LOOP, go to step 5). If scan tool does not display CLOSED LOOP, go to next step. 3. Turn ignition off. Disconnect HO2S connector. Connect a jumper wire between HO2S harness connector signal and ground circuits, and chassis ground. Turn ignition on, engine off. If voltage is less than 0.2 volt, go to step 7). If voltage is not less than 0.2 volt, go to next step. 4. Remove jumper wire. Turn ignition off. Reconnect HO2S connector. Disconnect Blue VCM connector. Connect a test light between Blue VCM harness connector signal circuit and battery voltage. If test light illuminates, go to step 6). If test light does not illuminate, go to step 9). 5. DTC P0154 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, go to DIAGNOSTIC AIDS. 6. Check HO2S harness connector signal circuit for open. If open is found, go to step 11). If no open is found, go to step 8). 7. Check HO2S for faulty connection. If faulty connection is found, go to step 11). If connection is okay, go to step 10). 8. Check VCM for faulty connection. If faulty connection is found, go to step 11). If faulty connection is not found, go to step 12). 9. Repair open ground circuit. After repairs, go to step 13). 10. Replace HO2S. After replacing sensor, go to step 13). 11. Repair circuit as necessary. After repairs, go to step 13). 12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0154. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. When ignition is turned on, battery voltage is supplied to HO2S heater to provide for faster sensor warm-up, thus allowing sensor to become active in a shorter period of time. VCM reads amount of time necessary for sensor to become active after startup. Conditions required to set DTC are:     

MAF less than 27 grams per second. Engine running greater than 2 seconds. ECT and IAT less than 89.6°F (32°C). Difference between ECT and IAT not greater than 41°F (5°C). Elapsed time HO2S bias voltage is greater than predetermined value.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. NOTE:

If engine has been operating, allow engine to cool for about one hour before proceeding with tests.

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13. 14. 15. 16.

Repair open HO2S ignition feed circuit. After repairs, go to step 16). Repair short to ground in HO2S ignition feed circuit. After repairs, go to step 16) Replace HO2S. After replacing sensor, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0155. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 17. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. Never solder HO2S wires. DTC P0171 - FUEL TRIM SYSTEM LEAN BANK 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM reads HO2S signal voltage and adjusts fuel delivery based on this voltage. A change made to fuel delivery is indicated by Long Term (LT) and Short Term (ST) FUEL TRIM values. ST FUEL TRIM values change rapidly in response to HO2S signal voltages. These changes fine tune engine fueling. LT FUEL TRIM values changes in response to trends in ST fuel trim. LT fuel trim makes coarse adjustments to fueling in order to re-center and restore control to ST fuel trim. LT and ST fuel trim can be read by using a scan tool. Ideal FUEL TRIM value is about 128. Fuel trim value greater than 128 indicates that VCM is adding fuel to compensate for a lean condition. Fuel trim less than 128 indicates that VCM is reducing amount of fuel to compensate for rich condition. DTC will set if VCM detects an excessively rich or lean condition. Conditions required to test for DTC are:        

No IAC DTCs set at idle No ECT, EGR, HO2S, IAT, MAF, MAP, TP or VSS sensor DTCs set. No EVAP or voltage system DTCs set. No misfire DTCs set. TP position less than 69.9 percent. Engine speed 575-4500 RPM. BARO greater than 70 kPa. ECT greater than 32°F (0°C) but less than 210°F (99°C).

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    

MAP greater than 20 kPa but less than 99 kPa. IAT greater than 29°F (-20°C) but less than 158°F (70°C). Airflow greater than 3 gm/s. but less than 150 gm/s. Vehicle speed less than 85 MPH. Average short term trim is not greater than 115.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Check exhaust system for corrosion, loose or missing hardware. Ensure HO2S is installed securely, and connector and harness are not contacting exhaust manifold or ignition wires. Check vacuum hoses for splits, kinks and proper routing. Check throttle body, intake manifold, and EGR valve for vacuum leaks. Check IAC, if high or unsteady idle condition exists. Check crankcase ventilation valve, spring and "O" ring for proper installation. Check for fuel contamination. Check for good VCM and sensor grounds. If any of these items isolate or require repair, go to step 8). If all items are okay, go to next step. 3. Cautiously connect a fuel pressure gauge to fuel rail. Turn ignition off for 10 seconds. Turn A/C off. Turn ignition on, engine off (fuel pump should run for about 2 seconds). Cycle ignition off and on until maximum pressure is obtained. Note fuel pressure while pump is running (pressure may vary slightly when pump stops). If pressure holds at 60-66 psi (4.2-4.6 kg/cm2 ), go to next step. If pressure is not as specified, go to step 11). 4. Start and idle engine. If fuel pressure drops 3-10 psi (0.2-0.7 kg/cm2 ), go to next step. If fuel pressure does not drop as specified, go to step 11). 5. Perform INJECTOR BALANCE TEST under FUEL SYSTEM in the SYSTEM/COMPONENT TESTS article. If an injector problem is found, go to step 9). If injectors are okay, go to next step. 6. Perform EVAP CANISTER PURGE SOLENOID CHECK. See FUEL EVAPORATION CONTROL, under EMISSION SYSTEMS & SUB-SYSTEMS in the BASIC TESTING - 4.3L article. If a solenoid problem is found, go to next step. If solenoid is okay, go to DIAGNOSTIC AIDS. 7. Repair EVAP system. Operate vehicle in closed loop mode while using scan tool to read LT and ST FUEL TRIM values. LT FUEL TRIM value should decrease to less than 158, ST FUEL TRIM value should decrease to less than 180. If FUEL TRIM values are as specified, go to step 10). If values are not as specified, see DIAGNOSTIC AIDS. 8. Repair items as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST FUEL TRIM values. LT FUEL TRIM value should decrease to less than 158, ST FUEL TRIM value should decrease to less than 180. If FUEL TRIM values are as specified, go to step 10). If values are not as specified, go to step 3). 9. Replace fuel injector(s) as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST FUEL TRIM values. LT FUEL TRIM value should decrease to less than 158, ST FUEL TRIM value should decrease to less than 180. If FUEL TRIM values are as specified, go to next step. If values are not as specified, go to step 6). 10. Lean condition does not exist. If driveability problem still exists, see the TESTS W/O CODES article. 11. See FUEL SYSTEM DIAGNOSIS under BASIC FUEL SYSTEM CHECKS in the BASIC TESTING Microsoft Saturday, August 29, 2009 11:39:11 AM

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4.3L article. 12. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0171. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 13. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

If problem cannot be isolated, attempt driving vehicle under various load conditions while using scan tool to read LT and ST FUEL TRIM values. This may help isolate condition which set DTC P0171. If condition to set DTC cannot be duplicated, problem could have been caused by a cylinder misfire. See DTC P0300 . DTC P0172 - FUEL TRIM SYSTEM RICH BANK 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM reads HO2S signal voltage and adjusts fuel delivery based on this voltage. A change made to fuel delivery is indicated by Long Term (LT) and Short Term (ST) FUEL TRIM values. ST FUEL TRIM values change rapidly in response to HO2S signal voltages. These changes fine tune engine fueling. LT FUEL TRIM values change in response to trends in ST fuel trim. LT fuel trim makes coarse adjustments to fueling in order to re-center and restore control to ST fuel trim. LT and ST fuel trim can be read by using a scan tool. Ideal FUEL TRIM value is about 128. Fuel trim value greater than 128 indicates that VCM is adding fuel to compensate for a lean condition. Fuel trim less than 128 indicates that VCM is reducing amount of fuel to compensate for rich condition. DTC will set if VCM detects an excessively rich or lean condition. Conditions required to test for DTC are:         

No IAC DTCs set (at idle) No ECT, EGR, HO2S, IAT, MAF, MAP, TP or VSS sensor DTCs set. No EVAP or voltage system DTCs set. No misfire DTCs set. Engine speed 575-4500 RPM. TP angle less than 70 percent. Engine speed is greater than 575 RPM but less than 4500 RPM. BARO is greater than 70 kPa. MAP greater than 20 kPa, but less 99 kPa.

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   

IAT greater than -4°F (-20°C), but less than 158°F (70°C). MAF greater than 3 gm/s. but less than 150 gm/s. Vehicle speed less than 85 MPH. Average short term fuel trim is not greater than 115.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Check air intake duct for restrictions. Check for plugged air filter. Check IAC, if low or unsteady idle condition exists. Check throttle body for coking and IAC passages for blockage. Check fuel pressure regulator for proper operation. See FUEL SYSTEM DIAGNOSIS under BASIC FUEL SYSTEM CHECKS in the BASIC TESTING - 4.3L article. Check TP sensor for loose or missing mounting bolts. Using scan tool, read TP sensor voltage while slowly opening throttle from closed (0.20-0.74 volt) to wide open (4 volts). A steady throttle movement from a stop should cause TP sensor voltage to increase smoothly as throttle is opened. If any of these items isolate or require repair, go to step 7). If all items are okay, go to next step. 3. Connect a fuel pressure gauge to fuel rail. Turn ignition off for 10 seconds. Turn A/C off. Turn ignition on, engine off (fuel pump should run for about 2 seconds). Cycle ignition off and on until maximum pressure is obtained. Note fuel pressure while pump is running (pressure may vary slightly when pump stops). If pressure holds at 60-66 psi (4.2-4.6 kg/cm2 ), go to next step. If pressure is not as specified, go to step 10). 4. Perform INJECTOR BALANCE TEST under FUEL SYSTEM in the SYSTEM/COMPONENT TESTS article. If an injector problem is found, go to step 8). If injectors are okay, go to next step. 5. Check HO2S for silicon contamination (powdery white) deposit. If contamination is evident, go to step 11). If contamination is not evident, go to next step. 6. Operate vehicle in closed loop mode while using scan tool to read LT and ST FUEL TRIM values. If LT FUEL TRIM value increases to greater than 100 and ST FUEL TRIM value increases to greater than 94, go to step 9). If values are not as specified, go to DIAGNOSTIC AIDS. 7. Repair items as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST FUEL TRIM values. LT FUEL TRIM value should increase to greater than 100, ST FUEL TRIM value should increase to greater than 94. If FUEL TRIM values are as specified, go to step 11). If values are not as specified, go to step 3). 8. Replace fuel injector(s) as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST FUEL in closed loop mode while using scan tool to read LT and ST FUEL TRIM values. If LT value increases to greater than 100 and ST fuel value increases to greater than 94, go to step 11). If values are not as specified, go to step 5). 9. Rich condition does not exist. If driveability problem still exists, see the TESTS W/O CODES article. 10. See FUEL SYSTEM DIAGNOSIS under BASIC FUEL SYSTEM CHECKS in the BASIC TESTING 4.3L article. 11. Replace HO2S (bank 2 sensor 1). After replacing sensor, go to next step. 12. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating Microsoft Saturday, August 29, 2009 11:39:11 AM

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temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0172. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 13. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

If problem cannot be isolated, attempt driving vehicle under various load conditions while using scan tool to read LT and ST FUEL TRIM values. This may help isolate condition which set DTC P0172. If condition to set DTC cannot be duplicated, problem could have been caused by a cylinder misfire. See DTC P0300 . DTC P0174 - FUEL TRIM SYSTEM LEAN BANK 2 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM reads HO2S signal voltage and adjusts fuel delivery based on this voltage. A change made to fuel delivery is indicated by Long Term (LT) and Short Term (ST) fuel trim values. ST fuel trim values change rapidly in response to HO2S signal voltages. These changes fine tune engine fueling. LT fuel trim values changes in response to trends in ST fuel trim. LT fuel trim makes coarse adjustments to fueling in order to re-center and restore control to ST fuel trim. LT and ST fuel trim can be read by using a scan tool. Ideal fuel trim value is about 128. Fuel trim value more than 128 indicates that VCM is adding fuel to compensate for a lean condition. Fuel trim less than 128 indicates that VCM is reducing amount of fuel to compensate for rich condition. DTC will set if VCM detects an excessively rich or lean condition. Conditions required to test for DTC are:           

No IAC DTCs set at idle. No ECT, EGR, HO2S, IAT, MAF, MAP, TP or VSS sensor DTCs set. No EVAP or voltage system DTCs set. No misfire DTCs set. Engine speed 575-4500 RPM. BARO is greater than 70 kPa. ECT is greater than 140°F (60°C) but less than 210°F (99°C). MAP greater than 20 kPa, but less than 99 kPa. IAT greater than -4°F (-20°C), but less than 159°F (70°C). MAF us greater than 3 gm/s., but less than 150 gm/s. Vehicle speed less than 85 MPH.

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

Average short term fuel trim is not greater than 115.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Check exhaust system for corrosion, loose or missing hardware. Ensure HO2S is installed securely, and connector and harness are not contacting exhaust manifold or ignition wires. Check vacuum hoses for splits, kinks and proper routing. Check throttle body, intake manifold, and EGR valve for vacuum leaks. Check IAC, if high or unsteady idle condition exists. Check crankcase ventilation valve, spring and "O" ring for proper installation. Check for fuel contamination. Check for good VCM and sensor grounds. If any of these items isolate or require repair, go to step 8). If all items are okay, go to next step. 3. Cautiously connect a fuel pressure gauge to fuel rail. Turn ignition off for 10 seconds. Turn A/C off. Turn ignition on, engine off (fuel pump should run for about 2 seconds). Cycle ignition off and on until maximum pressure is obtained. Note fuel pressure while pump is running (pressure may vary slightly when pump stops). If pressure holds at 60-66 psi (4.2-4.6 kg/cm2 ), go to next step. If pressure is not as specified, go to step 11). 4. Start engine and allow it to idle. If pressure drops 3-10 psi (0.2-0.7 kg/cm2 ), go to next step. If pressure does not drop as specified, go to step 11). 5. Perform INJECTOR BALANCE TEST under FUEL SYSTEM in the SYSTEM/COMPONENT TESTS article. If an injector problem is found, go to step 9). If injectors are okay, go to next step. 6. Perform CANISTER PURGE SOLENOID CHECK under EMISSION SYSTEMS & SUB-SYSTEMS in the SYSTEM/COMPONENT TESTS article. If a solenoid problem is found, go to next step. If solenoid is okay, go to DIAGNOSTIC AIDS. 7. Repair EVAP system. Operate vehicle in closed loop mode while using scan tool to read LT and ST fuel trim values. LT fuel trim value should decrease to less than 158, ST fuel trim value should decrease to less than 180. If fuel trim values are as specified, go to step 10). If values are not as specified, go to DIAGNOSTIC AIDS. 8. Repair items as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST fuel trim values. LT fuel trim value should decrease to less than 158, ST fuel trim value should decrease to less than 180. If fuel trim values are as specified, go to step 10). If values are not as specified, go to step 3). 9. Replace fuel injector(s) as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST fuel trim values. LT fuel trim value should decrease to less than 158, ST fuel trim value should decrease to less than 180. If fuel trim values are as specified, go to next step. If values are not as specified, go to step 6). 10. Lean condition does not exist. If driveability problem still exists, see the TESTS W/O CODES article. 11. See FUEL SYSTEM DIAGNOSIS under BASIC FUEL SYSTEM CHECKS in the BASIC TESTING 4.3L article. 12. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0174. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Microsoft Saturday, August 29, 2009 11:39:11 AM

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13. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

If problem cannot be isolated, attempt driving vehicle under various load conditions while using scan tool to read LT and ST fuel trim values. This may help isolate condition which set DTC P0174. If condition to set DTC cannot be duplicated, problem could have been caused by a cylinder misfire. See DTC P0300 . DTC P0175 - FUEL TRIM SYSTEM RICH BANK 2 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No IAC DTCs set at idle. No ECT, EGR, HO2S, IAT, MAF, MAP, TP or VSS sensor DTCs set. No EVAP or voltage system DTCs set. No misfire DTCs set. Engine speed 575-4500 RPM. ECT at normal operating temperature. Airflow 3-150 gm/s. Vehicle speed less than 85 MPH. BARO greater than 70 kPa. ECT greater than 140°F (60°C) but less than 212°F (100°C). MAP greater than 20 kPa but less than 99 kPa. IAT greater than -4°F (-20°C) but less than 158°F (70°C). MAF greater than 3 gm/s. but less than 150 gm/sec.

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

Average short term fuel trim is not greater than 115.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Check air intake duct for restrictions. Check for plugged air filter. Check IAC, if low or unsteady idle condition exists. Check throttle body for coking and IAC passages for blockage. Check fuel pressure regulator for proper operation. See FUEL SYSTEM DIAGNOSIS under BASIC FUEL SYSTEM CHECKS in the BASIC TESTING - 4.3L article. Check TP sensor for loose or missing mounting bolts. Using scan tool, read TP sensor voltage while slowly opening throttle from closed (0.20-0.74 volt) to wide open (4 volts). A steady throttle movement from a stop should cause TP sensor voltage to increase smoothly as throttle is opened. If any of these items isolate or require repair, go to step 8). If all items are okay, go to next step. 3. Cautiously connect a fuel pressure gauge to fuel rail. Turn ignition off for 10 seconds. Turn A/C off. Turn ignition on, engine off (fuel pump should run for about 2 seconds). Cycle ignition off and on until maximum pressure is obtained. Note fuel pressure while pump is running (pressure may vary slightly when pump stops). If pressure holds at 60-66 psi (4.2-4.6 kg/cm2 ), go to next step. If pressure is not as specified, go to step 11). 4. Perform INJECTOR BALANCE TEST under FUEL SYSTEM in the SYSTEM/COMPONENT TESTS article. If an injector problem is found, go to step 9). If injectors are okay, go to next step. 5. Check HO2S for silicone contamination (powdery white) deposit. If contamination is evident, go to step 12). If contamination is not evident, go to next step. 6. Perform CANISTER PURGE SOLENOID CHECK under EMISSION SYSTEMS & SUB-SYSTEMS in the SYSTEM/COMPONENT TESTS article. If a solenoid problem is found, go to next step. If solenoid is okay, go to DIAGNOSTIC AIDS. 7. Repair EVAP system. Operate vehicle in closed loop mode while using scan tool to read LT and ST fuel trim values. LT fuel trim value should increase to more than 100, ST fuel trim value should increase to more than 94. If fuel trim values are as specified, go to step 10). If values are not as specified, go to DIAGNOSTIC AIDS. 8. Repair items as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST fuel trim values. LT fuel trim value should increase to more than 100, ST fuel trim value should increase to more than 94. If fuel trim values are as specified, go to step 10). If values are not as specified, go to step 3). 9. Replace fuel injector(s) as necessary. Operate vehicle in closed loop mode while using scan tool to read LT and ST fuel trim values. LT fuel trim value should increase to more than 100, ST fuel trim value should increase to more than 94. If fuel trim values are as specified, go to next step. If values are not as specified, go to step 5). 10. Rich condition does not exist. If driveability problem still exists, see the TESTS W/O CODES article. 11. See FUEL SYSTEM DIAGNOSIS under BASIC FUEL SYSTEM CHECKS in the BASIC TESTING 4.3L article. 12. Replace HO2S (bank 2 sensor 1) and go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating Microsoft Saturday, August 29, 2009 11:39:11 AM

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temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0175. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

If problem cannot be isolated, attempt driving vehicle under various load conditions while using scan tool to read LT and ST fuel trim values. This may help isolate condition which set DTC P0175. If condition to set DTC cannot be duplicated, problem could have been caused by a cylinder misfire. See DTC P0300 . DTC P0300 - ENGINE MISFIRE DETECTED NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and sets DTC. Conditions required to test for DTC are:         

No IAC DTCs set. No CKP, MAF, TP or VSS sensor DTCs set. Rough road not detected. Engine speed 300-5600 RPM. ECT at normal operating temperature. System voltage 9-16 volts. Positive throttle position change is less than 2.9 percent for 100 msec. Negative throttle position change is less than 2.9 percent for 100 msec. A misfire is detected.

Diagnostic Procedures

1 Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2 Microsoft Saturday, August 29, 2009 11:39:11 AM

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Review FAILURE RECORDS data. If other DTCs are stored, diagnose affected DTCs. If no other DTCs are present, go to next step. 3 Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. 5 Turn ignition off, and then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If scan tool displays DTC P0300, PRESENT THIS IGN, go to next step. If scan tool does not display DTC P0300, PRESENT THIS IGN, go to step 10). 6 Install a spark tester on No. 1 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 11). 7 Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 12). 8 Perform INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in the BASIC TESTING 4.3L article. If fuel system is okay, go to next step. If not, go to step 13). 9 Diagnose and repair mechanical engine problem. 10 DTC P0300 is intermittent. See DIAGNOSTIC AIDS. 11 See IGNITION SYSTEM in the BASIC TESTING - 4.3L article. 12 Replace spark plug(s). After replacing spark plugs, go to step 14). 13 Microsoft Saturday, August 29, 2009 11:39:11 AM

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Repair as necessary. After repairs, go to next step. 14 Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0300. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15 Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

A misfire could be caused by excessive vibration from sources other than engine. Check following items for possible cause of misfire: tire/wheel out of balance/round, uneven brake rotor or drum surface, or a rough road condition. Check plug wires for proper installation and operation. Check fuel level, condition and quality. If problem is intermittent, see the TESTS W/O CODES article. DTC P0301 - CYLINDER NO. 1 MISFIRE DETECTED NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and sets DTC. Conditions for setting DTC are:         

No IAC DTCs set. No CKP, CMP, MAF, TP or VSS sensor DTCs set. ECT at least 19°F (-7°C). Fuel tank level is greater than 10 percent. Engine speed at least 600 RPM and less than 5600 RPM. System voltage at least 9 volts, but less than 14 volts. Positive throttle position change less than 4.9 percent for 100 msec. Negative throttle position change less than 2.9 percent for 100 msec. A misfire is detected.

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Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, go to next step. If no other DTCs are set, go to step 4). 3. Diagnose affected DTC. 4. Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. 5. Turn ignition off, and then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If DTC P0301 sets, go to next step. If DTC does not set, go to step 10). 6. Install a spark tester on No. 1 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 11). 7. Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 12). 8. Perform INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in the BASIC TESTING 4.3L article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 13). 9. Diagnose and repair mechanical engine problem. 10. DTC P0301 is intermittent. Go to DIAGNOSTIC AIDS. 11. See IGNITION SYSTEM in the BASIC TESTING - 4.3L article. 12. Replace spark plug(s). After replacing spark plugs, go to step 14). 13. Repair as necessary. After repairs, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0301. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and set DTC. Conditions for setting DTC are:         

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to step 4). 3. Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is more than 4 volts, go to DTC P0108 . If voltage is 4 volts or less, go to next step. 4. Turn ignition off, and then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If DTC P0302 sets, go to next step. If DTC does not set, go to step 9). 5. Install a spark tester on No. 2 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 10). 6. Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 11). 7. Perform cylinder compression test. See the BASIC TESTING - 4.3L article. If problem is found, repair as necessary. After repairs, go to step 13). If compression is okay, go to next step. 8. Perform INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in the BASIC TESTING 4.3L article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 12). 9. Misfire is currently not active. See DIAGNOSTIC AIDS. 10. See IGNITION SYSTEM in the BASIC TESTING - 4.3L article. 11. Replace spark plug(s). After replacing spark plug, go to step 13). 12. Repair as necessary. After repairs, go to next step. Microsoft Saturday, August 29, 2009 11:39:11 AM

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13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0302. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and set DTC. Conditions for setting DTC are:        

No CKP, CMP, IAC, MAF, TP or VSS sensor DTCs set. ECT at least 19°F (-7°C). Fuel tank level is greater than 10 percent. Engine speed at least 600 RPM and less than 5600 RPM. System voltage at least 9 volts, but less than 14 volts. Positive throttle position change less than 4.9 percent for 100 msec. Negative throttle position change less than 2.9 percent for 100 msec. A misfire is detected.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to step 4). 3. Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. Microsoft Saturday, August 29, 2009 11:39:11 AM

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4. Turn ignition off, and then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If DTC P0303 sets, go to next step. If DTC does not set, go to step 9). 5. Install a spark tester on No. 1 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 10). 6. Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 11). 7. Perform compression test. Repair as necessary. After repairs, go to step 13). If compression is okay, go to next step. 8. Diagnose fuel injector circuit. See the SYSTEM/COMPONENT TESTS article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 12). 9. Misfire is currently not active. Ensure ignition wires are securely attached to spark plugs and distributor cap. Check for secondary ignition cross firing. 10. See IGNITION SYSTEM in the SYSTEM/COMPONENT TESTS article. 11. Replace spark plug(s). After replacing spark plus(s), go to step 13). 12. Repair as necessary. After repairs, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0303. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. DTC P0304 - CYLINDER NO. 4 MISFIRE DETECTED NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and set DTC. Conditions for setting DTC are:      

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  

Positive throttle position change less than 4.9 percent for 100 msec. Negative throttle position change less than 2.9 percent for 100 msec. A misfire is detected.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to step 4). 3. Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. 4. Turn ignition off, and then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If DTC P0304 sets, go to next step. If DTC does not set, go to step 9). 5. Install a spark tester on No. 4 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 10). 6. Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 11). 7. Perform cylinder compression test. See the BASIC TESTING - 4.3L article. If problem is found, repair as necessary. After repairs, go to step 13). If compression is okay, go to next step. 8. Perform INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in the BASIC TESTING 4.3L article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 12). 9. Misfire is currently not active. See DIAGNOSTIC AIDS. 10. See IGNITION SYSTEM in the BASIC TESTING - 4.3L article. 11. Replace spark plug(s). After replacing spark plug(s), go to step 13). 12. Repair as necessary. After repairs, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0304. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

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NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and set DTC. Conditions for setting DTC are:         

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to step 4). 3. Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. 4. Turn ignition off, then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If DTC P0305 sets, go to next step. If DTC does not set, go to step 9). 5. Install a spark tester on No. 5 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 10). 6. Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 11). 7. Perform cylinder compression test. See the BASIC TESTING - 4.3L article. If problem is found, repair as necessary. After repairs, go to step 13). If compression is okay, go to next step. 8. Perform INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in the BASIC TESTING 4.3L article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 12). 9. Misfire is currently not active. See DIAGNOSTIC AIDS. 10. See IGNITION SYSTEM in the BASIC TESTING - 4.3L article. Microsoft Saturday, August 29, 2009 11:39:11 AM

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11. Replace spark plug(s). After replacing spark plug(s), go to step 13). 12. Repair as necessary. After repairs, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0305. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder and evaluates a random misfire and set DTC. Conditions for setting DTC are:         

Diagnostic Procedures

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2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to step 4). 3. Start engine and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. 4. Turn ignition off, and then on. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If DTC P0306 sets, go to next step. If DTC does not set, go to step 9). 5. Install a spark tester on No. 6 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark was okay on all wires, go to next step. If spark was not okay, go to step 10). 6. Remove and check spark plugs for wear, excessive air gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 11). 7. Perform cylinder compression test. See the BASIC TESTING - 4.3L article. If problem is found, repair as necessary. After repairs, go to step 13). If compression is okay, go to next step. 8. Perform INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in the BASIC TESTING 4.3L article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 12). 9. Misfire is currently not active. See DIAGNOSTIC AIDS. 10. See IGNITION SYSTEM in the BASIC TESTING - 4.3L article. 11. Replace spark plug(s). After replacing spark plugs, go to step 13). 12. Repair as necessary. After repairs, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0306. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

A misfire could be caused by excessive vibration from sources other than engine. Check following items for possible cause of misfire: tire/wheel out of balance/round, uneven brake rotor or drum surface, or a rough road condition. Check plug sires for proper installation and operation. Check fuel level, condition and quality. If problem is intermittent, see the TESTS W/O CODES article. DTC P0327 - KNOCK SENSOR LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Knock Sensor (KS) is used to detect engine detonation (knock). If excessive knock is present, VCM will retard timing until knock goes away. When KS module in VCM determines that an abnormally high knock level exist, VCM will set DTC P0327. Microsoft Saturday, August 29, 2009 11:39:11 AM

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Conditions for setting DTC are:      

Timing is retarded no more than zero degrees. System voltage is greater than 10 volts, but not greater than 17.1 volts. ECT greater than 140°F (60°C). Engine running at least 2 minutes. Engine speed is 500-900 RPM. Knock sensor noise less than 3 counts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to step 4). If scan tool does not display DTC P0327 FAILED THIS IGN, go to next step. 3. Turn engine off. Turn ignition on, with engine off. Retrieve and record FAILED RECORDS data for DTC P0327. Operate vehicle within conditions required to set DTC. select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0327 FAILED THIS IGN, see DIAGNOSTIC AIDS. 4. Disconnect knock sensor harness connector. Using a DVOM, check voltage between KS signal circuit and ground. Voltage reading should be about 5 volts. If voltage is not as specified, go to step 8). If voltage is as specified, go to next step. 5. Using DVOM, check resistance between knock sensor terminal and engine ground. Resistance should be about 100,000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, go to step 12). 6. Turn ignition off. Connect DVOM between knock sensor terminal and engine ground. Tap on engine while observing DVOM. If any signal is present, go to next step. If signal is not present, go to step 9). 7. Check KS harness connector signal circuit for faulty terminal connection at KS. Repair as necessary and go to step 14). If terminal connections are okay, go to step 10). 8. Turn ignition off. Disconnect VCM harness connector. Turn ignition on and check KS signal circuit between VCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 14). If circuit is okay, go to step 10). 9. Replace knock sensor. After replacing sensor, go to step 14). 10. Turn ignition off. Disconnect VCM harness connector. Check KS signal circuit for proper terminal connection at VCM. Repair or replace terminal as necessary. After repairs, go to step 14). If terminal is okay, go to next step. 11. Ensure KS module is fully seated and installed properly. If a problem is found, repair as necessary. After repairs, go to step 14). If no problem is found, go to next step. 12. Replace KS module. Operate vehicle within conditions required to set DTC. select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0327 FAILED THIS IGN, go to step 14). Microsoft Saturday, August 29, 2009 11:39:11 AM

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13. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0327. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connection at VCM. Check KS and VCM connectors for damage. Ensure KS harness is not routed too close to high-voltage wires, such as spark plug cables, ignition coils or other high-voltage components. Insure KS is installed properly and ensure torque is to specification. Torque specification is 14 ft. lbs. (19 N.m). DTC P0336 - CRANKSHAFT POSITION SENSOR CIRCUIT PERFORMANCE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Crankshaft Position (CKP) sensor sends reference signal to VCM to indicate position of crankshaft and engine speed (RPM). VCM uses this information to determine ignition coil, fuel injector and ignition timing. Conditions required to set DTC are:  

Engine cranking and VCM receives 4 or more camshaft signals without receiving CKP signal. CKP signal is missing for at least .5 second.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If vehicle starts and runs, see DIAGNOSTIC AIDS. If vehicle does not start and run, go to next step. 3. Disconnect CKP sensor harness connector. Using test light, probe ignition feed circuit of CKP sensor connector (engine side) to ground. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 6). 4. Connect test light between ignition feed circuit and sensor low circuit of CKP sensor connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 7). 5. Turn ignition off. Install Gray jumpers from Connector Test Kit (J 35616-A) between engine harness connector and CKP sensor connector. Install DVOM set on duty cycle between CKP sensor 3X signal and low circuit terminals. Crank engine. If duty cycle is 40-60 percent, go to step 8). If duty cycle is not Microsoft Saturday, August 29, 2009 11:39:11 AM

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6. 7. 8.

9. 10. 11. 12. 13.

14.

40-60 percent, go to step 10). Repair open or short to ground in CKP sensor ignition feed circuit. After repairs, go to step 13). Check for open in sensor low circuit. If a problem was found, go to step 11). If a problem was not found, go to step 9). With DVOM still connected between sensor 3X signal circuit and sensor low circuit, elect AC volt scale on DVOM. Crank engine. If voltage is greater than 10 volts, go to step 11). If voltage is not greater than 10 volts, go to next step. Check for open in CKP sensor 3X signal and low circuits. If circuit is open, go to step 11). If circuit is okay, go to step 12). Replace CKP sensor. Ensure CKP sensor mounting surface is clean and free of debris. After repairs, go to step 13). Repair as necessary. After repairs, go to step 13). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0336. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P0337 - CRANKSHAFT POSITION SENSOR CIRCUIT LOW FREQUENCY NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine speed less than 4000 RPM. MAF at least 5 grams per second. Crank sensor duty cycle high reference to low reference ratio is less than .3125.

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1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Disconnect CKP sensor harness connector. Connect a test light between engine ground and signal circuit at CKP sensor. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 8). 3. Turn ignition off. Connect test light between battery voltage and ground circuit at CKP sensor. If test light illuminates, go to next step. If test light does not illuminate, go to step 7). 4. Disconnect VCM Blue connector. Connect test light between battery voltage and ignition feed circuit at CKP sensor. If test light illuminates, go to step 10). If test light does not illuminate, go to next step. 5. Reconnect VCM Blue connector. Install Gray jumpers from Connector Tester Kit (J35616-A) between CKP sensor and CKP sensor harness connector. Start engine. Connect a DVOM (set to duty cycle) between CKP sensor signal and ground circuits. If duty cycle is less than 40 percent, go to step 11). If duty cycle is not less than 40 percent, go to next step. 6. Check for faulty connection at CKP sensor and go to step 12). 7. Check for open in CKP sensor ground circuit. If open is found, go to step 12). If circuit is okay, go to step 9). 8. Check for open or short to ground in CKP sensor signal circuit and go to step 12). 9. Check for faulty connection at VCM. If faulty connection is found, go to step 12). If connection is okay, go to step 13). 10. Repair short to ground in CKP sensor signal circuit. After repairs, go to step 14). 11. Replace CKP sensor. After replacing sensor, go to step 14). 12. Repair circuit as necessary. After repairs, go to step 14). 13. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0337. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P0338 - CRANKSHAFT POSITION SENSOR CIRCUIT HIGH FREQUENCY NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description Microsoft Saturday, August 29, 2009 11:39:11 AM

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Engine speed less than 4000 RPM. MAF at least 5 grams per second. Crank sensor duty cycle high reference to low reference ratio is greater than .6875.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If engine starts, go to step 4). If engine does not start, go to next step. 3. Using scan tool, clear DTCs. Crank engine for 10 seconds and read DTCs. If DTC P0338 resets, go to next step. If DTC does not reset, go to NO-START - ENGINE CRANKS OKAY in the BASIC TESTING - 4.3L article. 4. Start engine. Using scan tool, monitor engine speed (RPM). If RPM fluctuates up to twice desired RPM, go to step 14). If RPM does not fluctuate, go to next step. 5. Turn engine off. Turn ignition on, with engine off. Disconnect CKP sensor harness connector. Connect a test light between engine ground and signal circuit at CKP sensor. If test light illuminates, go to next step. If test light does not illuminate, go to step 8). 6. Connect test light between CKP sensor harness connector ground and signal circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 12). 7. Turn ignition off. Install Gray jumpers from Connector Tester Kit (J35616-A) between CKP sensor and CKP sensor harness connector. Using a DVOM, check voltage on CKP sensor harness connector signal circuit. If voltage is 2-3 volts, go to step 16). If voltage is not as specified, go to step 9). 8. Turn ignition off. Disconnect VCM Blue harness connector. Connect test light between battery voltage and ignition feed circuit at CKP sensor. If test light does not illuminate, go to step 15). If test light illuminates, go to step 11). 9. Check for open in CKP sensor ground circuit. If open is found, go to step 17). If circuit is okay, go to next step. 10. Check for short to ground in CKP sensor signal circuit. If short is found, go to step 17). If circuit is okay, go to step 13) 11. Repair short to ground in CKP sensor ignition feed circuit. After repairs, go to step 19). 12. Repair open CKP sensor ground circuit. After repairs, go to step 19). 13. Check for faulty connection at CKP sensor. If faulty connection is found, go to step 17). If connection is okay, go to next step. 14. Replace CKP sensor. After replacing sensor, go to step 19). 15. Check for open in CKP sensor harness connector ignition feed circuit. If open is found, go to step 17). If circuit is okay, go to next step. 16. Check for faulty connection at VCM. If faulty connection is found, go to next step. If connection is okay, Microsoft Saturday, August 29, 2009 11:39:11 AM

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17. 18. 19.

20.

go to step 18). Repair circuit as necessary. After repairs, go to step 19). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0338. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P0339 - CRANKSHAFT POSITION SENSOR CIRCUIT INTERMITTENT NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

MAF at least 5 grams per second. Change in calculated engine speed is at least 1000 RPM. Calculated engine speed equals zero RPM and 4 or more CMP cycles have occurred for a period of 2-3 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If engine starts and runs, see DIAGNOSTIC AIDS. If engine does not start and run, go to next step. 3. Disconnect CKP sensor harness connector. Connect a test light between engine ground and ignition feed circuit at CKP sensor. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 6). 4. Connect test light between CKP sensor harness connector ground and ignition feed circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 7). Microsoft Saturday, August 29, 2009 11:39:11 AM

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5. Turn ignition off. Install Gray jumpers from Connector Tester Kit (J 35616-A) between CKP sensor and CKP sensor harness connector. Connect a DVOM (set to duty cycle) between CKP sensor signal and ground circuits. Crank engine. If duty cycle is 40-60 percent, go to step 8). If duty cycle is not as specified, go to step 10). 6. Repair open or short to ground in CKP sensor ignition feed circuit. After repairs, go to step 13). 7. Check CKP sensor harness ground circuit for an open. If open is found, go to step 11). If no open is found, go to step 9). 8. Select DVOM AC volt scale. Crank engine. If voltage is greater than 10 volts, go to step 11). If voltage is not greater than 10 volts, go to next step. 9. Check CKP sensor harness connector signal and ground circuits for an open. If an open is found, go to step 11). If no open is found, go to step 12). 10. Ensure CKP sensor mounting surface is clean and free of debris. Replace CKP sensor. After replacing sensor, go to step 13). 11. Repair as necessary. After repairs, go to step 13). 12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0339. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Inspect face of CKP sensor for metal shavings. DTC P0340 - CAMSHAFT POSITION SENSOR CIRCUIT NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Camshaft Position (CMP) sensor is used to indicate camshaft position so that VCM can determine which cylinder is misfiring if misfire is present. CMP sensor also checks for properly installed high voltage switch. Conditions required to set DTC:  

Engine running. CMP sensor reference pulse is not seen once every 6 revolutions.

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Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Retrieve and record FREEZE FRAME and FAILED RECORDS data for DTC P0340. Continue to idle engine for one minute. Observe FREEZE FRAME, LAST TEST FAILED DTC. If DTC P0340 FAILED is not displayed, go to step 8). If DTC P0340 FAILED is displayed, turn engine off. Restart engine. If MIL remains on, go to next step. If MIL does not remain on, go to step 8). 3. Turn ignition on, with engine off. Disconnect CMP sensor harness connector. Connect a test light between engine ground and CKP sensor harness connector ignition feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 9). 4. Connect test light between CMP sensor harness connector ground and ignition feed circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 11). 5. Ignition off. Install Gray jumpers from Connector Test Kit (J35616-A) between CMP sensor and CMP sensor harness connector. Using a DVOM, check voltage between on CMP sensor signal circuit. If voltage is 5-7 volts, go to step 15). If voltage is not 5-7 volts, go to next step. 6. Check CMP sensor harness connector signal circuit for open. If open is found, go to step 13). If open is not found, go to next step. 7. Check CMP sensor harness connector signal circuit for short to voltage. If short is found, go to step 13). If short is not found, go to step 12). 8. DTC P0340 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 9. Check for open in CMP sensor harness connector ignition feed circuit. If open is found, go to step 13). If open is not found, go to next step. 10. Repair short to ground in CMP sensor harness connector ignition feed circuit. After repairs, go to step 17). 11. Repair open in CMP sensor harness connector ground circuit. After repairs, go to step 17). 12. Check for faulty connection at CMP sensor. If faulty connection is found, go to next step. If connection is okay, go to step 14). 13. Repair circuit as necessary. After repairs, go to step 17). 14. Replace CMP sensor. After replacing sensor, go to step 17). 15. Check for faulty connection at VCM. If faulty connection is found, go to step 13). If connection is okay, go to next step. 16. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 17. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0340. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 18. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Microsoft Saturday, August 29, 2009 11:39:11 AM

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Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

DTC P0341 will set if cam pulses are not in proper ratio to crank pulses. Conditions for setting DTC:  

Engine running. Cam sensor reference pulse is not detected at correct interval.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Check for intermittent short to voltage or Electromagnetic Interference (EMI) on CMP sensor wires such as wires run alongside spark plug wires or high power transistors (like mobile radios operating nearby). If problem is found, go to next step. If no problem is found, go to step 4). 3. Repair short to voltage or correct EMI interference. After repairs, go to next step. 4. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0341. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 5. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

VCM test Exhaust Gas Recirculation (EGR) valve by momentarily commanding valve on while monitoring engine MAP. VCM will illuminate MIL and store DTC P0401 if expected increase is not seen under certain conditions during deceleration. Conditions required to test for DTC are:         

No ECT, IAT, MAP, TP or VSS sensor DTCs set. No IAC, linear EGR (pintle position) or transmission DTCs set. Change in IAC less than 8 counts. ECT greater than 172°F (78°C). Vehicle speed greater than 27 MPH. BARO greater than 70 kPa. A/C clutch status unchanged. Transmission locked/unlocked status unchanged. No misfire DTC set.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start and warm engine to normal operating temperature. Run engine at greater than 1500 RPM. Using scan tool, command EGR duty cycle through 25, 50, 75 and 100 percent positions. If engine runs rough as EGR is cycled, go to step 5). If engine does not run rough, go to next step. 3. Turn engine off. Turn ignition on, engine off. Disconnect EGR valve harness connector. Connect a test light between EGR valve harness connector ignition feed and control circuits. If test light does not illuminate, go to next step. If test light illuminates, go to step 7). 4. Start engine. Using scan tool, select MISCELLANEOUS TESTS, EGR CONTROL. With test light still connected, command EGR duty cycle increase to 100 percent. If test light illuminates as EGR is cycled, go to step 8). If test light does not illuminate, go to step 11). 5. Remove EGR valve and inspect valve and passages for damage. Inspect valve pintle to ensure it is not sticking partially open. If a problem is found, go to step 10). If no problem is found, go to next step. 6. See DIAGNOSTIC AIDS. 7. Check for short to ground in EGR valve control circuit. If short is found, go to step 14). If no short is found, go to step 15). 8. Check for restriction in EGR tube or passage. If restriction is found, go to step 10). If no restriction is found, go to next step. 9. Check for faulty electrical connection at EGR valve. If faulty connection is found, go to step 14). If connection is okay, go to next step. 10. Replace faulty EGR valve. After replacing EGR, go to step 16). 11. Check for an open in EGR control circuit. If an open is found, go to step 14). If an open is not found, go Microsoft Saturday, August 29, 2009 11:39:11 AM

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12. 13. 14. 15. 16.

17.

to next step. Check for an open in EGR ignition feed circuit. If an open is found, go to step 14). If an open is not found, go to next step. Check for faulty connection at VCM. If faulty connection is found, go to next step. If connection is okay, go to step 15). Repair circuit as necessary. After repairs, go to step 16). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0401. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections or damaged harness. Inspect VCM harness connector EGR control circuit for backed-out terminal. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. If EGR valve shows signs of excessive heat, check exhaust system for blockage or plugged catalytic converter. Ensure fuel injectors are functioning properly and check engine oil for fuel contamination. DTC P0420 - TWC SYSTEM LOW EFFICIENCY BANK 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Three-Way Catalyst (TWC) system is used to control emission. VCM uses signal from Heated Oxygen Sensor (HO2S) behind TWC read efficiency of TWC. VCM will set DTC P0420 if TWC oxygen storage capacity is less than a predetermined threshold. Conditions for setting DTC:       

System in "closed-loop". Commanded air/fuel ratio is 14.7:1. Converter warm-up test passed. No ECT, HO2S, IAT, MAF, MAP, TP or VSS sensor DTCs set. No fuel trim or misfire DTCs set. ECT greater than 167°F (75°C). Vehicle in closed loop operation.

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      

Listed conditions met for at least 2 consecutive minutes. Engine load steady. Vehicle speed steady at 20-70 MPH. IAT at least 14.5°F (-9.75°C). MAF less than 50 grams per second. Throttle above idle. HO2S BANK 1, SENSOR 3 average value plus or minus 0.008 volts than HO2S BANK 1, SENSOR 2 value.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Diagnose any other DTCs before proceeding. If no other DTCs are set, go to next step. 3. Check for and repair the following condition(s):  Ensure TWC is an O.E. part.  TWC for damage.  Ensure no internal damaged catalyst rattle exists.  Exhaust system for leaks, damage, loose or missing hardware.  Ensure HO2S bank 1 sensor 3 is securely installed, and harness and connector are not damaged or contacting exhaust. If any problem is found, go to step 9). If no problems are found, go to next step. 4. Check all VCM ground circuits. If problem is found, go to step 9). If no problem is found, go to next step. 5. Check all sensor ground circuits. If problem is found, to step 9). If no problem is found, go to next step. 6. Check HO2S bank 1 sensor 3 signal and ground circuits for intermittent opens. If problem is found, go to step 9). If no problem is found, go to next step. 7. Check HO2S bank 1 sensor 3 signal and ground circuits for intermittent short to ground. If problem is found, go to step 9). If no problem is found, go to next step. 8. Replace TWC. Check for possible engine misfire DTC or engine mechanical problem. After repairs, go to step 10. 9. Repair problem as necessary. After repairs, go to next step. 10. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0420. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 11. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids Microsoft Saturday, August 29, 2009 11:39:12 AM

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Difficulty may be experienced in simulating conditions to set DTC, especially in urban areas. DTC P0440 - EVAP SYSTEM NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Evaporative (EVAP) emission system includes following components: fuel tank, EVAP vent solenoid, fuel tank pressure sensor, fuel pipes and hoses, vapor lines, fuel cap, EVAP emission canister, purge lines, and EVAP purge solenoid. Conditions required to set DTC are:     

No ECT, HO2S, IAT, MAP, TP or VSS sensor DTCs set. DTC P0125 not active. No fuel level related DTCs set. Fuel tank level greater than 12.5 and 87.5 percent. System voltage is greater than 10 volts but not less than 17 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition off. Remove fuel cap. Turn ignition on. Using scan tool, read FUEL TANK VACUUM. If scan tool displays zero in. H2O, go to next step. If scan tool does not display zero in. H2O, repair faulty fuel tank sensor circuit. 3. Zero pressure and vacuum gauges on EVAP Pressure/Purge Cart (J41413). Reinstall fuel cap. Read and Record FAIL RECORDS data for DTC P0440. Clear DTCs. Using scan tool, command EVAP vent solenoid ON (closed). Connect EVAP pressure/purge cart to EVAP service port. Using EVAP pressure/purge cart, attempt to pressurize EVAP system to 5 in. H2O. If specified pressure is achieved, go to next step. If specified pressure is not achieved, go to step 5). 4. Maintain EVAP system pressure at 5 in. H2O. Using scan tool, read FUEL TANK VACUUM. If scan tool displays 5 IN H2O, go to step 7). If scan tool does not display 5 IN H2O, go to step 6). 5. Disconnect fuel tank vapor and EVAP purge lines from EVAP canister. Plug fuel tank vapor line fitting at EVAP canister. Connect a hand-held vacuum pump to EVAP purge line fitting at EVAP canister. Ensure EVAP vent solenoid is still commanded ON (closed). Attempt to apply 5 in. Hg to EVAP canister. If vacuum is maintained as specified, go to step 10). If vacuum can not be maintained as specified, go to step 11). 6. Check EVAP purge line for restriction. If restriction is found, repair as necessary and go to step 15). If no restriction is found, repair faulty fuel tank sensor circuit. 7. Disconnect vacuum source line and plug vacuum source fitting at EVAP purge solenoid. Using scan tool, Microsoft Saturday, August 29, 2009 11:39:12 AM

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9. 10.

11.

12. 13. 14. 15.

16.

17.

command EVAP vent solenoid ON (closed) and EVAP purge solenoid ON (100%). Using EVAP pressure/purge cart, pressurize EVAP system to 5 in. H2O. Observe pressure gauge on EVAP pressure/purge cart while removing plug from vacuum source fitting line at EVAP purge solenoid. If fuel tank vacuum decreases to zero in. H2O within 15 seconds, go to step 10). If vacuum does not decrease as specified, go to step 12). Connect EVAP pressure/purge cart vacuum gauge to vacuum source line. Start engine. Run engine speed to greater than 2000 RPM while observing vacuum gauge. If vacuum is greater than 15 in. Hg, see DIAGNOSTIC AIDS. If vacuum is 15 in. Hg or less, go to step 13). Check if vent hose is disconnected or damaged. Check EVAP canister for damage. If a problem is found, repair as necessary. After repairs, go to step 15). If no problem is found, go to step 14). Check for missing or faulty fuel filler cap. Check for disconnected, leaking or damaged fuel tank vapor line or EVAP purge line. If a problem is found, repair as necessary. After repairs, go to step 15). If no problem is found, go to next step. Using scan tool, command EVAP vent solenoid ON (closed). With EVAP pressure/purge cart connected to EVAP service port, continuously attempt to pressurize EVAP system by leaving EVAP pressure/purge cart control knob in PRESSURIZE position. Using Ultrasonic Leak Detector (J41413), locate and repair EVAP system leak. It may be necessary to lower fuel tank to check connections at top of tank. Go to step 15). Replace EVAP purge solenoid. After replacing purge solenoid, go to step 15). Locate and repair cause of no source vacuum to EVAP purge solenoid. After repairs, go to step 15). Replace EVAP vent solenoid. After replacing solenoid, go to next step. Turn ignition on, engine off. Using scan tool, command EVAP vent solenoid ON (closed). Using EVAP pressure/purge cart pressurize EVAP system to 15 in. H2O. Monitor EVAP pressure/purge cart pressure gauge. Turn EVAP pressure/purge cart rotary switch to HOLD position. If pressure decreases to less than 10 in. H2O within 2 minutes, system is okay. If pressure does not decrease as specified, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0440. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check following items:    



For missing or damaged "O" rings at EVAP canister fuel vapor and purge line fittings. For cracks or punctures in EVAP canister. For damaged or disconnected source vacuum line, EVAP purge line, vent hose or fuel tank vapor line. For faulty connections at VCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. For damaged harness. Inspect wiring harness to EVAP vent solenoid, EVAP purge solenoid, and fuel tank pressure sensor for intermittent open or short.

Microsoft Saturday, August 29, 2009 11:39:12 AM

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DTC P0442 - EVAP SYSTEM SMALL LEAK DETECTED NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, HO2S, IAT, MAP, ODM, or TP sensor DTCs set. DTC P0125 not active. No fuel level DTCs. Fuel level is greater than 12.5 and 87.5 percent. Vacuum decay for a period of at least 15 seconds. Vacuum less than 7 in. H2O for less than 25 seconds. Vacuum greater than .1 in. H2O for longer than 35 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition off. Remove fuel cap. Turn ignition on. Using scan tool, read FUEL TANK VACUUM. If scan tool displays zero in. H2O go to next step. If scan tool does not display zero in. H2O, repair faulty fuel tank sensor circuit. 3. Zero pressure and vacuum gauges on EVAP Pressure/Purge Cart (J41413). Reinstall fuel cap. Read and Record FAIL RECORDS data for DTC P0442. Clear DTCs. Using scan tool, command EVAP vent solenoid on (closed). Connect EVAP pressure/purge cart to EVAP service port. Using EVAP pressure/purge cart, pressurize EVAP system to 5 in. H2O. Using scan tool, read FUEL TANK VACUUM. If scan tool displays -5 in. H2O, go to next step. If scan tool does not display -5 in. H2O, repair faulty fuel tank sensor circuit. 4. Turn ignition on, engine off. Using scan tool, command EVAP vent solenoid on (closed). Using EVAP pressure/purge cart pressurize EVAP system to 15 in. H2O. Monitor EVAP pressure/purge cart pressure gauge. Turn EVAP pressure/purge cart rotary switch to HOLD position. If pressure decreases to less than 10 in. H2O within 2 minutes, go to next step. If pressure does not decrease as specified, see DIAGNOSTIC AIDS. 5. Disconnect fuel tank vapor and EVAP purge lines from EVAP canister. Plug fuel tank vapor line fitting at EVAP canister. Connect a hand vacuum pump to EVAP purge line fitting at EVAP canister. Ensure EVAP vent solenoid is still commanded ON (closed). Attempt to apply 5 in. Hg to EVAP canister. If vacuum is maintained as specified, go to step 8). If vacuum cannot be maintained as specified, go to next Microsoft Saturday, August 29, 2009 11:39:12 AM

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6. 7. 8.

10.

11.

12.

step. Check if vent hose is disconnected or damaged. Check EVAP canister for damage. If a problem is found, repair as necessary. After repairs, go to step 10). If no problem is found, go to next step. Replace EVAP vent solenoid. After replacing solenoid, go to step 10). Check for missing or faulty fuel cap. Check for disconnected or leaking fuel tank vapor line. Check for disconnected or damaged EVAP purge line. If a problem is found, repair as necessary. After repairs, go to step 10. If no problem is found, go to next step. Using scan tool, command EVAP vent solenoid on (closed). With EVAP pressure/purge cart connected to EVAP service port, attempt to pressurize EVAP system by leaving EVAP pressure/purge cart control knob in PRESSURIZE position. Using Ultrasonic Leak Detector (J41413), locate and repair EVAP system leak. It may be necessary to lower fuel tank to check connections at top of tank. After repairs, go to next step. Turn ignition on, engine off. Using scan tool, command EVAP vent solenoid on (closed). Using EVAP pressure/purge cart pressurize EVAP system to 15 in. H2O. Monitor EVAP pressure/purge cart pressure gauge. Turn EVAP pressure/purge cart rotary switch to HOLD position. If pressure decreases to less than 10 in H2O within 2 minutes, return to step 2). If pressure does not decrease as specified, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0442. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check following items:   



For missing or damaged "O" rings at EVAP canister fuel vapor and purge line fittings. For cracks or punctures in EVAP canister. For damaged or disconnected source vacuum line, EVAP purge line, vacuum line, EVAP purge line, vent hose or fuel tank vapor line. For faulty connections at VCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. For damaged harness. Inspect wiring harness to EVAP vent solenoid, EVAP purge solenoid, and fuel tank pressure sensor for intermittent open or short.

DTC P0446 - EVAP SYSTEM CANISTER VENT BLOCKED NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Evaporative (EVAP) emission system includes following components: fuel tank, EVAP vent solenoid, fuel tank Microsoft Saturday, August 29, 2009 11:39:12 AM

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pressure sensor, fuel pipes and hoses, vapor lines, fuel cap, EVAP emission canister, purge lines, and EVAP purge solenoid. Conditions for setting DTC are:     

No ECT, HO2S, IAT, MAP, ODM, or TP sensor DTCs set. DTC P0125 not active. No fuel level DTCs. Fuel tank level is greater than 12.5 and 87.5 percent. Excess vacuum present in EVAP system.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on. Read and Record FAIL RECORDS data for DTC P0446. Clear DTCs. Turn ignition off. Remove fuel cap. Turn ignition on. Using scan tool, read FUEL TANK VACUUM. If scan tool displays zero in. H2O go to next step. If scan tool does not display zero in. H2O, repair faulty fuel tank sensor circuit. 3. Zero pressure and vacuum gauges on EVAP Pressure/Purge Cart (J41413). Reinstall fuel cap. Using scan tool, command EVAP vent solenoid ON (closed). Connect EVAP pressure/purge cart to EVAP service port. Using EVAP pressure/purge cart, pressurize EVAP system to 5 in. H2O. Using scan tool, read FUEL TANK VACUUM. If scan tool displays 5 in. H2O, go to next step. If scan tool does not display 5 in. H2O, repair faulty fuel tank sensor circuit. 4. Maintain EVAP system pressure at 5 in. H2O. Using scan tool, command EVAP vent solenoid OFF (open). Monitor EVAP pressure/purge cart pressure gauge. If pressure decreases to zero in H2O within 5 seconds, see DIAGNOSTIC AIDS. If pressure does not decrease as specified, go to next step. 5. Disconnect vent hose, marked "AIR", from EVAP canister. Switch EVAP pressure/purge cart rotary switch to PURGE. Warm engine to normal operating temperature. Monitor vacuum gauge while holding engine speed at 2500 RPM. If vacuum remains at less than 30 in. H2O, go to next step. If vacuum is not as specified, go to step 9). 6. Check if vent hose is between EVAP canister and EVAP solenoid is kinked, pinched or blocked. If a problem is found, repair as necessary. After repairs, go to step 9). If no problem is found, go to next step. 7. Replace EVAP vent solenoid. After replacing solenoid, go to step 9). 8. Replace EVAP canister. After replacing canister, go to next step. 9. Using scan tool, command EVAP vent solenoid ON (closed). With EVAP pressure/purge cart connected to EVAP service port, to pressurize EVAP system to 5 in. H2O. Switch EVAP pressure/purge cart rotary switch to HOLD. Using scan tool, command EVAP vent solenoid OFF (open). If pressure decreases to zero in H2O within 5 seconds, system is okay. If pressure does not decrease as specified, return to step 2). Diagnostic Aids

Check following items: Microsoft Saturday, August 29, 2009 11:39:12 AM

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 



For missing or damaged "O" rings at EVAP canister fuel vapor and purge line fittings. For faulty connections at VCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. For damaged harness. Inspect wiring harness to EVAP vent solenoid, EVAP purge solenoid, and fuel tank pressure sensor for intermittent open or short.

DTC P0461 - FUEL LEVEL SENSOR CIRCUIT MALFUNCTION NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Fuel level sensor information is used by VCM to determine volume of fuel in fuel tank. Fuel level affects rate or change in air pressure in EVAP system. Conditions required to set DTC are:    

Fuel tank level slosh test is completed Fuel tank main test is completed. Fuel tank level data valid. Fuel level signal has not changed for distance of 200 miles.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition off. Turn ignition on, with engine off. Using scan tool, compare fuel level on scan tool and vehicle fuel gauge. If fuel level are about the same, go to next step. If not, go to step 5). 3. Record vehicle fuel gauge reading. Turn ignition off. Disconnect Black VCM harness connector. Turn ignition on. If fuel gauge reading changed, go to next step. If fuel gauge reading did not change, go to step 5). 4. Turn ignition off. Locate fuel level sending unit harness connector forward of fuel tank. Disconnect fuel sending unit harness connector. Using jumper wire, jumper fuel level input to fuel level sensor ground. Turn ignition on. Check fuel gauge and scan tool reading. If both reads Empty (zero percent), go to next step. If not, go to step 6). 5. Check and repair circuit to fuel gauge sending unit. 6. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 7. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0461. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Microsoft Saturday, August 29, 2009 11:39:12 AM

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8. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. DTC P0462 - FUEL LEVEL SENSOR CIRCUIT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Fuel tank level slosh test is completed Fuel tank main test is completed. Fuel tank level data valid. Fuel level signal is less than .39 volt for a period greater than 20 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on, with engine off. Using scan tool, observe fuel level. If fuel level is 0-1 percent, go to step 4). If not, go to next step. 3. Diagnose vehicle's fuel level sender gauge module. 4. Using DVOM connected to ground, probe fuel level sensor input at fuel level sender gauge module. If voltage reading is less than .13 volt, go to next step. If voltage reading is not less than .13 volt, go to step 6). 5. Check for open in fuel level sensor input circuit. Repair as necessary. After repairs, go to step 9). If circuit is okay, go to next step. 6. Using DVOM connected to ground, probe fuel level output at fuel level sender gauge module. If voltage reading is less than .13 volt, go to next step. If voltage reading is not less than .13 volt, go to step 8). 7. Check for open in fuel level output circuit. Repair as necessary. After repairs, go to step 10). If circuit is okay, go to next step. 8. Using DVOM connected to ground, probe fuel level module output at fuel level sender gauge module. If voltage reading is greater than 2.9 volts, go to step 11). If voltage reading is not greater than 2.9 volts, go to step 12). 9. Repair open in fuel level sensor input circuit. After repairs, go to step 13). 10. Repair open in fuel level output circuit. After repairs, go to step 13). 11. Repair short to voltage in fuel level module output circuit. After repairs, go to step 13). Microsoft Saturday, August 29, 2009 11:39:12 AM

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12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0462. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. DTC P0463 - FUEL LEVEL SENSOR CIRCUIT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Fuel level sensor is an important input to VCM for enhanced evaporative system diagnostic. Fuel level is necessary for VCM to know volume of fuel in fuel tank. Fuel level affects rate of change in air pressure in EVAP system. Several enhanced evaporative system diagnostic sub-tests are dependent upon correct fuel level information. Diagnostic will not run when tank is greater than 85 percent or less than 15 percent full. Sensor signal will disable misfire when fuel levels are less than 15 percent. Conditions for setting DTC:    

Fuel tank level slosh test is completed. Fuel tank level main test is completed. Fuel tank level data valid. Fuel level signal voltage is greater than 2.9 volts for a period longer than 20 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on, with engine off. Using scan tool, observe fuel level. If fuel level is 99-100 percent, go to step 4). If not, go to next step. 3. Diagnose vehicle's fuel level sender gauge module. 4. Using DVOM connected to ground, probe fuel level sensor input at fuel level sender gauge module. If voltage reading is greater than 2.9 volts, go to next step. If voltage reading is not greater than 2.9 volts, go to step 6). 5. Check for short to voltage in fuel level sensor input circuit. Repair as necessary. After repairs, go to step 9). If circuit is okay, go to next step. 6. Using DVOM connected to ground, probe fuel level output (terminal "D") at fuel level buffer module. If voltage reading is greater than 2.9 volts, go to next step. If voltage reading is not greater than 2.9 volts, go Microsoft Saturday, August 29, 2009 11:39:12 AM

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7. 8. 9. 10. 11. 12. 13.

14.

to step 8). Check for short to voltage in fuel level output circuit. Repair as necessary. After repairs, go to step 10). If circuit is okay, go to next step. Check for open in fuel level buffer module sensor ground. Repair as necessary. After repairs, go to step 11). If circuit is okay, go to step 12). Repair short to voltage in fuel level input circuit. After repairs, go to step 13). Repair short to voltage in fuel level output circuit. After repairs, go to step 13). Repair open in fuel level buffer module sensor ground. After repairs, go to step 13). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0462. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

DTC P0500 - VEHICLE SPEED SENSOR CIRCUIT NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Vehicle Speed Sensor (VSS) is a magnetic induction type. Gear teeth pressed on outside of output shaft induce an AC current in sensor as shaft rotates. Signal goes directly to VCM. VCM uses pulsed signal to calculate vehicle speed based on time between pulses. Conditions required for setting DTC:      

No MAP DTCs set. Throttle angle less than 3.125 percent. ECT greater than 140°F (60°C). Engine speed 1400-4400 RPM. MAP less than 20 kPa. All conditions met for 5 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Using scan tool, clear DTCs. Using Connector Test Adapter Kit (J35616) and a DVOM set to AC 200 Microsoft Saturday, August 29, 2009 11:39:12 AM

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3. 4. 5.

6. 7. 8. 9. 10. 11. 12.

13.

volt scale, backprobe across VSS harness connector signal and ground circuits. Raise and support vehicle. Start engine and place transmission in gear. If voltage is constant, go to step 5). If voltage is not constant, go to next step. If voltage varies, see DIAGNOSTIC AIDS. If voltage does not vary, go to next step. If scan tool displays NO VOLTAGE, go to step 11). If scan tool does not display NO VOLTAGE, go to step12). With vehicle still raised, disconnect VSS connector. With engine running, place transmission in gear. Using a DVOM on 200-volt AC scale, check voltage across signal and ground circuits at VSS. If voltage varies with RPM, go to step 7). If voltage does not vary, go to next step. Replace VSS. After replacing sensor, go to step 12). Check for faulty connection at VCM and VSS. If faulty connection is found, go to step 9). If connections are okay, go to next step. Check for open or short in ground and signal circuits between VCM and VSS. If problem is found, go to step 10). If no problem is found, go to step 12). Repair connection as necessary. After repairs, go to step 12). Repair open or short as necessary. After repairs, go to step 12). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0500. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Ensure VCM is properly calibrated for vehicle speedometer. DTC P0506 - IDLE SPEED LOW IDLE AIR CONTROL RESPONDING NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM controls idle speed with an Idle Air Control (IAC) valve to a calculated RPM based on sensor inputs and actual engine RPM. VCM moves IAC valve in or out to vary amount of airflow into intake manifold and thus decrease or increase idle RPM. VCM commands IAC in counts. A higher count, allows more air to by-pass throttle plate (higher idle). Conditions required to test for DTC are: Microsoft Saturday, August 29, 2009 11:39:12 AM

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       

No ECT, MAP, TP or VSS sensor DTCs set. ECT greater than 122°F (50°C). IAT greater than -13°F (-25°C). BARO greater than 10.2 psi (0.72 kg/cm2 ) at less than 10,300 ft. Vehicle speed less than 2 MPH. Throttle angle at less than 1%. Engine running greater than 30 seconds. Conditions met for greater than 3 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Using scan tool, read DTCs. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step. 3. If DTC P0506 is active this ignition cycle, go to step 5). If DTC is not active this ignition cycle, go to next step. 4. DTC P0506 is intermittent. See DIAGNOSTIC AIDS. 5. Repair engine mechanical problem as necessary and go to next step. 6. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0506. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 7. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Ensure throttle stop screw has not been tampered with. Check for stuck IAC valve or throttle linkage. Reset IAC using scan tool MISC FUNCTIONS. Check if fuel system is running too rich or too lean. Inspect throttle body bore for foreign material. DTC P0507 - IDLE SPEED HIGH IDLE AIR CONTROL RESPONDING NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

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VCM commands IAC in counts. A higher count, allows more air to by-pass throttle plate (higher idle). Conditions required to test for DTC are:         

No ECT, MAP, TP or VS sensor DTCs set. ECT greater than 122°F (50°C). IAT greater than -13°F (-25°C). BARO greater than 70 kPa. Vehicle speed less than 2 MPH. System voltage greater than 10 volts, but less than 16 volts. Throttle at idle. Engine running longer than 30 seconds. Conditions met for more than 3 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Using scan tool, read DTCs. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step. 3. If DTC P0507 is active this ignition cycle, go to step 6). If DTC is not active this ignition cycle, go to next step. 4. DTC P0507 is intermittent. See DIAGNOSTIC AIDS. 5. Repair engine mechanical problem as necessary. After repairs, go to next step. 6. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0507. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 7. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Ensure throttle stop screw has not been tampered with. Check for stuck IAC valve or throttle linkage. Reset IAC using scan tool MISC FUNCTIONS. Check if fuel system is running too rich or too lean. Inspect throttle body bore for foreign material. DTC P0704 - CLUTCH SWITCH CIRCUIT (WITH MANUAL TRANSMISSION) NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

DTC determines if transmission clutch switch has failed by looking for a clutch switch transition within a range from zero MPH to some higher speed. DTC will set when the following conditions are present:   

No VSS DTCs are set. Vehicle speed is greater than 40 MPH. No clutch transition is detected.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. After performing OBD system check, go to next step. 2. Turn ignition off. Install scan tool. Turn ignition on, with engine off. Using scan tool, display clutch switch parameter. Engage and disengage clutch several times. If scan tool display change indicates when clutch is engaged and disengaged, go to step 7). If scan tool display change does not indicate when clutch is engaged and disengaged, go to next step. 3. Check if brake fuse is blown, go to step 8). If fuse is not blown, go to next step. 4. Turn ignition off. Disconnect clutch switch connector. Connect a jumper wire between ignition feed circuit and signal circuit of clutch switch connector. Turn ignition on, with engine off. Using scan tool, check if clutch switch is on. If scan tool indicates clutch switch is on, go to next step. If scan tool indicates clutch switch is off, go to step 6). 5. Remove jumper wire from clutch switch connector. Using scan tool, check if clutch switch is off. If scan tool indicates clutch switch is off, go to step 11). If scan tool indicates clutch switch is on, go to step 9). 6. Check for open in signal circuit. If a problem was found, go to step 12). If a problem was not found, go to step 10). 7. DTC is intermittent. See the TESTS W/O CODES article. 8. Check and repair conditions that caused fuse to blow. Replace fuse. After replacing fuse, go to step 14). 9. Check for short to battery in signal circuit. If a problem was found, go to step 12). If a problem was not found, go to step 13). 10. Check for poor connections at VCM. If a problem was found, go to step 12). If a problem was not found, go to step 13). 11. Replace clutch switch. After replacing switch, go to step 14). 12. Repair as necessary. After repairs, go to step 14). 13. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 14. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0704. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2). 15. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go Microsoft Saturday, August 29, 2009 11:39:12 AM

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to applicable DTC test. DTC P1106 - MAP SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure (vacuum). A 5-volt reference is applied to sensor. A variable resistor moves in relation to manifold pressure and a voltage signal is returned to VCM through MAP signal circuit. Voltage signal varies from 1.0-1.5 volts at closed throttle to 4.04.5 volts at wide open throttle (low vacuum). VCM utilizes MAP signal and throttle position to determine fuel delivery. DTC will set when the following conditions are present:    

No TP sensor DTCs are set. Throttle position is not greater than 96.8 percent when engine speed is not greater than 1000 RPM. Throttle position is not greater than 89.8 percent when engine speed is greater than 1000 RPM. MAP greater than 4.9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. After performing OBD system check, go to next step. 2. If engine idle is unstable, incorrect, or if manifold vacuum at idle is less than 15 in. Hg, repair as necessary. Install scan tool. With engine idling, monitor MAP sensor voltage using scan tool. If MAP sensor voltage is greater than 4 volts, go to next step. If MAP sensor voltage is not greater than 4 volts, go to step 4). 3. Turn ignition off. Disconnect MAP sensor connector. Turn ignition on. Monitor MAP sensor voltage using scan tool. If MAP sensor voltage is less than one volt, go to step 5). If MAP sensor voltage is not less than one volt, go to step 9). 4. DTC is intermittent. If no additional DTCs are set, see DIAGNOSTIC AIDS. If any additional DTCs are set, go to applicable DTC test. 5. With DVOM to ground, probe 5-volt reference circuit at MAP sensor connector. If voltage is greater than 5.2 volts, go to step 10). If not, go to next step. 6. Using test light, probe MAP sensor connector ground circuit to battery voltage. If test light illuminates, go to step 7). If test light does not illuminate, go to step 14). 7. Check for restriction in MAP sensor vacuum source. If a problem was found, go to step 15). If a problem was not found, go to next step. 8. Replace MAP sensor. After replacing sensor, go to step 19). 9. Check for short to voltage in MAP signal circuit. If a problem was found, go to step 15). If a problem was not found, go to step 18). Microsoft Saturday, August 29, 2009 11:39:12 AM

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10. Ignition off. Unplug VCM White connector. Ignition on. With DVOM to ground, check voltage on VCM connector MAP sensor 5-volt reference circuit terminal. If voltage is greater than 5.2 volts, go to next step. If not, go to step 13). 11. Unplug EGR electrical connector. Check voltage on VCM connector EGR sensor 5-volt reference circuit terminal. If voltage is greater than 5.2 volts, go to next step. If not, go to step 16). 12. Repair short to voltage on 5-volt reference circuit. After repairs, go to step 19). 13. With DVOM to ground, measure voltage on VCM connector TP sensor 5-volt reference circuit terminal. If voltage is greater than 5.2 volts, go to step 17). If not, go to step 18). 14. Repair MAP ground circuit. After repairs, go to step 19). 15. Repair as necessary. After repairs, go to step 19). 16. Replace EGR valve. After replacing EGR valve, go to step 19). 17. Repair short to voltage on the 5-volt reference circuit. After repairs, go to step 19). 18. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 19. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P1106. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2). 20. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go to applicable DTC test. Diagnostic Aids

An intermittent ground in MAP signal circuit or 5-volt reference circuit will result in DTC P1106 setting. With ignition on and engine off, manifold pressure is equal to atmospheric pressure with signal voltage high. VCM uses information as an indication of vehicle altitude. To test accuracy of a suspect sensor, compare reading with a known-good vehicle. Reading should be 3.6-4.9 volts. If DTC is intermittent, see the TESTS W/O CODES article. To check for intermittent connection, disconnect sensor from bracket and twist sensor by hand. Output changes greater than .1 volt indicates a poor connection or connector. If okay, replace sensor. Ensure electrical connection remains securely connected. If sensor is removed from intake manifold, sensor-to-manifold seal must be replaced. DTC P1107 - MAP SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Manifold Absolute Pressure (MAP) sensor measures changes in intake manifold pressure (vacuum). A low voltage signal, 1.0-1.5 volts, is sent to VCM on 5-volt reference circuit at closed throttle (high vacuum). A high voltage signal, 4.0-4.5 volts is sent at wide open throttle (low vacuum). Microsoft Saturday, August 29, 2009 11:39:12 AM

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Conditions required to set DTC are: 

 

Engine speed is 800 RPM or less with throttle closed, or more than 800 RPM with throttle slightly above idle. MAP sensor voltage less than 0.2 volt. No TP sensor DTCs are set.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is less than 0.5 volt, go to next step. If voltage is not less than 0.5 volt, go to step 5). 3. Turn ignition off. Disconnect MAP sensor harness connector. Connect a jumper wire between MAP sensor harness connector 5-volt reference and signal circuits. Turn ignition on. If voltage is greater than 4.7 volts, go to step 6). If voltage is not greater than 4.7 volts, go to next step. 4. Turn ignition off. Disconnect jumper wire. Connect a test light between battery voltage and MAP sensor harness connector signal circuit. Turn ignition on. If voltage is greater than 4.7 volts, go to step 9). If voltage is not greater than 4.7 volts, go to step 7). 5. DTC P1107 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, go to DIAGNOSTIC AIDS. 6. Check for faulty connection at MAP sensor. If faulty connection is found, go to step 12). If connection is okay, go to step 11). 7. Check for open MAP sensor signal circuit. If circuit is open, go to step 12). If circuit is okay, go to next step. 8. Check MAP sensor signal circuit for short to ground. If short is found, go to step 12). If circuit is okay, go to step 13). 9. Check for open in MAP sensor 5-volt reference circuit. If open is found, go to step 12). If circuit is okay, go to next step. 10. Check MAP sensor 5-volt reference circuit for short to ground. If short is found, go to step 12). If circuit is okay, go to step 13). 11. Replace faulty MAP sensor. After replacing sensor, go to step 14). 12. Repair circuit as necessary. After repairs, go to step 14). 13. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1107. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Microsoft Saturday, August 29, 2009 11:39:12 AM

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Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Intake Air Temperature (IAT) sensor is a thermistor. VCM applies and reads a 5-volt reference signal to sensor. When air is cold, sensor resistance is high and VCM will measure a high signal voltage. If air is warm, sensor resistance is low causing VCM to measure low voltage. Conditions required to set DTC are:     

No ECT, VSS, MAF sensor DTCs not set. Vehicle speed less than 2 MPH. ECT greater than 183.2°F (84°C). IAT greater than -34.6°F (-37°C). Engine run time greater than 100 seconds.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Using scan tool, read IAT sensor voltage. If voltage is greater than 4.9 volts, go to next step. If voltage is not greater than 4.9 volts, go to step 6). 3. Turn ignition off. Disconnect IAT sensor harness connector. Connect a jumper wire between IAT sensor harness connector 5-volt reference and ground circuits. Turn ignition on. If voltage is less than 0.82 volt, go to step 7). If voltage is not less than 0.82 volt, go to next step. 4. Connect jumper wire between IAT sensor harness connector signal circuit and engine ground. If voltage is less than 0.82 volt, go to step 8). If voltage is 0.82 volt or greater, go to next step. 5. If DTC P0123 is also set, go to DTC P0123 for diagnosis. If DTC is not set, go to step 9). 6. DTC P1111 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. Microsoft Saturday, August 29, 2009 11:39:12 AM

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7. Check for faulty connection at IAT sensor and at VCM. If faulty connection is found, go to step 10). If connections are okay, go to step 11). 8. Check for open IAT sensor ground circuit. If open is found, go to step 10). If circuit is okay, go to step 12). 9. Check for open IAT sensor signal circuit. If open is found, go to next step. If circuit is okay, go to step 12). 10. Repair circuit as necessary. After repairs, go to step 13). 11. Replace IAT sensor. After replacing sensor, go to step 13). 12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1111. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections at IAT sensor and at VCM. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for skewed IAT sensor. See IAT TEMPERATURE-TO-RESISTANCE VALUES table. DTC P1112 - IAT SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No VSS DTCs set. Vehicle speed at least 2 MPH. Engine running longer than 100 seconds. IAT sensor voltage less than 0.82 volt.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L Microsoft Saturday, August 29, 2009 11:39:12 AM

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2. 3. 4. 5. 6. 7. 8. 9.

10.

article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. Turn engine on and allow it to idle. Using scan tool, read IAT sensor voltage. If voltage is less than 0.82 volt, go to next step. If voltage is not less than 0.82 volt, go to step 5). Turn engine off. Turn ignition on. Disconnect IAT sensor harness connector. If voltage is greater than 4 volts, go to step 7). If voltage is not greater than 4 volts, go to next step. Turn ignition off. Using DVOM, check resistance across IAT sensor harness connector. If resistance is infinite, go to step 8). If resistance is not infinite, go to step 6). DTC P1112 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. Repair short to ground in IAT sensor signal circuit. After repairs, go to step 9). Replace IAT sensor. After replacing sensor, go to step 9). Replace VCM. Replacement VCM requires special equipment for programming procedures. After replacing VCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1112. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections at IAT sensor and at VCM. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for skewed IAT sensor. See IAT TEMPERATURE-TO-RESISTANCE VALUES. DTC P1114 - ECT SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine Coolant Temperature (ECT) sensor is a thermistor that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. High temperature will result in a low signal voltage. DTC will set when VCM sees an ECT sensor voltage of less than 0.82 volt with engine running for 5 seconds. Conditions for setting DTC:   

Engine run time greater than 5 seconds. ECT less than 0.25 volt (low resistance pull-up). ECT less than 0.25 volt (high resistance pull-up).

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Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Using scan tool, read ECT sensor voltage. If voltage is less than 0.82 volt, go to next step. If voltage is not less than 0.82 volt, go to step 5). 3. Turn engine off. Disconnect ECT sensor harness connector. Turn ignition on. If voltage is greater than 4 volts, go to step 7). If voltage is not greater than 4 volts, go to next step. 4. Turn ignition off. Using DVOM, check resistance across ECT sensor harness connector. If resistance is infinite, go to step 8). If resistance is not infinite, go to step 6). 5. DTC P1114 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Repair short to ground in ECT sensor signal circuit. After repairs, go to step 9). 7. Replace ECT sensor. After replacing sensor, go to step 9). 8. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 9. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1114. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for short to ground in ECT sensor harness connector 5-volt reference circuit. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. Check for skewed ECT sensor. See ECT TEMPERATURE-TO-RESISTANCE VALUES . DTC P1115 - ECT SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine Coolant Temperature (ECT) sensor is a thermistor or a variable resistor, that varies resistance based on temperature. As temperature of sensor increases, resistance decreases. Low temperature will result in a high signal voltage. DTC will set when VCM sees an ECT sensor voltage of greater than 5 volts. Condition for setting DTC: 

Engine run time greater than 5 seconds.

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

ECT greater than 4.9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn engine on and allow it to idle. Using scan tool, read ECT sensor voltage. If voltage is greater than 4.9 volts, go to next step. If voltage is not greater than 4.9 volts, go to step 5). 3. Turn engine off. Turn ignition on. Disconnect ECT sensor harness connector. Connect a jumper wire across ECT sensor harness connector. If voltage is less than 0.82 volt, go to step 6). If voltage is not less than 0.82 volt, go to next step. 4. Connect jumper wire between ECT sensor harness connector signal circuit and chassis ground. If voltage is less than 0.82 volt, go to step 7). If voltage is not less than 0.82 volt, go to step 8). 5. DTC P1115 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, go to DIAGNOSTIC AIDS. 6. Inspect VCM and ECT sensor for proper connection. If a problem is found, go to step 10). If connections are okay, go to step 11). 7. Check ECT sensor harness connector ground circuit for open between VCM and ECT sensor. If open is found, go to step 10). If open is not found, go to step 12). 8. If DTC P0123 is also set, go to DTC P0123 . If DTC is not set, go to next step. 9. Check ECT sensor harness connector signal circuit for open between VCM and ECT sensor. If open is found, go to next step. If open is not found, go to step 12). 10. Repair circuit as necessary. After repairs, go to step 13). 11. Replace ECT sensor. After replacing sensor, go to step 13). 12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1115. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or open in 5-volt reference and ground circuits. Check for skewed ECT sensor. See ECT TEMPERATURE-TO-RESISTANCE VALUES . DTC P1121 - TP SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

TP signal voltage is greater than 4.8 volts.



MAP is less than 7.4 psi (0.51 kg/cm2 ) for greater than 4 seconds with engine running.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. With throttle closed, use scan tool to read TP signal voltage. If voltage is greater than 4.8 volts, go to next step. If voltage is not greater than 4.8 volts, go to step 6). 3. Disconnect TP sensor harness connector. If voltage is less than 0.2 volt, go to next step. If voltage is not less than 0.2 volt, go to step 5). 4. Connect a test light between TP sensor harness connector ground circuit and battery voltage. If test light illuminates, go to step 7). If test light does not illuminate, go to step 9). 5. If DTC P0108 is also set, go to DTC P0108 for diagnosis. If DTC is not set, go to step 8). 6. DTC P1121 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 7. Check for faulty connection at TP sensor. If faulty connection is found, go to step 10). If connection is okay, go to step 11). 8. Check for short to voltage in TP sensor harness connector signal circuit. If short is found, go to step 10). If short is not found, go to step 12). 9. Check for open in TP sensor harness connector ground circuit. If circuit is open, go to next step. 10. Repair circuit as necessary. After repairs, go to step 13). 11. Replace TP sensor. After replacing sensor, go to step 13). 12. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 13. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1121. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 14. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for and repair the following condition(s): Microsoft Saturday, August 29, 2009 11:39:12 AM

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  

DTC P1122 - TP SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine running. TP sensor signal voltage less than .25 volt.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. With throttle closed, use scan tool to read TP signal voltage. If voltage is less than 0.15 volt, go to next step. If voltage is not less than 0.15 volt, go to step 5). 3. Disconnect TP sensor harness connector. Connect a jumper wire between TP sensor harness connector sensor signal and 5-volt reference circuits. If voltage is greater than 4 volts, go to step 13). If voltage is not greater than 4 volts, go to next step. 4. Connect a test light between TP sensor harness connector signal circuit and battery voltage. If voltage is greater than 4 volts, go to step 6). If voltage is not greater than 4 volts, go to step 8). 5. DTC P1122 is intermittent. If any additional DTCs are set, diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS. 6. Check for open in TP sensor harness connector 5-volt reference circuit. If open is found, go to step 11). If open is not found, go to next step. 7. Check for short to ground in TP sensor harness connector 5-volt reference circuit. If short is found, go to step 11). If short is not found, go to step 10). 8. Check for open in TP sensor harness connector signal circuit. If open is found, go to step 11). If open is not found, go to next step. 9. Check for short to ground in TP sensor harness connector signal circuit. If short is found, go to step 11). If short is not found, go to next step. 10. Check for faulty connection at VCM. If faulty connection is found, go to next step. If connection is okay, Microsoft Saturday, August 29, 2009 11:39:12 AM

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11. 12. 13. 14.

15.

go to step 13). Repair circuit as necessary. After repairs, go to step 14). Replace TP sensor. After replacing sensor, go to step 14). Replace VCM. Program replacement VCM using required equipment. After replacing PCM, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1122. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for and repair the following condition(s):  



DTC P1133 - HO2S INSUFFICIENT SWITCHING BANK 1, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. VCM determines if HO2S is functioning properly by reading number of Lean/Rich (L/R) and Rich/Lean (R/L) switches. Conditions required to set DTC are:        

No fuel trim DTCs set. L/R and R/L switches less than 30. No ECT, IAT, MAP, or TP sensor DTCs set. No EGR or EVAP DTCs set. DTC P0135 not set. Vehicle operating in closed loop mode. HO2S voltage 0.3-0.6 volt. TP angle value 10-20 percent.

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Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step. 3. Turn engine on and allow it to idle. Using scan tool, read MAP sensor voltage. If voltage is greater than 4 volts, go to DTC P0108 . If voltage is not greater than 4 volts, go to next step. 4. Check air intake duct for improper installation, collapse, restriction, or missing or plugged air filter. Check throttle body and intake manifold for vacuum leaks. Check throttle body for damage to inlet or foreign objects blocking inlet, or for coking. Check exhaust system for corrosion, leaks, loose or missing hardware. Check HO2S for proper installation and for HO2S harness not contacting exhaust manifold. Check vacuum hoses for splits, kinks and proper connections. Check for fuel contamination. Check for good VCM and sensor grounds. If any of these items isolate or require repair, go to step next step. If all items are okay, go to step 6). 5. Repair or replace as necessary. After repairs, go to step 10). 6. Perform INJECTOR BALANCE TEST under FUEL SYSTEM in the SYSTEM/COMPONENT TESTS article. If an injector problem is found, go to step 9). If injectors are okay, go to next step. 7. Remove and inspect HO2S (bank 1, sensor 1) for contamination. If contamination is evident, go to next step. If contamination is not evident, see DIAGNOSTIC AIDS. 8. Replace HO2S. After replacing sensor, go to step 10). 9. Replace fuel injector(s). After replacing injector(s), go to next step. 10. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1133. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 11. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check HO2S heater operation. DTC P1134 - HO2S TRANSITION TIME RATIO BANK 1, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM reads Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this period, VCM counts the number of Lean/Rich (L/R) and Rich/Lean (R/L) switches. With this information, an average time for all transitions can be determined. VCM then divides R/L average by Microsoft Saturday, August 29, 2009 11:39:12 AM

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L/R rich average to obtain a ratio. If HO2S ratio is not within range, DTC will set. Conditions required to set DTC are:           

No fuel trim DTCs set. L/R and R/L switches less than 30 counts. No ECT, IAT, MAP, or TP sensor DTCs set. No EGR or EVAP DTCs set. DTC P0131, P0132, P0134 or P0135 not set. Vehicle operating in closed loop mode. HO2S voltage 0.3-0.6 volt. TP ANGLE value 10-20 percent. Average response time calculated for this ignition cycle. Ratio of HO2S (bank 1, sensor 1) L/R to R/L switches greater than 64 counts. Ratio of HO2S (bank 1, sensor 1) L/R to R/L switches greater than 48 counts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step. 3. Turn engine on and allow it to reach normal operating temperature. Set engine speed at 1200-2000 RPM for 2 minutes. Using scan tool, read HO2S BANK 1 SENSOR 1 voltage. If voltage rapidly switches from less than 0.3 volt to greater than 0.6 volt, go to next step. If voltage does not switch as specified, go to step 5). 4. With engine speed still at 1200-2000 RPM, read LOOP MODE. If scan tool displays CLOSED LOOP, see DIAGNOSTIC AIDS. If scan tool does not display CLOSED LOOP, go to step 8). 5. If voltage stays within 0.3-0.6 volt longer than it stays out of range, go to step 10). If voltage stays outside 0.3-0.6 volt longer than it stays within range, go to next step. 6. Check for faulty connection at VCM HO2S (bank 1, sensor 1) terminals. If faulty connection is found, go to step 10). If connection is okay, go to next step. 7. Check for faulty connection at HO2S (bank 1, sensor 2). If faulty connection is found, go to step 10). If connection is okay, go to next step. 8. Replace HO2S (bank 1, sensor 1) and go to step 11). 9. Check for HO2S contamination caused by leaded fuel, incorrect gasket sealer or over-rich operation. If problem is found, go to next step. If no problem is found, go to step 11). 10. Repair or replace as necessary. After repairs, go to next step. 11. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1134. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Microsoft Saturday, August 29, 2009 11:39:12 AM

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12. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Never solder HO2S wires. DTC P1153 - HO2S INSUFFICIENT SWITCHING BANK 2, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM provides about 0.45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. VCM determines if HO2S is functioning properly by reading number of Lean/Rich (L/R) and Rich/Lean (R/L) switches. Conditions required to set DTC are:        

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step. 3. Turn engine on and allow it to reach normal operating temperature. Set engine speed at 1200-2000 RPM for 2 minutes. Using scan tool, read HO2S BANK 2 SENSOR 1 voltage. If voltage rapidly switches from less than 0.3 volt to more than 0.6 volt, go to next step. If voltage does not switch as specified, go to step 5). 4. With engine speed still at 1200-2000 RPM, read LOOP MODE. If scan tool displays CLOSED LOOP, see DIAGNOSTIC AIDS. If scan tool does not display CLOSED LOOP, go to step 8). 5. If voltage stays within 0.3-0.6 volt longer than it stays out of range, go to step 10). If voltage stays outside 0.3-0.6 volt longer than it stays within range, go to next step. 6. Check for faulty connection at VCM HO2S (bank 2, sensor 1) terminals. If faulty connection is found, go Microsoft Saturday, August 29, 2009 11:39:12 AM

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7. 8. 9. 10. 11.

12.

to step 10). If connection is okay, go to next step. Check for faulty connection at HO2S (bank 2, sensor 1). If faulty connection is found, go to step 10). If connection is okay, go to next step. Replace HO2S. After replacing sensor, go to step 11). Check for HO2S contamination caused by leaded fuel, incorrect gasket sealer or over-rich operation. If problem is found, go to next step. If no problem is found, go to step 11). Repair or replace as necessary. After repairs, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1153. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Never solder HO2S wires. DTC P1154 - HO2S TRANSITION TIME RATIO BANK 2, SENSOR 1 NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No fuel trim DTCs set. L/R and R/L switches less than 30 counts. No ECT, IAT, MAP, or TP sensor DTCs set. No EGR or EVAP DTCs set. DTC P0155 not set. Vehicle operating in closed loop mode. HO2S voltage 0.3-0.6 volt. TP ANGLE value 10-20 percent. Average response time calculated for this ignition cycle. Ratio of HO2S (bank 2, sensor 1) L/R to R/L switches more than 64 counts.

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

Ratio of HO2S (bank 2, sensor 1) L/R to R/L switches more than 48 counts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step. 3. Turn engine on and allow it reach normal operating temperature. Set engine speed at 1200-2000 RPM for 2 minutes. Using scan tool, read HO2S BANK 2 SENSOR 1 voltage. If voltage rapidly switches from less than 0.3 volt to more than 0.6 volt, go to next step. If voltage does not switch as specified, go to step 5). 4. With engine speed still at 1200-2000 RPM, read LOOP MODE. If scan tool displays CLOSED LOOP, see DIAGNOSTIC AIDS. If scan tool does not display CLOSED LOOP, go to step 8). 5. If voltage stays within 0.3-0.6 volt longer than it stays out of range, go to step 10). If voltage stays outside 0.3-0.6 volt longer than it stays within range, go to next step. 6. Check for faulty connection at VCM HO2S (bank 2, sensor 1) terminal. If faulty connection is found, go to step 10). If connection is okay, go to next step. 7. Check for faulty connection at HO2S (bank 2, sensor 1). If faulty connection is found, go to step 10). If connection is okay, go to next step. 8. Replace HO2S (bank 2, sensor 1). After replacing HO2S sensor, go to step 11). 9. Check for HO2S contamination caused by leaded fuel, incorrect gasket sealer or over-rich operation. If problem is found, go to next step. If no problem is found, go to step 11). 10. Repair or replace as necessary. After repairs, go to next step. 11. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1154. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 12. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Never solder HO2S wires. DTC P1345 - CRANKSHAFT/CAMSHAFT POSITION SENSOR CORRELATION NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

If VCM sets DTC P1345, it has determined that distributor is installed incorrectly, or a mechanical malfunction in engine has occurred. Microsoft Saturday, August 29, 2009 11:39:12 AM

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Condition required to set DTC is: 

With engine running, Camshaft Position (CMP) sensor pulse is not detected at correct time relative to Crankshaft Position (CKP) sensor pulse.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Start engine. Using scan tool, read engine speed (RPM). If RPM fluctuates up to twice desired RPM, go to next step. If RPM does not fluctuate as specified, go to step 4). 3. Replace CKP sensor. After replacing sensor, go to step 6). 4. Check for proper distributor installation. If problem is found, go to next step. If no problem is found, go to step 6). 5. Repair as necessary. After repairs, go to next step. 6. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1345. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 7. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. DTC P1351 - IGNITION CONTROL CIRCUIT HIGH VOLTAGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Crankshaft Position (CKP) sensor provides VCM with reference pulse input. VCM uses CKP input to determine ignition spark timing for each cylinder. Once VCM calculates ignition timing, it sends a signal to ignition coil module on Ignition Control (IC) circuit. Conditions required to set DTC are:  

Engine speed less than 250 RPM. IC circuit voltage greater than 4.9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Clear DTCs. Disconnect fuel injector connector. Crank engine 30 seconds. Read DTCs. If DTC P1351 Microsoft Saturday, August 29, 2009 11:39:12 AM

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5. 6. 7. 8. 9. 10. 11.

12. 13. 14. 15. 16.

17.

sets, go to next step. If DTC does not set, see DIAGNOSTIC AIDS. Turn ignition off. Reconnect fuel injector connector. Disconnect ignition coil module connector. Using voltmeter in AC scale, check voltage between engine ground and IC control circuit at ignition coil module, while cranking engine. If voltage is 1-4 volts, go to step 9). If voltage is not as specified, go to next step. Turn ignition off. Disconnect VCM White connector. Check resistance of IC control circuit between VCM White harness connector and ignition coil module. If resistance is less than 10 ohms, go to step 6). If resistance is not less than 10 ohms, go to next step. Repair open IC control circuit between VCM and ignition coil module and go to step 16). Check for faulty connection at VCM. If faulty connection is found, go to next step. If connection is okay, go to step 8). Repair faulty VCM connection. After repairs, go to step 16). Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to step 16). Turn ignition off. Connect a test light between battery voltage and ignition coil module harness connector ground circuit. If test light illuminates, go to step 11). If test light does not illuminate, go to next step. Repair open ignition coil module ground circuit and go to step 16). Turn ignition on. Connect test light between engine ground and ignition coil module harness connector ignition feed circuit, and then ignition coil module harness connector tachometer signal circuit. If test light illuminates on both circuits, go to step 13). If test light does not illuminate on both circuits, go to next step. Repair faulty circuit. After repairs, go to step 16). Check for faulty connection at ignition coil module. If faulty connection is found, go to step 15). If connection is okay, go to next step. Replace ignition coil module. After replacing module, go to step 16). Repair faulty connection. After repairs, go to next step. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1351. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Diagnostic Aids

Check for faulty connections or damaged harness. If connections and harness appear okay, observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P1361 - IGNITION CONTROL CIRCUIT NOT TOGGLING NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

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Circuit Description

EST enabled. Engine speed less than 250 RPM. EST voltage less than .40 volt.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Clear DTCs. Disconnect fuel injector connector. Crank engine 15 seconds. Read DTCs. If DTC P1361 sets, go to next step. If DTC does not set, see DIAGNOSTIC AIDS. 3. Turn ignition off. Reconnect fuel injector connector. Disconnect ignition coil module connector. Using voltmeter in AC scale, check voltage between engine ground and IC control circuit at ignition coil module, while cranking engine. If voltage is 1-4 volts, go to step 9). If voltage is not as specified, go to next step. 4. Turn ignition off. Disconnect VCM White connector. Connect a test light between battery voltage and ignition coil module harness connector IC control circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 6). 5. Repair short to voltage in IC control circuit. After repairs, go to step 14). 6. Connect test light between engine ground and IC control circuit at VCM. If test light illuminates, go to next step. If test light does not illuminate, go to step 8). 7. Repair short to voltage in IC control circuit. After repairs, go to step 14). 8. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to step 14). 9. Turn ignition off. Connect a test light between battery voltage and ignition coil module harness connector ground circuit. If test light illuminates, go to step 11). If test light does not illuminate, go to next step. 10. Repair open ignition coil module ground circuit. After repairs, go to step 14). 11. Check for faulty connection at ignition coil module. If faulty connection is found, go to step 13). If connection is okay, go to next step. 12. Replace ignition coil module. After replacing module, go to step 14). 13. Repair faulty connection. After repairs, go to next step. 14. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1361. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). Microsoft Saturday, August 29, 2009 11:39:12 AM

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15. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

This test determines if ABS system is capable of detecting a rough road situation. Conditions for setting DTC:    

Vehicle speed at least 1 MPH. Engine speed less than 5800 RPM. Engine load not greater than 90 percent. DTC P0300 is set with MIL on.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Disconnect VCM and Electronic Brake Control (EBCM) module connectors. Check for open in serial data circuit between EBCM and VCM. If open is found, go to next step. If open is not found, perform ABS system diagnosis. See the BRAKES SYSTEM - ANTI-LOCK article in the BRAKES section. 3. Repair as necessary. After repairs, go to next step. 4. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1380. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 5. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

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DTC P1381 - MISFIRE DETECTED NO EBCM/VCM SERIAL DATA NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

This test detects a serial data malfunction which could inhibit the transfer of the ABS rough road data to VCM. Conditions for setting DTC:  

DTC P0300 is set with MIL on. EBCM not sending rough road data.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Disconnect VCM and Electronic Brake Control (EBCM) module connectors. Check for open in serial data circuit between EBCM and VCM. If open is found, go to next step. If open is not found, perform ABS system diagnosis. See the BRAKES SYSTEM - ANTI-LOCK article in the BRAKES section. 3. Repair as necessary. After repairs, go to next step. 4. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1381. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 5. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

VCM constantly reads EGR valve pintle position sensor to ensure valve is responding to commands from VCM. Conditions required to set DTC are: Microsoft Saturday, August 29, 2009 11:39:12 AM

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

EGR pintle position signal voltage out of normal range, or 10 percent greater or less than VCM commanded position. Ignition voltage greater than 9 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition on. Using scan tool, read EGR PINTLE POS. If scan tool displays zero percent, go to next step. If scan tool does not display zero percent, go to step 8). 3. Using scan tool, select MISC TESTS and command EGR duty cycle through 25, 50, 75 and 100 percent positions. Compare scan tool display DESIRED EGR POSITION and ACTUAL EGR POS. If both readings are close, see DIAGNOSTIC AIDS. If readings are not close, go to next step. 4. Disconnect EGR valve harness connector. Connect a test light between EGR harness connector control and ignition feed circuits. Using scan tool, command EGR position to 100 percent. If test light illuminates, go to step 26). If test light does not illuminate, go to next step. 5. Connect test light between engine ground and EGR valve harness connector ignition feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 12). 6. Check for faulty connections at VCM harness and EGR valve harness connectors. Check for open circuits between VCM and EGR valve. If problem is found, go to next step. If no problem is found, go to step 8). 7. Repair faulty connection(s) or open circuit(s). After repairs, go to step 39). 8. Disconnect EGR valve harness connector. Using scan tool, read EGR PINTLE POS. If scan tool displays zero percent, go to step 16). If scan tool does not display zero percent, go to next step. 9. If DTC P0108 is also set, go to DTC P0108 . If DTC is not set, go to next step. 10. Check for short to voltage in EGR pintle position circuit. If short is found, go to next step. If no short is found, go to step 12). 11. Repair short to voltage in EGR pintle position circuit. After repairs, go to step 39). 12. Check for blown fuse No. 4. If fuse is blown, go to next step. If fuse is okay, go to step 16). 13. Replace fuse No. 4. After repairs, go to next step. 14. Repair short to ground in EGR control circuit. After repairs, go to step 39). 15. Repair high circuit. After repairs, go to step 40). 16. Connect test light between battery voltage and EGR valve harness connector ground circuit. If test light illuminates, go to step 19). If test light does not illuminate, go to next step. 17. Check for open EGR valve ground circuit. If open is found, go to next step. If open is not found, go to step 19). 18. Repair open ground circuit. After repairs, go to step 40). 19. Connect test light between battery voltage and EGR valve harness connector low circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 23). 20. Disconnect VCM Blue harness connector. Using a test light connected to battery voltage, probe EGR harness connector terminal "A". If test light illuminates, go to next step. If test light does not illuminate, go to step 39). Microsoft Saturday, August 29, 2009 11:39:12 AM

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21. Check for short to ground in EGR valve control low circuit. If short is found, go to next step. If no short is found, go to step 23). 22. Repair short to ground in EGR valve control low circuit. After repairs, go to step 40). 23. Check for faulty connection at EGR valve. If faulty connection is found, go to next step. If connection is okay, go to step 25). 24. Repair faulty connection at EGR harness connector. After repairs, go to step 40). 25. Replace EGR valve. After replacing EGR valve, go to step 40). 26. Using DVOM, check voltage between EGR valve harness connector ground and 5-volt reference circuits. If voltage reading is about 5 volts, go to step 31). If voltage reading is not about 5 volts, go to next step. 27. Using DVOM, check voltage between engine ground and VCM harness connector 5-volt reference circuit. If voltage is 5 volts, go to next step. If voltage is not 5 volts, go to step 29). 28. Check for faulty connection at VCM harness connector 5-volt reference circuit. If faulty connection is found, go to next step. If connection is okay, go to step 30). 29. Repair faulty connection at VCM harness connector 5-volt reference circuit. After repairs, go to step 40). 30. Repair open 5-volt reference circuit. After repairs, go to step 40). 31. Connect test light between battery voltage and EGR valve harness connector pintle position signal circuit. If test light illuminates, go to step 34). If test light does not illuminate, go to next step. 32. Check for short to ground in EGR pintle position signal circuit. If short is found, go to next step. If short is not found, go to step 34). 33. Repair short to ground in EGR pintle position signal circuit. After repairs, go to step 40). 34. Connect appropriate adapters from Connector Test Kit (J-35616) between EGR valve and EGR valve harness connector. Using DVOM, check voltage between engine ground and EGR valve pintle position signal circuit at EGR valve. Using scan tool, command EGR position to 100 percent. If voltage is 3.5-5.0 volts, go to next step. If voltage is not as specified, go to step 36). 35. Check for open in EGR pintle position circuit. Check for poor connection at EGR valve connector. If a problem is found, go to step 37). If no problem is found, go to next step. 36. Check for faulty connection at VCM harness connector pintle position signal circuit. If faulty connection is found, go to step 38). If connection is okay, go to step 39). 37. Repair open EGR pintle position signal circuit. After repairs, go to step 40). 38. Repair faulty connection. After repairs, go to step 40). 39. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 40. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1406. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 41. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for faulty connections or damaged harness. If connections and harness appear okay, observe scan tool Microsoft Saturday, August 29, 2009 11:39:12 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P1441 - EVAP SYSTEM FLOW DURING NON-PURGE NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Evaporative (EVAP) emissions canister purge is controlled by a solenoid valve which allows ported vacuum to purge canister when energized by VCM. A vacuum switch in purge line is used to detect when system is being purged. VCM supplies and reads a 12-volt reference to switch. If switch is open (purge detected) when commanded by VCM, DTC P1441 is set. Conditions required to set DTC are:    

No HO2S, ECT, EGR, IAT, MAP, TP, VSS sensor DTCs set. DTC P0125 not active. Fuel tank greater than 12.5 percent but not greater than 87.5 percent. System voltage is greater than 10 volts but less than 17 volts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition off. Remove fuel cap. Turn ignition on. Using scan tool, observe fuel tank pressure parameter. If fuel tank pressure is zero H2O, go to next step. If fuel tank pressure is not zero in. H2O, diagnose EVAP control system. See the SYSTEM/COMPONENT TESTS article. 3. Ensure gauges on Enhanced EVAP Pressure Purge Diagnostic Cart (J-41413) are zeroed. Replace fuel filler cap. Install diagnostic cart. Using scan tool, command EVAP vent on (closed). Pressurize EVAP system to 5 in. H2O using diagnostic cart. Observe fuel tank pressure on scan tool. If fuel tank pressure is 5 in. H2O, go to next step. If fuel tank pressure is not 5 in. H2O, go to step 5). 4. Maintain fuel tank pressure at 5 in. H2O. Observe fuel tank pressure parameter on scan tool. If fuel tank pressure is maintained at 5 in. H2O, go to next step. If fuel tank pressure is not maintained at 5 in. H2O, diagnose EVAP control system. See the SYSTEM/COMPONENT TESTS article. 5. Remove EVAP purge solenoid from intake manifold. Connect a hand-held vacuum pump to EVAP purge solenoid. Apply 15 in. Hg vacuum to solenoid. If solenoid holds vacuum, go to next step. If solenoid does not hold vacuum, go to step 7). 6. Check EVAP purge line for proper routing. Check for proper vacuum source to EVAP purge solenoid. Repair as necessary. After repairs, go to step 8). If no problems are found, see DIAGNOSTIC AIDS. 7. Replace EVAP purge solenoid. After repairs, go to step 9). Also, see DIAGNOSTIC AIDS. 8. Repair as necessary. After repairs, go to next step. Also, see DIAGNOSTIC AIDS. 9. Start engine. Remove fuel cap. Using scan tool, command EVAP vent valve on (closed) and EVAP purge Microsoft Saturday, August 29, 2009 11:39:12 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

solenoid off (zero percent). Replace fuel cap. Run engine at 2500 RPM. Monitor fuel tank pressure parameter on scan tool. If fuel tank pressure remains at zero in. H2O, system is okay. If fuel tank pressure does not remain at zero in H2O, repeat step 2). Diagnostic Aids

Check vacuum hoses for damage. Check for faulty connections or damaged harness. If connections and harness appear okay, observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location. DTC P1508 - IAC SYSTEM LOW RPM NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

No ECT, MAP, TP or VSS sensor DTCs set. ECT greater than 122°F (50°C). IAT greater than -13°F (-25°C). BARO greater than 10.2 psi (0.72 kg/cm2 ) at less than 10,300 ft. Vehicle speed less than 2 MPH. Throttle at idle or less than 1%. Engine running longer than 30 seconds. Listed conditions met for more than 3 seconds. Change in calculated airflow greater than 2 counts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition off. Connect IAC driver to IAC valve. Set parking brake, brake drive wheels and turn A/C off. Start engine and allow it to idle in Park (A/T) or Neutral (M/T). Using scan tool, read engine speed (RPM). Using IAC driver, extend and retract IAC valve. If engine RPM decreases and increases as IAC valve is cycled, go to next step. If engine RPM does not change, go to step 4). Microsoft Saturday, August 29, 2009 11:39:12 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

3. If engine speed changes smoothly between 700-1500 RPM, go to step 5). If RPM does not change smoothly, go to next step. 4. Check IAC valve passage. If passage is not okay, clean passage and go to step 12). If passage is okay, replace IAC valve. Disconnect negative battery cable for 10 seconds, then reconnect cable. Turn ignition on, engine off for 5 seconds. Turn ignition off for at least 10 seconds and go to step 12). 5. Install IAC Node Light (J37027-A) in VCM harness. Cycle IAC driver and note lights. Both lights should cycle Green and Red, but not OFF as RPM changes from 700-1500 RPM. If lights flash as specified, go to step 8). If lights do not flash as specified, go to next step. 6. Check for faulty connector terminal contacts, open circuits, short to ground or voltage, faulty VCM connection. If problem is found, go to next step. If no problem is found, go to step 11). 7. Repair connection, terminal contact or circuit as necessary. After repairs, go to step 12). 8. Using other connector on IAC driver pigtail, check resistance across IAC valve coils. Check resistance of IAC coil "B" HI and LO circuits. Check resistance of coil "A" HI and LO circuits. If resistance on both coils is 40-80 ohms, go to next step. If resistance is not as specified on both coils, go to step 10). 9. Check resistance between coil "B" HI circuit and coil "A" LO circuit. Check resistance between coil "B" LO circuit and coil "A" HI circuit. Resistance should be infinite. If resistance is as specified between both coils, see DIAGNOSTIC AIDS. If resistance is not as specified, go to next step. 10. Replace IAC valve. Disconnect negative battery cable for 10 seconds, then reconnect cable. Turn ignition on, engine off for 5 seconds. Turn ignition off for at least 10 seconds. After repairs, go to step 12). 11. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 12. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1508. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 13. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

Check for stopped IAC valve, tampered throttle stop screw, and damaged throttle or linkage. Check for fuel system running too rich or too lean. Check throttle body bore for foreign material. Reset IAC using scan tool. DTC P1509 - IAC SYSTEM HIGH RPM NOTE:

For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

VCM commands IAC in counts. A higher count, allows more air to by-pass throttle plate (higher idle). Conditions required to set DTC are:         

No ECT, MAP, TP or VSS sensor DTCs set. ECT greater than 161.6°F (72°C). IAT greater than -13°F (-25°C). BARO greater than 10.2 psi (0.72 kg/cm2 ) at less than 10,300 ft. Vehicle speed less than 2 MPH. Throttle at idle. Engine running more than 30 seconds. Listed conditions met for more than 3 seconds. Change in calculated airflow more than 2 counts.

Diagnostic Procedures

1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 4.3L article. Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step. 2. Turn ignition off. Connect IAC driver to IAC valve. Set parking brake, brake drive wheels and turn A/C off. Start engine and allow it to idle in Park (A/T) or Neutral (M/T). Using scan tool, read engine speed (RPM). Using IAC driver, extend and retract IAC valve. If engine RPM decreases and increases as IAC valve is cycled, go to next step. If engine RPM does not change, go to step 4). 3. If engine speed changes smoothly between 700-1500 RPM, go to step 5). If RPM does not change smoothly, go to next step. 4. Check IAC valve passage. If passage is not okay, clean passage and go to step 12). If passage is okay, replace IAC valve. Disconnect negative battery cable for 10 seconds, then reconnect cable. Turn ignition on, engine off for 5 seconds. Turn ignition off for at least 10 seconds and go to step 12). 5. Install IAC Node Light (J37027-A) in VCM harness. Cycle IAC driver and note lights. Both lights should cycle Green and Red, but not OFF as RPM changes from 700-1500 RPM. If lights cycle as specified, go to step 8). If lights do not cycle as specified, go to next step. 6. Check for faulty connector terminal contacts, open circuits, short to ground or voltage, faulty VCM connection. If problem is found, go to next step. If no problem is found, go to step 11). 7. Repair connection, terminal contact or circuit as necessary. After repairs, go to step 12). 8. Using other connector on IAC driver pigtail, check resistance across IAC valve coils. Check resistance between IAC coil "B" ground and signal circuits. Check resistance across coil "A" ground and signal circuits. If resistance on both coils is 40-80 ohms, go to next step. If resistance is not as specified on both coils, go to step 10). 9. Check resistance between coil "B" signal circuit and coil "A" ground circuit. Check resistance between coil "B" ground circuit and coil "A" signal circuit. Resistance should be infinite. If resistance is as specified between both coils, see DIAGNOSTIC AIDS. If resistance is not as specified, go to next step. 10. Replace IAC valve. Disconnect negative battery cable for 10 seconds, then reconnect cable. Turn ignition on, engine off for 5 seconds. Turn ignition off for at least 10 seconds. After repairs, go to step 12). Microsoft Saturday, August 29, 2009 11:39:12 AM

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1997 Chevrolet S10 Pickup 1997 ENGINE PERFORMANCE Self-Diagnostics - 4.3L S/T Series

11. Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step. 12. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1509. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2). 13. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay. Diagnostic Aids

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Page 135

1997 Chevrolet S10 Pickup A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

DESCRIPTION & OPERATION WARNING: To avoid injury from accidental air bag deployment, read and follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section. NOTE:

Powertrain Control Module (PCM) may also be known as Vehicle Control Module (VCM).

The A/C compressor clutch relay is controlled by the PCM. The PCM improves idle quality by delaying A/C compressor clutch engagement until idle speed is increased, or disengages A/C compressor clutch when idle speed is too low. A/C compressor clutch is cycled by PCM. PCM smooths cycling of A/C compressor clutch by adding fuel the instant A/C compressor clutch is applied.

TROUBLE SHOOTING NOTE:

This article contains testing that is part of General Motors Computerized Engine Controls. Only testing procedures required to test A/C compressor clutch control circuit is included. Other diagnostic information may be referenced while performing A/C compressor clutch control diagnosis. For complete information on General Motors Computerized Engine Control systems, see TESTS W/CODES article in the ENGINE PERFORMANCE section.

RELAY LOCATION A/C COMPRESSOR CLUTCH RELAY LOCATION Application Location S/T Series In Engine Compartment, On Bracket At Center Of Firewall

SCAN TOOL A variety of information is transmitted through Data Link Connector (DLC). This data is transmitted at a high frequency which requires a Tech 1 scan tool, appropriate cartridge kit and vehicle interface module kit, or other scan tool for interpretation. Several scan tools are available for diagnostic work. Scan tools other than Tech 1 scan tool will function and provide information for diagnostic work. WARNING: Vehicles may be equipped with a PCM using an Electronically Erasable Programmable Read Only Memory (EEPROM). When replacing PCM, the new PCM must be programmed. Microsoft Saturday, August 29, 2009 11:42:06 11:42:03 AM

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1997 Chevrolet S10 Pickup A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

NOTE:

A/C CLUTCH CIRCUIT DIAGNOSIS (2.2L VIN 4 - S10 & SONOMA ONLY) Description

PCM receives an A/C request signal from Instrument Panel Cluster (IPC) over serial data line. When A/C is requested, PCM provides a ground path to A/C clutch relay control circuit. When relay circuit is grounded, A/C compressor clutch relay is energized. After A/C request has been selected, PCM will delay grounding A/C compressor relay control circuit for .3 second. This allows PCM to adjust engine idle RPM for additional load. PCM will temporarily de-energize A/C compressor clutch relay for a hot engine restart, wide open throttle, engine speed greater than 6000 RPM, or Idle Air Control (IAC) valve reset. A/C compressor (DTC) P0530 is set, or there is no A/C request signal due to an open A/C select switch circuit. Compressor Clutch Control Circuit Diagnosis

1. If On-Board Diagnostic (OBD) System Check has not been performed, see the TESTS W/CODES article in the ENGINE PERFORMANCE section and go to OBD SYSTEM CHECK. If OBD SYSTEM CHECK has been performed, go to next step. 2. Install scan tool. Check if DTC P0530 is set. If DTC P0530 is set, see the TESTS W/CODES article in the ENGINE PERFORMANCE section. If DTC P0530 is not set, go to next step. 3. Turn ignition on, engine off. Check if A/C compressor clutch is engaged. If A/C compressor clutch is engaged, go to next step. If A/C compressor clutch is not engaged, go to step 5). 4. Disconnect A/C relay. If A/C compressor clutch disengages, go to step 6). If A/C compressor clutch does not disengage, go to step 7). 5. Start engine and allow it to reach normal operating temperature. Cycle A/C selector switch on, then off. If A/C compressor clutch cycles on, then off, go to step 8). If A/C compressor clutch does not cycle on, then off, go to step 9). 6. Using a test light connected to battery voltage, probe A/C relay control circuit (Dark Green/White wire). If test light comes on, go to step 10). If test light does not come on, go to step 11). 7. Disconnect A/C compressor clutch harness connector. If A/C compressor clutch disengages, go to step 12). If A/C compressor clutch does not disengage, go to step 13). 8. Turn ignition on, engine off. Install A/C manifold gauge set. Observe A/C high-side pressure readings on gauge set and scan tool. If high-side pressures are within 20 psi (1.4 kg/cm2 ) of each other, go to step 36). If high-side pressures are not as specified, go to step 14). 9. Turn A/C on, then off. If scan tool indicates that A/C was requested, then not requested, go to step 15). If operation is not as specified, go to step 16). 10. Check A/C compressor clutch relay control circuit (Dark Green/White wire) for a short to ground. Repair as necessary. Go to step 36). If no problem is found, go to step 22). 11. Replace A/C compressor clutch relay. Go to step 36). Microsoft Saturday, August 29, 2009 11:42:03 AM

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1997 Chevrolet S10 Pickup A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

12. Repair short to power in A/C compressor clutch ignition feed circuit (Dark Green wire). Go to step 36). 13. Replace faulty A/C compressor clutch assembly. Go to step 36). 14. Turn ignition on, engine off. Disconnect A/C refrigerant pressure sensor harness connector. Using a voltmeter, measure voltage between battery positive and Black wire at A/C refrigerant pressure sensor harness connector. If reading is battery voltage, go to step 18). If reading is not as specified, go to step 19). 15. With ignition on, engine off, observe A/C HIGH-SIDE pressure reading on scan tool. If reading is 40-430 psi (2.8-30.2 kg/cm2 ), go to step 20). If reading is not as specified, go to step 21). 16. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Using a test light connected to ground, probe A/C selector switch input circuit (Light Green wire) at PCM harness connector. Cycle A/C selector switch on, then off. If test light toggles on, then off, go to next step. If operation is not as specified, go to step 23). 17. Check Light Green wire for a poor connection at PCM. Repair as necessary. Go to step 36). If no problem is found, go to step 22). 18. Replace A/C refrigerant pressure sensor. Go to step 36). 19. Repair open or poor connection in A/C refrigerant pressure sensor ground circuit (Black wire). Go to step 36). 20. Disconnect A/C relay. Using a test light connected to ground, probe A/C relay ignition feed circuits (Orange and Pink wires). If test light comes on for both circuits, go to step 24). If test light does not come on for both circuits, go to step 25). 21. Install A/C manifold gauge set. With ignition on, engine off, observe A/C high-side pressure readings on gauge set and scan tool. If high-side pressures are within 20 psi (1.4 kg/cm2 ) of each other, see the A/CHEATER SYSTEM - MANUAL article. If high-side pressures are not as specified, go to step 18). 22. Replace PCM. Go to step 36). 23. Repair A/C request signal circuit (Light Green wire) from A/C selector switch. Go to step 36). 24. Connect a fused jumper wire between A/C relay harness connector cavities No. 87 (Orange wire) and No. 30 (Dark Green wire). If A/C compressor clutch engages, go to step 26). If A/C compressor clutch does not engage, leave jumper wire installed and go to step 27). 25. If test light did not come on at Orange wire, check for a short to ground in A/C compressor clutch ignition feed circuit (Dark Green wire), or for a faulty A/C compressor clutch diode. Repair as necessary. Go to step 36). If no problem is found, go to step 28). 26. Remove jumper wire. Start engine and let idle. Using a test light connected to battery positive, probe A/C relay harness connector cavity No. 85 (Dark Green/White wire). Using scan tool, command A/C relay on. If test light comes on, go to step 11). If test light does not come on, go to step 29). 27. Disconnect A/C compressor clutch harness connector. Using a test light connected to ground, probe Dark Green wire at A/C compressor clutch harness connector. If test light comes on, go to step 30). If test light does not come on, go to step 31). 28. Repair open in Orange wire or Pink wire to A/C relay. Go to step 36). 29. Using a test light connected to ground, probe A/C relay harness connector cavity No. 85 (Dark Green/White wire). If test light comes on, go to step 32). If test light does not come on, go to step 33). 30. Using a test light connected to battery positive, probe A/C compressor clutch ground circuit (Black wire) at A/C compressor clutch harness connector. If test light comes on, go to step 34). If test light does not Microsoft Saturday, August 29, 2009 11:42:03 AM

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1997 Chevrolet S10 Pickup A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

31. 32. 33. 34. 35. 36.

come on, go to step 35). Repair open in A/C compressor clutch ignition feed circuit (Dark Green wire). Go to step 36). Check A/C compressor clutch relay control circuit (Dark Green/White wire) for a short to power. Repair as necessary. Go to step 36). If no problem is found, go to step 17). Check A/C compressor clutch relay control circuit (Dark Green/White wire) for an open or poor connection. Repair as necessary. Go to step 36). If no problem is found, go to step 17). Replace A/C compressor clutch coil. Go to step 36). Repair open or poor connection in A/C compressor clutch ground circuit (Black wire). Go to next step. Start engine and let idle. Cycle A/C selector switch on, then off. If A/C compressor clutch cycles on, then off, system is okay at this time.See DIAGNOSTIC AIDS. If operation is not as specified, go to step 2).

Diagnostic Aids

If DTC P0530 is set, do not perform this diagnostic procedure. Diagnose appropriate DTC before proceeding. See the TESTS W/CODES article in the ENGINE PERFORMANCE section. A/C refrigerant pressure less than 43 psi (3.0 kg/cm2 ), or greater than 428 psi (30.1 kg/cm2 ) will cause PCM to disable A/C compressor clutch. With engine running and A/C on, use scan tool to monitor A/C high-side system pressure for 2 minutes. If pressure goes out of range, see the A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL article. A/C CLUTCH CIRCUIT DIAGNOSIS (4.3L VIN W & X - ALL MODELS) Description

Vehicle Control Module (VCM) controls A/C clutch to improve idle quality and performance by delaying clutch engagement until idle speed is increased, releasing clutch when idle speed is too low, and smooths cycling of compressor by providing additional fuel the instant clutch is applied. Turning on A/C supplies battery voltage through pressure switches to VCM. When VCM receives voltage on A/C request signal, A/C enable relay circuit is grounded. As a result, A/C compressor clutch engages. Compressor Clutch Control Circuit Diagnosis

1. Before performing diagnosis, ensure A/C system is adequately charged. If system is not adequately charged, evacuate and recharge system. If system is adequately charged, go to next step. 2. Start engine and allow it to reach normal operating temperature. Turn A/C on, then off. If A/C clutch engages, then disengages within 20 seconds, go to the A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL article for A/C system diagnosis. If operation is not as specified, go to step 3). 3. Connect scan tool. Turn A/C on. Monitor A/C REQUEST data. If display reads YES, go to next step. If display does not read YES, go to step 8). 4. Disconnect A/C compressor clutch harness connector. Connect a test light between A/C clutch signal circuit (Dark Green wire) and ground circuit (Black wire) of A/C compressor clutch harness connector. If test light comes on, go to next step. If test light does not come on, go to step 12). 5. Check for a faulty A/C compressor clutch harness connector. Repair as necessary. Go to next step. If no Microsoft Saturday, August 29, 2009 11:42:03 AM

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1997 Chevrolet S10 Pickup A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

6. 7. 8.

9. 10. 11. 12.

13. 14. 15. 16. 17.

18. 19. 20. 21.

22. 23.

24. 25. 26. 27.

problem is found, go to step 7). Repair A/C compressor clutch harness connector. Go to step 27). Replace A/C compressor clutch. Go to step 27). Turn ignition off. Disconnect VCM connector C3. Turn ignition on. Using a test light connected to ground, probe A/C request signal circuit (Dark Green/White wire) at VCM harness connector C3. If test light comes on, go to next step. If test light does not come on, go to step 11). Check for poor connection at VCM harness connector C3. If a problem is found, go to next step. If no problem is found, go to step 26). Repair VCM harness connector C3. Go to step 27). Repair open or short to ground in Dark Green/White wire to A/C pressure switch and/or A/C control switch. Go to step 27). Using a test light connected to ground, probe A/C compressor clutch signal circuit (Dark Green wire) at A/C compressor clutch harness connector. If test light comes on, go to next step. If test light does not come on, go to step 14). Repair open in A/C compressor clutch ground circuit (Black wire). Go to step 27). Install scan tool. Turn ignition on, engine off. Using scan tool, command A/C relay on. If A/C relay clicks, go to step 23). If A/C relay does not click, go to next step. Disconnect A/C relay. Using a test light connected to ground, probe A/C relay harness connector cavity No. 85 (Pink wire). If test light comes on, go to step 17). If test light does not come on, go to next step. Repair open or short to ground in A/C relay ignition feed circuit (Pink wire). Go to step 27). Connect a test light between A/C relay harness connector cavities No. 85 (Pink wire) and No. 86 (Dark Green/White wire). Using scan tool, command A/C relay on. If test light comes on, go to next step. If test light does not come on, go to step 19). Replace A/C relay. Go to step 27). Check for a faulty connection at VCM harness connector C3. If a problem is found, go to next step. If no problem is found, go to step 21). Repair faulty connection at VCM connector C3. Go to step 27). Check for an open Dark Green/White wire between A/C relay harness connector cavity No. 86 and VCM harness connector C3, terminal No. 9. If a problem is found, go to next step. If no problem is found, go to step 26). Repair open in Dark Green/White wire between A/C relay harness connector cavity No. 86 and VCM connector C3, terminal No. 9. Go to step 27). Remove A/C relay. Using a fused jumper wire, jumper A/C relay harness connector cavities No. 30 (Orange wire) and No. 87 (Dark Green wire) together. If A/C compressor clutch engages, go to next step. If A/C compressor clutch does not engage, go to step 25). Replace A/C relay. Go to step 27). Repair open or short to ground in A/C compressor clutch control circuit (Dark Green wire). Go to step 27). Replace VCM. Go to next step. Using scan tool, select DTC CLEAR INFO. Start engine and allow it to reach normal operating temperature. Select DTC SPECIFIC, then enter DTC number that was set. Operate vehicle within conditions that may have set this DTC. If DTC does not reset, go to next step. If DTC resets, go to step

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1997 Chevrolet S10 Pickup A/C COMPRESSOR CLUTCH CONTROLS 1997 A/C GENERAL SERVICING General Motors Corp. - A/C Compressor Clutch Controls

2). 28. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any DTCs are displayed that have not been diagnosed, perform diagnosis for applicable DTC. See the TESTS W/CODES article in the ENGINE PERFORMANCE section. If no DTCs are displayed, testing is complete.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

CONNECTOR IDENTIFICATION NOTE:

To identify SIR wiring connector terminals, see Fig. 1 .

Fig. 1: Connector Terminal Identification Courtesy of GENERAL MOTORS CORP.

DIAGNOSIS & TESTING WARNING: Failure to follow service precautions may result in air bag deployment and personal injury. See SERVICE PRECAUTIONS . After component replacement, check system operation. See SYSTEM OPERATION CHECK .

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

SELF-DIAGNOSIS Diagnostic Trouble Codes (DTCs)

Diagnostic Energy Reserve Module (DERM) provides a record of DTCs stored according to type. Current DTCs are faults presently being detected. Current DTCs are stored in Random Access Memory (RAM) and are erased when fault is corrected. Current DTCs can be read using a scan tester such as Tech 1. Scan Tester Diagnostics

A scan tester will read and clear current codes and history codes. Ensure scan tester contains correct cartridge for SIR diagnostics. To use scan tester, connect it to DLC connector, plug in power source and turn ignition switch to ON position. Follow scan tester manufacturer instructions for communication with SIR system. Scan tester reads serial data from DERM data link output to DLC connector. NOTE:

Failure to follow diagnostic procedures may result in extended diagnostic time and incorrect diagnosis and parts replacement.

Diagnostic Procedure

1. SIR SYSTEM DIAGNOSTIC CHECK should always be starting point of SIR diagnostics. See SIR DIAGNOSTIC SYSTEM CHECK under DIAGNOSTIC TABLES. SIR DIAGNOSTIC SYSTEM CHECK checks for proper INFLATABLE RESTRAINT indicator light operation and SIR trouble codes using flash code and scan tester methods. 2. SIR DIAGNOSTIC SYSTEM CHECK will lead to correct diagnostic table to diagnose SIR problems. Always perform SIR DIAGNOSTIC SYSTEM CHECK after repair or diagnostic procedures to ensure repair is correct and no other problems are present.

DIAGNOSTIC TABLES SIR DIAGNOSTIC SYSTEM CHECK WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When ignition switch is turned ON, IGNITION 1 voltage is applied from AIR BAG fuse to DERM at IGNITION 1 input terminal Nos. A9 and A10 and from GAUGES fuse to DERM at REDUNDANT INDICATOR IGNITION 1 input terminal No. B2. DERM responds by flashing AIR BAG indicator 7 times then turning off while performing tests on SIR system. When engine is being cranked, system voltage is applied from CRANK fuse to DERM at CRANK input terminal No. B10. DERM responds by grounding SIR Indicator output terminal No. B1 until system voltage is Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

removed from CRANK input. This results in AIR BAG indicator being on steady during cranking. After cranking, DERM will flash AIR BAG indicator 6 times and perform test on SIR system. Diagnostic Aids

The order in which diagnostic trouble codes are diagnosed is important. Failure to diagnose the DTCs in order specified may result in extended diagnostic time, incorrect diagnosis, or incorrect parts replacement. NOTE:

1. 2. 3. 4. 5. 6. 7. 8.

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

AIR BAG indicator should flash 7 times after ignition switch is turned to ON. AIR BAG indicator should remain on steady during cranking. After cranking, AIR BAG indicator should flash 6 times then turn off. This test checks for proper operation of Serial Data line. Test also will determine whether history diagnostic trouble codes are stored and, if so, identify them. This test checks for DERM ability to communicate through the Serial Data line. This test refers to appropriate DTC table for diagnosis of history DTCs set to memory in DERM. When AIR BAG warning light flashes four times during BULB TEST, this indicates a malfunction in redundant lamp driver circuitry. These malfunctions are diagnosed by DTC B1062 table. Improper operation of AIR BAG indicator is indicated. This test differentiates an indicator stays ON condition from an indicator does not come ON condition.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 2: SIR Diagnostic System Check Courtesy of GENERAL MOTORS CORP. TABLE A - DERM INTEGRITY CHECK WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

When DERM recognizes IGNITION 1 voltage applied to terminal Nos. A9 and A10 is in normal operating voltage range, AIR BAG indicator is flashed 7 times to verify operation. At this time DERM performs Turn ON tests followed by CONTINUOUS MONITORING tests. When no malfunctions are detected, DERM proceeds to INITIATOR ASSEMBLY RESISTANCE test. When a malfunction is detected, DERM sets a current diagnostic trouble code and turns AIR BAG indicator on. DERM will clear current diagnostic trouble codes and move them to a history file when malfunction is not longer detected and/or ignition switch is cycled, except for DTC B1051. DTC B1051 can only be cleared using a scan tool clear codes command. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1. The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2. This test confirms a current malfunction. If no current malfunction is occurring (History DTC set) Diagnostic Aids for appropriate diagnostic trouble code should be referenced. DERM should not be replaced for a History DTC, except when directed by appropriate diagnostic table. 3. This test checks for a malfunction introduced into SIR system during diagnostic process. It is extremely unlikely that a malfunctioning DERM would cause a new malfunction to occur during diagnostic process. 4. When all circuitry outside DERM has been found to operate properly, as indicated by appropriate diagnostic table, then and only then should DERM be replaced. 5. The symptom or DTC is no longer occurring. The condition may be intermittent or inadvertently repaired during diagnosis of SIR system.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 3: Table A - DERM Integrity Check Courtesy of GENERAL MOTORS CORP. TABLE B - AIR BAG INDICATOR COMES ON STEADY WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When ignition switch is first turned ON, IGNITION 1 voltage is applied from GAUGES fuse to REDUNDANT INDICATOR IGNITION 1 terminal No. B2 and to AIR BAG indicator which is connected to SIR INDICATOR terminal No. B1. AIR BAG fuse applies voltage to IGNITION 1 terminal Nos. A9 and A10. DERM responds by flashing AIR BAG indicator 7 times. If IGNITION 1 voltage is outside of normal operating voltage range, AIR BAG indicator will come on steady with no DTCs set. Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

When engine is cranked, IGNITION 1 voltage is applied from CRANK fuse to DERM at CRANK input. DERM responds by grounding SIR INDICATOR output until IGNITION 1 voltage is removed from CRANK input. This results in AIR BAG indicator being on during cranking. After cranking, DERM will flash AIR BAG indicator 6 times. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) An open AIR BAG fuse would cause AIR BAG indicator to come on steady. 3) A disconnected DERM harness connector will cause AIR BAG indicator to come on steady via shorting bar from terminal No. A1 to terminal No. B1. 9) This test checks for an open in ground circuit to DERM. 11) This test checks for an open in CKT 1139. 16) This test checks for short from CRANK input circuit to B+. 17) This test isolates the short to B+ in CKT 806/1035 to one side of connector C203.

Fig. 4: Table B - Air Bag Indicator Comes On Steady (1 Of 3) Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 5: Table B - Air Bag Indicator Comes On Steady (2 Of 3) Courtesy of GENERAL MOTORS CORP.

Fig. 6: Table B - Air Bag Indicator Comes On Steady (3 Of 3) Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Courtesy of GENERAL MOTORS CORP. TABLE C - AIR BAG INDICATOR DOES NOT COME ON WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When ignition switch is first turned ON, IGNITION 1 voltage is applied from GAUGES fuse to REDUNDANT INDICATOR IGNITION 1, terminal No. B2 and to AIR BAG indicator which is connected to SIR INDICATOR terminal No. B1. AIR BAG fuse applies system voltage to IGNITION 1 inputs, terminal Nos. A9 and A10. DERM responds by flashing AIR BAG indicator 7 times. When engine is being cranked, Ignition 1 voltage is applied from CRANK fuse to DERM at CRANK input. DERM responds by grounding SIR INDICATOR output until IGNITION 1 voltage is removed from CRANK input. This results in AIR BAG indicator being on during cranking. After cranking, DERM will flash AIR BAG indicator 6 times. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) This test determines whether malfunction is in DERM circuit or in instrument cluster power feed circuit. 8) This test checks for open in SIR INDICATOR circuit, instrument cluster circuit and AIR BAG indicator circuit. 9) This test determines if malfunction is a short from SIR INDICATOR circuit to B+. 16) This test checks if open is due to bad bulb. 18) This test determines if malfunction is an open in SIR INDICATOR circuit or an open in instrument cluster. 22) This test determines where open in CKT 358 is located. 26) This test determines if blown fuse was result of fatigue or a circuit short. 28) This test determines if short to ground is due to a short in wiring or a malfunctioning DERM. 34) This test checks whether malfunction is due to an open power feed circuit from GAUGES fuse to instrument cluster or an open power feed to GAUGES fuse.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 7: Table C - Air Bag Indicator Does Not Come On (1 Of 4) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 8: Table C - Air Bag Indicator Does Not Come On (2 Of 4) Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 9: Table C - Air Bag Indicator Does Not Come On (3 Of 4) Courtesy of GENERAL MOTORS CORP.

Fig. 10: Table C - Air Bag Indicator Does Not Come On (4 Of 4) Courtesy of GENERAL MOTORS CORP. TABLE D -AIR BAG INDICATOR DOES NOT COME ON STEADY DURING CRANK WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) This test checks whether malfunction is due to an open CRANK fuse. 9) This test determines if lack of proper crank signal is due to an open CRANK input circuit or an open power feed to CRANK fuse. 13) This test determines where open in CKT 806/1035 is located. 16) This test checks whether CRANK fuse is open due to short to ground in CRANK input circuit. 17) This test checks whether short to ground is in wiring harness.

Fig. 11: Table D - Air Bag Indicator Does Not Come On Steady During Crank (1 Of 3) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 12: Table D - Air Bag Indicator Does Not Come On Steady During Crank (2 Of 3) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 13: Table D - Air Bag Indicator Does Not Come On Steady During Crank (3 Of 3) Courtesy of GENERAL MOTORS CORP. DTC B1014 - ARMING SENSOR DISCONNECTED WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

DERM monitors voltage at DRIVER SOURCE SENSE terminal No. A5, DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8 during CONTINUOUS MONITORING tests. When all voltages are simultaneously below a specified value for 500 milliseconds, DTC B1014 sets. DTC Will Set

When voltages at terminal Nos. A5, B9 and B8 of DERM harness connector are simultaneously below a specified value for 500 milliseconds. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When voltage at terminal Nos. A5, B9 and B8 of DERM harness connector is above a specified value for 500 milliseconds. Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Diagnostic Aids

It is highly unlikely that an intermittent condition has set this diagnostic trouble code as this would require a poor connection at terminal Nos. A and B or terminal Nos. C and D. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1. The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2. This test checks for proper connection at arming sensor jumper harness electrical connector. 3. This test checks for proper connection of arming sensor to SIR wiring harness.

Fig. 14: DTC B1014 - Arming Sensor Disconnected Courtesy of GENERAL MOTORS CORP. DTC B1021 - DRIVER INITIATOR CIRCUIT RESISTANCE HIGH WARNING: To avoid air bag deployment and injury when trouble shooting system, Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During INITIATOR ASSEMBLY RESISTANCE test, DERM grounds DRIVER-SIDE LOW terminal No. B8 and turns on driver current source at DRIVER-SIDE HIGH terminal No. B9. This causes a known amount of current flow through driver initiator circuit. By monitoring difference between voltage at DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8, DERM calculates combined resistance of driverside air bag module, SIR coil assembly, harness wiring CKTs 347 and 348 and connector terminal contact. DTC Will Set

When the combined resistance of the driver-side air bag module, SIR coil assembly, harness wiring CKTs 347 and 348 and connector terminal contact is above a specified value. This test is run once each ignition cycle during INITIATOR ASSEMBLY RESISTANCE test when: 1) No higher priority faults are detected during Turn ON. 2) No higher priority faults are detected during CONTINUOUS MONITORING for 1 second. 3) No CRANK signal present. 4) IGNITION 1 voltage is above a specified value. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF. Diagnostic Aids

An intermittent condition is likely to be caused by poor connection at Yellow 2-way connector at base of steering column, DERM terminal Nos. B8 or B9, or connection at top of steering column to driver-side air bag module. The test for this diagnostic trouble code is only run while AIR BAG indicator is performing BULB TEST. When scan tool CLEAR CODES command is issued and malfunction is still present, DTC will not reappear until next ignition cycle. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 7) This test checks for terminal deformation or contamination. 8) This test checks whether malfunction is in driver-side air bag module circuit or in DERM wiring harness circuit. Microsoft Saturday, August 29, 2009 11:47:21 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

9) This test determines whether the malfunction is in driver-side air bag module or in SIR coil assembly. 16) This test checks for high resistance in DRIVER-SIDE LOW circuit. 18) This test checks for high resistance in DRIVER-SIDE HIGH circuit.

Fig. 15: DTC B1021 - Driver Initiator Circuit Resistance High (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 16: DTC B1021 - Driver Initiator Circuit Resistance High (2 Of 2) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

DTC B1022 - DRIVER INITIATOR CIRCUIT RESISTANCE LOW WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When the combined resistance of the driver-side air bag module, SIR coil assembly, harness wiring CKTs 347 and 348 and connector terminal contact is above a specified value. This test is run once each ignition cycle during INITIATOR ASSEMBLY RESISTANCE test when: 1) No higher priority faults are detected during Turn ON. 2) No higher priority faults are detected during CONTINUOUS MONITORING for 1 second. 3) No CRANK signal is present. 4) IGNITION 1 voltage is above a specified value Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF. Diagnostic Aids

An intermittent condition is likely to be caused by a short between CKT 347 and CKT 348, or a malfunctioning shorting bar on driver-side air bag module or SIR coil assembly which would require replacement of component. The test for this diagnostic trouble code is only run while AIR BAG indicator is performing BULB TEST. When scan tool CLEAR CODES command is issued and malfunction is still present, DTC will not reappear until next ignition cycle. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

2) This test checks for proper connector engagement. 3) This test determines if problem is in steering column or SIR harness. 4) This test checks for short between CKTs 347 and 348. 6) This test isolates the malfunction to either the SIR coil assembly or air bag module.

Fig. 17: DTC B1022 - Driver Initiator Circuit Resistance Low (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 18: DTC B1022 - Driver Initiator Circuit Resistance Low (2 Of 2) Courtesy of GENERAL MOTORS CORP. DTC B1023 - DRIVER INITIATOR CIRCUIT VOLTAGE HIGH WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During normal, non-deployment operation, a small amount of current flows through driver deployment loop. Diagnosis resistors within arming sensor and discriminating sensors, along with resistance of air bag module, cause voltage drops within deployment loop. DERM monitors voltage at DRIVER-SIDE LOW terminal No. B8 to detect shorts or opens within driver deployment loop. When measured voltage is above a specified percentage of DRIVER 36 VLR for 500 milliseconds, DTC B1023 will set. DTC Will Set

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is above a specified percentage of DRIVER 36 VLR for 500 milliseconds during CONTINUOUS MONITORING and DTC B1035 is not set. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is within a specified percentage of DRIVER 36 VLR for 500 milliseconds during CONTINUOUS MONITORING. Diagnostic Aids

An intermittent condition is likely to be caused by backed out or shorted terminals on arming sensor harness connector, poor connection at any of the discriminating sensor terminals, a short from CKT 236 to CKT 347 or CKT 348, a short from CKT 347 to CKT 1400, or an open or high resistance in CKTs 348. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) This test checks whether malfunction is due to a component or the wiring. 3) This test checks for short from DRIVER 36 VLR circuit to DRIVER-SIDE LOW circuit. 5) This test checks for short from DRIVER 36 VLR circuit to DRIVER-SIDE HIGH circuit. 6) This test determines where the short from DRIVER 36 VLR circuit to DRIVER-SIDE HIGH circuit is located. 13) This test checks for open between driver-side air bag module and discriminating sensor network. 16) This test determines where the open in CKT 348 is located. 19) This test checks for open in left forward discriminating sensor between terminal Nos. A and B. 20) This test checks for short inside arming sensor. 23) This test checks for short in DRIVER-SIDE HIGH circuit to the DRIVER-SIDE LOW circuit. 26) This test determines where the short from DRIVER-SIDE HIGH circuit to the DRIVER-SIDE LOW circuit is located. 29) This test checks for partial short inside arming sensor. 32) This test checks for increased resistance of discriminating sensor intermediate harness and/or the left forward discriminating sensor. 37) This test checks for increased resistance of left forward discriminating sensor. 38) This test checks for increased resistance of discriminating sensor intermediate harness and/or the right forward discriminating sensor. 43) This test checks for increased resistance of right forward discriminating sensor.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 19: DTC B1023 - Driver Initiator Circuit Voltage High (1 Of 5) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 20: DTC B1023 - Driver Initiator Circuit Voltage High (2 Of 5) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 21: DTC B1023 - Driver Initiator Circuit Voltage High (3 Of 5) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 22: DTC B1023 - Driver Initiator Circuit Voltage High (4 Of 5) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 23: DTC B1023 - Driver Initiator Circuit Voltage High (5 Of 5) Courtesy of GENERAL MOTORS CORP. DTC B1024 - DRIVER INITIATOR CIRCUIT VOLTAGE LOW WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During normal, non-deployment operation, a small amount of current flows through driver deployment loop. Diagnostic resistors within arming sensor and discriminating sensors, along with resistance of air bag module, cause voltage drops within deployment loop. DERM monitors voltage at DRIVER-SIDE LOW terminal No. B8 to detect shorts or opens within driver deployment loop. When measured voltage is below a specified percentage of DRIVER 36 VLR for 500 milliseconds, DTC B1024 will set. DTC Will Set

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is below a specified percentage of DRIVER 36 VLR for 500 milliseconds during CONTINUOUS MONITORING. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

DTC Will Clear

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is within a specified percentage of DRIVER 36 VLR for 500 milliseconds during CONTINUOUS MONITORING. Diagnostic Aids

An intermittent condition is likely to be caused by a poor connection at DERM terminal No. A4, arming sensor or arming sensor jumper harness electrical connector terminal Nos. B or D, water intrusion in either discriminating sensor, an open in CKT 347, or a short to ground on CKT 347, CKT 348 or 349. Refer to DTC B1025 to diagnose possible short to B+. When malfunction occurs during an ignition cycle, DTC B1024 will set. If malfunction is present at beginning of next ignition cycle, DTC B1025 will set and DTC B1024 will be moved to history file. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) This test determines if malfunction is in steering column circuitry. 4) This test checks whether malfunction is due to a component or the wiring. 17) This test checks for increased resistance of arming sensor. 18) This test checks for partial short inside left forward discriminating sensor. 20) This test checks for partial short inside right forward discriminating sensor. 24) This test checks for open in CKT 347. 26) This test determines where the open in CKT 347 is located. 29) This test checks for short from DRIVER-SIDE HIGH circuit to ground. 31) This test checks for short from DRIVER-SIDE LOW circuit to ground. 33) This test checks for short from discriminating sensor interconnect circuit to ground. 35) This test checks for short inside left forward discriminating sensor. 36) This test checks for short inside right forward discriminating sensor.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 24: DTC B1024 - Driver Initiator Circuit Voltage Low (1 Of 4) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 25: DTC B1024 - Driver Initiator Circuit Voltage Low (2 Of 4) Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 26: DTC B1024 - Driver Initiator Circuit Voltage Low (3 Of 4) Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Courtesy of GENERAL MOTORS CORP.

Fig. 27: DTC B1024 - Driver Initiator Circuit Voltage Low (4 Of 4) Courtesy of GENERAL MOTORS CORP. DTC B1025 - DRIVER INITIATOR CIRCUIT SHORT TO IGNITION WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During INITIATOR ASSEMBLY RESISTANCE TEST, DERM grounds DRIVER-SIDE LOW terminal No. B8 through internal resistor and measures voltage at DRIVER-SIDE LOW. For properly operating circuit the voltage measurement will be below a specified value. When voltage measured at DRIVER-SIDE LOW is above a specified value, DTC B1025 will set. DTC Will Set

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is above a specified value while DERM attempts to ground terminal. This test is run during INITIATOR ASSEMBLY RESISTANCE TEST and 10 Microsoft Saturday, August 29, 2009 11:47:22 AM

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MINUTE LOOP TEST when: 1) No higher priority faults are detected during Turn ON. 2) No higher priority faults are detected during CONTINUOUS MONITORING for 1 second. 3) No CRANK signal present. 4) IGNITION 1 is above a specified value. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is below a specified value while DERM grounds terminal.. Diagnostic Aids

This diagnostic trouble code can only be set when malfunction is present as ignition switch is turned ON. After INITIATOR ASSEMBLY RESISTANCE TEST is completed, a short to B+ in steering column, CKT 347, CKT 348 or CKT 349 will cause DTC B1024 to set. When a scan tool clear codes command is issued and malfunction is still present, DTC B10will not reappear for 10 minutes or until next ignition cycle. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) This test determines whether malfunction is occurring in steering column wiring. 4) This test checks for short from DRIVER-SIDE HIGH circuit to B+. 6) This test checks for short from DRIVER-SIDE LOW circuit to B+. 8) This test checks for short from discriminating sensor interconnect circuit to B+.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 28: DTC B1025 - Driver Initiator Circuit Short to Ignition (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 29: DTC B1025 - Driver Initiator Circuit Short to Ignition (2 Of 2) Courtesy of GENERAL MOTORS CORP. DTC B1026 - DRIVER INITIATOR CIRCUIT OPEN WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When there is an open in driver-side air bag module or SIR coil assembly, resistance between DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8 increases. This causes a larger voltage drop from DRIVER-SIDE HIGH to DRIVER-SIDE LOW across a resistor inside DERM which connects these 2 terminals. The increase in voltage difference between DRIVER-SIDE HIGH and DRIVER-SIDE low is detected by DERM during CONTINUOUS MONITORING tests and DTC B1026 will set. DTC Will Set

When voltage difference between DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8 is above or equal to a specified value for 500 milliseconds. Action Taken Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When voltage difference between DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8 is below a specified value for 500 milliseconds. Diagnostic Aids

This diagnostic trouble code will only set when there is an improper connection of either the Yellow 2-way connector at the base of the steering column or the Yellow 2-way connector at the top of the steering column, an open SIR coil assembly or an open air bag module. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 7) This test determines whether a steering column malfunction is occurring. 8) This test determines whether malfunction is occurring in air bag module or SIR coil assembly.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 30: DTC B1026 - Driver Initiator Circuit Open Courtesy of GENERAL MOTORS CORP. DTC B1028 - CURRENT SINK OR SOURCE FAILURE

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During INITIATOR ASSEMBLY RESISTANCE test, DERM grounds DRIVER-SIDE LOW terminal No. B8 and turns on driver current source at DRIVER-SIDE HIGH terminal No. B9. During this test, DERM monitors voltage at DRIVER-SIDE LOW and difference between DRIVER-SIDE HIGH and DRIVER-SIDE LOW. When measured voltages are outside expected range, DTC B1028 will set. DTC Will Set

When voltage measured at DRIVER-SIDE LOW is below a specified value while its initiator resistance is in range or when voltage measured at DRIVER-SIDE LOW is above a specified value. This test is run once each ignition cycle during INITIATOR ASSEMBLY RESISTANCE TEST when: 1) No higher priority faults are detected during Turn ON. 2) No higher priority faults are detected during CONTINUOUS MONITORING for 1 second. 3) No CRANK signal present. 4) IGNITION 1 voltage is above a specified value. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF. Diagnostic Aids

During INITIATOR ASSEMBLY RESISTANCE test, DERM checks for proper resistance of CKT 347, 348, SIR coil assembly and air bag module. This test is performed by causing a known amount of current through a known amount of resistance causing a known amount of voltage at DRIVER-SIDE LOW. When measured resistance is in range and voltage at DRIVER-SIDE LOW is too high or too low, DTC B1028 will set.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 31: DTC B1028 - Current Sink Or Source Failure Courtesy of GENERAL MOTORS CORP. DTC B1031 - DRIVER LOOP ENERGY RESERVE FEED OPEN WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During CONTINUOUS MONITORING tests, DERM monitors voltage at DRIVER SOURCE SENSE terminal No. A5. When circuit is operating normally the measured voltage will be slightly less than DRIVER 36 VLR. If DRIVER 36 VLR circuit opens, voltage measured at DRIVER SOURCE SENSE will decrease to slightly less than IGNITION 1 voltage. When voltage measured at DRIVER SOURCE SENSE is within a specified range of IGNITION 1 for 500 milliseconds, DTC is set. DTC Will Set

When voltage measured at DRIVER SOURCE SENSE terminal No. A5 is within a specified range of IGNITION 1 for 500 milliseconds during CONTINUOUS MONITORING. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When voltage measured at DRIVER SOURCE SENSE terminal No. A5 is outside a specified range of IGNITION 1 for 500 milliseconds. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Diagnostic Aids

An intermittent condition is likely to be caused by a poor connection at arming sensor or arming sensor jumper harness electrical connector (C110) terminal Nos. B or C, poor connection at DERM terminal Nos. A4 or A5, an open in CKT 236 or CKT 1400 to B+, or high resistance inside arming sensor. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 12) This test checks for an open in DRIVER 36 VLR circuit between the DERM and arming sensor connector. 15) This test checks for an open in DRIVER 36 VLR circuit between the DERM and arming sensor jumper harness connector. 18) This test checks for high resistance in DRIVER SOURCE SENSE circuit between DERM and arming sensor connector. 21) This test checks for high resistance in DRIVER SOURCE SENSE circuit between DERM and arming sensor jumper harness electrical connector (C110). 24) This test checks for a short from DRIVER SOURCE SENSE circuit to B+.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 32: DTC B1031 - Driver Loop Energy Reserve Feed Open (1 Of 3) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 33: DTC B1031 - Driver Loop Energy Reserve Feed Open (2 Of 3) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 34: DTC B1031 - Driver Loop Energy Reserve Feed Open (3 Of 3) Courtesy of GENERAL MOTORS CORP. DTC B1034 - ARMING SENSOR IGNITION FEED OPEN WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During Turn ON tests, performed at beginning of each ignition cycle, DERM delays charging of DRIVER 36 VLR power supply. While delay is active, DERM measures voltage at DRIVER 36 VLR terminal No. A4 and DRIVER SOURCE SENSE terminal No. A5. When voltage measured at DRIVER 36 VLR power supply indicates it is in a discharged state and voltage measured at DRIVER SOURCE SENSE is a specified amount below IGNITION 1 voltage, DTC B1034 is set. DTC Will Set

With DRIVER 36 VLR power supply in a discharged state, voltage measured at DRIVER SOURCE SENSE terminal No. A5 is a specified amount below IGNITION 1 voltage and no higher priority faults are detected. This test is run once each ignition cycle during Turn ON tests while 36 VLR delay is active. Action Taken Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When DRIVER 36 VLR power supply is in a discharged state, voltage measured at DRIVER SOURCE SENSE terminal No. A5 is within specified range of IGNITION 1 voltage. When neither the set nor clear conditions are met, the state of the diagnostic trouble code from the previous ignition cycle is used. Diagnostic Aids

An intermittent condition is likely to be caused by a poor connection at arming sensor terminal Nos. A or C, poor connection at DERM terminal No. A5, open ignition feed to arming sensor, open DRIVER SOURCE SENSE circuit or a malfunctioning arming sensor diode. The test for this diagnostic trouble code is only run while AIR BAG indicator is performing BULB TEST. When a scan tool clear codes command is issued and malfunction is still present, DTC will not reappear until ignition switch is turned off for at least 2 minutes with entire SIR system connected, and then the ignition switch is turned ON. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 7) This test checks whether a malfunction is occurring. 13) This test checks for an open in arming sensor ignition feed circuit. 16) This test locates the open in arming sensor ignition feed circuit. 19) This test determines whether malfunction is an open in DRIVER SOURCE SENSE circuit or an open in arming sensor. 22) This test locates open in DRIVER SOURCE SENSE circuit.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 35: DTC B1034 - Arming Sensor Ignition Feed Open (1 Of 3) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 36: DTC B1034 - Arming Sensor Ignition Feed Open (2 Of 3) Courtesy of GENERAL MOTORS CORP.

Fig. 37: DTC B1034 - Arming Sensor Ignition Feed Open (3 Of 3) Courtesy of GENERAL MOTORS CORP. DTC B1035 - DISCRIMINATING SENSOR OPEN OR MISSING WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During normal non-deployment operation a small amount of current flows through driver deployment loop. Diagnostic resistors within arming sensor and discriminating sensors, along with resistance of air bag module, cause voltage drops within deployment loop. DERM monitors voltage at DRIVER-SIDE LOW terminal No. B8 to detect shorts or opens within deployment loop. When measured voltage is within a specified percentage of DRIVER 36 VLR power supply for 500 milliseconds, DTC B1035 is set. DTC Will Set

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is within a specified percentage of DRIVER 36 VLR power supply voltage for 500 milliseconds during CONTINUOUS MONITORING. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

DTC Will Clear

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is above or below percentage of DRIVER 36 VLR power supply voltage which sets DTC B1035. Diagnostic Aids

An intermittent condition is likely to be an improper connection at any of the discriminating sensor terminals, an open in either ground feed to discriminating sensors, an open discriminating sensor interconnect circuit, increased resistance of either discriminating sensor or decreased resistance of arming sensor. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 7) This test checks for increased resistance of left forward discriminating sensor. 8) This test checks for open in ground feed to left forward discriminating sensor. 11) This test locates open in ground feed to left forward discriminating sensor. 19) This test checks for increased resistance of right forward discriminating sensor. 21) This test checks for open in ground feed to right forward discriminating sensor. 24) This test locates open in ground feed to right forward discriminating sensor. 27) This test checks for open in discriminating sensor interconnect circuit. 29) This test checks arming sensor loop resistance.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 38: DTC B1035 - Discriminating Sensor Open Or Missing (1 Of 3) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 39: DTC B1035 - Discriminating Sensor Open Or Missing (2 Of 3) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 40: DTC B1035 - Discriminating Sensor Open Or Missing (3 Of 3) Courtesy of GENERAL MOTORS CORP. DTC B1042 - LOOP ENERGY RESERVE VOLTAGE LOW WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During Turn ON tests, performed at beginning of each ignition cycle, DERM delays charging of DRIVER 36 VLR terminal No. A4 power supply. After delay has expired the DRIVER 36 VLR power supply is allowed to charge. DERM monitors DRIVER 36 VLR power supply to ensure it has charged to a voltage above a specified value within 10 seconds after IGNITION 1 voltage is first applied to DERM. When DRIVER 36 VLR power supply does not reach specified voltage within allowed time or, once reaching voltage, falls below it for 500 milliseconds, DTC B1042 is set. DTC Will Set

When voltage measured at DRIVER 36 VLR power supply does not exceed a specified value within 10 seconds after IGNITION 1 voltage is first applied to DERM or, once having reached the specified value, falls below specified value for 500 milliseconds during CONTINUOUS MONITORING. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When voltage measured at DRIVER 36 VLR terminal No. A4 is above a specified value for 500 milliseconds during CONTINUOUS MONITORING. Diagnostic Aids

An intermittent condition is likely to be caused by a short from DRIVER 36 VLR to B+ or ground or a short inside arming sensor. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2) This test checks whether diagnostic trouble code has set falsely. 3) This test checks whether a malfunctioning arming sensor is preventing DRIVER 36 VLR from charging. This test will cause DTC B1014 (Arming Sensor Disconnected) to set. 5) This test checks whether a short to B+ is preventing DRIVER 36 VLR from charging. 6) This test locates short to B+ that is preventing DRIVER 36 VLR from charging. 9) This test checks whether a short to ground is preventing DRIVER 36 VLR from charging. 10) This test checks locates short to ground that is preventing DRIVER 36 VLR from charging.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 41: DTC B1042 - Loop Energy Reserve Voltage Low (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 42: DTC B1042 - Loop Energy Reserve Voltage Low (2 Of 2) Courtesy of GENERAL MOTORS CORP. DTC B1043 - DRIVER SOURCE FEED LOW WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During normal non-deployment operation of SIR system, DERM monitors voltage supplied through arming sensor to high side of driver deployment loop at DRIVER SOURCE SENSE terminal No. A5. This measured voltage will have a value approximately equal; to DRIVER 36 VLR. When voltage measured at DRIVER-SIDE LOW terminal No. B8 is in its normal operating range, indicating driver deployment loop integrity has been maintained, while simultaneously the voltage measured at DRIVER SOURCE SENSE terminal No. A5 is a specified amount below DRIVER 36 VLR for 500 milliseconds, DTC B1043 will set. DTC Will Set

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is within a specified percentage of DRIVER Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

36 VLR while simultaneously voltage measured at DRIVER SOURCE SENSE terminal No. A5 is a specified amount below DRIVER 36 VLR for 500 milliseconds during CONTINUOUS MONITORING. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When voltage measured at DRIVER-SIDE LOW terminal No. B8 is within a specified percentage of DRIVER 36 VLR while simultaneously voltage measured at DRIVER SOURCE SENSE terminal No. A5 is within a specified amount of DRIVER 36 VLR for 500 milliseconds during CONTINUOUS MONITORING. Diagnostic Aids

An intermittent condition is likely to be caused by a poor connection to DERM at terminal No. A5, a poor connection to arming sensor or arming sensor jumper harness electrical connector at terminal No. C, an open or short to ground in CKT 1400 or increased resistance of arming sensor. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 12) This test checks for open in DRIVER SOURCE SENSE circuit. 15) This test locates open in DRIVER SOURCE SENSE circuit. 18) This test checks for a short in DRIVER SOURCE SENSE circuit to ground. 19) This test checks for a short in DRIVER SOURCE SENSE circuit to ground. 22) This test determines whether malfunction is due to increased resistance across DRIVER SOURCE SENSE resistor in arming sensor.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 43: DTC B1043 - Driver Source Feed Low (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 44: DTC B1043 - Driver Source Feed Low (2 Of 2) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

DTC B1051 - FRONTAL CRASH DETECTED WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

Closure of arming sensor is detected when voltage measured at DRIVER-SIDE HIGH terminal No. B9 is within a specified amount of its deployment loop supply voltage. Closure of either discriminating sensor is detected when voltage measured at DRIVER-SIDE LOW terminal No. B8 is within a specified amount of ground potential. When both conditions are met simultaneously for not less than 250 microseconds, CRASH DATA is recorded and DTC B1051 is set. DTC Will Set

When closure of arming sensor and at least one of the discriminating sensors is detected simultaneously for not less than 250 microseconds. Action Taken

DERM turns on AIR BAG indicator, records CRASH DATA and sets a diagnostic trouble code. DTC Will Clear

A scan tool clear codes command is received by DERM. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. When DTC B1042 and DTC B1051 are set simultaneously, perform DTC B1042 diagnosis first. If air bag module has not deployed, DTC B1051 may have set falsely. If DTC B1051 has set with no signs of frontal impact, diagnostic trouble code has set falsely. When frontal crash has occurred, it is necessary to perform indicated procedures to ensure SIR system is fully functional. 6. This test checks for a DERM malfunction setting diagnostic trouble code. 7. This test checks for a DERM malfunction setting diagnostic trouble code. 8. This test determines whether diagnostic trouble code was set inadvertently during diagnosis or by DERM malfunction.

1. 2. 3. 4. 5.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 45: DTC B1051 - Frontal Crash Detected Courtesy of GENERAL MOTORS CORP. DTC B1052 - DATA AREA FULL WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

When there is a frontal crash of sufficient force to activate arming sensor and at least one discriminating sensor simultaneously, DTC B1051 is set. At this time, DERM will record information regarding SIR system status and vehicle status in EEPROM. DTC B1052 will set when DERM has stored information regarding eight frontal crash events. DTC Will Set

When DERM attempts to store frontal crash information and finds EEPROM data area full. Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

DERM receives scan tool clear codes command. If, at next ignition ON after receiving clear codes command DERM detects data area is full, a history diagnostic trouble code is set. This allows AIR BAG indicator to illuminate should any additional malfunctions be detected.

Fig. 46: DTC B1052 - Data Area Full Courtesy of GENERAL MOTORS CORP. DTC B1053 - DERM DRIVER INITIATOR CIRCUITS HIGH RESISTANCE WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During INITIATOR ASSEMBLY RESISTANCE test, DERM grounds DRIVER-SIDE LOW terminal No. B8 Microsoft Saturday, August 29, 2009 11:47:22 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

and turns on driver current source at DRIVER-SIDE HIGH terminal No. B9. This causes a known amount of current to flow through driver initiator circuit. By monitoring difference between voltage at DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8, DERM calculates combined resistance of driver-side air bag module, SIR coil assembly, harness wiring CKTs 347 and 348 and connector terminal contact. DTC Will Set

When voltage difference between DRIVER-SIDE HIGH terminal No. B9 and DRIVER-SIDE LOW terminal No. B8 is above a specified value and voltage at DRIVER-SIDE LOW is within a specified range. This test is run once each ignition cycle during INITIATOR ASSEMBLY RESISTANCE TEST when: 1) No higher priority faults are detected during Turn ON. 2) No higher priority faults are detected during CONTINUOUS MONITORING. 3) No CRANK signal is present. 4) IGNITION 1 voltage is above a specified value Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF. Diagnostic Aids

An intermittent condition is likely to be caused by a poor connection at DERM terminal No. B8 or B9, an open in CKT 347 or CKT 348. The test for this diagnostic trouble code is only run while AIR BAG indicator is performing BULB TEST. When scan tool clear codes command is issued and malfunction is still present, DTC will not reappear until next ignition cycle. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 7) This test checks whether malfunction is due to high resistance or open in DRIVER-SIDE LOW circuit. 9) This test checks whether malfunction is due to high resistance or open in DRIVER-SIDE HIGH circuit.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 47: DTC B1053 - DERM Driver Initiator Circuits High Resistance (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 48: DTC B1053 - DERM Driver Initiator Circuits High Resistance (2 Of 2) Courtesy of GENERAL MOTORS CORP. DTC B1055 - DERM INCOMPATIBILITY WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When IGNITION 1 voltage is first applied to DERM it will perform Turn ON tests followed by CONTINUOUS MONITORING for one second. DERM also monitors DRIVER-SIDE LOW terminal No. B8 to ensure voltage is being applied to air bag module and monitors DRIVER SOURCE SENSE terminal No. A5 to ensure DRIVER 36 VLR is supplying voltage to deployment loop. Ground is applied at terminal No. B7 (passenger-side low for a Driver/Passenger DERM) and voltage is measured at DRIVER-SIDE LOW and at terminal No. A6 (passenger source sense for a Driver/Passenger DERM). When grounding terminal No. B7 grounds DRIVER-SIDE LOW or voltage is measured at terminal No. A6, DTC B1055 is set. DTC Will Set

When circuit descriptions indicate a Driver/Passenger DERM has been installed in vehicle. This test is run once each ignition cycle during INITIATOR ASSEMBLY RESISTANCE TEST when: 1) No higher priority faults are detected during Turn ON. 2) No higher priority faults are detected during CONTINUOUS MONITORING for 1 second. 3) No CRANK signal present. 4) IGNITION 1 voltage is above a specified value. Microsoft Saturday, August 29, 2009 11:47:22 AM

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Action Taken

DERM turns on AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF.

Fig. 49: DTC B1055 - DERM Incompatibility Courtesy of GENERAL MOTORS CORP. DTC B1061 - SIR INDICATOR CIRCUIT FAILURE WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

When ignition switch is first turned ON, battery voltage is applied to AIR BAG indicator and to IGNITION 1 input terminal Nos. A9 and A10. DERM responds by flashing AIR BAG indicator 7 times alternating between primary and redundant lamp drivers. DERM monitors primary lamp driver output by comparing output state at AIR BAG indicator terminal No. B1 to microprocessor commanded state. When IGNITION 1 is above a specified value and output state does not match commanded state of primary lamp driver for 400 milliseconds, DTC B1061 is set. DTC Will Set

When IGNITION 1 voltage is above a specified value and output state at AIR BAG indicator terminal No. B1 does not match commanded state of primary lamp driver for 400 milliseconds during CONTINUOUS MONITORING. Microsoft Saturday, August 29, 2009 11:47:22 AM

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Action Taken

DERM attempts to turn on AIR BAG indicator using redundant lamp driver and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF. Diagnostic Aids

See TABLE B and TABLE C to diagnose warning lamp circuit malfunctions. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1. The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 2. When DERM is configured for a serial data controlled warning lamp (smart cluster), DTC B1061 will set. Clearing SIR diagnostic trouble codes will reset DERM allowing lamp driver in DERM to control AIR BAG indicator.

Fig. 50: DTC B1061 - SIR Indicator Circuit Failure Courtesy of GENERAL MOTORS CORP. DTC B1062 - REDUNDANT SIR INDICATOR CIRCUIT FAILURE WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description Microsoft Saturday, August 29, 2009 11:47:22 AM

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When ignition switch is first turned ON, battery voltage is applied to AIR BAG indicator and to IGNITION 1 input terminal Nos. A9 and A10. DERM responds by flashing AIR BAG indicator 7 times alternating between primary and redundant lamp drivers. DERM monitors redundant lamp driver output by comparing output state at AIR BAG indicator terminal No. B1 to microprocessor commanded state. When IGNITION 1 is above a specified value and output state does not match commanded state of primary lamp driver for 400 milliseconds, DTC B1062 is set. DTC Will Set

When IGNITION 1 voltage is above a specified value and output state at AIR BAG indicator terminal No. B1 does not match commanded state of redundant lamp driver for 400 milliseconds during CONTINUOUS MONITORING. Action Taken

DERM attempts to turn on AIR BAG indicator using primary lamp driver and sets a diagnostic trouble code. DTC Will Clear

When ignition switch is turned OFF. Diagnostic Aids

An intermittent condition is likely to be caused by a poor connection to DERM at terminal Nos. A2 or B2, an open in CKT 1851 or an open in CKT 39. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

1) The SIR DIAGNOSTIC SYSTEM CHECK must be starting point for all diagnostics. 8) This test checks for an open in REDUNDANT INDICATOR ground circuit. 10) This test checks for an open in REDUNDANT INDICATOR IGNITION 1 circuit. 13) This test locates open in REDUNDANT INDICATOR IGNITION 1 circuit.

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Fig. 51: DTC B1062 - Redundant SIR Indicator Circuit Failure (1 Of 2) Courtesy of GENERAL MOTORS CORP.

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Fig. 52: DTC B1062 - Redundant SIR Indicator Circuit Failure (2 Of 2) Courtesy of GENERAL MOTORS CORP. DTC B1071 AND/OR 75 - INTERNAL DERM FAULT WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no circumstances should battery powered test equipment or test light be Microsoft Saturday, August 29, 2009 11:47:22 AM

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used. Carefully follow all instructions. Description

DTC B1071 and/or DTC B1075 is an indication of an internal DERM malfunction and will set if any of the following conditions are detected: 1) DERM energy reserve voltage discharge time failure for 3 consecutive ignition cycles. 2) DERM unable to read from or write to EEPROM. 3) DRIVER 36 VLR power supply voltage is above a specified value for 500 milliseconds. 4) DERM calculated number for vehicle in which it is installed does not match value stored in EEPROM. DTC Will Set

DTC will set when any of the indicated malfunctions are detected by the DERM. Action Taken

DERM turns ON AIR BAG indicator and sets a diagnostic trouble code. DTC Will Clear

The indicated malfunctions are not detected by DERM.

Fig. 53: DTC B1071 And/Or 75 - Internal DERM Fault Courtesy of GENERAL MOTORS CORP. DTC B1083 - DRIVER RESERVE DIODE SHORTED WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tables. Under no Microsoft Saturday, August 29, 2009 11:47:22 AM

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circumstances should battery powered test equipment or test light be used. Carefully follow all instructions. Description

During Turn ON tests, performed at beginning of each ignition cycle, DERM delays charging of DRIVER 36 VLR power supply. While delay is active, DERM measures voltage at DRIVER 36 VLR terminal No. A4 and DRIVER SOURCE SENSE terminal No. A5. When driver reserve diode is shorted, IGNITION 1 voltage is measured at DRIVER 36 VLR from forward biased driver ignition diode. When voltage is measured at DRIVER 36 VLR is within a specified range of IGNITION 1 voltage for 8 consecutive Turn ON tests, history DTC B1083 is set. DTC Will Set

When voltage measured at DRIVER 36 VLR terminal No. A4 is within a specified range of IGNITION 1 voltage for 8 consecutive turn on tests and no higher priority faults are detected. This test is run once each ignition during Turn ON test while 36 VLR delay is active. Action Taken

DERM sets a history diagnostic trouble code. DTC Will Clear

When voltage measured at DRIVER 36 VLR terminal No. A4 indicates that power supply is in a discharged state during Turn ON tests. Diagnostic Aids

This diagnostic trouble code will not set as a current DTC. Follow DTC table to diagnose malfunction. NOTE:

Test numbers refer to test numbers on diagnostic table. For circuit number identification, see WIRING DIAGRAM .

2) This test determines if malfunction is due to a shorted driver reserve diode within arming sensor.

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Fig. 54: DTC B1083 - Driver Reserve Diode Shorted Courtesy of GENERAL MOTORS CORP.

DESCRIPTION & OPERATION WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all WARNINGS and SERVICE PRECAUTIONS . SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM The Supplemental Inflatable Restraint (SIR) system is designed to protect the driver in a frontal collision. The air bag will deploy only upon frontal or near frontal impact of no more than 30 degrees off the center line of vehicle. System is not designed to deploy in rear impacts, side impacts, or rollovers. A frontal impact of sufficient severity (comparable to a collision into a solid wall at approximately 14 MPH or more) will cause sensors in vehicle to detect this sudden deceleration. These sensors, in turn, trigger the air bag module. DIAGNOSTIC ENERGY RESERVE MODULE (DERM) DERM performs diagnostic monitoring of all system components, stores both current and past SIR system fault Microsoft Saturday, August 29, 2009 11:47:22 AM

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code information, warns driver of SIR system faults by controlling AIR BAG warning light, and records SIR system status during a vehicle accident. In addition, DERM maintains a 36-Volt Loop Reserve (36VLR) energy supply to provide sufficient deployment energy for about 2 minutes if vehicle system voltage is low or is lost in an accident. A 24-pin connector connects DERM to SIR harness. Harness connector uses terminals and shorting bar in terminal contact area. DERM connector also has a shorting bar that connects AIR BAG warning input to ground when the DERM connector is disconnected. With DERM disconnected, AIR BAG warning light remains on when ignition switch is in RUN, BULB TEST, or START positions. DERM is located under or behind instrument panel. AIR BAG WARNING LIGHT When ignition switch is in RUN, BULB TEST, or START positions, battery voltage is applied to AIR BAG warning light. DERM illuminates this light by providing a ground to a lamp driver. DERM transmits a request to turn on AIR BAG warning light via the serial data line. When ignition is first turned on, AIR BAG warning light verifies light and DERM operation by flashing 7 times. Light is also used to warn driver of SIR electrical system faults which could potentially affect SIR system operation. AIR BAG warning light is the key to driver notification of SIR system faults. In addition, the light provides diagnostic information by flashing Diagnostic Trouble Codes (DTCs) when the flash code diagnostic mode is entered on models without on-board diagnosis. AIR BAG warning light notifies driver of SIR system faults. ARMING SENSOR Arming sensor is a protective switch located in power feed side (positive side) of deployment loop. It is calibrated to close at low-level velocity changes (lower than discriminating sensors). This assures that the air bag module is connected directly to 36VLR output of DERM or ignition voltage when either of the discriminating sensors close. Arming sensor consists of a sensing element, normally open switch contacts, a diagnostic resistor, and 2 diodes. Sensing element closes switch contacts when velocity of vehicle changes at a rate indicating potential need for deployment. A diagnostic resistor is connected in parallel with normally open switch contacts and allows for a small amount of current flow through deployment loop during normal undeployed conditions. This small current flow results in voltage drops across each component within loop. DERM monitors these voltage drops to detect circuit or component faults. The 2 diodes provide isolation between 36VLR output of DERM and ignition voltage. DISCRIMINATING SENSORS SIR systems have 2 discriminating sensors: the left forward discriminating sensor and the right forward discriminating sensor. Discriminating sensors are wired in parallel on the ground side of deployment loop. These sensors are calibrated to close when deceleration velocity changes are severe enough to warrant deployment. Microsoft Saturday, August 29, 2009 11:47:22 AM

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Sensors consist of a sensing element, normally open switch contacts, and a diagnostic resistor. Sensing element closes the normally open switch contacts when vehicle velocity changes are severe enough to warrant deployment. A diagnostic resistor is connected in parallel with the normally open switch contacts within each of the sensors. These parallel resistors supply the ground path for current passing through the deployment loop during normal undeployed conditions. This small current flow results in a voltage drop across each component within loop. DERM monitors these voltage drops to detect circuit or component faults. SIR COIL ASSEMBLY SIR coil assembly consists of 2 current-carrying coils. It is installed in steering column and allows rotation of steering wheel while maintaining continuous (directly wired) contact of deployment loop through steering wheel air bag module. Slip rings are not used in SIR system to transmit current from column to steering wheel. Terminals and a shorting bar are used on coil assembly lower steering column Yellow 2-way connector. Shorting bar shorts the circuits to main coil and steering wheel air bag module when lower steering column connector is disconnected. This shorts the circuit to the air bag module, preventing unwanted deployment of the air bags when servicing the steering column or other SIR components. AIR BAG MODULE When the vehicle is in an accident of sufficient force to simultaneously close the arming sensor and at least one discriminating sensor, nitrogen gas inflates the cloth bag packed inside the steering wheel hub. As air bag is contacted by driver or passenger, the gas is vented through openings in the bag, which deflates almost as soon as it is completely deployed. There is a shorting bar on the air bag module side of the upper steering column connector which connects the SIR coil to the air bag module. The shorting bar shorts the air bag module circuit when the upper steering column connector is disconnected. The circuit to the air bag module is shorted in this way to help prevent unwanted deployment of the air bag when servicing the air bag module or steering column.

SERVICE PRECAUTIONS The following precautions should be observed when working with SIR system: 



 

The DERM maintains sufficient voltage to cause air bag deployment for up to 2 minutes after ignition is turned OFF, battery is disconnected, or fuse powering DERM is removed. In order to begin servicing immediately, air bag modules must be removed from the deployment loop. See DISABLING SYSTEM . After repairs, ensure AIR BAG warning light is working properly and no system faults are indicated. See SYSTEM OPERATION CHECK . Always wear safety glasses when servicing or handling an air bag module. Air bag module must be stored in its original special container until used for service. It must be stored in a clean, dry place, away from sources of extreme heat, sparks, or high electrical energy. Air bag modules or DERMs should not be subjected to temperatures above 150°F (65°C). Air bag modules or DERMs should not be used if they have been dropped from a height of 3 ft (0.9 m) or

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

 



greater. When placing a live air bag module on a bench or other surface, always make certain that the trim cover (finished side) is up and away from surface. This will reduce motion of module if accidentally deployed. After deployment, air bag surface may contain deposits of sodium hydroxide, which can irritate skin. Always wear safety glasses, rubber gloves and long-sleeved shirt during clean-up, and wash hands using mild soap and water. Follow correct disposal procedures. See DISPOSAL PROCEDURES . At no time should any electrical source be allowed near inflator on back of air bag module. DO NOT apply power to SIR system unless all components are connected or a diagnostic chart requests it, as this will set a diagnostic trouble code. When carrying a live air bag module, trim cover should be pointed away from your body to minimize injury in case of accidental deployment. DO NOT attempt to service DERM, front end discriminating sensor, SIR coil assembly, or air bag modules. If defective, these parts must be replaced. DO NOT probe a wire through insulator; this will damage it and eventually cause failure due to corrosion. When performing electrical tests, prevent accidental shorting of terminals. Such mistakes can damage fuses or components and may cause a second fault code to set, making diagnosis of original problem more difficult. When using diagnostic charts to diagnose SIR system, under no circumstances should a volt/ohmmeter, test light or any type of electrical equipment not specified by manufacturer be used. See SPECIAL TOOLS . If SIR system is not fully functional for any reason, vehicle should not be driven until system is repaired. DO NOT remove bulbs, modules, sensors or other components or in any way disable system from operating normally. If SIR system is not functional, park vehicle until repairs can be made.

SPECIAL TOOLS To avoid deployment when working on SIR system, DO NOT use electrical test equipment such as test lights, battery or A/C-powered volt/ohmmeter, or any type of electrical equipment other than those specified by manufacturer. See SIR RECOMMENDED TOOLS table. SIR RECOMMENDED TOOLS Tool Name Connector Test Adapter Kit Digital Volt/Ohmmeter Air Bag Module & Steering Column Replacement Load Wire Repair Kit Scan Tool

Tool Number J-35616 J-39200 J-38715-A J-38125-A Tech 2

DISABLING & ACTIVATING SIR SYSTEM WARNING: Wait about 2 minutes after disabling air bag system. The SDM maintains system voltage for about 2 minutes after battery is disconnected. Microsoft Saturday, August 29, 2009 11:47:22 AM

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Servicing air bag system before 2 minutes may cause accidental air bag deployment, possibly causing personal injury. CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. Record customer radio stations, as memory will be lost. Code equipped radios may also lock. Obtain code from customer. See COMPUTER RELEARN PROCEDURES in GENERAL INFORMATION before disconnecting battery. DISABLING SYSTEM 1. Turn steering wheel to place vehicle wheels in straight-ahead position. Turn ignition switch to LOCK position. 2. Remove AIR BAG fuse. Remove I/P sound insulator. Remove Connector Position Assurance (CPA) clip and disconnect Yellow 2-way SIR connector at base of steering column. 3. Wait 2 minutes before beginning service. All connectors in SIR system use CPA clips to ensure connector retention. Even if system is disconnected, use caution when working near air bags. ACTIVATING SYSTEM Connect Yellow 2-way SIR connector at base of steering column. Install CPA clips, fuse and light I/P sound insulator. Turn ignition switch to RUN position and ensure AIR BAG warning light flashes 7 times and then goes out.

POST-COLLISION INSPECTION When a vehicle has been involved in a collision, certain components of the passive restraint system must be inspected or replaced. See PASSIVE RESTRAINT SYSTEM INSPECTION article in the GENERAL INFORMATION section for post-collision inspection information.

ADJUSTMENTS CENTERING COIL ASSEMBLY While holding coil assembly housing, depress spring lock and rotate hub in direction of arrow until it stops. Coil assembly should now be wound up snug against center hub. Rotate coil assembly hub in opposite direction approximately 2 1/2 turns. Release spring lock between locking tabs in front of arrow. See Fig. 55 .

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Fig. 55: Centering SIR Coil Assembly Courtesy of GENERAL MOTORS CORP.

DISPOSAL PROCEDURES WARNING: Undeployed air bag module contains substances that can cause illness or injury if handled improperly. Disposing of an air bag module without first deploying it may violate federal, state and/or local laws. This also applies to vehicles being scrapped. After deployment, air bag module can be disposed of as would any other part. Wear safety glasses and gloves when handling an air bag module. AIR BAG DEPLOYMENT NOTE:

If vehicle is to be scrapped, perform on-vehicle air bag deployment procedure. WARNING: During deployment, air bag module can become hot enough to burn you. Wait 30 minutes after deployment before touching the assembly.

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1. Before proceeding, read service precautions. See SERVICE PRECAUTIONS . Ensure air bag assemblies are securely mounted to steering wheel. Turn ignition to LOCK position, remove key and put on safety glasses. Remove all loose objects from front seats. Disconnect air bag module Yellow 2-way connector located at base of steering column. 2. Cut air bag module Yellow 2-way harness connector from instrument panel harness. Leave at least 6 inches (16 cm) of wire at connector. Strip .5 inch (13 mm) of insulation from each wire lead of connector. Cut 2 15 foot (4.6 meters) deployment wires from 18 gauge (.8 mm) or thicker multi strand wire. These wires will be used to fabricate deployment harness. Strip .5 inch (13 mm) of insulation from both ends of the wires. 3. Twist together one connector wire lead to one deployment wire. The connection should be mechanically secure. Bend twisted connection flat and wrap tightly with electrical tape to insulate and secure. Twist together, bend and tape remaining connector wire to the remaining deployment wire. Connect deployment harness to air bag module, Yellow 2-way connector at base of steering column. Route deployment harness out of driver-side of vehicle. WARNING: Never connect deployment wires to any power source before connecting to air bag module leads. The air bag will immediately deploy when a power source is connected to it. 4. Verify that inside of vehicle and area surrounding vehicle area are clear of all people and loose or flammable objects. 5. Stretch driver and passenger deployment harness to full length. Completely cover windshield area and front door window openings with a drop cloth to reduce possibility of injury due to fragmentation of glass or other objects. 6. Notify all people in the area that you are going to deploy the air bags and that the deployment will be accompanied by a substantial noise. 7. Separate the two ends of the deployment harness wires. Connect driver-side deployment wires to a 12 volt minimum, 2 amps minimum power source. A vehicle battery is suggested. The driver-side air bag will immediately deploy. WARNING: Observe safety precautions when handling a deployed air bag module. After deployment, metal surfaces of assembly will be very hot. Allow air bag module to cool before handling any metal portion of it. Do not place hot deployed assembly near any flammable objects. 8. Short deployment harness wires by twisting together one end from each. Carefully remove drop cloth from vehicle and clean off any fragments or discard drop cloth entirely. 9. In the unlikely event that either or both of the air bag assemblies did not deploy after following these procedures, remove undeployed air bag module from vehicle. See AIR BAG MODULE under REMOVAL & INSTALLATION. Temporarily store air bag module with air bag opening facing up, away from surface upon which it rest. NOTE:

Before proceeding, read service precautions. See SERVICE PRECAUTIONS .

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The following procedure requires the use of the SRS Deployment Harness (J 38826) with the appropriate pigtail adapter. Do not attempt procedure without the SRS Deployment Harness (J 38826) and adapter. WARNING: Never connect deployment wires to any power source before connecting to air bag module leads. The air bag will immediately deploy when a power source is connected to it. Off-Vehicle

1. Turn ignition to "LOCK", remove key and put on safety glasses. Using SRS Deployment Harness (J 38826), short the two SRS deployment leads by fully seating one banana plug into the other. Connect appropriate pigtail adapter to SRS deployment harness. Remove air bag module from vehicle. See AIR BAG MODULE under REMOVAL & INSTALLATION. 2. Place air bag module on work bench away from all loose or flammable objects with trim cover facing up. Clear a space on ground about 6 feet (183 cm) around area where air bag will be deployed. Place driverside air bag module, with trim cover facing up, on ground in center of 6 foot area just cleared. 3. Stretch SRS Deployment Harness and pigtail adapter to its full length and place a power source near the shorted end of the SRS deployment harness. A vehicle battery is suggested. Connect air bag module to pigtail adapter. Deployment harness should remain shorted and not be connected to power source until air bag is to be deployed. The air bag module will deploy immediately when a power source is connected. NOTE:

Ensure pigtail adapter is firmly seated into driver-side air bag module connector. Failure to fully seat connectors may leave shorting bar functioning (shorted) and result in non-deployment of driver air bag module.

NOTE:

Notify all people in immediate area that you are about to deploy the driverside air bag. The deployment will make a substantial noise. WARNING: Never connect deployment wires to any power source before connecting to air bag module leads. The air bag will immediately deploy when a power source is connected to it.

4. Separate the two banana plugs on the SRS deployment harness. Connect SRS deployment harness wires to power source to immediately deploy drive-side air bag. Disconnect SRS deployment harness from power source and short together the two deployment harness leads by fully seating one banana plug into the other. WARNING: During deployment, air bag module can become hot enough to burn you. Wait 30 minutes after deployment before touching the assembly. NOTE:

Disconnect pigtail adapter from air bag module as soon after deployment as possible. This will prevent damage to adapter or harness due to possible

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contact with hot air bag assembly canister. Be sure to inspect harness and pigtail for damage before reuse.

REMOVAL & INSTALLATION WARNING: Failure to follow air bag service precautions may result in air bag deployment and personal injury. Refer to SERVICE PRECAUTIONS . After component replacement, perform a system operational check to ensure proper system operation. See SYSTEM OPERATION CHECK . DERM Removal

1. Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS . Disable the air bag restraint system. Refer to DISABLING & ACTIVATING SIR SYSTEM . 2. Remove right sound insulator, sill plate, and cowl side trim plate. Remove CPA clip and disconnect DERM electrical connector from DERM. Remove DERM after electrical connections have been disconnected. See Fig. 56 .

Fig. 56: Removing DERM Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:22 AM

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Installation

To install, reverse removal procedure. See Fig. 56 . Reactivate air bag system. See DISABLING & ACTIVATING SIR SYSTEM . Check AIR BAG warning light to ensure system is functioning properly. See SYSTEM OPERATION CHECK . ARMING SENSOR Removal

1. Before proceeding, follow air bag service precautions. Refer to SERVICE PRECAUTIONS . Disable the air bag restraint system. See DISABLING & ACTIVATING SIR SYSTEM . 2. Remove sensor connector from retainer. Remove CPA clip. Disconnect sensor connector. Remove fasteners and sensor. See Fig. 57 .

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Fig. 57: Removing Arming Sensor Courtesy of GENERAL MOTORS CORP. Installation Microsoft Saturday, August 29, 2009 11:47:23 AM

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To install, reverse removal procedure. See Fig. 57 . Reactivate air bag system. See DISABLING & ACTIVATING SIR SYSTEM . Check AIR BAG warning light to ensure system is functioning properly. See SYSTEM OPERATION CHECK . FORWARD DISCRIMINATING SENSORS Removal

1. Before proceeding, follow air bag service precautions. Refer to SERVICE PRECAUTIONS . Disable the air bag restraint system. See DISABLING & ACTIVATING SIR SYSTEM . 2. Drill out mounting bolts. Remove CPA clip from connector and disconnect sensor electrical connector. Remove sensor. See Fig. 58 .

Fig. 58: Removing Forward Discriminating Sensor Courtesy of GENERAL MOTORS CORP. Installation

To install, reverse removal procedure. See Fig. 58 . Ensure arrow on sensor is installed pointing forward. Reactivate air bag system. See DISABLING & ACTIVATING SIR SYSTEM . Check AIR BAG warning light to make sure the system is functioning properly. Refer to SYSTEM OPERATION CHECK . STEERING WHEEL Microsoft Saturday, August 29, 2009 11:47:23 AM

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Removal

1. Before proceeding, follow air bag service precautions. Refer to SERVICE PRECAUTIONS . Disable the air bag restraint system. See DISABLING & ACTIVATING SIR SYSTEM . 2. Remove air bag module. See AIR BAG MODULE under REMOVAL & INSTALLATION. Remove steering wheel locking nut. Horn plunger contact. Using Steering Wheel Puller (J-1859-03), remove steering wheel. See Fig. 59 . DO NOT install puller bolts too far, as damage to coil assembly can result.

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Fig. 59: Removing Steering Wheel Microsoft Saturday, August 29, 2009 11:47:23 AM

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Courtesy of GENERAL MOTORS CORP. Installation

To install, reverse removal procedure. See Fig. 59 . Tighten locking nut. See TORQUE SPECIFICATIONS . Reactivate air bag system. See DISABLING & ACTIVATING SIR SYSTEM . Check AIR BAG warning light to make sure the system is functioning properly. Refer to SYSTEM OPERATION CHECK . SIR COIL ASSEMBLY Removal

1. Before proceeding, follow air bag service precautions. Refer to SERVICE PRECAUTIONS . Disable the air bag restraint system. See DISABLING & ACTIVATING SIR SYSTEM . Ensure front wheels are in straight ahead position. 2. Lower or remove steering column from vehicle. Remove lower column shroud. Lift upper shroud to gain access to lock cylinder hole. Hold key in START position. Using wrench, push on lock cylinder retaining pin. Release key to RUN position and pull steering column lock cylinder set from lock module assembly. Remove upper column shroud. 3. Remove air bag module. See AIR BAG MODULE . Remove steering wheel. See STEERING WHEEL . DO NOT install puller bolts too far, as damage to coil assembly can result. Remove retaining ring and coil assembly. See Fig. 60 . Remove wave washer and two wire harness straps from steering column wire harness.

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Fig. 60: Removing SIR Coil Assembly Courtesy of GENERAL MOTORS CORP. NOTE:

New SIR coil assembly comes pre-centered. Remove and dispose centering tab when installing.

Installation

1. Ensure coil assembly hub and steering shaft are centered. Coil assembly will become uncentered if column is separated from steering gear and is allowed to rotate, or if centering spring is depressed, allowing hub to rotate while coil assembly is removed from column. To center coil assembly, see CENTERING COIL ASSEMBLY under ADJUSTMENTS. 2. Ensure front wheels are in straight ahead position and turn ignition to LOCK position. Install wave washer. To install coil assembly, align coil assembly with horn tower and slide onto shaft. See Fig. 60 . Install retaining ring securely in groove on shaft. Route lower coil wire along steering column jacket assembly. 3. Install two wire straps to steering column wire harness. Move shift and multifunction lever seal to ease installation of column shrouds. Install upper column shroud and steering lock cylinder set. Install lower Microsoft Saturday, August 29, 2009 11:47:23 AM

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column shroud. Move shift and multifunction lever seal into position. 4. Install steering wheel and air bag module. See STEERING WHEEL and AIR BAG MODULE. Reactivate air bag system. See procedures under DISABLING & ACTIVATING SIR SYSTEM . Check AIR BAG warning light for proper system function. See SYSTEM OPERATION CHECK . AIR BAG MODULE Removal

1. Before proceeding, follow air bag service precautions. Refer to SERVICE PRECAUTIONS . Disable the air bag restraint system. See DISABLING & ACTIVATING SIR SYSTEM . 2. Turn steering wheel 90 degrees to access rear shroud holes to air bag module. Insert screw driver and push leaf spring to release pin. Turn steering wheel 180 degrees to access remaining rear shroud holes. Insert screw driver and push leaf spring to release pin. Remove air bag module. Disconnect SIR lead wire from clip on air bag module and steering wheel. Remove CPA clip and retainer from air bag module. See Fig. 61 .

Fig. 61: Removing Driver-Side Air Bag Module Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:47:23 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Installation

1. Install CPA clip and retainer to air bag module. Connect SIR lead wire to clip on steering wheel and air bag module. Install air bag module by pressing it firmly into steering wheel enough to engage and latch all four notched pins in the leaf spring. Do not pinch wires. See Fig. 61 . 2. Reactivate air bag system. See DISABLING & ACTIVATING SIR SYSTEM . Check AIR BAG warning light to ensure system is functioning properly. See SYSTEM OPERATION CHECK .

SYSTEM OPERATION CHECK If system is functioning normally, air bag warning light flashes 7 times when ignition switch is turned to ON position and goes out. Four possible warning light conditions can indicate a system failure:    

Light does not illuminate at all. Light comes on while vehicle is driven. Light flashes 7 times, and remains on. Light does not flash but remains lit when ignition is turned on.

SIR system faults are usually due to a disconnected/loose electrical connector caused by previous service on vehicle. Always check Yellow SIR connector at base of steering column for loose or damaged wiring.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Steering Wheel Nut

Ft. Lbs. (N.m) 30 (41) INCH Lbs. (N.m)

Air Bag Module Nut/Screw Driver-Side SIR Coil Mounting Screw Turn Signal Switch Screw Turn Signal Switch Arm Screw

27 (3) 30 (3.4) 30 (3.4) 20 (2.3)

WIRING DIAGRAM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Microsoft Saturday, August 29, 2009 11:47:23 AM

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1997 Chevrolet S10 Pickup AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT General Motors - Air Bag Restraint System

Fig. 62: SIR System Wiring Diagram

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

DESCRIPTION The Kelsey-Hayes 4-Wheel Anti-Lock (4WAL) brake system is used to prevent wheel lock-up during heavy braking. This allows driver to maintain steering control while stopping vehicle in shortest distance possible. The system consists of Brake Pressure Modulator Valve (BPMV), Vehicle Speed Sensor (VSS), Powertrain Control Module (PCM) or Vehicle Control Module (VCM), Wheel Speed Sensors (WSS), warning lights, electrical wiring and hydraulic lines. The Electro-Hydraulic Control Unit (EHCU) is the entire unit, including the BPMV, Electronic Brake Control Module (EBCM) and combination valve. The EBCM is the electronic control portion of the ABS assembly. It is mounted on top of the BPMV located on left side of engine compartment, above fender well.

OPERATION When ignition is turned on, Yellow ANTI-LOCK and Red BRAKE warning lights will illuminate for 2 seconds as a bulb check. VCM performs a self-check of the 4WAL system, once each ignition cycle, when vehicle speed reaches 8 MPH. If faults are detected by VCM, ANTI-LOCK light will illuminate (in most cases) and 4WAL functions will be disabled while ANTI-LOCK light is on. A related Diagnostic Trouble Code (DTC) will be stored. The Red BRAKE light illuminates if parking brake is applied or a mechanical brake problem is detected. When brake pedal is depressed, brake switch voltage to VCM drops from 12 volts to one volt. At this point, VCM monitors wheel speed through an AC signal generated by speed sensors located at each wheel. If the deceleration rate of wheel speed reaches a preprogrammed rate, PCM/VCM will activate various control valves to prevent wheel lock-up by increasing or decreasing hydraulic pressure to each channel: left front, right front or rear wheels.

BLEEDING BRAKE SYSTEM ABS BLEEDING PROCEDURE NOTE:

Bleeding ABS system requires the use of Tech 1 scan tool. An assistant is required when performing bleeding procedures.

1. Raise and support vehicle. Begin bleeding at right rear wheel. Install a clear plastic hose to bleed screw. Immerse other end of hose in container that is partially filled with clean brake fluid. 2. Open bleed screw 1/2 to 1 full turn. Have assistant slowly depress brake pedal until it reaches full travel. Hold pedal until bleed screw is closed. Release brake pedal and wait 10-15 seconds. Repeat until clean bubble-free brake fluid is present at wheel bleed screw. 3. Check master cylinder fluid level every 4-6 strokes of brake pedal to avoid running system dry. Repeat steps 2) and 3) on left rear, then right front, then left front. After bleeding all 4 wheels, go to next step. 4. Using scan tool in FUNCTION TEST, run FUNCTION TEST 4 times consecutively while applying the Microsoft Saturday, August 29, 2009 11:26:16 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

brake pedal firmly. Release brake pedal between each test. 5. Rebleed all 4 wheels using steps 2) and 3) to remove remaining air from brake system. Ensure brake pedal feel is appropriate before attempting to drive vehicle. Rebleed as many times as necessary to obtain appropriate pedal feel.

DIAGNOSIS NOTE:

When testing and diagnosing 4WAL system, use of Tech 1 scan tool is required.

The Vehicle Control Module (VCM) contains a self-diagnostic capability to detect system failures. When a DTC is set, the VCM may disable 4WAL system and illuminate ANTI-LOCK light for duration of ignition cycle. DTCs stored by VCM can be displayed using Tech 1 and appropriate cartridge. Before diagnosing 4WAL system, perform a comprehensive visual inspection of system by checking wiring harness connectors, harness routing (pay particular attention to wheel speed sensor wiring harness routing), applicable fuses in fuse block, and ground connections. Ensure brake fluid level in master cylinder reservoir is full. Start 4WAL system diagnosis using DIAGNOSTIC SYSTEM CHECK . If failures are found when performing diagnostic system check, you will be directed to enter diagnostics to retrieve DTCs or perform SYMPTOM TESTS. DIAGNOSTIC SYSTEM CHECK may indicate that system is functioning properly. RETRIEVING DTCS Connect Tech 1 scan tool to DLC located under steering column. Access 4WAL brake DTCs. Repair DTCs in the order they appear. See 4WAL DIAGNOSTIC TROUBLE CODE (DTC) table for diagnosis. Before diagnosing DTC(s), perform DIAGNOSTIC SYSTEM CHECK first. 4WAL DIAGNOSTIC TROUBLE CODE (DTC) DTC C0021 C0022 C0023 C0025 C0026 C0027 C0029 C0035 C0036 C0037 C0038 C0041 C0042

(1) Definition

Right Front Wheel Speed Sensor Circuit Open Or Shorted To Battery Voltage Right Front Wheel Speed Sensor Signal Missing Right Front Wheel Speed Sensor Signal Erratic Left Front Wheel Speed Sensor Circuit Open Or Shorted To Battery Voltage Left Front Wheel Speed Sensor Signal Missing Left Front Wheel Speed Sensor Signal Erratic Simultaneous Dropout Of Front Wheel Speed Sensor Signal Rear Speed Sensor Signal Circuit Open Or Grounded Rear Speed Sensor Signal Missing Rear Speed Sensor Signal Erratic Wheel Speed Signal Malfunction Right Front Isolation Solenoid Circuit Open Right Front Dump Solenoid Circuit Open

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

C0043 Right Front Isolation Solenoid Circuit Shorted C0044 Right Front Dump Solenoid Circuit Shorted C0045 Left Front Isolation Solenoid Circuit Open C0046 Left Front Dump Solenoid Circuit Open C0047 Left Front Isolation Solenoid Circuit Shorted C0048 Left Front Dump Solenoid Circuit Shorted C0051 Rear Isolation Solenoid Circuit Open C0052 Rear Dump Solenoid Circuit Open C0053 Rear Isolation Solenoid Circuit Shorted C0054 Rear Dump Solenoid Circuit Shorted C0065 Pump Motor Relay Circuit Open C0066 Pump Motor Relay Circuit Shorted C0067 Pump Motor Circuit Open C0068 Pump Motor Locked Or Pump Motor Circuit Shorted C0071 EBCM Internal Fault C0072 EBCM Internal Fault C0073 EBCM Internal Fault C0074 EBCM Internal Fault C0081 Stoplight Switch Always Closed Or Shorted C0086 Anti-Lock Indicator Light Circuit Shorted To Battery Voltage C0088 Brake Warning Light Circuit Shorted To Battery Voltage (1) Always perform DIAGNOSTIC SYSTEM CHECK before performing DTC tests. CLEARING DTCS A DTC set in a current ignition cycle will not clear during that same ignition cycle. Cycle ignition switch off for 10 seconds and then on to clear a DTC set in current ignition cycle. If ANTI-LOCK light is staying on, DTCs can be cleared with a scan tool. Verify DTCs are cleared. See RETRIEVING DTCS . DIAGNOSTIC SYSTEM CHECK NOTE:

For circuit reference, see WIRING DIAGRAMS .

System Description

The diagnostic system check is an organized approach to identifying a problem created by an ABS malfunction. It must be the starting point of any ABS complaint diagnosis because it directs to the next logical step in diagnosing the complaint. Serial data is exchanged by EBCM through harness connector C1, terminal "F", and Class 2 data is exchanged through harness connector C1, terminal "G". EBCM is supplied switched ignition voltage through harness connector C1, terminal "A", and ground is provided through harness connector C1, terminal "J". Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Diagnostic Procedures

1. Verify all EBCM connectors are connected properly. Install scan tool with proper cartridge. Turn ignition switch to RUN position. Using scan tool, select FO: DATA LIST. If data is being received from EBCM, go to step 7). If data is not received from EBCM, go to next step. 2. Observe scan tool. If scan tool displays WAITING FOR DATA, go to next step. 3. Ensure scan tool is properly connected to DLC. If connection is okay, go to next step. If not, go to step 5). 4. Turn ignition off. Remove and inspect 10A brake fuse. If fuse is open, go to step 11). If fuse is okay, go to step 6). 5. Reconnect scan tool to DLC connector and repeat step 1). 6. Turn ignition off. Install brake fuse. Disconnect negative battery terminal. Disconnect 10-pin EBCM harness connector C1. Check resistance between negative battery terminal and 10-pin EBCM harness connector C1 terminal "J". If resistance is 0-2 ohms, go to step 14). If resistance is not 0-2 ohms, go to step 17). 7. Using scan tool, select DTC(s). If DTC(s) are present, go to appropriate DTC test. If DTC(s) are not present, go to next step. 8. Turn ignition off for 10 seconds. Turn ignition switch to RUN position. If ABS warning light illuminates for 3 seconds, and then goes off, go to next step. If not, go to step 10). 9. Select DTC HISTORY. If DTC(s) are present, diagnose affected DTC(s). Go to DIAGNOSTIC TROUBLE CODES (DTC). If DTC(s) are not present, system is okay. 10. Observe ABS warning light. If warning light stays on, go to TEST "B" under SYMPTOM TESTS . If warning light does not stay on, go to TEST "A" under SYMPTOM TESTS . 11. Replace brake fuse. Turn ignition switch to RUN position for 10 seconds. Turn ignition off. Remove and inspect fuse. If fuse is blown, go to next step. If fuse is okay, go to step 19). 12. Disconnect 10-pin EBCM harness connector C1. Replace brake fuse. Turn ignition switch to RUN position for 10 seconds. Turn ignition off. Remove and inspect fuse. If fuse is blown, go to step 20). If fuse is okay, go to next step. 13. Inspect ignition and brake switch input circuits and 10-pin EBCM harness connector C1 for physical damage which could cause a short to ground with EBCM harness connector connected to EBCM. Repair as necessary. After repairs, reconnect all connectors. Turn ignition switch to RUN position for 10 seconds. Turn ignition off. Remove and inspect fuse. If fuse is blown, go to step 21). If fuse is okay, check for intermittent or poor connections. 14. Reconnect negative battery terminal. Turn ignition switch to RUN position. Check voltage between 10pin EBCM harness connector C1 terminal "A" and ground. If voltage reading is 10-15 volts, go to next step. If not, go to step 22). 15. Turn ignition off. Disconnect positive battery terminal. Turn ignition switch to RUN position. Check resistance between positive battery cable and 10-pin EBCM connector C1, terminal "A". If resistance is 0-2 ohms, go to next step. If resistance is not 0-2 ohms, go to step 22). 16. Inspect EBCM and EBCM harness connector terminals for poor contact. Inspect battery terminals and battery cable terminals for poor connection. Repair as necessary. After repairs, go to step 24). If connections or terminals are okay, go to step 25). 17. Repair open or high resistance in EBCM ground circuit. See WIRING DIAGRAMS . After repairs, repeat step 1). Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

18. Repair short to ground in brakelight control circuit. After repairs, repeat step 1). 19. Check and repair short to ground in battery feed circuit. After repairs, install fuse and repeat step 1). 20. Check and repair short to ground in ignition input or battery circuit to EBCM. See WIRING DIAGRAMS . After repairs, repeat step 1). 21. Replace EBCM and brake fuse. After repairs, repeat step 1). 22. Repair open in ignition input or battery circuit to EBCM. See WIRING DIAGRAMS . After repairs, repeat step 1). 23. Repair open or high resistance in ignition input circuit or battery circuit to EBCM. After repairs, repeat step 1). 24. Replace terminals or repair poor connection. After repairs, repeat step 1). 25. Reconnect EBCM harness connectors and battery terminals. If communications cannot be established between scan tool and EBCM, try scan tool on similar vehicle with the same system to determine if scan too is malfunctioning or if Class 2 data line is faulty. See appropriate WIRING DIAGRAM article. Repair or replace as necessary.

DIAGNOSTIC TROUBLE CODES DTC C0021: RIGHT FRONT WHEEL SPEED SENSOR CIRCUIT OPEN OR SHORTED TO BATTERY VOLTAGE NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

As a toothed ring passes by the Wheel Speed Sensor (WSS), changes in electromagnetic field cause wheel speed sensor to produce an AC voltage signal. Voltage signal frequency and amplitude are proportional to wheel speed. The magnitude of this signal is directly related to wheel speed and proximity of wheel speed sensor to toothed ring, often referred to as the air gap. Conditions for setting DTC:  

No output signal from right front wheel sensor for one second. Excessive right front wheel speed sensor resistance for one second.

Diagnostic Procedures

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

4. Check resistance between right WSS harness connector terminals "A" and "B". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to step 7). If not, go to step 11). 5. Inspect 4-pin EBCM harness connector for signs of damage or corrosion. If damage is present, go to step 8). If no signs of damage are present, go to next step. 6. Reconnect all harness connectors. Test drive vehicle at speed greater than 15 MPH. If DTC C0021 sets, go to step 9). If not, go to next step. 7. Malfunction is intermittent. Check all connectors and harnesses for damage which may result in high resistance when components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Repair 4-pin EBCM harness connector. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 9. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in wheel speed sensor circuits between sensor and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 11. Replace wheel speed sensor. After replacing sensor, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Also, check sensor terminals harness connectors. WSS TEMPERATURE-VS-SENSOR RESISTANCE Temperature °F (°C) AWD -40 To 40 (-40 To 4) 41-110 (5-43) 111-200 (44-93) 201-302 (94-150) 2WD & 4WD -40 To 40 (-40 To 4) 41-110 (5-43) 111-200 (44-93) 201-302 (94-150)

Ohms 089-1630 1337-1900 1560-2230 1850-2651 920-1440 1125-1700 1305-2000 1530-2310

DTC C0022: RIGHT FRONT WHEEL SPEED SENSOR SIGNAL MISSING NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

As a toothed ring passes by the Wheel Speed Sensor (WSS), changes in the electromagnetic field cause the wheel speed sensor to produce an AC voltage signal. Voltage signal frequency and amplitude are proportional to wheel speed. The magnitude of this signal is directly related to wheel speed and proximity of wheel speed Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

sensor to toothed ring, often referred to as the air gap. Conditions for setting DTC:   

Right front wheel speed is less than 4 MPH. All other wheel speeds are greater than 8 MPH. Unexpected wheel acceleration/deceleration. Anything that keeps the right front wheel speed sensor signal low while vehicle is moving at greater than 8 MPH.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Inspect right front wheel speed sensor, sensor cable and connectors for signs of damage or corrosion. Inspect wheel sensor toothed ring for looseness. Inspect 4-pin EBCM harness connector. If any damage is found, go to step 7). If no damage is found, go to next step. 3. Raise and support vehicle. Disconnect right front WSS harness connector. Using DVOM, check resistance between sensor terminals "A" and "B". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to next step. If not, go to step 8). 4. Select AC scale on DVOM. Connect DVOM to sensor terminals "A" and "B". Spin wheel by hand while observing voltage reading on DVOM. If DVOM reads greater than 100 mV, go to next step. If not, go to step 8). 5. Disconnect 4-pin EBCM harness connector. Check resistance between harness connector terminals "C" and "E". If reading is infinite, go to next step. If reading is not infinite, go to step 10). 6. Reconnect all harness connectors. Test drive vehicle at speed greater than 15 MPH. If DTC C0022 sets, go to step 9). If not, go to step 11). 7. Make necessary repairs. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Replace right front wheel speed sensor. After replacing sensor, perform DIAGNOSTIC SYSTEM CHECK . 9. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair short between wheel speed sensor circuits. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 11. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

For circuit reference, see WIRING DIAGRAMS .

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Circuit Description

Average wheel speed for all wheel speed signals is greater than 25 MPH. Average right front wheel speed is greater than 25 MPH. No output from right front wheel speed signal for 15 milliseconds. Anything which suddenly prevents (intermittent) the right front wheel speed signal to drop to zero wile vehicle is moving greater than 25 MPH.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 4-pin EBCM harness connector and inspect for signs of corrosion or damage. Inspect wheel speed sensor, sensor cable and connectors for signs of damage or corrosion. If connections are okay, go to next step. If connections are damaged or corroded, go to step 6). 3. Using DVOM, check resistance between 4-pin EBCM harness connector terminals "C" and "E". Wiggle harness in various locations while monitoring DVOM reading. See WSS TEMPERATURE-VSSENSOR RESISTANCE table. If resistance is as specified and does not fluctuate, go to step 5). If not, go to next step. 4. Disconnect wheel speed sensor harness connector. Check resistance between wheel sensor terminals "A" and "B". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to step 7). If not, go to step 8). 5. Reconnect all harness connectors. Remove right front tire, hub and rotor. Verify right front wheel speed sensor is securely mounted and tone wheel is in good condition. If damage is not found, go to step 9). If damage is found, go to step 10). 6. Make necessary repairs. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open, short or high resistance in wheel speed sensor circuits. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Replace wheel speed sensor. After replacing sensor, perform DIAGNOSTIC SYSTEM CHECK . 9. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Make necessary repairs. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

DTC C0025: LEFT FRONT WHEEL SPEED SENSOR CIRCUIT OPEN OR SHORTED TO BATTERY VOLTAGE NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

No output signal from left front wheel sensor for one second. Excessive left front wheel speed sensor resistance for one second.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 4-pin EBCM harness connector. Check resistance between 4-pin harness connector terminals "A" and "D". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to step 5). If not, go to next step. 3. Disconnect left WSS harness connector. Using a fused jumper wire, jumper sensor harness connector terminals "A" and "B". Using DVOM, check resistance between 4-pin EBCM harness connector terminals "A" and "D". If sensor resistance is 0-2 ohms, go to next step. If not, go to step 10). 4. Check resistance between right WSS harness connector terminals "A" and "B". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to step 7). If not, go to step 11). 5. Inspect 4-pin EBCM harness connector for signs of damage or corrosion. If damage is present, go to step 8). If no signs of damage are present, go to next step. 6. Reconnect all harness connectors. Test drive vehicle at speed greater than 15 MPH. If DTC C0025 sets, go to step 9). If not, go to next step. 7. Malfunction is intermittent. Check all connectors and harnesses for damage which may result in high resistance when components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Repair 4-pin EBCM harness connector. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 9. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in wheel speed sensor circuits. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 11. Replace wheel speed sensor. After replacing sensor, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

Left front wheel speed is less than 4 MPH. All other wheel speeds are greater than 8 MPH. No unexpected wheel acceleration/deceleration. Anything that keeps the left front wheel speed sensor signal low while vehicle is moving at greater than 8 MPH.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Inspect left front wheel speed sensor, sensor cable and connectors for signs of damage or corrosion. Inspect wheel sensor toothed ring for looseness. Inspect 4-pin EBCM harness connector. If any damage is found, go to step 7). If no damage is found, go to next step. 3. Raise and support vehicle. Disconnect left front WSS harness connector. Using DVOM, check resistance between sensor terminals "A" and "B". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to next step. If not, go to step 8). 4. Select AC scale on DVOM. Connect DVOM to sensor terminals "A" and "B". Spin wheel by hand while observing voltage reading on DVOM. If DVOM reads greater than 100 mV, go to next step. If not, go to step 8). 5. Disconnect 4-pin EBCM harness connector. Check resistance between harness connector terminals "A" and "D". If reading is infinite, go to next step. If reading is not infinite, go to step 10). 6. Reconnect all harness connectors. Test drive vehicle at speed greater than 15 MPH. If DTC C0026 sets, go to step 9). If not, go to step 11). 7. Make necessary repairs. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Replace left front wheel speed sensor. After replacing sensor, perform DIAGNOSTIC SYSTEM CHECK . 9. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair short between wheel speed sensor circuits. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

11. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

Average wheel speed for all wheel speed signals is greater than 25 MPH. Average left front wheel speed is greater than 25 MPH. No output from left front wheel speed signal for 15 milliseconds. Anything which suddenly prevents (intermittent) the right front wheel speed signal to drop to zero while vehicle is moving greater than 25 MPH.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 4-pin EBCM harness connector and inspect for signs of corrosion or damage. Inspect wheel speed sensor, sensor cable and connectors for signs of damage or corrosion. If connections are okay, go to next step. If connections are damaged or corroded, go to step 6). 3. Using DVOM, check resistance between 4-pin EBCM harness connector terminals "A" and "D". Wiggle harness in various locations while monitoring DVOM reading. See WSS TEMPERATURE-VSSENSOR RESISTANCE table. If resistance is as specified and does not fluctuate, go to step 5). If not, go to next step. 4. Disconnect wheel speed sensor harness connector. Check resistance between wheel sensor terminals "A" and "B". See WSS TEMPERATURE-VS-SENSOR RESISTANCE table. If resistance is as specified, go to step 7). If not, go to step 8). 5. Reconnect all harness connectors. Remove left front tire, hub and rotor. Verify right front wheel speed sensor is securely mounted and tone wheel is in good condition. If damage is not found, go to step 9). If damage is found, go to step 10). Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

6. Make necessary repairs. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open, short or high resistance between wheel speed sensor circuits. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Replace wheel speed sensor. After replacing sensor, perform DIAGNOSTIC SYSTEM CHECK . 9. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Make necessary repairs. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

EBCM losing both front wheel speed signals when vehicle is at speeds greater than 12 MPH (brake released) or 20 MPH (brake applied).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 4-pin EBCM harness connector. Inspect harness connector and terminals for damage or corrosion. If harness or terminal is damaged or corroded, go to step 4). If harness and terminal are okay, go to next step. 3. Reconnect harness connector. Clear DTC. Road test vehicle at speeds greater than 15 MPH. Retrieve DTCs. If DTC C0029 resets, go to step 5). If DTC does not reset, go to step 6). 4. Make necessary repairs to harness connector or terminals. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 5. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 6. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The rear wheel speed sensor signal originates from the VSS which is connected to the PCM/VCM. The EBCM receives the rear wheel speed sensor signal from the PCM/VCM. Conditions for setting DTC: 

EBCM not seeing the correct voltage level from the PCM/VCM at start-up.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 10-pin EBCM harness connector. Turn ignition switch to RUN position. Check voltage between 10-pin EBCM harness connector terminal "E" and ground. If voltage is greater than 10 volts, go to step 4). If not, go to next step. 3. Turn ignition off. Disconnect PCM/VCM harness connector C1. Check resistance between 10-pin EBCM harness connector terminal "E" and PCM/VCM harness connector terminal No. 15. If resistance is 0-2 ohms, go to step 5). If not, go to step 8). 4. Turn ignition off. Reconnect PCM/VCM harness connector. Turn ignition switch to RUN position. Using scan tool, clear DTCs. Test drive vehicle at speed greater than 15 MPH. Check for DTCs. If DTC C0035 resets, go to step 6). If DTC does not reset, go to step 7). 5. Check resistance between 10-pin EBCM harness connector terminal "E" and ground. If resistance is infinite, check VSS. If resistance is not infinite, go to step 9). 6. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 7. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Repair open in VSS signal circuit between VCM and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 9. Repair short to ground in VSS signal circuit. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

This DTC can be set by a faulty VSS or a fault in VSS signal circuit. DTC C0036: REAR SPEED SENSOR SIGNAL MISSING NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The rear wheel speed sensor signal originates from the VSS which is connected to the PCM/VCM. The EBCM receives the rear wheel speed sensor signal from the PCM/VCM. Conditions for setting DTC: 

EBCM losing rear wheel speed signal for at least 5 seconds at speeds greater than 8 MPH with brake pedal released. If DTC C0035 is also present, diagnose that DTC first.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 10-pin EBCM harness connector. Turn ignition switch to RUN position. Check voltage between 10-pin EBCM harness connector terminal "E" and ground. If voltage is greater than 10 volts, go to step 4). If not, go to next step. 3. Turn ignition off. Disconnect PCM/VCM harness connector C1. Check resistance between 10-pin EBCM harness connector terminal "E" and PCM/VCM harness connector terminal No. 15 (terminal No. 70 on 2.2L engines). If resistance is 0-2 ohms, go to step 5). If not, go to step 8). 4. Turn ignition off. Reconnect PCM/VCM harness connector. Turn ignition switch to RUN position. Using scan tool, clear DTCs. Test drive vehicle at speed greater than 15 MPH. Check for DTCs. If DTC C0036 resets, go to step 6). If DTC does not reset, go to step 7). 5. Check resistance between 10-pin EBCM harness connector terminal "E" and ground. If resistance is infinite, check VSS. If resistance is not infinite, go to step 9). 6. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 7. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Repair open in VSS signal circuit between VCM and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 9. Repair short to ground in VSS signal circuit. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

This DTC can be set by a faulty VSS or a fault in VSS signal circuit between EBCM and VCM. DTC C0037: REAR SPEED SENSOR SIGNAL ERRATIC Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The rear wheel speed sensor signal originates from the VSS which is connected to the VCM. The EBCM receives the rear wheel speed sensor signal from the VCM. Conditions for setting DTC: 

EBCM seeing the rear speed signal line drop out and return. This DTC can be caused by a malfunction in the VSS or a fault in VSS signal circuit.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 10-pin EBCM harness connector. Turn ignition switch to RUN position. Check voltage between 10-pin EBCM harness connector terminal "E" and ground. If voltage is greater than 10 volts, go to step 4). If not, go to next step. 3. Turn ignition off. Disconnect VCM harness connector C1. Check resistance between 10-pin EBCM harness connector terminal "E" and VCM harness connector terminal No. 15 (VSS signal output circuit). If resistance is 0-2 ohms, go to step 5). If not, go to step 8). 4. Turn ignition off. Reconnect VCM harness connector. Turn ignition switch to RUN position. Using scan tool, clear DTCs. Test drive vehicle at speed greater than 15 MPH. Check for DTCs. If DTC C0037 resets, go to step 6). If DTC does not reset, go to step 7). 5. Check resistance between 10-pin EBCM harness connector terminal "E" and ground. If resistance is infinite, check VSS. If resistance is not infinite, go to step 9). 6. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 7. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when all components are connected. See DIAGNOSTIC AIDS. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Repair open in VSS signal circuit between EBCM and VCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 9. Repair short to ground in VSS signal circuit. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

This DTC can be set by a faulty VSS or a fault in VSS signal circuit between EBCM and VCM. DTC C0038: WHEEL SPEED SIGNAL MALFUNCTION NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Any wheel speed differing from the vehicle speed for any of the following causes: - One mismatched wheel speed more than double or less than half the other 3 wheel speeds. - All 4 wheel speeds differing from each other by 8 percent.

 

Vehicle speed greater than 12 MPH. No unexpected wheel acceleration. Anything that generates consistent differences between wheel speed signals.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Inspect vehicle tires for variation in tire size. If all 4 tires are the same, go to next step. 3. Clear DTCs using scan tool. Test drive vehicle. While test driving vehicle, use DATA LIST function on scan tool to monitor wheel speeds. If scan tool indicates a faulty sensor, go to affected DTC test to diagnose problem. If scan tool does not indicate a faulty sensor, problem is intermittent. DTC C0041: RIGHT FRONT ISOLATION SOLENOID CIRCUIT OPEN NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When right front isolation solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will close isolation valve by magnetic force created by solenoid coil. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

3. 4. 5. 6. 7. 8. 9. 10.

go to step 6). Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. Inspect ABS fusible link. If fusible link is open, go to step 9). If fusible link is okay, go to step 10). Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . Repair open or high resistance in battery circuit. After repairs, perform DIAGNOSTIC SYSTEM CHECK .

DTC C0042: RIGHT FRONT DUMP SOLENOID CIRCUIT OPEN NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When right front dump solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will open dump valve by magnetic force created by solenoid coil. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

7. 8. 9. 10.

CHECK . Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . Repair short to ground in battery circuit between underhood duse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . Repair open or high resistance in battery circuit. After repairs, perform DIAGNOSTIC SYSTEM CHECK .

DTC C0043: RIGHT FRONT ISOLATION SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood duse/relay block and EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0044: RIGHT FRONT DUMP SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0045: LEFT FRONT ISOLATION SOLENOID CIRCUIT OPEN NOTE:

For circuit reference, see WIRING DIAGRAMS .

Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Circuit Description

When left front isolation solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will close isolation valve by magnetic force created by solenoid coil. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0046: LEFT FRONT DUMP SOLENOID CIRCUIT OPEN NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When left front dump solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will open dump valve by magnetic force created by solenoid coil. Conditions for setting DTC: Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

 

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0047: LEFT FRONT ISOLATION SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

ANTI-LOCK indicator light check complete. High voltage on EBCM solenoid driver circuit when expected to be low (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0048: LEFT FRONT DUMP SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

ANTI-LOCK indicator light check complete. High voltage on EBCM solenoid driver circuit when expected to be low (solenoid not energized).

Diagnostic Procedures

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0051: REAR ISOLATION SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When rear isolation solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will close isolation valve by magnetic force created by solenoid coil. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which can result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0052: REAR DUMP SOLENOID CIRCUIT OPEN NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When rear dump solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will open dump valve by magnetic force created by solenoid coil. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK .

Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

DTC C0053: REAR ISOLATION SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When rear isolation solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will open isolation valve by magnetic force created by solenoid coil. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. Low voltage on EBCM solenoid driver circuit when expected to be high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse is open, go to step 9). If fuse is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0054: REAR DUMP SOLENOID CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

When rear dump solenoid is needed, EBCM will ground solenoid circuit to energize coil within solenoid. This will open dump valve by magnetic force created by solenoid coil. Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Conditions for setting DTC: 

High voltage on EBCM solenoid driver circuit when expected to be low (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). 3. Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). 4. Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. 5. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). 6. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. 8. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 9. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . DTC C0065: PUMP MOTOR RELAY CIRCUIT OPEN NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The relay supplies power to all 6 solenoid coils (3 isolation solenoid coils and 3 dump solenoid coils) when ABS is required. The relay and the 6 solenoid coils are located within the EBCM. Conditions for setting DTC:  

EBCM microprocessor commands the relay on. Low voltage on all 8 solenoid driver circuits when all are expected to high (solenoid not energized).

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

3. 4. 5. 6. 7. 8. 9. 10.

system check, go to next step. Turn ignition off. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could result in loss of power to EBCM. If connector is okay, go to next step. If connector is not okay, go to step 6). Check resistance between ground and 2-pin EBCM harness connector terminal "B". If resistance is 0-2 ohms, go to next step. If not, go to step 7). Check voltage between ground and 2-pin EBCM harness connector terminal "A". If voltage reading is greater than 10 volts, go to step 8). If not, go to next step. Inspect ABS fuse or fusible link. If fuse or fusible link is open, go to step 9). If fuse or fusible link is okay, go to step 10). Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Repair open or high resistance in ground circuit to EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK .

DTC C0066: PUMP MOTOR RELAY CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The relay supplies power to pump motor when ABS is required. The relay is located within the EBCM. Conditions for setting DTC:  

ANTI-LOCK indicator light check complete. High voltage on pump motor driver circuit when all are expected to low (relay not commanded on).

Diagnostic Procedures

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The pump motor circuit is integral to EBCM. The EBCM energizes relay within EBCM to supply battery voltage to high side of pump motor. When pump motor activation is required, EBCM grounds low side of pump motor. Conditions for setting DTC:   

EBCM internal relay on. Pump motor off. Low voltage from low side of pump motor when expected to be high.

Diagnostic Procedures

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

7. Check ABS fuse or fusible link. If fuse or fusible link is open, go to step 13). If fuse or fusible link is okay, go to step 14). 8. Inspect 2-pin EBCM harness connector for poor terminal contact or corrosion. Check for open in ground circuit to EBCM. See WIRING DIAGRAMS . Repair as necessary. Reconnect harness connectors. Using scan tool, clear DTC. Test drive vehicle at speed greater than 10 MPH. If DTC C0067 resets as current DTC, go to step 12). If DTC does not reset, malfunction is intermittent. See DIAGNOSTIC AIDS. 9. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair 2-pin pump motor pigtail connector or wiring. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 11. Repair open or high resistance in ground circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 12. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 13. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 14. Repair open or high resistance in battery circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 15. Replace BPMV assembly. After replacing assembly, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

Pump motor is integral with BPMV assembly and cannot be separately serviced. DTC C0067 can be caused by poor power and ground at the 2-pin EBCM or 2-pin motor harness from the EBCM to the pump motor. The EBCM or BPMV must be replaced if these tests show the pump motor EBCM internal circuitry has failed. DTC C0068: PUMP MOTOR LOCKED OR PUMP MOTOR CIRCUIT SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The pump motor circuit is integral to EBCM. The EBCM energizes the relay within EBCM to supply battery voltage to high side of pump motor. When pump motor activation is required, EBCM grounds low side of pump motor. Conditions for setting DTC:    

Vehicle speed at 8 MPH or greater. EBCM internal relay on. Pump motor commanded on and then off. High voltage from low side of pump motor for 100 milliseconds when expected to be low.

Diagnostic Procedures Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition off. Disconnect 2-pin pump motor pigtail connector from EBCM. Inspect connector and wiring for damage or corrosion that could cause an open circuit between pump motor and EBCM. If connector and wiring are okay, go to next step. If connector or wiring is faulty, go to step 10). 3. Check resistance between terminals No. 1 and 2 of 2-pin pump motor pigtail connector. If resistance is 0.1-0.3 ohm, go to step 15). If not, go to next step. 4. Disconnect 2-pin EBCM harness connector. Inspect connector for damage or corrosion which could cause a loss of power to EBCM. If connector is okay, go to next step. If connector is faulty, go to step 9). 5. Check resistance between ground and terminal No. 2 of 2-pin EBCM harness connector. If resistance is 02 ohms, go to next step. If not, go to step 11). 6. Turn ignition switch to RUN position. Check voltage between ground and terminal No. 1 of EBCM harness connector. If voltage reading is 10 volts or greater, go to step 8). If not, go to next step. 7. Check ABS fuse. If fuse is open, go to step 13). If fuse is okay, go to step 14). 8. Inspect 2-pin EBCM harness connector for poor terminal contact or corrosion. Check for open in ground circuit to EBCM. See WIRING DIAGRAMS . Repair as necessary. Reconnect harness connectors. Using scan tool, clear DTC. Test drive vehicle at speed greater than 10 MPH. If DTC C0068 resets as current DTC, go to step 12). If DTC does not reset, malfunction is intermittent. See DIAGNOSTIC AIDS. 9. Repair 2-pin EBCM harness connector as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair 2-pin pump motor pigtail connector or wiring. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 11. Repair open or high resistance in ground circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 12. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 13. Repair short to ground in battery circuit between underhood fuse/relay block and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 14. Repair open or high resistance in ground circuit to EBCM. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 15. Replace BPMV assembly. After replacing assembly, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

For circuit reference, see WIRING DIAGRAMS .

Circuit Description Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

The EBCM intializes a self-test when ignition switch is turned to RUN position. The EBCM self-test verifies all internal circuitry within the EBCM is operating correctly. Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Using scan tool, attempt to clear DTCs. If DTCs cleared, go to next step. If not, go to step 4). 3. Check for history DTCs and data. If this is the first time DTC has set, perform DIAGNOSTIC SYSTEM CHECK . If DTC was set before, go to next step. 4. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . DTC C0081: STOPLIGHT SWITCH ALWAYS CLOSED OR SHORTED NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The stoplight switch is a normally closed switch. With ignition switch in the RUN position and brake pedal not depressed, ignition voltage will be present at the EBCM. When brakes are applied, the ignition voltage at the EBCM will be zero. Conditions for setting DTC:  

Vehicle speed greater than 35 MPH for 10 seconds followed by vehicle at rest for one second. Stoplight switch never switching during the described condition.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition on. Using scan tool, select DATA LIST function. Check the status of the stoplight switch while applying and releasing brake pedal. If scan tool indicates switch is closed (pedal not applied) at all times, go to next step. If not, go to step 4). 3. Turn ignition off. Disconnect stoplight switch connector. Turn ignition switch to RUN position. Using scan tool, check status of stoplight switch. If scan tool indicates switch is closed (pedal not applied), go to step 7). If not, go to step 8). 4. If scan tool indicates that switch is open (pedal applied) at all times, go to next step. If not, go to step 7). 5. Turn ignition off. Disconnect 10-pin EBCM harness connector. Turn ignition switch to RUN position. Using DVOM, check voltage between ground and terminal "C" of 10-pin EBCM harness connector. If voltage reading is greater than 10 volts, go to next step. If not, go to step 8). 6. Turn ignition off. Reconnect all harness connectors. Turn ignition switch to RUN position. Select DATA LIST function on scan tool. Using scan tool, check status of stoplight switch while applying and releasing brake pedal. If scan tool indicates switch is open (pedal applied) at all times, go to step 9). If not, go to next step. Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

7. Malfunction is intermittent. See DIAGNOSTIC AIDS. After performing necessary repairs, perform DIAGNOSTIC SYSTEM CHECK . 8. Repair faulty stoplight switch or open in stoplight switch circuit between EBCM and stoplight switch. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 9. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . DTC C0086: ANTI-LOCK INDICATOR LIGHT CIRCUIT SHORTED TO BATTERY VOLTAGE NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The ANTI-LOCK indicator light is powered by ignition voltage through the GAUGE fuse. The EBCM output will be high (battery voltage) when indicator light is off, and will be low (ground) when light is on. If DTC C0086 sets, the EBCM will store the code in memory but will not disable the ABS. If DTC C0086 is in memory and a different fault occurs, EBCM will illuminate the BRAKE indicator light to notify operator of the problem. Conditions for setting DTC:  

High voltage on ANTI-LOCK indicator light circuit when expected to be low (light commanded on). Anything that keeps the ANTI-LOCK indicator light circuit high when light is supposed to be illuminated, such as a short to voltage on ABS indicator light circuit between instrument cluster and EBCM. See WIRING DIAGRAMS .

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition switch to RUN position and observe ANTI-LOCK indicator light operation. If indicator light illuminates and then turn off after 3 seconds, go to step 5). If not, go to next step. 3. Turn ignition off. Disconnect 10-pin EBCM harness connector. Using a fused (3-amp) jumper wire, jumper terminal "B" of 10-pin harness connector to ground. Turn ignition switch to RUN position. If ANTI-LOCK indicator light illuminates, go to step 6). If not, go to next step. 4. Inspect jumper wire fuse. If fuse is blown, go to step 7). If fuse is not blown, go to next step. 5. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when components are connected. See DIAGNOSTIC AIDS. After performing necessary repairs, perform DIAGNOSTIC SYSTEM CHECK . 6. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair short to voltage in ANTI-LOCK indicator light circuit between instrumetn cluster and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . Diagnostic Aids

DTC C0086 is typically set by a shorted ANTI-LOCK indicator light, although it can be set from a short to Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

voltage in the circuit between indicator light and EBCM, or a faulty EBCM. DTC C0088: BRAKE WARNING LIGHT CIRCUIT SHORTED TO BATTERY VOLTAGE NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The BRAKE warning light is powered by ignition voltage through the GAUGE fuse. The BRAKE warning light can be illuminated by the EBCM, Daytime Running Lights Module (DRL), brake pressure differential switch or by the park/stoplight switch. If DTC C0088 sets, the EBCM will store the code in memory but will not disable the ABS. If DTC C0086 is also in memory, the EBCM will not attempt to perform the bulb check at start-up. Conditions for setting DTC:  

High voltage on BRAKE warning light circuit when expected to be low (light commanded on). Anything that keeps the BRAKE warning light circuit high when light is supposed to be illuminated, such as a short to voltage on BRAKE warning light control circuit.

Diagnostic Procedures

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK . After performing diagnostic system check, go to next step. 2. Turn ignition switch to RUN position and observe BRAKE warning light operation. If indicator light illuminates and then turn off after 3 seconds, go to step 5). If not, go to next step. 3. Turn ignition off. Disconnect 10-pin EBCM harness connector. Using a fused (3-amp) jumper wire, jumper terminal "H" of 10-pin harness connector to ground. Turn ignition switch to RUN position. If BRAKE warning light illuminates, go to step 6). If not, go to next step. 4. Inspect jumper wire fuse. If fuse is blown, go to step 7). If fuse is not blown, go to next step. 5. Malfunction is intermittent. Inspect all connectors and harnesses for damage which may result in high resistance when components are connected. See DIAGNOSTIC AIDS. After performing necessary repairs, perform DIAGNOSTIC SYSTEM CHECK . 6. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 7. Repair short to voltage in BRAKE warning light circuit. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK. Diagnostic Aids

DTC C0088 is typically set by a shorted BRAKE warning light, although it can be set from a short to voltage in the circuit between indicator light and EBCM, or a faulty EBCM.

SYMPTOM TESTS TEST A: ANTI-LOCK LIGHT DOES NOT ILLUMINATE - NO DTCS Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

NOTE:

For circuit reference, see WIRING DIAGRAMS .

Circuit Description

The EBCM controls the ANTI-LOCK indicator light by supplying ground to turn on or battery voltage to turn off the indicator light. If indicator light is off constantly, check for an open or short to voltage in the light circuit between indicator light and EBCM. Also check for open in GAUGES fuse or faulty light bulb. Diagnostic Procedures

1. Perform Diagnostic System Check. If diagnostic system check has been performed, go to next step. If not, go to DIAGNOSTIC SYSTEM CHECK . 2. Turn ignition off. Disconnect 10-pin EBCM harness connector. Using a fused jumper wire, jumper terminal "B" of 10-pin harness connector to ground. Turn ignition switch to RUN position. If ANTILOCK indicator light illuminates, go to next step. If not, go to step 4). 3. Inspect 10-pin EBCM harness connector for damage or corrosion. If connector is okay, go to step 9). If connector is not okay, go tostep 8). 4. Inspect jumper wire fuse. If fuse is blown, go to step 10). If fuse is okay, go to next step. 5. Inspect 10-amp GAUGE fuse. If fuse is blown, go to next step. If fuse is okay, go to step 7). 6. Turn ignition off. Replace fuse. Turn ignition switch to RUN position. Remove and inspect GAUGE fuse. If fuse is blown, go to step 13). If fuse is okay, go to step 14). 7. Remove and inspect ANTI-LOCK indicator light bulb. If bulb is okay, go to step 12). If bulb is faulty, go to step 11). 8. Repair 10-pin EBCM harness connector. After repairs, perform DIAGNOSTIC SYSTEM CHECK . 9. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 10. Repair short to voltage in ANTI-LOCK indicator light circuit between EBCM and instrument cluster. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 11. Replace ANTI-LOCK indicator light bulb. After replacing light bulb, perform DIAGNOSTIC SYSTEM CHECK . 12. Repair open in circuit between fuse block and instrument cluster, or ANTI-LOCK indicator light control circuit between instrument cluster and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 13. Repair short to ground in brake warning light control circuit between instrument cluster and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK . 14. Problem is an intermittent short to ground in brake warning light control circuit between instrument cluster and EBCM. See WIRING DIAGRAM. Repair as necessary. After repairs, perform DIAGNOSTIC SYSTEM CHECK . TEST B: ANTI-LOCK LIGHT IS ON AT ALL TIMES - NO DTCS NOTE:

For circuit reference, see WIRING DIAGRAMS .

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Circuit Description

The EBCM controls the ANTI-LOCK indicator light by supplying ground to turn on or battery voltage to turn off the indicator light. If indicator light is on constantly, check for short to ground in the light circuit between indicator light and EBCM, or EBCM is not capable of turning off indicator light. Diagnostic Procedures

1. Perform Diagnostic System Check. If diagnostic system check has been performed, go to next step. If not, go to DIAGNOSTIC SYSTEM CHECK . 2. Turn ignition off. Disconnect 10-pin EBCM harness connector from EBCM. Turn ignition switch to RUN position. If ANTI-LOCK indicator light illuminates and stays illuminated, go to step 4). If not, go to next step. 3. Replace EBCM. After replacing EBCM, perform DIAGNOSTIC SYSTEM CHECK . 4. Repair short to ground in ANTI-LOCK indicator light control circuit between instrument cluster and EBCM. See WIRING DIAGRAMS . After repairs, perform DIAGNOSTIC SYSTEM CHECK.

1. Disconnect negative battery terminal. Remove bolts to shield and mounting bracket to BPMV and EBCM. Disconnect harness connector from BPMV. Remove brake lines from BPMV. Remove bolts to separate combination valve and BPMV. Remove 2 transfer tubes. NOTE:

DO NOT reuse transfer tubes.

2. To install, reverse removal procedure. Bleed brake system, including BPMV. See BLEEDING BRAKE SYSTEM . DO NOT overtighten BPMV-to-bracket bolts during installation. This may cause excessive noise transfer into vehicle. See TORQUE SPECIFICATIONS . ELECTRONIC BRAKE CONTROL MODULE Removal & Installation

1. Disconnect negative battery terminal. Disconnect harness connector from EBCM and combination valve. Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Remove 4 module retaining screws. 2. To install, reverse removal procedure. DO NOT use RTV or any other type of sealant on EBCM gasket or mating surfaces. FRONT WHEEL SPEED SENSOR NOTE:

For installation purposes, note speed sensor wire routing before removing. Misrouted wiring may cause electromagnetic interference failures.

Removal & Installation (2WD)

1. Remove wheel. Remove brake caliper and wire aside. Remove hub and rotor. Disconnect speed sensor connector. Remove splash shield and speed sensor assembly. To install, reverse removal procedure. Tighten wheel bearing nut to 12 ft. lbs. (16 N.m), then back off until just loose. 2. Hand tighten wheel bearing nut. Back off wheel bearing nut no more than 1/2 of a flat, until hole in spindle aligns with slot in wheel bearing nut. If wheel bearing nut is adjusted properly, hub end play should be .001-.005" (.03-.13 mm). If hub end play is not within specification, repeat procedure. Speed sensor air gap is non-adjustable. Removal & Installation (4WD)

1. Remove wheel. Remove brake caliper and wire aside. Remove drive axle nut. Disconnect speed sensor electrical connector. Remove speed sensor wire from clip on upper control arm. Remove bolts retaining hub and bearing. Remove splash shield bolts. Using a puller, remove hub and bearing. 2. Remove splash shield and speed sensor assembly. Remove speed sensor from splash shield. Remove speed sensor wire harness from splash shield. To install, reverse removal procedure. Ensure drive axle nut is properly tightened. 3. DO NOT move drive axle nut more than 1/6 of a turn to align cotter pin. If speed sensor is being replaced, drill out rivet in splash shield, and replace rivet with a small bolt, nut and washer. Speed sensor air gap is non-adjustable. VEHICLE SPEED SENSOR Removal & Installation

1. Vehicle Speed Sensor (VSS) is located in left rear of transmission (2WD) or transfer case (4WD). Ensure ignition is off. Raise and support vehicle. Disconnect VSS electrical connector. Place a container under VSS mounting area to catch transmission fluid when VSS is removed. 2. Remove VSS mounting bolt. Remove VSS and "O" ring using J-38417. To install, coat NEW "O" ring with transmission fluid. Install "O" ring onto VSS. Install VSS and "O" ring into transmission using J38417. Tighten mounting nuts or bolts to specification. See TORQUE SPECIFICATIONS table.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Application Axle Nut (4WD) BPMV Bracket-To-Body Bolt Brake Caliper Mounting Bolt Brakeline-To-Combination Valve Front & Rear Combination Valve-To-BPMV

Ft. Lbs. (N.m) 103 (140) 21 (28) 37 (50) 22 (29) 22 (29) 12 (16)

Front Wheel Speed Sensor Mounting Bolt (1) 2WD 4WD Splash Shield Bolt Tube Adapters-To-BPMV

19 (26) 13 (18) 12 (16) 23 (31) 12 (16)

Wheel Bearing Nut (2WD) (2) Wheel Lug Nut

95 (129) INCH Lbs. (N.m) EBCM-To-BPMV 39 (5) Speed Sensor Harness Clip Bolt 9 (12) (1) Not all models have speed sensor mounting bolts. Some models have a speed sensor which is mounted on splash shield. (2) See FRONT WHEEL SPEED SENSOR under REMOVAL & INSTALLATION for proper adjustment.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Microsoft Saturday, August 29, 2009 11:26:12 AM

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Fig. 1: 4WAL Brake System Wiring Diagram (2.2L)

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

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1997 Chevrolet S10 Pickup ANTI-LOCK BRAKE SYSTEM 1997 BRAKES General Motors Corp. - Anti-Lock - 4WAL

Fig. 2: 4WAL Brake System Wiring Diagram (4.3L)

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

APPLICATION TRANSMISSION APPLICATIONS Application Chevrolet Blazer S10 Pickup GMC Envoy (1998) Jimmy Sonoma Isuzu Hombre Oldsmobile Bravada

Transmission Model 4L60-E 4L60-E 4L60-E 4L60-E 4L60-E 4L60-E 4L60-E

IDENTIFICATION The 4L60-E transmission can be identified by a letter code contained in identification number. Identification number is stamped on transmission case above oil pan rail on right rear side, or to rear of oil pan. See Fig. 1 . Identification number contains information which must be used when ordering replacement parts. Transmission RPO code is M30.

Microsoft Saturday, August 29, 2009 11:54:38 11:54:33 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 1: Locating Transmission Identification Number Courtesy of GENERAL MOTORS CORP.

DESCRIPTION Microsoft Saturday, August 29, 2009 11:54:33 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

The 4L60-E is a fully automatic transmission consisting of a 3-element hydraulic torque converter with a Torque Converter Clutch (TCC). The 4-speed transmission is equipped with 2 planetary gear sets, 5 multipledisc clutches, one sprag clutch, one roller clutch and a 2-4 band. See Fig. 2 . A hydraulic system, pressurized by a variable capacity vane type oil pump, provides pressure required to operate friction elements and automatic controls. The 4L60-E also contains electronic solenoids to control hydraulic operations. A Powertrain Control Module (PCM) receives signals from Vehicle Speed Sensor (VSS), Throttle Position (TP) Sensor, fluid pressure switch assembly, and temperature sensor. These signals help PCM determine when to switch 2 shift solenoids, 3-2 downshift solenoid, and/or TCC solenoid on or off. PCM can also control line pressure via pressure control solenoid (force motor).

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 2: Locating 4L60-E Transmission Components Courtesy of GENERAL MOTORS CORP.

LUBRICATION & ADJUSTMENTS See TRANSMISSION SERVICING - A/T article in the TRANSMISSION SERVICING section.

ON-VEHICLE SERVICE Microsoft Saturday, August 29, 2009 11:54:33 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

OIL COOLER FLUSHING 1. If available, fill Line Flusher (J-35944) with solution, and install line flusher to transmission end of cooler line that feeds bottom fitting of transmission cooler. Connect discharge hose to top cooler line and attach drain hose to oil drain container. Follow manufacturer's instructions to flush oil cooler and cooler lines. 2. If line flusher is not available, flush cooler and cooler lines with a mixture of clean solvent and water. Flush cooler in both directions until all old fluid and debris are removed. If necessary, replace plugged or damaged cooler and/or lines. REAR OIL SEAL Removal & Installation

Mark drive shaft for reassembly reference. Remove drive shaft. Pry oil seal from extension housing. Coat outside edge of NEW oil seal with non-hardening sealer. Using Seal Installer (J-21426), install oil seal. To complete installation, install drive shaft. Check fluid level. VALVE BODY CAUTION: Note valve body bolt length and location during removal procedure. Transmission case damage may occur if bolts are incorrectly installed. Removal

1. Remove transmission oil pan. Remove oil filter and "O" ring. Ensure "O" ring is removed from transmission case. Remove electrical connectors from switches and solenoids, and mark for reassembly reference. Remove pressure switch assembly. Remove detent spring bolt. Remove detent spring. Remove valve body bolts. Note length and location of bolts for installation reference. 2. Note direction of manual valve link. Remove manual valve link from manual valve at valve body. See Fig. 3 . Remove valve body. Note location of check balls. DO NOT lose balls. See Fig. 4 and Fig. 5 .

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 3: Installing Manual Valve Link Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 4: Locating Valve Body Check Balls Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 5: Locating Check Balls In Case Courtesy of GENERAL MOTORS CORP. Installation

1. Coat check balls with petroleum jelly. Install check balls in proper locations on separator plate. See Fig. 4 and Fig. 5 . Install manual valve link. Ensure manual valve link is properly seated in manual valve. See Fig. 3 . Improper positioning may prevent vehicle operation in "D" range. NOTE:

Improper positioning of throttle valve link will result in erratic shift points or high oil pressure.

2. Install valve body and retaining bolts. Tighten all bolts to specification. See TORQUE SPECIFICATIONS . Lubricate oil filter "O" ring with ATF before installation. To complete installation, reverse removal procedure. Fill transmission with fluid. Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

2-4 SERVO ASSEMBLY Removal & Installation

Install Piston Compressor (J-29714) on oil pan. Compress servo cover, and remove retaining ring. See Fig. 6 . Remove servo cover and "O" ring. Remove 2-4 servo assembly. To install, reverse removal procedure. For servo pin length check, see 2-4 SERVO ASSEMBLY under TRANSMISSION DISASSEMBLY .

Fig. 6: Compressing Servo Cover Courtesy of GENERAL MOTORS CORP.

TROUBLE SHOOTING NOTE:

For testing and diagnostic procedures of electronic components, see AUTO TRANS DIAGNOSIS article.

NOTE:

For clutch and band applications, see CLUTCH & BAND APPLICATION CHART .

SYMPTOM DIAGNOSIS Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

1st Gear Only, No Upshift

Check 1-2 shift valve sticking in valve body. Spacer plate or gaskets damaged or not positioned properly. Caseto-valve body face damaged or not flat. 2-4 servo assembly restricted or blocked case passages. Nicks or burrs on servo pin or case pin bore. Missing or damaged piston or pin seals. 4th servo piston installed backward. 2-4 band worn or damaged, or band anchor pin not engaged. Check shift solenoids. Slips In 1st Gear

Defective forward clutch assembly. Clutch plates worn. Piston porous or damaged. Piston seals missing or damaged. Input housing-to-forward clutch housing "O" ring seal missing or damaged. Damaged housing. Housing retainer and ball assembly damaged or not seating. Input shaft and housing assembly turbine shaft seals missing or damaged. Accumulator valve stuck in valve body. Valve body face not flat, damaged lands, or interconnected passages. Spacer plate or gaskets incorrect, damaged or not positioned properly. Check for defective 1-2 accumulator piston assembly. Porosity in piston or cover and pin assembly. Damaged piston ring grooves. Piston seal missing or damaged. Cover gasket missing or damaged. Broken accumulator spring. Incorrect oil pressure. Torque converter stator roller clutch not holding or 4th servo piston in backward. Damage to low roller clutch lugs or inner ramps. Rollers not free moving, inadequate spring tension or damage to inner splines. Oil passage plugged. Forward clutch accumulator piston seal missing or damaged. Piston out of its bore. Stuck abuse valve. Slipping Or Rough 1-2 Shift

Check for defective valve body assembly. 1-2 shift valve train or accumulator valve stuck. Gaskets or spacer plate incorrect, damaged or not installed properly. Valve body face not flat. Defective 2-4 servo assembly. Apply pin length incorrect. Servo seals or "O" ring seals missing or damaged. Restricted or missing oil passages. Case servo bore damaged. Defective 2nd accumulator. Porosity in 1-2 accumulator housing or piston. Piston seal or groove damaged. Nicks or burrs in 1-2 accumulator housing. Missing or restricted oil passages or 2-4 band worn or not positioned properly. Oil pump assembly or case faces not flat. Slipping, Rough Or No 2-3 Shift

Check for defective valve body assembly. 2-3 shift valve train or accumulator valve stuck. Gaskets or spacer plate incorrect, damaged or not installed properly. Valve body face not flat. Defective 2-4 servo assembly. Apply pin length incorrect. Servo seals or "O" ring seals missing or damaged. Restricted or missing oil passages. Case servo bore damaged. Defective 2nd accumulator. Porosity in 1-2 accumulator housing or piston. Piston seal or groove damaged. Nicks or burrs in 1-2 accumulator housing. Missing or restricted oil passages or 2-4 band worn or not positioned properly. Oil pump assembly or case faces not flat. 1st & 4th Or 2nd & 3rd Gear Only Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Check shift solenoids for dirt, damaged seals or electrical connections. 3rd Gear Only

Check 2-3 shift solenoid and 3-2 control solenoid circuits, damaged seals or electrical connections. 3-2 Flare Or Tie Up

Check 3-2 control solenoid for dirt, damaged seals or electrical connections. Slipping, Rough Or No 3-4 Shift

Check oil pump assembly faces not flat or pump cover retainer and ball assembly omitted or damaged. Valve body assembly 2-3 shift train, accumulator valve, 1-2 shift valve or 3-2 control valve stuck. Manual valve link bent or damaged. Spacer plate or gaskets incorrect, damaged or not positioned properly. Defective 2-4 servo assembly. Incorrect band apply pin. Servo seals missing or damaged. Porosity in pistons, cover or case. Plugged or missing orifice cup plug. Case 3rd accumulator retainer and ball assembly leaking. Porosity in 3-4 accumulator piston or bore. 3-4 accumulator piston seal or seal grooves damaged. Restricted oil passage. Defective input housing assembly. Forward or 3-4 clutch plates worn, or excessive plate travel. Forward or 3-4 piston seals damaged. Porosity in 3-4 clutch housing or piston. 3-4 piston check ball stuck, damaged or not sealing. Restricted apply passages. Forward clutch piston retainer and ball assembly not seating. 2-4 band worn or not positioned properly. Sealing balls loose or missing. No Reverse Or Slips In Reverse

Defective input housing assembly. 3-4 apply ring stuck in applied position. Forward clutch not releasing. Turbine shaft seals missing or damaged. Manual valve link disconnected. Defective valve body assembly. 2-3 shift valve stuck. Manual linkage out of adjustment. Spacer plate and gaskets incorrect, damaged or not positioned properly. Defective reverse input clutch assembly. Clutch plate worn. Housing and drum assembly cracked at weld. Clutch plate or return spring assembly retaining ring out of groove. Piston deformed or dished. Seals damaged or missing. Retainer and ball assembly not sealing. Restricted apply passage. Defective lowreverse clutch. Clutch plates worn or retaining ring not positioned properly. Porosity in piston. Seals damaged. Return spring assembly retaining ring not positioned properly. Case porosity. Case cover plate not tightened properly or gasket missing or damaged. No Part-Throttle Or Delayed Downshifts

Check for defective 2-4 servo assembly. Servo cover retaining ring missing or not assembled properly. 4th apply piston damaged or not assembled properly. Inner housing damaged or not assembled properly. Defective valve body assembly. 3-2 control valve stuck. 4-3 sequence valve body channel blocked. No. 5 check ball missing. Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Harsh Garage Shifts

Check valve body for missing check ball, or orifice cup plug. No Overrun Braking In Manual 3-2-1

Defective valve body assembly. 4-3 sequence valve or throttle valve stuck. No. 3 check ball not positioned properly. Spacer plate and gaskets incorrect, damaged or not positioned properly. Defective input clutch assembly. Turbine shaft oil passages plugged or not drilled. Turbine shaft seal rings damaged. Turbine shaft sealing balls loose or missing. Porosity in forward or overrun clutch piston. Overrun piston seals damaged or cut. Overrun piston check ball not sealing. Drives (Creeps) In Neutral

Forward clutch not releasing. Manual valve link disconnected. Converter clutch apply valve stuck in oil pump. Face of transmission case not flat or internal leakage in case. Starts In 2nd In "D"

Forward sprag clutch assembly installed backward. No Park

Parking linkage binding, loose, missing or not positioned properly. Oil Pressure High Or Low

Oil pressure regulator valve stuck or valve spring damaged. Rotor guide omitted or not assembled properly. Rotor cracked or reverse boost valve or sleeve stuck, damaged or not assembled properly. Orifice hole in pressure regulator valve plugged. Sticking slide or excessive rotor clearance. Pressure relief ball not seated or damaged. Pump cover or body has porosity. Incorrect pump cover or pump face not flat. Excessive rotor clearance. Intake pipe restricted by casting flash. Cracks in filter body or intake pipe. "O" ring seal missing, cut or damaged. Incorrect lubricant used during rebuild procedure. Manual valve scored or damaged. Spacer plate or gaskets incorrect, damaged or not assembled properly. Check for stuck 2-3 shift valve, damaged pressure control solenoid or damaged pressure switch assembly. Check for missing check balls or incorrect assembly. Case-to-valve body face not flat. Harsh Shifts

Check PCM input signals from TP sensor, pressure switch assembly, fluid temperature sensor, VSS and engine coolant temperature sensor. Inspect pressure control solenoid for damaged pins or seals, or dirt in oil circuits. High Or Low Shift Points

Check for stuck pressure regulator valve or pump slide sticking. Spacer plate or gaskets damaged, incorrect or Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

not assembled properly. Valve body pad porous or damaged. 2-4 accumulator has porosity. Servo piston seals damaged. Apply pin damaged or has improper length. 2-4 band burned or anchor pin not engaged. Throttle Position (TP) sensor, VSS and/or 4WD low switch (if equipped) disconnected or damaged. No Converter Clutch Apply

Transmission not supplied 12 volts. Outside electrical connector damaged. Inside electrical connector wiring harness or solenoid damaged. Solenoid wire pinched. Solenoid not grounded. Pressure switches incorrect or damaged. Temperature sensor damaged. Damaged engine speed sensor or pressure switch assembly. Converter internal damage. Converter clutch valve stuck or assembled backward, or retaining ring not positioned properly. Pump-to-case gasket not positioned properly. Orifice cup plug restricted or damaged. Solenoid "O" ring seal cut or damaged. Pump-to-body cover high or uneven bolt torque.Turbine shaft "O" ring seal cut or damaged. Turbine shaft retainer and ball assembly restricted or damaged. TCC shift valve or apply valve stuck. Solenoid "O" ring leaking. Solenoid screen is blocked. Converter Shudder

Torque converter has internal damage. Converter clutch valve stuck. Restricted oil passages. Crack in filter body. Restriction in filter neck. "O" ring seal cut or damaged. Turbine shaft "O" ring cut or damaged. Turbine shaft retainer and ball assembly restricted or damaged. Low oil pressure. Engine not tuned properly. No Converter Clutch Release

Solenoid external ground. Converter internal damage. Converter clutch valve stuck. Converter clutch apply valve stuck in apply position. PCM external ground faulty. Converter Clutch Applies When Cold

Check engine coolant temperature sensor and trouble codes. Ratcheting Noise

Parking pawl return spring weak, damaged or not assembled properly. Oil Leaking Out Vent

Chamber in pump body rotor pocket too large. Fluid level overfilled. Cross leak out of pump body and cover. Vibration In Reverse & Whining Noise In Park

Broken oil pump vane rings. Front Oil Leak Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Torque converter welded seam leaking. Damaged torque converter hub. Damaged front seal. Pump Bushing Spins Out, "Walks" Into Seal, Or Seizes To Converter Hub

Transmission and engine center lines do not match. Excessive crankshaft runout. Bent flexplate (drive plate). Excessive converter hub runout. Pump bushing I.D. not centered in pump. Bushing too loose in pump. Not enough hub-to-bushing clearance. Falls Out Of 4th Gear During Coasting

Low line pressure at idle (weak pressure regulator spring). Binds Up On 3-4 Shift (Feels Like Brake Drag)

Forward pressure plate installed incorrectly. Too many plates in overrun clutch. Incorrect top steel plate installed in overrun clutch. No Forward Or Reverse Gears (Line Pressure Reading Okay)

Mismatched converter input shaft or broken turbine hub. Binds Up In Reverse

Stator sleeve rotated out of position. Stuck2-3 shift valve. Servo pin jammed in case. Stuck 3-4 relay or 4-3 sequence valve. No Drive In "D" Range

Torque converter stator roller clutch not holding. No Drive In "OD" Range

Faulty output sprag. Teeth "hammered" out of forward friction plates. CLUTCH & BAND APPLICATION CLUTCH & BAND APPLICATION CHART Shift Solenoid Selector Lever Position Position "D" (Overdrive) First 1-2 ON/2-3 ON Gear "D" (Overdrive) Second 1-2 OFF/2-3 ON Gear "D" (Overdrive) Third 1-2 OFF/2-3 OFF Gear "D" (Overdrive) 1-2 ON/2-3 OFF Overdrive

Elements In Use Forward Clutch, Forward Sprag & Low Roller Clutch Forward Clutch, Forward Sprag & 2-4 Band Forward Clutch, Forward Sprag & 3-4 Clutch Forward Clutch, 2-4 Band & 3-4 Clutch

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

"D" (Drive) First Gear 1-2 ON/2-3 ON "D" (Drive) Second Gear 1-2 OFF/2-3 ON "D" (Drive) Third Gear

1-2 OFF/2-3 OFF

"2" (Intermediate) First 1-2 ON/2-3 ON Gear "2" (Intermediate) Second 1-2 OFF/2-3 ON Gear "1" (Low) First Gear "1" (Low) Second Gear (1)

1-2 ON/2-3 ON 1-2 OFF/2-3 ON

"R" (Reverse) 1-2 ON/2-3 ON "P" (Park) 1-2 ON/2-3 ON "N" (Neutral) 1-2 ON/2-3 ON (1) Gear is only available above 30-35 MPH.

Forward Clutch, Forward Sprag & Low Roller Clutch Forward Clutch, Forward Sprag & 2-4 Band Forward Clutch, Forward Sprag, Overrun Clutch & 3-4 Clutch Forward Clutch, Forward Sprag, Low Roller Clutch & Overrun Clutch Forward Clutch, Forward Sprag, Overrun Clutch & 2-4 Band Forward Clutch, Forward Sprag, Low Reverse Clutch, Low Roller Clutch & Overrun Clutch Forward Clutch, Forward Sprag, Overrun Clutch & 2-4 Band Low Reverse Clutch & Reverse Input Clutch Low Reverse Clutch All Clutches & Bands Released Or Ineffective

TORQUE CONVERTER NOTE:

Torque converter is a sealed unit and must be serviced as a complete assembly.

INSPECTION Torque converter must be replaced for any of the following reasons:        

Damage To Pump Assembly Metal Particles Present In Oil Leaks In Hub Weld Area Hub Scored Or Damaged Stator Failure Torque Converter Imbalance Engine Coolant Contamination Excessive End Play

STALL TEST 1. Torque converter whine is usually noticed when vehicle is stopped and transmission is in Reverse or Drive. Whine will increase when engine RPM is increased and will stop when vehicle is moving or when torque converter clutch is applied. Stall test is to ensure whine is coming from torque converter. 2. Start engine, and allow it to reach normal operating temperature. Apply parking and service brakes. Put transmission in Drive. Depress accelerator to about 1200 RPM for less than 6 seconds. DO NOT depress Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

accelerator for more than 6 seconds or transmission damage may occur. Torque converter noise will increase under this load. NOTE:

Torque converter whine should not be confused with pump whine, which is usually noticeable in Park, Neutral and all other gear ranges. Pump whine will vary with pressure.

STATOR CHECK 1. Torque converter stator roller clutch can either remain locked up at all times or freewheel in both directions. If stator is freewheeling at all times, vehicle tends to have poor acceleration from a stop. Vehicle may act normal at speeds above 30-35 MPH. 2. If poor acceleration is noted, ensure exhaust system is not blocked, engine timing is correct and transmission is in 1st gear when starting from a stop. If stator is locked up at all times, performance from a stop appears normal. Engine RPM and acceleration is limited at high speeds. Engine may overheat from this condition. 3. A visual inspection of torque converter may reveal converter is Blue from overheating. If torque converter has been removed from vehicle, stator roller clutch can be checked by inserting a finger into splined inner race of roller clutch and trying to turn race in both directions. Inner race should turn freely clockwise but should not turn or should be difficult to turn counterclockwise. TORQUE CONVERTER END PLAY CHECK 1. Inspect torque converter for hub scoring, cracks or weld area cracks before checking end play. Install End Play Checking Tool(J-35138) on torque converter. See Fig. 7 . 2. Note end play of torque converter. End play must be within specification. See TORQUE CONVERTER END PLAY SPECIFICATIONS table. Replace torque converter if end play is not within specification or damage to hub area exists. TORQUE CONVERTER END PLAY SPECIFICATIONS Converter Diameter: In. (mm) 9.65 (245.0) 11.73 (298.0)

End Play: In. (mm) .0-.020 (.0-.51) .0-.024 (.0-.61)

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 7: Checking Torque Converter End Play Courtesy of GENERAL MOTORS CORP.

ELECTRONIC SELF-DIAGNOSTICS & ELECTRONIC TESTING NOTE:

See AUTO TRANS DIAGNOSIS - 4L60-E article.

TESTING ROAD TEST NOTE:

Shift speed charts reference throttle position angle instead of minimum or wide open throttle position. This measurement is more accurate. A scan tool should be used to monitor throttle position angle. For transmission model code, refer to metal identification tag attached to transmission.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Gear Selector Position "D4" (Overdrive)

1. With gear selector in "D4" (overdrive) position, choose throttle position angle of 12 or 25 percent. See Fig. 8 or Fig. 9 . Set scan tool to monitor throttle position angle and vehicle speed. Accelerate vehicle to chosen throttle position angle and hold throttle steady. 2. Note shift speed engagement points in 2nd gear, 3rd gear and overdrive gear. Use charts as a reference for proper shift speeds. See Fig. 8 or Fig. 9 . Also note Torque Converter Clutch (TCC) engagement point while in overdrive. Repeat procedure using different throttle position angle. NOTE:

Shift speeds may vary due to slight hydraulic delays responding to electronic controls. A change from original equipment tire size also affects shift speeds. Ensure TCC engages in 3rd or overdrive. TCC should not apply unless transmission has reached a minimum operating temperature of 64°F (18°C) and engine coolant temperature is 140°F (60°C).

3. At vehicle speeds of 40-50 MPH in overdrive, quickly increase throttle position angle to more than 50 percent. Verify TCC releases, transmission immediately downshifts to 3rd gear and 1-2 shift solenoid turns off. 4. At vehicle speeds of 40-50 MPH in overdrive, quickly depress accelerator to wide open position (full throttle detent downshift). Verify TCC releases, transmission immediately downshifts to 2nd gear, 1-2 solenoid is off and 2-3 solenoid is on. 5. At vehicle speeds of 40-55 MPH in overdrive, release accelerator pedal while moving gear selector to "D3" (third gear) position. Verify TCC releases, transmission immediately downshifts into 3rd gear, and engine braking slows vehicle. 6. Move gear selector to "D4" (overdrive) position, and accelerate to 40-45 MPH. Release accelerator pedal while moving gear selector to "D2" (2nd gear) position. Verify TCC releases, transmission immediately downshifts to 2nd gear, and engine braking slows vehicle. 7. Move gear selector to "D4" (overdrive) position, and accelerate to 30 MPH. Release accelerator pedal while moving gear selector to "D1" (1st gear) position. Verify TCC releases, transmission immediately downshifts to 1st gear and engine braking slows vehicle. 8. With gear selector in the "D4" (overdrive) position, accelerate vehicle to overdrive gear with TCC applied. Release accelerator pedal, and lightly apply brakes. Verify TCC releases and downshifts occur at speeds shown in shift speed charts. See Fig. 8 or Fig. 9 . NOTE:

Upshifts in manual gear ranges are controlled by shift solenoids. Perform following steps by accelerating vehicle at throttle position angle of 10-15 percent.

Gear Selector Position "D3" (3rd Gear)

With vehicle stopped, move gear selector to "D3" (3rd gear) position and steadily increase throttle pressure to accelerate vehicle. Note speeds at which vehicle shifts into 2nd and 3rd gears. See Fig. 8 or Fig. 9 . Gear Selector Position "D2" (2nd Gear)

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

With vehicle stopped, move gear selector to "D2" (2nd gear) position. Accelerate vehicle and note speed at which vehicle shifts from 1st gear to 2nd gear. Accelerate vehicle to 35 MPH. Verify transmission does not shift into 3rd gear, and TCC does not apply. Gear Selector Position "D1" (1st Gear)

With vehicle stopped, move gear selector to "D1" (1st gear) position. Accelerate vehicle to 20 MPH. Verify transmission does not upshift, and TCC does not apply. Gear Selector Position "R" (Reverse)

With vehicle stopped, move gear selector to "R" (Reverse) position. Verify 1-2 and 2-3 shift solenoids are on. SHIFT SPEED CHARTS

Fig. 8: Hydra-Matic 4L60-E Shift Speed Charts (1997) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 9: Hydra-Matic 4L60-E Shift Speed Charts (1998) Courtesy of GENERAL MOTORS CORP. HYDRAULIC PRESSURE TEST CAUTION: Parking and service brakes must be applied throughout hydraulic pressure test. Total time for testing with vehicle in any driving gear should not exceed 2 minutes. Transmission damage may occur. 1. Before performing hydraulic pressure test, check fluid level and condition. Check manual control linkages for correct adjustment, and ensure engine is properly tuned. 2. Connect scan tool to Data Link Connector (DLC). Apply parking brake and start engine. Check for stored trouble codes. If trouble codes are present, diagnose as necessary. See AUTO TRANS DIAGNOSIS article. Turn engine off. Connect oil pressure gauge to line pressure test port. See Fig. 10 . 3. Start engine and warm to normal operating temperature. With vehicle in Reverse, line pressure should be 64-324 psi (441-2234 kPa). With vehicle in Park, Neutral or Drive, line pressure should be 55-189 psi (379-1303 kPa). 4. Shift transaxle into Park. Access Pressure Control Solenoid (PCS) test on scan tool. Increase DESIRED PCS in .1 amp increments and read corresponding line pressure on oil pressure gauge. Allow pressure to stabilize for 5 seconds after each current change. Compare readings to LINE PRESSURE SPECIFICATIONS . If pressure readings are not as specified, and no trouble codes are present, internal malfunction exists. See TROUBLE SHOOTING . NOTE:

Scan tool is only able to control pressure control solenoid in Park and Neutral

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

with vehicle stopped. This protects clutches from extremely high or low pressures in Reverse and Drive. LINE PRESSURE SPECIFICATIONS PCS Current (Amp) .02 .10 .20 .30 .40 .50 .60 .70 .80 .90 .98

Line Pressure - psi (kPa) 170-190 (1172-1310) 165-185 (1137-1275) 160-180 (1103-1241) 155-175 (1068-1207) 148-168 (1020-1158) 140-160 (965-1103) 130-145 (896-1000) 110-130 (758-896) 90-115 (621-793) 65-90 (448-621) 55-65 (379-448)

Fig. 10: Installing Oil Pressure Gauge Courtesy of GENERAL MOTORS CORP.

REMOVAL & INSTALLATION See TRANSMISSION REMOVAL & INSTALLATION - A/T article in the TRANSMISSION SERVICING Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

section.

TRANSMISSION DISASSEMBLY NOTE:

Beginning at start of production for all 1996 models, some 4L60-E transmissions were built with a bolt-on bellhousing. Design change will make 4L60-E transmission more versatile for a wide variety of engine sizes. Bolts securing bellhousing require a Torx-Plus 50-IP bit for removal. Bolt heads will strip if incorrect tool is used during removal. Transmission case has a totally different casting design for bolt-on bellhousing. Oil pump body has a machined ring added to front of pump body to center bellhousing on installation.

2-4 SERVO ASSEMBLY 1. Mount transmission on bench using Holding Fixture (J-8763-02). Remove torque converter. Install Servo Cover Compressor (J-29714) on oil pan. See Fig. 6 . Compress servo cover. Remove retaining ring, servo cover and "O" ring. 2. Remove 2-4 servo assembly. Servo pin length should be checked before disassembling assembly to determine 2-4 band and reverse input drum wear or damage. CHECKING SERVO PIN LENGTH 1. Remove 4th apply piston and return spring. See Fig. 11 . Remove retainer ring, washer, apply pin spring and 2nd apply pin. Install Piston Compressor (J-22269-01) on 2nd apply piston. See Fig. 12 . 2. Remove retainer ring, cushion spring and spring retainer. Install Band Apply Pin Tool (J-33037) and apply pin. See Fig. 13 . Apply 100 INCH lbs. (11 N.m) torque. 3. White line on band apply tool should be within gauge slot if pin length is correct. If White line is not within gauge slot, inspect 2-4 band and reverse input drum for wear and damage during disassembly. 4. Servo pin length must be checked during reassembly. Servo pin is preset and must not be readjusted. See SERVO PIN SPECIFICATIONS table under 2-4 BAND & SERVO ASSEMBLY under TRANSMISSION REASSEMBLY.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 11: Exploded View Of 2-4 Servo Assembly Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 12: Compressing 2nd Apply Piston Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 13: Measuring Servo Pin Length Courtesy of GENERAL MOTORS CORP. EXTENSION HOUSING Remove speed sensor retaining bolt. Using Puller (J-38417), remove speed sensor assembly and "O" ring. See Fig. 16 . Remove extension housing and seal. Remove output shaft sleeve and "O" ring (if equipped). Remove speed sensor rotor from output shaft (if necessary). Install Gear Puller (J-21427-01) and Adapter (J-8433) on rotor. Pull rotor from output shaft. 1-2 ACCUMULATOR & SPACER PLATES 1. Remove solenoid retaining bolts. Remove solenoid and "O" ring. Remove wiring harness, and note location for reassembly reference. Carefully remove accumulator cover retaining bolts, 1-2 accumulator cover and pin assembly. See Fig. 16 . 2. Remove 1-2 accumulator piston, seal and spring. Remove spacer plate, and note check ball and filter locations. Remove spring, 3-4 accumulator piston and pin. Note spacer plate and gasket locations. See Fig. 5 for check ball and filter locations. TRANSMISSION END PLAY CHECK NOTE:

Check transmission end play before disassembly. If end play is not within specification, check for damaged parts during disassembly.

Install Pump Remover/End Play Fixture (J-24773-A) and End Play Adapter (J-25022-A) on end of turbine shaft. See Fig. 14 . Clamp dial indicator on long bolt with indicator tip on end play fixture. Zero dial indicator. Pull up on end play fixture. Measure transmission end play. Transmission end play should be .005-.036" (.13.91 mm).

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 14: Checking Transmission End Play Courtesy of GENERAL MOTORS CORP. OIL PUMP, INPUT CLUTCH & REVERSE CLUTCH 1. Ensure TCC solenoid assembly and oil filter are removed before oil pump removal. Remove oil pump retaining bolts. Using Oil Pump Remover (J-37789-A) and Adapter (J-39119), pull oil pump assembly free from case. See Fig. 15 . 2. Remove oil pump, seal and gasket. Remove reverse input clutch-to-pump thrust washer from pump. Lift out turbine shaft with reverse input clutch assembly.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 15: Removing Oil Pump Assembly Courtesy of GENERAL MOTORS CORP. 2-4 BAND & INPUT GEAR SET 1. Remove band anchor pin from case. See Fig. 16 . Remove 2-4 band assembly from case. Remove input sun gear. See Fig. 17 . CAUTION: Output shaft must be held in place when removing input carrier retainer ring. 2. Install Output Shaft Support (J-29837) on output shaft. See Fig. 18 . Remove input carrier to output shaft retainer ring. Remove input carrier. Remove output shaft. Remove input carrier thrust bearing from reaction carrier shaft.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 16: Exploded View Of 4L60-E Transmission External Components Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 17: Exploded View Of 4L60-E Transmission Internal Components Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 18: Installing Output Shaft Support Courtesy of GENERAL MOTORS CORP. REACTION GEAR SET 1. Remove input internal gear and reaction carrier shaft. Remove reaction sun shell and thrust washer. Remove sun shell-to-clutch race thrust washer. Remove support-to-case snap ring. 2. Remove support retainer spring from low-reverse support. Remove reaction sun gear, low-reverse roller clutch race, roller clutch, support assembly and reaction carrier assembly. See Fig. 17 . 3. Remove low-reverse clutch plates. Note locations of components. Remove internal reaction gear and thrust bearing. Remove internal reaction gear support-to-case thrust bearing. LOW-REVERSE CLUTCH NOTE:

Parking pawl may require removal to access low-reverse clutch.

1. Remove parking lock bracket retaining bolts. Remove lock bracket. Using screw extractor, remove shaft plug. Remove parking pawl shaft, parking pawl and return spring if necessary. See Fig. 16 . 2. Using Clutch Spring Compressor (J-23327), compress low reverse clutch spring retainer. Remove spring retaining ring and low-reverse spring assembly. Remove low-reverse clutch piston by applying air pressure in case apply passage. See Fig. 19 .

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Fig. 19: Removing Low-Reverse Clutch Piston Courtesy of GENERAL MOTORS CORP. INNER MANUAL SHAFT LINKAGE Remove manual shaft nut. Remove manual shaft and retainer. Remove parking lock actuator assembly and inner detent lever. Remove manual shaft seal from transmission case. See Fig. 16 . 3RD ACCUMULATOR CHECK VALVE 1. Check 3rd accumulator check valve before removing it. DO NOT remove check valve unless it is leaking. Install servo assembly in bore. Install servo cover and retaining ring. See Fig. 6 . Pour clean solvent in bore. Inspect for leaks in transmission case. Replace check valve assembly if it leaks. See Fig. 20 . Remove servo assembly. 2. For check valve removal, install No. 4 screw extractor in check valve assembly. Remove check valve. Ensure bore is free of burrs. Installation tool must be made to ensure proper installation depth is obtained. Using a 3/8" O.D. rod, scribe indicator mark at 1.653" (41.98 mm) from end of rod. Install check valve until scribe mark on rod is flush with case. See Fig. 20 .

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Fig. 20: Installing 3rd Accumulator Check Valve Assembly Courtesy of GENERAL MOTORS CORP.

CLEANING & INSPECTION TRANSMISSION CASE Cleaning & Inspection

Clean transmission case and dry with compressed air. Inspect case assembly for damage, cracks and damaged bolt hole threads. Inspect valve body surface for flatness and land damage. Check case oil passages for Microsoft Saturday, August 29, 2009 11:54:34 AM

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restrictions and blockage. Inspect case internal clutch plate lugs for damage and wear. Inspect servo and accumulator bores for damage. Inspect all snap ring grooves for damage. CASE ATTACHMENTS Cleaning & Inspection

Clean all parts and dry with compressed air. Inspect 1-2 and 3-4 accumulator parts for damage to pistons or housing. Inspect for flatness and condition of accumulator, oil passage plate and gasket. Inspect wiring harness leads and connectors for damage. Inspect speed sensor rotor teeth for damage and distortion. REACTION & INPUT GEAR SETS, LOW-REVERSE CLUTCH & SUPPORT Cleaning & Inspection

1. Clean all parts and dry with compressed air. Inspect reaction and input carriers for pinion gear damage, excessive wear and improper staking of pinion pins. Inspect carrier bearings for heat damage, flatness and roller condition. Place output shaft sleeve inside reaction carrier and input carrier. 2. Rotate sleeve and note smoothness of bearing operation. Replace carrier assembly if roughness is felt. Check pinion gear end play on reaction and input carriers. 3. Pinion gear end play should be .008-.024" (.20-.61 mm). Inspect internal reaction gear and support for cracks and damaged splines. Inspect low-reverse clutch plates for wear and signs of excessive heat. 4. Inspect low-reverse clutch piston for roughness or damage in seal ring area. Inspect retainer ring and spring assembly for damage. Inspect sun and internal gears and supports for spline and bushing wear and damage. Replace damaged parts as necessary.

COMPONENT DISASSEMBLY & REASSEMBLY REVERSE INPUT CLUTCH Disassembly

1. Remove snap ring from reverse input clutch housing. Remove selective backing plate, steel plates, composition plates and Belleville plate. See Fig. 17 . Note number of clutch plates for reassembly reference. Compress reverse input clutch spring assembly. 2. Remove retainer ring and spring assembly. Remove piston and seals. Thickness of composition plates should be .068-.074" (1.73-1.88 mm). Thickness of steel plates should be .075-.081" (1.90-2.05 mm). Thickness of Belleville plate should be .087-.091" (2.21-2.31 mm). Inspection

Inspect all plates for damage, distortion, flatness and burred edges. Inspect spring retainer for distortion. Check piston for deformation or damage. Inspect clutch housing bushings for wear. Inspect clutch housing for dishing. Replace worn or damaged parts as necessary. NOTE:

Soak clutch plates in ATF before installation.

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Reassembly

1. Apply ATF to piston seals. Install seals on piston with seal lips facing away from plates. Install piston in clutch housing. Install spring assembly with large opening toward piston. Compress spring assembly. Install retainer ring. CAUTION: Ensure correct retainer ring is used. Ensure reverse input clutch retainer ring is not interchanged with low-reverse retainer ring. 2. Install Belleville plate. Install clutch plates starting with steel plate and alternating with composition plate. Install backing plate with chamfered side upward. Install snap ring. Apply even pressure to backing plate using fingers. 3. DO NOT apply too much pressure or Belleville plate will be distorted. Using feeler gauge, measure clearance between snap ring and backing plate. Clearance should be .040-.076" (1.02-1.93 mm). Select backing plate. See REVERSE INPUT CLUTCH BACKING PLATE SPECIFICATIONS table. REVERSE INPUT CLUTCH BACKING PLATE SPECIFICATIONS Identification Number 2 3 4

Thickness In. (mm) .285-.292 (7.24-7.42) .257-.263 (6.53-6.68) .228-.234 (5.79-5.94)

LOW-REVERSE SUPPORT ASSEMBLY CAUTION: Note direction roller clutch is installed in support. Roller clutch must be installed in proper direction to provide lockup of inner race when rotated. Disassembly & Inspection

Remove inner race and snap ring. Remove roller clutch assembly. Check inner race for damage and surface finish. See Fig. 21 . Inspect roller and springs for damage and distortion. Inspect support for loose cam, cracks and damaged surface finish. Replace damaged parts as necessary. Reassembly

1. Install roller clutch assembly in low-reverse support. See Fig. 21 . Place support in case with hub facing downward. Install inner race. Rotate inner race while pushing downward. Use care not to damage roller and springs during installation. 2. Ensure inner race is fully seated. Bottom tangs will be flush with carrier hub when fully seated. Inner race should rotate clockwise and lock counterclockwise with clutch hub downward. Insert support retainer spring into case between case lug and open notch in support.

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Fig. 21: Exploded View Of Low-Reverse Clutch Assembly Courtesy of GENERAL MOTORS CORP. INPUT CLUTCH & FORWARD CLUTCH HUB ASSEMBLY Disassembly

1. Remove snap ring and backing plate. Remove 3-4 clutch plates. Note number and location of parts for reassembly reference. Remove 3-4 apply plate and clutch ring retainer. See Fig. 17 . Microsoft Saturday, August 29, 2009 11:54:34 AM

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2. Remove forward clutch snap ring, and remove backing plate. Remove forward clutch sprag assembly and bearing. Remove input housing seal. Remove forward clutch plates. Note number and location of parts for reassembly reference. Remove waved and apply plates. Remove overrun clutch plates (2 steel and 2 composition). Compress overrun clutch spring retainer. 3. Remove snap ring and spring assembly. Remove overrun clutch piston and forward clutch piston. Remove seals from pistons. Note direction of seals. Remove forward clutch housing. Remove 3-4 clutch spring, 3-4 clutch apply ring and piston. Remove "O" ring from input housing. Remove turbine shaft oil seal rings. 4. Remove forward clutch race. Remove snap ring and overrun clutch hub. Remove sprag retainer and race. Note direction race is installed. Use care not to lose rollers from roller cage. Inspection

1. Inspect sprag assembly for weak or damaged springs and retainers and worn rollers. Inspect overrun clutch hub for spline damage, excessive wear and open oil passages. Inspect retainer and race for spline damage, surface wear and damaged ring grooves. 2. Replace sprag assembly if damaged. Inspect forward clutch race for spline damage, excessive wear and open oil passages. Inspect input shaft and housing for spline damage, wear and open feed passages. 3. Inspect 3 sealing check balls located in rear of turbine shaft for tightness. Turbine shaft contains one open lubrication hole. Ensure orifice cup plug is installed. Inspect turbine shaft seal areas for roughness and burrs. 4. Inspect check ball located in input housing for free operation. Inspect pistons for wear, damage and porosity. Inspect spring assemblies for damage and distortion. 5. Inspect steel and composition plates for damage. Inspect snap rings for distortion and damage. Check backing plates for flatness and distortion. Inspect clutch apply rings for distortion and damaged tangs. 6. Inspect forward clutch housing check ball for proper operation (if equipped). Inspect housing for cracks and damage in seal areas. Inspect bearings for excessive wear, flatness, damage and flat rollers. Reassembly

1. For input housing check ball replacement, drive retainer and ball assembly from housing using 1/4" diameter drift. Install NEW check ball assembly using 1/4" drift. Check ball assembly should seat on housing shoulder. Assemble forward clutch sprag assembly. 2. Install sprag assembly in forward clutch race. Notches located in sprag must face upward. See Fig. 22 . Install snap ring on sprag retainer and race. Snap ring flange must face away from retainer and race.

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Fig. 22: Installing & Checking Forward Clutch Sprag Assembly Courtesy of GENERAL MOTORS CORP. 3. Hold forward clutch race in left hand. Support sprag assembly. Install sprag retainer and race assembly in Microsoft Saturday, August 29, 2009 11:54:34 AM

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4. 5. 6. 7.

sprag assembly. See Fig. 17 . Rotate sprag retainer and race assembly counterclockwise. Install remaining retainer ring. Install overrun clutch hub. Install snap ring. Check sprag operation. Holding forward clutch race, rotate overrun clutch hub. Overrun clutch hub should turn freely clockwise and lock counterclockwise. See Fig. 22 . Place input clutch housing with turbine shaft downward. Install 3-4 piston seals with lips facing away from hub. Install 3-4 piston in input housing. Install 3-4 clutch apply ring. Install "O" ring seal in input clutch housing. Install forward clutch housing. Install seals on forward clutch piston with lips facing away from tangs. Install forward clutch piston in forward clutch housing. Install 3-4 spring on 3-4 clutch apply ring. Install forward clutch assembly on3-4 spring assembly. Align forward clutch piston legs with tangs of3-4 apply ring. Install Seal Protector (J-29883) on input housing. Install 3-4 apply ring and forward clutch assembly in input clutch housing. Hold apply ring tangs while installing. DO NOT allow forward clutch piston to separate from assembly. Ensure assembly is firmly seated. Install Seal Protector (J-29883) on input housing. Install overrun clutch piston with hub facing upward. If fully seated, overrun piston should be 3/16" below top of snap ring groove in input housing hub. Install spring assembly on overrun clutch piston. Compress springs, and install snap ring. Install input housing seal. NOTE:

Soak clutch plates in ATF before installation. Coat all seals and "O" rings with ATF. Coat thrust washers and bearings with petroleum jelly.

10. Install 4 overrun clutch plates, starting with steel plate. Align wide notches with case lugs. Install remaining clutch plates, alternating steel and composition plates. 11. Install bearing assembly on input clutch hub. Bearing inner race must face input housing hub. Ensure bearing is centered. Align clutch plate tabs. Install forward clutch sprag assembly in input housing. Align overrun clutch hub with clutch plates. 12. Install forward clutch apply plate in input housing. Install forward clutch waved plate. Ensure all plates are aligned with input housing tangs. Starting with steel plate, install clutch plates, alternating steel and composition plates. Install backing plate and snap ring. See FORWARD CLUTCH PLATE SPECIFICATIONS table. 13. Using 2 feeler gauges, measure clearance between backing plate and snap ring. Clearance should be .030.063" (.75-1.60 mm). Install proper size backing plate with chamfered side upward. See FORWARD CLUTCH BACKING PLATE SPECIFICATIONS table. Install snap ring. 14. Install 3-4 clutch plates and backing plate. Install clutch plates and backing plate with chamfered side upward. Install retainer ring. Using feeler gauge, measure clearance between backing plate and first composition plate. Clearance should be .035-.083" (.89-2.11 mm). 15. Select proper backing plate to obtain correct clearance. See 3-4 BACKING PLATE SPECIFICATIONS table. Air check all clutches at feed holes in turbine shaft. 16. During overrun clutch test, air pressure will blow past forward clutch piston seals and exit out forward clutch feed hole in turbine shaft. Turbine shaft seals require sizing and should be installed just before oil pump installation. FORWARD CLUTCH PLATE SPECIFICATIONS Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Plate Type Apply Backing Composition Flat Steel Waved Steel

Quantity 1 1 5 5 1

Thickness In. (mm) .169 (4.29) Selective .070 (1.78) .090 (2.29) .070 (1.78)

FORWARD CLUTCH BACKING PLATE SPECIFICATIONS Identification Letter A B C D E 3-4 CLUTCH PLATE SPECIFICATIONS Plate Type Quantity Backing 1 Composition 6 (1) 1 Flat Steel Flat Steel 5 Stepped Apply 1 (1) Same spline configuration as apply plate.

Thickness In. (mm) .274-.278 (6.96-7.06) .250-.255 (6.35-6.48) .227-.232 (5.77-5.89) .205-.208 (5.21-5.28) .180-.185 (4.57-4.70)

Thickness In. (mm) Selective .079 (2.01) .070 (1.78) .107 (2.71) .220 (5.59)

3-4 BACKING PLATE SPECIFICATIONS Identification A B C

Thickness In. (mm) .224-.231 (5.69-5.87) .187-.196 (4.75-4.98) .153-.161 (3.89-4.09)

OIL PUMP ASSEMBLY Disassembly

1. Remove reverse input clutch drum-to-oil pump thrust washer, pump-to-case gasket and pump-to-case oil seal ring from pump assembly. Remove pump cover retaining bolts. Separate pump cover from pump body. CAUTION: Pump slide spring and pressure relief spring rivet are under high pressure. To prevent possible injury, cover springs during removal.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

2. Using needle-nose pliers, compress pump slide spring. Remove from pump by pulling straight out. Remove pump vane rings, pump vanes, pump rotor and rotor guide from pump pocket. CAUTION: Keep pump vanes in installed position. If pump vanes are installed upside-down or backwards, they will quickly wear out. 3. Remove slide from pump pocket. Remove slide seal and seal support from pump slide. See Fig. 23 . Remove pivot pin and pivot pin spring. Remove seal ring and "O" ring from pump slide. Remove seal retainer and seal from pump body. 4. Check condition of pump bushing. If bushing is in good condition, DO NOT remove it. Push inward on converter clutch valve stop to compress spring. Remove snap ring. Remove valve stop, converter clutch apply valve and springs. 5. Using a small punch, remove pressure relief spring retaining rivet. Remove relief spring and check ball. Remove oil screen and "O" ring from pump cover. Remove reverse boost valve sleeve. Remove reverse boost valve, pressure regulator valve spring and pressure regulator valve.

Fig. 23: Exploded View Of Oil Pump Assembly Courtesy of GENERAL MOTORS CORP. Inspection

1. Inspect all valves, springs, sleeves and bushings for chips, burrs, distortion and free movement in bores. Check pressure relief check ball and spring for damage and distortion. Low line pressure will exist if check ball and spring are damaged. 2. Inspect pump cover screen and "O" ring for wear and damage. Clean pump body and cover. Check all Microsoft Saturday, August 29, 2009 11:54:34 AM

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bores for obstructions. Inspect mating sides of cover and body for scoring, flatness and damage between channels. Check channels for dirt and damaged passages. Inspect stator shaft and pump body bushings for damage. 3. Inspect rotor and slide for scoring, cracks and damage. Check rotor guide and pump vane rings for excessive wear and damage. Inspect all seals for damage. Measure pump rotor and slide thickness in undamaged area if replacement is required. See OIL PUMP COMPONENT THICKNESS table. Ensure replacement parts are matched to fit within specification. OIL PUMP COMPONENT THICKNESS Component In. (mm) Pump Rotor & .7066-.7071 (17.948-17.960), .7071-.7076 (17.960-17.973), .7076-.7081 (17.973Slide 17.986), .7081-.7086 (17.976-17.998), .7086-.7091 (17.998-18.011) Reassembly

1. Install "O" ring and seal ring in groove on back side of pump slide. Retain seal ring using petroleum jelly. Install pivot pin and spring in pump body. Install pump slide. Notch in pump slide must align with pivot pin hole and with flat oil seal ring facing downward in pump pocket. Install slide seal and support. CAUTION: Keep pump vanes in installed position. If pump vanes are installed upside-down or backwards, they will quickly wear out. 2. Install pump vane ring into pump pocket. Coat rotor guide with petroleum jelly. Install rotor guide on rotor. Install rotor and guide into pump pocket with guide toward pump pocket. Install vanes in rotor. Install vane guide ring. Compress pump slide spring and install into pump pocket. All parts must be even with pump body surface. Install "O" ring on pump screen, and install screen in pump cover with "O" ring end out. 3. Install oil seal in pump body. Install seal retainer. Install pressure relief check ball and spring in pump cover. Install retaining rivet. Install converter clutch valve springs and converter clutch valve. Install valve stop and snap ring. Install pressure regulator valve and spring in pump cover. See Fig. 23 . 4. Coat reverse boost valve with petroleum jelly. Install reverse boost valve in boost valve sleeve with small end first. Install reverse boost valve sleeve in pump cover. 5. Install pump cover on pump body. Install retaining bolts finger tight. Align pump body and cover using Alignment Strap (J-21368). Place bolt through pump-to-case bolt hole. Tighten retaining bolts to specification. See TORQUE SPECIFICATIONS . Remove alignment strap. 6. Position pump-to-case gasket on pump, and retain it using petroleum jelly. Install oil seal rings on stator hub. Retain oil seal rings using petroleum jelly. Install pump-to-case oil seal on cover. Ensure seal is not twisted. Coat seal with ATF. Install pump-to-drum thrust washer. Ensure tangs on washer engage with holes in hub. 2-4 SERVO ASSEMBLY Disassembly

1. Remove 4th apply piston and housing from 2nd apply piston assembly. Remove return spring from apply Microsoft Saturday, August 29, 2009 11:54:34 AM

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pin. Install Piston Compressor (J-22269-01) on 2nd apply piston. See Fig. 12 . 2. Compress 2nd servo apply piston assembly. Remove retainer ring. Separate 2nd apply piston, spring and retainer. Remove retainer ring, washer and spring from apply pin, and remove pin. Remove all oil seal rings. See Fig. 11 . Inspection

Inspect all pistons for porosity and damage. Check for ring groove damage and servo bore in case for any wear which may cut servo seals. Check all springs and oil seal rings for distortion and damage. Reassembly

Different servo piston housings and 2nd apply pistons are used for different applications. If servo piston housing or 2nd apply piston is replaced, inside dimension of parts must be checked. Measure inside diameter of piston housing and 2nd apply piston. Dimension must be same as original. To reassemble, reverse disassembly procedure. Coat seals with petroleum jelly before assembly. VALVE BODY NOTE:

Valves are held in valve body by pins or retainers. Valves may be under spring pressure. Note location of all parts during disassembly for reassembly reference.

Disassembly

Remove valve train, and note direction of valve installation. See Fig. 24 . Remove all valve pins, retainers and bore plugs. Remove shift solenoids. Note locations of all parts. Inspection

Inspect valves and sleeves for scoring and cracks. Ensure valves move freely in bores. Inspect valve body for cracks and scored bores. Inspect machined surfaces for damage. Inspect springs for damaged coils. Replace damaged parts as necessary. Reassembly

For reassembly, reverse disassembly procedure. Ensure all parts are installed in correct location. See Fig. 24 . Ensure pins, retainers and bore plugs are fully installed and do not extend into machined areas.

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Fig. 24: Exploded View Of Valve Body Courtesy of GENERAL MOTORS CORP.

TRANSMISSION REASSEMBLY NOTE:

To identify bushing, seal, thrust bearing and thrust washer locations and direction, see BUSHINGS, SEALS, BEARINGS & THRUST WASHERS . See Fig. 26 and Fig. 27 .

LOW-REVERSE CLUTCH 1. Place transmission in a vertical position. Install seals on low-reverse clutch piston. Apply petroleum jelly to seals. Align and install piston with notch in bottom of transmission case. Ensure piston is fully seated and parking pawl aligns with opening in piston wall. Install spring assembly with flat side of retainer upward. Compress springs and install retainer ring. 2. Coat bearing assembly with petroleum jelly. Install bearing assembly on case hub with outside bearing race toward case hub. Install internal reaction gear and support. Install bearing assembly onto support with outside bearing race toward support. Install oil deflector (if equipped) and reaction carrier assembly in case. See Fig. 17 . Ensure clutch plates are proper thickness. 3. Install clutch plates. See LOW-REVERSE CLUTCH PLATE USAGE table. Ensure clutch plates align with splines of reaction carrier and case and that steel plates are aligned. Place waved plate on work Microsoft Saturday, August 29, 2009 11:54:34 AM

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bench. Install 5 composition plates and 4 steel plates alternately, starting with composition plate. 4. Install low-reverse support. Apply light pressure to low-reverse support. DO NOT flatten waved plate. Measure height of clutch pack from work bench to top of low-reverse support. Using height dimension, determine proper selective spacer plate to be used. See SPACER PLATE SELECTION table. 5. Place spacer plate between waved plate and first composition plate with identification facing upward. Measure overall height of clutch pack. Overall height should be 1.15-1.18" (29.2-29.9 mm). Install clutch pack assembly in transmission case. 6. Install low-reverse support in case with hub downward. Install inner race by pushing downward while rotating until it is fully engaged. Bottom tangs will be flush with hub when fully installed. Install spring retainer in case between case lug and open notch in support. Install low-reverse snap ring. LOW-REVERSE CLUTCH PLATE USAGE Type No. Used Composition 5 Flat Steel 4

Thickness: In. (mm) .089 (2.26) .069 (1.75)

SPACER PLATE SELECTION (1) Measured Clutch Pack Height: In. (mm) (2) Plate Thickness: In. (mm) 1.084-1.105 (27.53-28.07) .066-.072 (1.67-1.85) 1.105-1.125 (28.07-28.58) .046-.052 (1.17-1.31) 1.064-1.084 (27.03-27.53) .087-.092 (2.19-2.34) (1) Spacer plates are available in select sizes. Plate .066-.072" (1.67-1.85 mm) thick has no identifying marks. Other plates are marked "0" or "1". (2) Clutch pack height is measured without spacer plate in position. REACTION & INPUT GEAR SETS 1. Install retainer ring on reaction sun gear (if removed). Install sun gear into reaction carrier. Install thrust washer on low-reverse clutch race. Install reaction sun gear shell on reaction sun gear. 2. Install thrust washer on reaction sun gear shell. Ensure thrust washer tangs engage on gear shell. Install input internal gear and reaction carrier shaft in sun gear shell. Carrier shaft splines must engage with reaction carrier. See Fig. 17 . 3. Install thrust washer on reaction carrier shaft. Outer race must face toward reaction carrier shaft. Install output shaft in transmission. Ensure output shaft engages with all parts. 4. Install Output Shaft Support (J-29837). Adjust support so output shaft is positioned upward as far as possible. Install input carrier assembly with hub end down on output shaft. Install NEW retainer ring on output shaft. Remove output shaft support. Install input sun gear, indexing gear end with input carrier pinions. REVERSE INPUT ASSEMBLY & INPUT CLUTCH Install selective thrust washer on input housing. Install bearing assembly on selective thrust washer. Inner race (Black) must go toward oil pump. Position reverse input assembly on input clutch assembly. Reverse input Microsoft Saturday, August 29, 2009 11:54:34 AM

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clutch plates must align with input clutch hub. Ensure all clutch plates are fully engaged. REVERSE & INPUT CLUTCHES Install reverse and input clutch assemblies in transmission case as an assembly. Align 3-4 clutch plates of input assembly with input internal gear. Assembly is fully seated when reverse input clutch housing is just below oil pump face of case. 2-4 BAND & SERVO ASSEMBLY 1. Install 2-4 band in case. Align band anchor pin end with case pin hole. Install band anchor pin in case. Ensure band anchor pin aligns with end of 2-4 band. 2. Install 2-4 servo assembly into case, and index apply pin on band end. Check for proper engagement of apply pin on band end. Recheck 2-4 servo apply pin selection to ensure correct pin is installed. See CHECKING SERVO PIN LENGTH under TRANSMISSION DISASSEMBLY. 3. Different length servo pins are available. See SERVO PIN SPECIFICATIONS table. Select proper length servo pin. Install servo cover and "O" ring. Compress cover and install cover retaining ring. Index ring ends with slot in case. SERVO PIN SPECIFICATIONS Pin ID 1 Groove 2 Grooves No Groove

Pin Length - In. (mm) 2.59-2.60 (65.8-66.0) 2.65-2.66 (67.3-67.5) 2.70-2.71 (68.6-68.8)

BUSHINGS, SEALS, BEARINGS & THRUST WASHERS NOTE:

To identify bushing, seal, thrust bearing and thrust washer locations and direction, see Fig. 26 and Fig. 27 .

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Fig. 25: Locating Oil Screens Courtesy of GENERAL MOTORS CORP.

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Fig. 26: Location & Direction Of Transmission Oil Seals Courtesy of GENERAL MOTORS CORP.

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Fig. 27: Location & Direction Of Transmission Bushings, Thrust Bearings & Thrust Washers Courtesy of GENERAL MOTORS CORP. OIL PUMP ASSEMBLY 1. Turbine shaft seals should be installed prior to oil pump installation. Position Seal Installer (J-36418-1) on input shaft. See Fig. 28 . Adjustment screw in seal installer must be adjusted to obtain correct height for each seal installation. Install 4 turbine shaft seals.

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Fig. 28: Installing & Sizing Turbine Shaft Seals Courtesy of GENERAL MOTORS CORP. 2. Turbine shaft seals must be sized using Seal Sizer (J-36418-2A) after installation. Install aligning pins in 2 opposing pump bolt holes in case. Ensure thrust washer is installed on rear of oil pump. Thrust washer can be retained using petroleum jelly. 3. Install oil pump into case, aligning filter and pressure regulator holes with holes in case. Install retaining bolts. Tighten bolts to specification. See TORQUE SPECIFICATIONS . Place transmission in a horizontal position. 4. Turbine shaft should rotate by hand. If turbine shaft will not rotate, loosen pump retaining bolts and attempt to rotate shaft again. If shaft now turns, reverse and input assemblies have not been indexed properly or some other assembly problem has occurred, such as thrust washer not positioned properly. 5. Check transmission end play. See TRANSMISSION END PLAY CHECK under TRANSMISSION Microsoft Saturday, August 29, 2009 11:54:34 AM

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DISASSEMBLY. Transmission end play should be .005-.036" (.13-.91 mm). If transmission end play is not within specification, thrust washer must be changed between oil pump and input housing. 6. See OIL PUMP THRUST WASHER SPECIFICATIONS table. Install thrust washer, and recheck end play. Install torque converter. Ensure converter hub is aligned with oil pump. Install torque converter retaining strap to hold converter. OIL PUMP THRUST WASHER SPECIFICATIONS Identification Number 67 68 69 70 71 72 73 74

Thickness In. (mm) .074-.078 (1.88-1.98) .080-.084 (2.03-2.13) .087-.091 (2.21-2.31) .094-.098 (2.39-2.49) .100-.104 (2.54-2.64) .107-.111 (2.72-2.82) .113-.118 (2.87-3.00) .120-.124 (3.05-3.15)

1-2 ACCUMULATOR & SPACER PLATES CAUTION: If spacer plate and gasket replacement is required, ensure NEW spacer plate and gasket are identical as those removed. 1. Install 3-4 accumulator piston pin in case. Install 3-4 piston seal on piston. Install 3-4 accumulator piston on pin. Legs of piston must face valve body. 2. Install 3-4 accumulator spring. Install oil screens in proper locations. See Fig. 25 . Install special retainer and ball assembly. See Fig. 5 for check ball and filter installation locations. Install spacer plate gasket and spacer plate. 3. Install 1-2 accumulator spring, oil seal ring and 1-2 accumulator piston. Install accumulator cover and bolts. Tighten bolts to specification. See TORQUE SPECIFICATIONS . VALVE BODY Install valve body. See VALVE BODY under ON-VEHICLE SERVICE . EXTENSION HOUSING 1. Install speed sensor rotor retaining clip on output shaft. Install "O" ring in output shaft sleeve. Install output shaft sleeve on output shaft. DO NOT position output sleeve past machined surface of output shaft. Install seal ring on extension housing. 2. Position extension housing on transmission case. Install retaining bolts. Install oil seal in extension housing. Install speed sensor assembly. Install retainer and bolt. Tighten bolt to specification. Install outside electrical connector and manual shift lever.

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

TECHNICAL SERVICE BULLETINS 1-2 &/OR 2-3 UPSHIFT SLIP/FLARE, NO 3RD OR 4TH GEAR, (DTC P1870) 1996 GM Trucks & Oldsmobile Bravada With 4L60-E Transmission (GM Service Bulletin No. 66-71-03A)

Some owner's may complain that vehicle has either a slip or flare on 1-2 and/or 2-3 upshift, or no 3rd or 4th gear. DTC P1870 may also be present. This condition may be caused by a poor internal ground between 2 circuit boards of Vehicle Control Module (VCM), which can cause VCM to command erratic line pressure at pressure control solenoid. To correct this condition, a revised Wiring Harness (12167310) has been designed to replace current wiring harness at VCM. Corrections were made to VCM beginning February 14, 1996. Corrected VCM's are identified by service number 16244210, located on VCM identification label. ATF LEAKING OUT VENT All GM Models With 4L60 Or 4L60-E Transmission (ATRA TSB No. 449)

Vehicles equipped with 4L60 or 4L60-E transmission may leak fluid out transmission vent. Fluid may splash out vent due to high fluid level. Fluid may also be pumped out due to an oil pump that is not flat or has been machined, and now bolts are too long, allowing converter charge pressure to squeeze into vent cavity. To correct this condition, check oil pump surface for flatness. Repair as necessary. Ensure both stator support pump bolts and oil pump-to-case bolts are not too long. It may be necessary to add washers to bolts. Apply a thin sealant to vent cavity surface area of oil pump and stator support, located between 9 and 10 o'clock position on pump body. See Fig. 23 . TRANSMISSION OVERHEATING &/OR CONVERTER DISCOLORED All Models With 4L60-E Transmission

Transmission may show signs of overheating or torque converter is discolored. This condition may be caused by regulated apply oil not available due to a TCC PCM solenoid filled with debris, which does not allow TCC signal oil to lubricate TCC regulator apply valve in valve body. No DTCs are stored, as TCC PWM solenoid is still working electronically. To eliminate the possibility of this condition, TCC regulator apply valve should be machined to create 2 flat surfaces on opposite sides of first land on valve. Machined surface should be even with wide head of valve. See No. 37 in Fig. Fig. 24 . Machining valve will completely bypass TCC regulator apply valve, provide a more positive lock up apply feel and guarantee apply oil is always available. DESIGN IMPROVEMENTS 1998 GM Vehicles With 4L60-E Transmission (ATRA TSB No. 458)

Manufacturer has made several design changes to 1998 4L60-E transmission. For improved drain back to reduce aeration of fluid, transmission case has a larger cutout between 2 slots located above 1-2 accumulator piston (at No. 1 check ball). See Fig. 5 . The 1998 design removed one slot to increase cutout size. A NEW Black manual shaft has enhanced coating. Case extension housings are more rigid for improved durability. Microsoft Saturday, August 29, 2009 11:54:34 AM

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Pressure Control Solenoid (PCS) has NEW design filter screen. Input sun gear to forward sprag inner race is a press fit design. Transmission oil pan has a deep design with improved oil filter. Control valve body has a chamfered edge for different dipstick stops. Dipstick stop has 2 different designs for regular or deep oil pan design. OIL PUMP INTERCHANGE NOTE:

On GM vehicles with 4L60-E transmission, oil pump bodies have various designs. Ensure components are not mismatched when pump components are replaced.

1993-94

Pump body uses a 10 vane rotor and slide assembly. This pump body has the same casting and worm track configuration as 1985-1993 models. Pump cover has a larger diameter filter seal bore. 1995-96

Pump body also uses a 10 vane rotor and slide assembly, but this pump body has a different casting and worm track configuration than 1993-94 models and is not interchangeable. Pump body is identified by "PWM" cast into front side of pump body. Bolt-on bellhousing also was introduced in 1996 and requires added flange to center bellhousing during installation. Pump cover has a different casting and worm track configuration from 1993-94 models and is not interchangeable. Pump cover also includes "PWM" cast into back side of cover. 1997

Pump body has same worm track configuration as 1995-96 models, but a 13 vane rotor and slide assembly is used. The 13 vane slide has longer porting slots. Pump body also has "PWM" cast into front side. Pump cover has same worm track configuration as 1995-96 models, but porting slots are a different configuration from 1995-96 pump cover to accommodate changes in 13 vane and rotor and slide. Pump cover is identified by "13 V" cast into back side of pump cover. Pump cover is not interchangeable with other year models.

TRANSMISSION SPECIFICATIONS TRANSMISSION SPECIFICATIONS Application Clearance Forward Clutch Reverse Input Clutch 3-4 Clutch End Play Reaction & Input Planetary Pinion Gear Torque Converter 9.65" (245 mm) 11.73" (298 mm)

In. (mm) .030-.063 (.75-1.60) .040-.076 (1.02-1.93) .035-.083 (.89-2.11) .008-.024 (.20-.61) .0-.020 (.0-.51) .0-.024 (.0-.61)

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1997 Chevrolet S10 Pickup 1997-98 AUTOMATIC TRANSISSIONS Hydra-Matic 4L60-E Overhaul - Isuzu Hombre & S/T Series

Transmission Height Low-Reverse Clutch

.005-.036 (.13-.91) 1.15-1.18 (29.2-29.9)

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Converter Housing Bolt Cooler Pipe Connector Detent Spring-To-Valve Body Bolt Extension Housing Bolt Fill Tube Bolt Manual Shaft-To-Detent Lever Nut Oil Pump Cover-To-Body Bolt Oil Pump-To-Case Bolt Park Bracket-To-Case Bolt Torque Converter-To-Flexplate Bolt Transmission-To-Engine Bolt Accumulator Cover-To-Case Bolt Line Pressure Plug Oil Pan-To-Case Bolt Oil Passage Cover Bolt Pressure Switch Assembly Solenoid Bolt Speed Sensor Bolt Valve Body-To-Case Bolt (1) (1) Tighten valve body bolts in a spiral pattern starting in center of valve body.

Ft. Lbs. (N.m) 55 (75) 28 (38) 18 (24) 26 (35) 35 (47) 23 (31) 18 (24) 18 (24) 23 (31) 46 (62) 35 (47) INCH Lbs. (N.m) 96 (11) 96 (11) 96 (11) 96 (11) 96 (11) 96 (11) 96 (11) 96 (11)

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1997 Chevrolet S10 Pickup 1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

MODEL IDENTIFICATION MODEL IDENTIFICATION Series (1) "C" "G" "K" "L" "M" "P" "S" "T" "U" (1) Vehicle series is fifth character of VIN.

Model 2WD Pickup, Sierra, Suburban, Tahoe & Yukon (2) RWD Van

4WD Pickup, Sierra, Suburban, Tahoe & Yukon AWD Astro & Safari 2WD Astro & Safari Commercial Van/Motorhome 2WD Blazer, Jimmy, Pickup & Sonoma 4WD Blazer, Jimmy, Pickup & Sonoma, AWD Bravada Lumina Van, Silhouette, Trans Sport & Venture

(2) Includes Express and Savana.

LUBRICATION SERVICE INTERVALS Transmission/Transaxle ("C" & "K" Series)

Check transmission/transaxle fluid level at each engine oil change. Under severe driving conditions or for vehicles over 8600 GVWR, change transmission fluid and filter every 50,000 miles. For other vehicles under normal driving conditions, fluid and filter do not require periodic changing. Transmission/Transaxle ("T" Series Bravada Only)

Check transmission/transaxle fluid level at each engine oil change. Under normal driving conditions, fluid and filter do not require periodic changing. Under severe driving conditions, change transmission fluid and filter every 50,000 miles. Transmission/Transaxle ("U" Series)

Check transmission/transaxle fluid level at each engine oil change. Under normal driving conditions, change transmission fluid and filter every 100,000 miles. Under severe driving conditions, change fluid and filter every 15,000 miles. Transmission/Transaxle (All Other Models) Microsoft Saturday, August 29, 2009 11:53:56 11:53:53 AM

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1997 Chevrolet S10 Pickup 1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

Check transmission/transaxle fluid level at each engine oil change. Under normal driving conditions, for vehicles over 8600 GVWR, change transmission fluid and filter every 24,000 miles. For vehicles under 8600 GVWR, change fluid and filter every 30,000 miles. Under severe driving conditions, for vehicles over 8600 GVWR, change transmission fluid and filter every 12,000 miles. For vehicles under 8600 GVWR, change fluid and filter every 15,000 miles. Transfer Case

Check transfer case lubricant at every oil change or every 12 months. Under severe conditions check more frequently. CHECKING FLUID LEVEL NOTE:

Transmission/transaxle must be at normal operating temperature (180-200°F) when checking fluid level. One pint of fluid will raise level from ADD 1 PT. or .5L to FULL mark on dipstick with transmission/transaxle at normal temperature. DO NOT overfill.

Transmission/Transaxle

With vehicle parked on a level surface and engine at idle, move selector lever through all positions, ending in Park. Remove dipstick, wipe clean and check fluid level. Fluid level should be between ADD 1 PT. and FULL marks on dipstick. If vehicle has been driven for extended period of time at high speed, in city traffic or pulling a trailer, an accurate fluid level cannot be immediately determined. Allow transmission/transaxle to cool for about 30 minutes after vehicle is parked, then check fluid level. Transfer Case

Remove fill plug. Check oil level. If level is not up to fill plug opening, add lubricant as necessary. RECOMMENDED FLUID Transmissions/transaxles and transfer cases use Dexron-III ATF. FLUID CAPACITY Transmission/Transaxle

The transmission/transaxle refill capacities given below are approximate. Correct fluid level should always be determined by marks on dipstick, rather than by amount of fluid added. DO NOT overfill transmission/transaxle. See appropriate REFILL CAPACITIES table. TRANSMISSION/TRANSAXLE REFILL CAPACITIES Dry Fill Refill (Service) Qts. (Overhaul) Qts. (L) (L) 4.0 (3.8) 7.0 (6.6)

Application 3T40 Microsoft Saturday, August 29, 2009 11:53:53 AM

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1997 Chevrolet S10 Pickup 1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

4L60-E 4T60-E 4L80-E "C", "G" & K" Series "P" Series TRANSFER CASE REFILL CAPACITIES Application Models 231 & 233 Model 241 Model 243 Model 4401 Model 4470 Model 4472

5.0 (4.8) 6.0 (5.7)

11.0 (10.6) 8.0 (7.6)

7.7 (7.3) 5.0 (4.7)

13.5 (12.8) 11.5 (10.9)

Capacity 2.5 Pts. (1.8L) 5.2 Pts. (2.5L) 2.5 Pts. (1.8L) 2.9 Pts. (1.4L) 6.6 Pts. (3.1L) 3.0 Pts. (1.5L)

DRAINING & REFILLING Transmission/Transaxle

1. Loosen transmission/transaxle oil pan bolts. Pry pan loose and allow fluid to drain. Remove oil pan, gasket, and filter or filter screen. Replace paper element filter (if equipped). 2. Clean filter screen (if equipped) and pan with solvent, and blow dry with compressed air. Install oil pan with NEW gasket. Add fluid to proper mark on dipstick. NOTE:

On 4WD vehicles it may be necessary to remove the crossmember at the rear of the transmission to allow adequate clearance for transmission oil pan removal. Forcing the pan past the crossmember may damage the internal transmission wiring harness or solenoid connections.

Transfer Case

Remove drain plug from transfer case. Remove fill plug for easier draining. With fluid drained, reinstall drain plug. Fill transfer case to bottom of filler plug opening with appropriate fluid.

ADJUSTMENTS THROTTLE VALVE (TV) CABLE NOTE:

The Hydra-Matic 4L60-E, 4T60-E and 4L80-E are electronically controlled transmissions/transaxles, and do not require adjustment.

3T40

Depress metal lock tab on adjuster and hold. Move slider back through fitting away from throttle body lever Microsoft Saturday, August 29, 2009 11:53:53 AM

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1997 Chevrolet S10 Pickup 1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

until slider stops at fitting. See Fig. 1 . Release lock tab and open throttle body lever to full throttle stop. This automatically adjusts slider to correct setting.

Fig. 1: Adjusting Throttle Valve (TV) Cable Courtesy of GENERAL MOTORS CORP. SHIFT LINKAGE NOTE:

Shift linkage adjustment information for "G", "S" and "T" series is not available from manufacturer.

"C", "K", "L" & "M" Series

1. Ensure shift cable is not restricted. Set transmission range selector lever to Neutral position. Raise and support vehicle. At transmission, set transmission shift lever to Neutral position. Turn shift lever clockwise to stop, then counterclockwise 2 detents. This is Neutral position. 2. Disconnect shift cable end from shift lever. Pull cable end completely forward and release it. Adjustment spring will position cable to its most rearward position. Reconnect shift cable end to shift lever. "P" Series

1. Remove clevis pin retaining clip and clevis pin. Move shift lever arm at transmission fully forward and then pull back 2 detents to Neutral position. 2. Loosen jam nut and adjust cable end to align with shift lever arm at transmission. Tighten jam nut. Reinstall clevis pin and clip. Ensure engine starts in Park and Neutral only. "U" Series

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1997 Chevrolet S10 Pickup 1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

Place shift lever in Neutral. Neutral can be found by rotating transaxle select lever clockwise from Park to Reverse to Neutral. Push tab on cable adjuster to adjust cable in cable mounting bracket. PARK/LOCK CONTROL CABLE NOTE:

Park/lock control cable adjustment information for all other models is not available from manufacturer.

"U" Series

1. Lift cable lock button. Move shift lever to Park. Snap cable connector into shifter base. Ensure ignition key is in RUN position. 2. Snap cable housing into ignition switch inhibitor. Turn key to LOCK position. Snap cable end onto park lock lever pin. Remove slack from cable connector. Snap cable connector lock button down. PARK NEUTRAL POSITION (PNP) SWITCH "C", "G", "K", "L", "M", "P", "S" & "T" Series (Transmission Mounted Switch)

1. Disconnect negative battery cable. Place transmission gear selector in Neutral position. Neutral position can be found by rotating gear lever clockwise from Park (full counterclockwise position) to Reverse, and then to Neutral. 2. Raise and support vehicle. Move shift lever arm at transmission fully forward and then pull back 2 detents to Neutral position. Loosen shift lever nut from shift shaft. Disconnect PNP switch wiring harness connector. Remove shift cable from shift lever arm. Remove shift lever nut and shift lever. 3. Remove 2 PNP switch bolts and PNP switch. Position PNP switch Adjusting Tool (J41364-A) on PNP switch. Ensure 2 lower tabs on tool align with 2 slots on PNP switch. Rotate tool until upper locator pin on tool aligns with slot on top of switch. Leave tool on PNP switch. Ensure no burrs exist on shift lever shaft. 4. Align PNP switch hub flats with manual shaft flats. Slide PNP switch on shift lever shaft until PNP switch mounting bracket contacts mounting bosses on transmission. Install 2 PNP switch bolts and tighten to 21 ft. lbs. (28 N.m). Remove tool. Reconnect PNP switch wiring harness connector. CAUTION: Hold shift lever while tightening nut to prevent internal transmission damage. 5. Install shift lever and nut. Tighten nut to 21 ft. lbs. (28 N.m). Install shift cable. Lower vehicle. Reconnect negative battery cable. Ensure vehicle does not start in any gear selector position except Park and Neutral. If further adjustment is necessary, loosen PNP switch bolts. Rotate switch slightly, tighten bolts and recheck for proper operation. "U" Series (Transmission Mounted Switch)

1. Raise and support vehicle. Loosen switch mounting bolts. Align hole in switch lever with hole in switch assembly. Insert a gauge pin through switch holes to hold switch in Neutral position. Microsoft Saturday, August 29, 2009 11:53:53 AM

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1997 Chevrolet S10 Pickup 1996-97 AUTOMATIC TRANSMISSION SERVICING Automatic Transmission

2. With selector lever on transmission in Neutral position, tighten switch mounting bolts and remove gauge pin. Lower vehicle. Ensure vehicle does not start in any gear selector position except "P" and "N".

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Oil Pan Bolts 3T40 4L60-E & 4L80-E 4T60-E Park Neutral Position Switch ("U" Series) 3T40 4T60-E Shift Linkage Spring Washer Screw "C" & "K" Series "L" & "M" Series

Ft. Lbs. (N.m) 8 (11) 15 (20) 13 (18) 22 (30) 15 (20) 18 (24) 26 (35)

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

DESCRIPTION & OPERATION NOTE:

Information in this article also applies to vehicles equipped with Anti-Lock Brake System (ABS); however, not all information on ABS is included in this article. See ANTI-LOCK BRAKE SYSTEM article.

NOTE:

Brake drum can be removed without removing axle shaft.

BRAKE SHOE ASSEMBLY Vehicles are equipped with dual-servo brakes, identified by adjuster screw hole at bottom of backing plate. Brake assembly consists of backing plate, brake shoes, return springs, automatic adjusting assembly and a wheel cylinder. Automatic adjusting assembly consists of an actuator lever, return spring, actuator link, adjusting screw and spring. Automatic adjustment is accomplished through movement of actuating lever and secondary shoe. BRAKE WARNING LIGHT Pressure differential warning switch in combination valve energizes brake warning light on instrument panel when front or rear brakes lose hydraulic pressure. After repairing failed side of hydraulic system, depress brake pedal with moderate to heavy pressure to hydraulically center the piston. This will turn off brake warning light. CALIPERS Front brakes are floating caliper or sliding caliper design. See Fig. 5 and Fig. 8 . Rear brakes are sliding caliper design. Caliper is attached to caliper mount. Caliper is mounted to steering knuckle or caliper adapter, depending on application. Caliper assembly slides back and forth in machined cut-outs. HYDRAULIC CONTROL VALVES Combination Valve

System uses a combination valve to regulate brake system hydraulic pressure. Combination valve, located in brake lines between master cylinder and wheels, has 3 pressure control functions: 



Metering (or hold-off) section of valve limits pressure to front brakes until pressure of rear brake shoe retractor springs is overcome, then allows pressure to front brakes. Warning switch section of valve constantly compares front and rear brake pressures from master cylinder. See BRAKE WARNING LIGHT under DESCRIPTION & OPERATION . Proportioning section of valve allows input pressure to rise to predetermined level before allowing output pressure to rear brakes. This prevents rear wheel lock-up on vehicles with light rear wheel loads.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Combination valve also contains a by-pass feature. This ensures full system pressure is applied to rear brakes if front brakes lose hydraulic pressure (or if rear brakes lose hydraulic pressure, full pressure is applied to front brakes).

BLEEDING BRAKE SYSTEM MASTER CYLINDER BLEEDING NOTE:

To prevent air from entering brake system, bench bleed master cylinder before installing.

1. Place master cylinder in soft-jawed vise with front end tilted slightly down. DO NOT overtighten vise. Plug both outlet ports of master cylinder. Fill master cylinder reservoir. 2. Press and release piston about 1" (25 mm) several times. As air is bled from master cylinder, the primary piston will not travel the full 1" (25 mm) stroke. 3. Repeat previous step with front end of master cylinder tilted slightly up. Reposition master cylinder in vise to level position. Loosen front outlet plug and push piston into bore to expel air from cylinder. Tighten plug and allow piston to return to original position. Repeat procedure at rear outlet plug. 4. Fill reservoir and install master cylinder. DO NOT fully tighten brake lines at this time. Slowly press brake pedal to floor and hold. Tighten brake lines. Release brake pedal. Bleed brake system. See MANUAL BLEEDING or PRESSURE BLEEDING. MANUAL BLEEDING NOTE:

Air tends to cling to caliper walls. When bleeding vehicles with disc brakes, lightly tap caliper to help remove air.

1. Deplete vacuum reserve from power brake booster by depressing brake pedal several times with engine off. Fill master cylinder and keep at least half full during bleeding procedure. If master cylinder is not known or suspected to have air in bore, go to step 4). If master cylinder is known or suspected to have air in bore, go to next step. 2. Disconnect forward brakeline fitting at master cylinder. Allow fluid to flow from fitting. Tighten fitting to specification. See TORQUE SPECIFICATIONS . Have an assistant depress brake pedal slowly and hold. Loosen forward fitting. Tighten fitting while pedal is still at floor. Release brake pedal slowly. Wait 15 seconds. NOTE:

Rapid pumping of brake pedal causes master cylinder secondary piston to move into a position that makes bleeding system difficult.

3. Repeat step 2), including 15 second wait, until fluid is clear and free of air bubbles. Repeat procedure at other (rearmost) brakeline fitting on master cylinder. Master cylinder is now bled. If wheel cylinders/calipers are not suspected to have air in them, it is not necessary to bleed them. NOTE:

On vehicles with 4WAL, if Brake Pressure Modulator Valve was replaced,

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

or is suspected to have air trapped inside, it must be bled next. See ANTILOCK BRAKE SYSTEM article. 4. If wheel cylinders/calipers are known or suspected to have air in them, raise and support vehicle. Remove bleeder valve cap from right rear wheel. Place proper size box end wrench over bleeder valve. Attach one end of clear tube over valve and submerge other end in container partially filled with clean brake fluid. 5. Have an assistant depress brake pedal slowly and hold. Loosen bleeder valve to purge air from cylinder. Tighten bleeder valve and slowly release brake pedal. Wait 15 seconds. Repeat sequence, including 15 second wait, until all air is removed. 6. Remove tube and wrench. Repeat step 5) at left rear, right front, and left front wheels in this order. Fill master cylinder reservoir, and install cover. Ensure there is no sponginess in brake pedal and that BRAKE warning light is off. PRESSURE BLEEDING NOTE:

Air tends to cling to caliper walls. When bleeding vehicles with disc brakes, lightly tap caliper to help remove air. WARNING: DO NOT use rigid clamp to position hold-off valve stem. This may damage valve assembly, causing brake failure.

1. Retain hold-off valve stem of combination valve using Valve Retainer (J-39177). See Fig. 1 . This allows brake fluid to flow through combination valve and entire system during bleeding. 2. Clean master cylinder cap and surrounding area. Remove cap. With pressure tank at least 2/3 full, connect pressure bleeder to master cylinder with adapters. Attach bleeder hose to right rear bleeder valve. NOTE:

On vehicles with 4WAL, if Brake Pressure Modulator Valve was replaced, or is suspected to have air trapped inside, it must be bled next. See ANTILOCK BRAKE SYSTEM article.

3. Place other end of hose in glass jar partially filled with brake fluid so end of hose is submerged in fluid. Open release valve on pressure bleeder. Set pressure bleeder to 20-25 psi (1.4-1.8 kg/cm2 ) or pressure specified by equipment manufacturer. 4. Open bleeder screw 3/4 - 1 turn and note fluid flow. Close bleeder screw when no air bubbles are present in fluid flow. Repeat procedure on left rear, right front, and left front wheels in this order. 5. Check brake pedal operation. Remove pressure bleeder. Remove valve retainer from hold-off valve. Refill master cylinder reservoir, if necessary.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 1: Positioning Hold-Off Valve On Combination Valve (Typical) Courtesy of GENERAL MOTORS CORP.

ADJUSTMENTS PARKING BRAKE Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

NOTE:

Ensure rear brake shoes are adjusted before adjusting parking brake. See REAR BRAKE SHOES under ADJUSTMENTS .

Raise and support vehicle. Loosen parking brake cable adjusting nut. Fully release parking brake pedal. Tighten adjusting nut until wheels will not rotate forward without excessive force. Back off adjusting nut until little or no drag exists when wheels are rotated forward. Lower vehicle. REAR BRAKE SHOES 1. Ensure parking brake is released. Raise and support vehicle. Knock out lanced area in backing plate with a punch (if not already removed) and remove from brake assembly. 2. Working through hole in backing plate, rotate adjusting screw until brake shoes expand and wheels can just be turned by hand. Ensure drag is equal at both wheels. Back off adjusting screw 24 notches at each wheel. 3. If heavy drag is present after adjusting screw is backed off 12 notches, check parking brake adjustment. See PARKING BRAKE under ADJUSTMENTS . To complete procedure, install plug in backing plate. Check parking brake adjustment. STOPLIGHT SWITCH NOTE:

Stoplight switch is installed along with brake push rod and is not adjustable.

TESTING BRAKE WARNING LIGHT Electrical Circuit

Disconnect wire from switch terminal on combination valve. Connect wire to ground. Turn ignition on. If brake warning light does not come on, repair brake warning light bulb or wiring circuit. If light operates, brake warning light electrical circuit is okay. Warning Light Switch

1. Fill master cylinder reservoir. Attach bleeder hose to bleeder screw at either rear wheel. Immerse other end of hose in container of brake fluid. Turn ignition on. 2. While depressing brake pedal, open bleeder screw (close bleeder screw before releasing pedal). If light comes on, go to next step. If light does not come on, switch is defective; replace combination valve. 3. Close bleeder screw. Depress brake pedal with moderate to heavy pressure. If light goes out, switch is okay. If light stays on, switch is defective, replace combination valve. Repeat test on front brake system. System should function in same manner as rear.

REMOVAL & INSTALLATION FRONT BRAKE CALIPER Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

NOTE:

For front disc pad removal and installation, perform FRONT BRAKE CALIPER removal and installation procedures but do not disconnect brake hose from caliper (hang caliper out of way with wire). Replace all pads on an axle if wear indicator on any pad contacts rotor or if pad is worn to within 1/32" (.8 mm) of pad backing.

Removal (Floating Caliper)

1. Remove two-thirds of brake fluid from master cylinder. Raise and support vehicle. Remove wheel. Using "C" clamp or large pliers, compress caliper piston until it bottoms in its bore. 2. Disconnect brake hose from caliper. Remove caliper guide pins. See Fig. 3 . Remove caliper. Remove pads from caliper. Note retainer spring on inner pad (some models) and remove if replacing pads. Installation

1. Remove caliper sleeves from caliper. See Fig. 3 . Apply silicone grease to outer diameter of caliper sleeves and inner diameter of bushings. Insert caliper sleeves into bushings. 2. Install retainer spring on inner pad (if removed). Install pads in caliper. Install caliper. Install guide pins and tighten to specification. See TORQUE SPECIFICATIONS . 3. Connect brake hose to caliper and tighten hose bolt to 32 ft. lbs. (43 N.m). Bleed brake system. See MANUAL BLEEDING or PRESSURE BLEEDING under BLEEDING BRAKE SYSTEM . 4. If outer pads are equipped with locking ears, bend ears toward caliper until ears touch caliper. This prevents movement of outer pad in caliper. See Fig. 2 . Install wheel.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 2: Bending Outer Pad Ears Toward Caliper Courtesy of GENERAL MOTORS CORP. Removal (Sliding Caliper)

1. Remove two-thirds of brake fluid from master cylinder. Raise and support vehicle. Remove wheel. Using "C" clamp or large pliers, compress caliper piston until it bottoms in its bore. 2. Disconnect brake hose from caliper. Remove caliper support key bolt. See Fig. 5 . Using hammer and brass punch, drive out caliper support key and spring. Remove caliper. Remove inner and outer pads. Installation

1. Using wire brush, clean corrosion from machined ways on caliper and caliper mount. Apply silicone Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

grease to these surfaces. Install inner pad and anti-rattle spring on caliper mount. See Fig. 5 . Install outer pad in caliper. Place caliper on caliper mount. 2. Install caliper support key and spring. Install caliper support key bolt, ensuring bolt boss fits into circular cutout on caliper support key. Tighten bolt to 15 ft. lbs. (20 N.m). 3. Connect brake hose to caliper and tighten hose bolt to specification. See TORQUE SPECIFICATIONS . Bleed brake system. See MANUAL BLEEDING or PRESSURE BLEEDING under BLEEDING BRAKE SYSTEM . Install wheel. FRONT BRAKE ROTOR Removal (2WD)

Remove brake caliper (DO NOT disconnect brake hose). See FRONT BRAKE CALIPER under REMOVAL & INSTALLATION. Remove grease cap from end of hub. Remove cotter pin, nut, washer and outer bearing. Remove rotor and hub assembly. Inspection

Inspect rotor lateral runout and parallelism. See DISC BRAKE SPECIFICATIONS . If lateral runout cannot be corrected check hub bearing for excessive lateral runout or looseness. Hub bearing assembly lateral runout cannot exceed .0016" (.040 mm). Installation

1. Clean and pack wheel bearings. Install rotor and hub assembly. Install outer bearing, washer and nut. Tighten nut to 12 ft. lbs. (16 N.m) while rotating rotor and hub assembly. This seats bearings. 2. Back off nut until it just begins to loosen. Finger-tighten nut. Back off nut until hole in spindle aligns with hole in nut (DO NOT back off more than 1/2 of a flat). Install new cotter pin, bend ends over and ensure ends will not contact grease cap when installed. To complete installation, reverse removal procedure. Removal & Installation (4WD)

Remove brake caliper (DO NOT disconnect brake hose). See FRONT BRAKE CALIPER under REMOVAL & INSTALLATION. Remove rotor. To install, reverse removal procedure. REAR BRAKE CALIPER NOTE:

For rear disc pad removal and installation, perform REAR BRAKE CALIPER removal and installation procedures but DO NOT disconnect brake hose from caliper (hang caliper out of way with wire). Replace all pads on an axle if wear indicator on any pad contacts rotor or if pad is worn to within 1/32" (.8 mm) of pad backing.

Removal

1. Remove two-thirds of brake fluid from master cylinder. Raise and support vehicle. Remove wheel. Using Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

"C" clamp or large pliers, compress caliper piston until it bottoms in its bore. 2. Disconnect brake hose from caliper. Remove caliper support key bolt. See Fig. 5 . Drive out caliper support key and spring. Remove caliper. Remove inner and outer pads. Installation

1. Clean corrosion from machined ways on caliper and caliper mount. Apply silicone grease to these surfaces. Install inner pad and anti-rattle spring on caliper mount. Install outer pad in caliper. Install caliper. 2. Install caliper support key and spring. Install caliper support key bolt, ensuring bolt boss fits into circular cutout on caliper support key. Tighten bolt to 15 ft. lbs. (20 N.m). 3. Connect brake hose to caliper and tighten hose bolt to specification. See TORQUE SPECIFICATIONS . Bleed brake system. See MANUAL BLEEDING or PRESSURE BLEEDING under BLEEDING BRAKE SYSTEM . Install wheel. REAR BRAKE DRUM Removal & Installation

Ensure parking brake is released. On Savana and Express, remove left kick panel. Place parking brake lever in full upright position. With an assistant in vehicle, raise and support vehicle. Pull rearward on front of cable strand until parking brake lever reaches its full reset position. Insert a pin into parking brake lever to hold tension. See Fig. 6 . On all models, remove wheel. Reference mark rear brake drum-to-axle. Remove brake drum (if necessary, back off adjuster wheel before removing brake drum). To install, reverse removal procedure. Adjust rear brake shoes. See REAR BRAKE SHOES under ADJUSTMENTS . REAR BRAKE SHOES NOTE:

For rear brake shoe removal and installation, see Fig. 6 , 16 and 17. DO NOT interchange left and right adjusting screw assemblies as one side is right-hand thread and other is left-hand thread.

WHEEL CYLINDER Removal & Installation

Remove rear brake shoes. See REAR BRAKE SHOES under REMOVAL & INSTALLATION . Disconnect brake line from wheel cylinder. Remove brake cylinder retaining bolts and brake cylinder. To install, reverse removal procedure. Bleed brake system. See MANUAL BLEEDING or PRESSURE BLEEDING under BLEEDING BRAKE SYSTEM . MASTER CYLINDER Removal

1. With engine off, press brake pedal several times to release vacuum in power brake unit. Clean dirt and Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

grease from master cylinder brake line fittings. Disconnect brake lines from master cylinder and plug line ends. 2. On vehicles with combination valve and bracket attached to master cylinder mounting studs, remove combination valve and bracket. On vehicles without power brake unit, disconnect brake pedal push rod at brake pedal. On all vehicles, remove master cylinder retaining nuts and master cylinder. Installation

1. Bench bleed master cylinder before installing. See MASTER CYLINDER BLEEDING under BLEEDING BRAKE SYSTEM . Position master cylinder on mounting studs. Position combination valve and bracket on mounting studs (if applicable). Loosely install master cylinder retaining nuts. Connect brake lines to master cylinder but DO NOT tighten. 2. Tighten master cylinder retaining nuts. Tighten brake lines. Connect brake pedal push rod (if disconnected). Fill fluid reservoir. Bleed brake system. See MANUAL BLEEDING or PRESSURE BLEEDING under BLEEDING BRAKE SYSTEM . POWER BRAKE BOOSTER Removal & Installation

1. Remove master cylinder. See MASTER CYLINDER under REMOVAL & INSTALLATION . Ensure no brake fluid contacts ABS control unit or related electrical connectors and wiring. 2. Disconnect vacuum hose from booster. Disconnect booster push rod from brake pedal. Remove booster mounting nuts from inside vehicle. Remove booster and gasket. 3. To install, reverse removal procedure. Bleed brake system if lines were disconnected from master cylinder. See MANUAL BLEEDING or PRESSURE BLEEDING under BLEEDING BRAKE SYSTEM . REAR AXLE BEARING & OIL SEAL (SEMI-FLOATING AXLE) Removal

1. Raise and support vehicle. Remove wheels and brake drums. Loosen differential cover plate and drain lubricant from axle. Remove cover plate. 2. Remove pinion shaft lock bolt. See Fig. 3 and Fig. 4 . Remove pinion shaft. Push axle shaft toward center of vehicle and remove "C" lock from end of axle shaft. Remove axle shaft. 3. Pry seal from axle housing. Using Slide Hammer (J-2619-01) and Axle Bearing Puller (J-22813-01), remove bearing from axle housing.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 3: Locating "C" Lock & Pinion Shaft Lock Bolt Courtesy of GENERAL MOTORS CORP. Installation

1. Lubricate bearing with gear lubricant. Using Handle (J-8092) and Bearing Installer (J-23765), install bearing in axle housing until bearing installer bottoms against shoulder of axle housing. 2. Using Seal Installer (J-23771), install seal until even with surface of axle housing. Lubricate seal lips with gear lubricant. Install axle shaft and "C" lock. See Fig. 3 and Fig. 4 . Pull axle shaft outward to ensure "C" lock seats in side gear. 3. Install pinion shaft. Install NEW pinion shaft lock bolt. Tighten lock bolt to 25 ft. lbs. (34 N.m). Install differential cover and new gasket. Fill drive axle with gear lubricant. Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 4: Removing & Installing "C" Lock & Pinion Shaft On Locking Differential (Typical) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

OVERHAUL NOTE:

Use exploded view illustrations for overhaul of brake assemblies. See Fig. 5 Fig. 12 . WARNING: DO NOT hone master cylinder bore. Honing destroys hardened surface, causing premature piston seal failure. If bore surface is rough or pitted, replace master cylinder.

Fig. 5: Exploded View Of Sliding Caliper Assembly (Typical) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 6: Exploded View Of Rear Brake Assembly Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 7: Exploded View Of Power Brake Booster (Dual Diaphragm) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 8: Exploded View Of Floating Caliper Assembly (Typical) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 9: Exploded View Of Power Brake Booster (Single Diaphragm) Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Courtesy of GENERAL MOTORS CORP.

Fig. 10: Exploded View Of Cast Iron Master Cylinder Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Microsoft Saturday, August 29, 2009 11:25:29 AM

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Fig. 11: Exploded View Of Composite Master Cylinder Courtesy of GENERAL MOTORS CORP.

Fig. 12: Exploded View Of Rear Wheel Cylinder (Typical) Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Backing Plate Bolts Brakerake Cylinder Bolts

Ft. Lbs. (N.m) 103 (140) 15 (20)

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1997 Chevrolet S10 Pickup BRAKE SYSTEM 1997 BRAKES Disc & Drum - General Motors

Brake Line Fittings (Except To EBCM) Brake Line Fittings (To EBCM) Brake Hoses Banjo Bolts-To-Front Caliper Caliper Guide Pin (Floating Caliper) Caliper Support Key Bolt (Sliding Caliper) Combination Valve Allen Bolts Differential Cover Bolt Front Brake Hose-To-Caliper Bolt

22 (30) 15 (20) 15 (20) 37 (50) 37 (50) 15 (20) 12 (16) 20 (27) 32 (43)

Pinion Shaft Lock Bolt (1) Standard Differential Locking Differential 7 5/8", 8 1/2" & 8 5/8 Ring Gear 9 1/2" Ring Gear Power Booster Nuts Wheel Lug Nut (1) Use NEW pinion shaft lock bolt. DO NOT reuse bolt.

25 (34) 27 (37) 37 (50) 27 (37) 95 (130)

DRUM BRAKE SPECIFICATIONS DRUM BRAKE SPECIFICATIONS Application Original Diameter Discard Diameter Maximum Refinish Diameter Width

In. (mm) 9.50 (241.3) 9.59 (243.6) 9.56 (242.8) 2.00 (50.8)

DISC BRAKE SPECIFICATIONS DISC BRAKE SPECIFICATIONS Application Lateral Runout Parallelism Original Thickness Minimum Refinish Thickness (1) Discard Thickness (1) Use specification stamped on rotor (if available).

In. (mm) .004 (.10) .0005 (.013) 1.03 (26.2) .980 (24.89) .965 (24.51)

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

DESCRIPTION The CS130 (Charging System) generators have a high amperage output. The 130 designation is the outside diameter of the stator laminations, measured in millimeters. CS series generators include a delta stator, rectifier bridge, and a rotor with slip rings and brushes. A built-in regulator incorporates fault detection circuitry. See Fig. 1 . A conventional pulley and external fan are used to cool slip ring end frame, rectifier bridge and regulator. Most CS series generators operate with 2 wire connections and a ground path through the mounting bracket. The first wire connection is the BAT (output) terminal. This terminal must be connected to the battery during operation. The second wire connection is through the charge indicator light or an external resistor to terminal "L" of the regulator. This connection provides initial excitation at start-up. Three other regulator terminals, "P", "F/I" and "S", are provided for optional use. Terminal "P" is connected to the stator and may be connected to a tachometer. Terminal "F/I" provides an alternative method for turning on the generator without going through the charge indicator light or external resistor. Terminal "S" may be used to sense electrical system voltage at a remote point on the vehicle. If terminal "S" is not used, the regulator senses internal generator voltage. Regulated voltage varies with temperature. System limits voltage by controlling rotor field current while field current is on. Regulator switches rotor field current on and off at a fixed frequency of 400 cycles per second to help control radio noise. By varying overall on/off time, correct average field current for proper system voltage control is obtained. At high speeds, with lower electrical loads, on-time may be 10 percent of off-time. At low speeds, with higher electrical loads, on-time may be 90 percent of off-time. See the GENERATOR USAGE/AMP OUTPUT RATING table.

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

Fig. 1: Charging System Wiring Schematic CS130 Series Courtesy of GENERAL MOTORS CORP. GENERATOR USAGE/AMP OUTPUT RATING Microsoft Saturday, August 29, 2009 11:29:16 AM

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

Generator CS130D

RPO Code K60

Rated Output 100

ADJUSTMENTS NOTE:

No adjustment or maintenance is required on generator assembly. Regulator voltage is preset and no adjustment is possible. On all models drive belt tension is controlled by a belt tensioner.

TROUBLE SHOOTING NOTE:

For information not covered in this article, see the TROUBLE SHOOTING BASIC PROCEDURES article in the GENERAL INFORMATION section.

ON-VEHICLE TESTING NOTE:

All generators are serviced by replacement only.

NOTE:

Before making electrical checks, visually inspect all terminals for clean, tight connections. Check generator mounting bolts and drive belt tension. Ensure battery is in good condition prior to testing charging system. CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in the GENERAL INFORMATION section before disconnecting battery.

CHARGE INDICATOR LIGHT NOTE:

Perform this test only if charge indicator light does not illuminate when ignition is turned on, or does not go out after engine is started. CAUTION: DO NOT run engine with generator output terminal disconnected from battery.

1. Ensure battery is fully charged. Visually check generator belt and wiring. Turn ignition switch to ON position (engine not running). Charge indicator light should illuminate. If charge indicator light does not illuminate, go to next step. If charge indicator light illuminates, go to step 4). 2. Turn ignition off. Disconnect generator harness connector. Using a fused (5-amp) jumper wire, connect terminal "L" of generator harness connector to ground. Turn ignition on (engine not running). If charge indicator light illuminates, replace or repair generator. Microsoft Saturday, August 29, 2009 11:29:17 AM

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

3. If charge indicator light still does not illuminate, check for open in circuit between generator terminal "L" and ignition switch. Also check charge indicator light bulb. See WIRING DIAGRAM . 4. Start engine and run at 1500 RPM. Charge indicator light should go off. If charge indicator light remains illuminated, turn ignition off. Disconnect generator harness connector. If charge indicator light goes out, replace or repair generator. If charge indicator light remains illuminated, check for short to ground in generator terminal "L" circuit wiring harness. UNDERCHARGED OR OVERCHARGED BATTERY NOTE:

Ensure battery is fully charged and in good condition before performing the following steps. If battery is not at (or near) a fully charged condition, service as necessary before proceeding.

1. Turn ignition and all accessories off. Using a voltmeter, measure and record battery voltage for use in step 4). Disconnect generator harness connector. Turn ignition switch to ON position (engine not running). 2. Connect negative lead of a voltmeter to a good engine ground. Connect positive voltmeter lead to terminal "L" of generator harness connector. On models with gauges, also connect positive voltmeter lead to terminal F/I of generator harness connector. See WIRING DIAGRAM . 3. Battery voltage should be present at terminal "L" or F/I (gauges only). If battery voltage is not present, repair open circuit between generator connector terminal and battery. If battery voltage is present, reconnect generator harness connector and go to next step. 4. Start engine and slowly increase speed to approximately 1500 RPM. Using a voltmeter, measure voltage between battery terminals. If voltage is greater than 16 volts, or less than voltage as measured in step 1), replace or repair generator. If voltage is less than 16 volts, or greater than voltage as measured in step 1), go to next step. CAUTION: To prevent injury and/or damage to vehicle, disconnect negative battery cable before connecting or disconnecting a series type ammeter to generator. CAUTION: Carbon pile testing is part of this procedure. To avoid battery explosion, turn carbon pile OFF before connecting to or disconnecting from vehicle battery. 5. Disconnect negative battery cable. Install ammeter to voltmeter. Connect voltmeter to generator output (BAT) terminal. Connect negative battery cable. With load off, connect carbon pile load tester across battery terminals. Run engine at approximately 1500 RPM, turn accessories on and load battery with carbon pile load until maximum generator output is reached. Adjust carbon pile to maintain 13 volts or more. Measure amp output. 6. If amp output is within 15 amps of rated output, generator is okay. If amp output is not within 15 amps of rated output, repair or replace generator. See GENERATOR USAGE/AMP OUTPUT RATING table.

BENCH TESTING Microsoft Saturday, August 29, 2009 11:29:17 AM

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

NOTE:

Information not available from manufacturer at time of publication.

Disconnect negative battery cable. Remove drive belt. Remove nut retaining positive battery cable to generator BAT terminal. Disconnect generator electrical connector. Remove mounting bolts, nuts, braces and brackets. Remove other components as necessary. Remove generator. To install, reverse removal procedure.

OVERHAUL NOTE:

All generators are serviced by replacement only.

WIRING DIAGRAM

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

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1997 Chevrolet S10 Pickup GENERATOR & REGULATOR 1997 ELECTRICAL General Motors Corp. - Generators & Regulators

Fig. 2: Charging System Wiring Diagram

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

1996-97 CLUTCHES General Motors Corp. Trucks

DESCRIPTION The hydraulic clutch system consists of a clutch plate, pressure plate, release bearing and pilot bearing. Hydraulic clutch has a master cylinder with a reservoir. Clutch pedal moves master cylinder push rod which activates a concentric slave (actuator) cylinder located in transmission bellhousing, which moves the release bearing. See Fig. 1 . Hydraulic clutch system provides automatic clutch adjustment. No adjustment of clutch linkage or pedal position is required. Master cylinder, hydraulic line and actuator cylinder assembly is furnished pre-filled and pre-bled.

Fig. 1: Identifying Concentric Clutch Slave Cylinder Courtesy of GENERAL MOTORS CORP.

LUBRICATION Microsoft Saturday, August 29, 2009 11:55:21 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

RECOMMENDED FLUID TRANSMISSION/TRANSFER CASE LUBRICATION FLUID Application Fluid Type Transmission C/K Series NV3500 GM Synchro-Mesh Transmission Oil (12345349) NV4500 Castrol Syntorq LT Transmission Oil S/T Series NV1500 GM Synchro-Mesh Transmission Oil With Friction Modifier (12377916) NV3500 GM Synchro-Mesh Transmission Oil (12345349) P Series NV4500 Castrol Syntorq LT Transmission Oil Transfer Case C/K Series Dexron-III S/T Series Dexron-III

ADJUSTMENTS NOTE:

The hydraulic clutch system provides automatic clutch adjustment; no manual clutch adjustments are necessary.

BLEEDING CLUTCH SYSTEM NOTE:

DO NOT reuse fluid that has been bled from system.

1. First clean and then remove reservoir cap. Top-off reservoir with NEW DOT 3 brake fluid. 2. Have an assistant depress and hold clutch pedal. Open bleed screw located on left side of transmission to expel air. Close bleed screw and release clutch pedal. 3. Repeat step 2) until all air is out of system. Check and refill reservoir as needed during bleeding to remove air from system. After bleeding, pump clutch pedal several times. If clutch engagement is not satisfactory, repeat bleeding procedure. 4. If normal bleeding procedure is unsuccessful, perform the following:  Remove reservoir cap.  Pump pedal very fast for 30 seconds.  Stop to allow air to escape.  Repeat procedure as necessary.

DRIVE SHAFT PARKING BRAKE (C/K SERIES) Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

1. Remove clevis pin from parking brake lever. Set parking brake by pushing pedal down 18 degrees. Insert a .125" (3 mm) pin into locating hole in pedal assembly. See Fig. 2 . Push pedal down until pin contacts parking brake outer flange. Install tension scale with a small length of cable or chain, and a tightening device (i.e. turn buckle) on frame. Install small chain on lever near spring at bottom of lever. See Fig. 3 . 2. Tighten tightening device until tension scale reads 50 ft. lb. (222 N.m). Loosen nut and turn clevis until pin slides freely in lever with all slack removed from cable. Install clevis pin and cotter pin. Remove tension scale and all extensions used. Release parking brake. Rotate drum to make sure that there is no drag.

Fig. 2: Identifying Brake Adjustment Locating Hole (C/K Series) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

Fig. 3: Identifying Drive Shaft Parking Brake Components (C/K Series) Courtesy of GENERAL MOTORS CORP.

DRIVE SHAFT PARKING BRAKE (P SERIES) Raise and support vehicle. Install drum over first rivet section, leaving adjuster screw accessible. Place two .010" (.254 mm) shims between both shoes and drum. Shims should be 140-180 degrees apart. Rotate adjuster screw until shims indicate spacing has been met (no clearance). Remove shims and complete drum installation. Rotate drum. Drum should spin freely with only a slight drag.

TRANSFER CASE LINKAGE (C/K SERIES) Place shift lever in 4-HI position. Raise and support vehicle. Disconnect linkage rod from console shift lever. Shift transfer case into 4-HI position by moving transfer case shift lever in full back position. A clicking sound will indicate that transfer case lever is in full back position. Adjust swivel to align with notch in console shift lever. Connect linkage rod to console shift lever.

TRANSFER CASE CABLE (S/T SERIES) Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

Remove shift lever knob retainer and shift lever knob. Remove front floor console. Place shift lever in Neutral position. Pry control cable end from shift lever. Loosen control cable lock nut. Ensure transfer case is in Neutral position. Place shift lever in Neutral position. Turn shift lever end of cable in or out, until it is aligned with shift lever. Install control cable to shift lever and control cable lock nut.

TROUBLE SHOOTING NOTE:

For trouble shooting not covered in this article, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

Hydraulic system should not require additional fluid under normal circumstances. Reservoir fluid level will increase as normal clutch wear occurs. Avoid overfilling or removing fluid from reservoir. This will cause clutch release problems.

TESTING Apply parking brake. Block vehicle wheels. Shift transmission into Neutral. Start engine and run at idle. Engage clutch. Disengage clutch. Wait 9 seconds. Shift transmission into Reverse. If grinding noise is heard, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

DO NOT disassemble transmission shift housing. Internal parts for shift housing are not available. Also, opening shift housing voids warranty.

Removal (C/K & P Series)

1. Disconnect negative battery cable. Shift transmission into 3rd or 4th gear. Remove shift lever retainer screws and retainer. Remove 8 shift lever boot mounting screws and boot. Remove shift lever insulator. Remove shift lever. Remove 4 exposed bolts on base of housing, not bolts under rubber boot located at top of housing. Remove insulator from transmission case. Raise and support vehicle. Drain transmission fluid. 2. Mark drive shaft for reassembly reference. Remove drive shaft(s). On 4WD, remove transfer case shield. Drain oil from transfer case. Remove vent hose and electrical connectors. Remove transfer case shift linkage. Using a jack, support transfer case. Remove transfer case and discard transmission adapter gasket. 3. On vehicles equipped with drive shaft parking brake, release parking brake. Raise and support vehicle. Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

Remove nut and washer from center of brake drum. Remove drum yoke assembly, bolts, washers and drum yoke. Remove cotter pin, clevis pin, clevis, and nut from brake cable. Remove parking brake cable grommet, and cable from bracket. 4. On all vehicles, disconnect exhaust pipes from exhaust manifold, and catalytic converter from muffler assembly (if necessary). Disconnect electrical connectors from speed sensor and back-up light switch. Using Quick Connect Disconnect Tool (J-36221), remove clutch line from concentric slave cylinder quick connect coupling. See Fig. 4 . Remove starter and clutch housing cover. Remove transmission vent hose. 5. Support transmission and engine. Remove crossmember. Remove clutch plate and clutch cover from flywheel. Remove transmission-to-engine bolts and studs. Pull transmission straight back on clutch hub splines. Remove clutch and clutch cover plates during transmission-to-engine separation. Remove transmission. Installation

1. To install, reverse removal procedure. If equipped with drive shaft parking brake, adjust parking brake. See DRIVE SHAFT PARKING BRAKE (C/K SERIES) or DRIVE SHAFT PARKING BRAKE (P SERIES) under ADJUSTMENTS. On 4WD, install NEW transmission adapter gasket. Adjust transfer case shift linkage. See TRANSFER CASE LINKAGE (C/K SERIES) under ADJUSTMENTS. 2. Lightly coat input shaft splines with high-temperature grease. Tighten bolts to specifications. See TORQUE SPECIFICATIONS (C/K SERIES) table or TORQUE SPECIFICATIONS (P SERIES) table. Fill transmission and transfer case with fluid. See TRANSMISSION/TRANSFER CASE LUBRICATION FLUID table under LUBRICATION. Removal (S/T Series)

1. Disconnect negative battery cable. Shift transmission into 3rd or 4th gear. Remove shift lever knob and nut. Remove shift lever retainer screws and retainer (if equipped). Remove shift lever boot mounting screws and boot. Remove shift lever and nut. 2. Remove exposed bolts on base of housing. DO NOT remove bolts under rubber boot at top of housing. Remove shift lever housing. Raise and support vehicle. Drain transmission fluid. Remove parking brake cable for clearance. Mark drive shaft(s) for reassembly reference. Remove drive shaft(s). 3. Disconnect electrical connectors from speed sensor and back-up switch. On all models, disconnect exhaust pipe from exhaust manifold. Remove catalytic converter and hanger. If equipped, remove right and left side transfer case-to-transmission braces. On 4WD, place transfer case in 4H position. Remove skid plate. Drain fluid from transfer case. Disconnect vacuum lines and electrical connectors from transfer case (if equipped). 4. Disconnect shift cable from transfer case. Support transfer case with jack. Remove transfer case-totransmission mounting bolts. Slide transfer case rearward until free of transmission output shaft. Lower and remove transfer case. Remove and discard gasket. Using Quick Connect Disconnect Tool (J-36221), remove clutch line from concentric slave cylinder quick connect coupling. See Fig. 4 . 5. Remove clutch housing cover. Remove clutch plate and clutch cover from flywheel. Support transmission. Using a fuel pressure gauge, purge fuel system, and disconnect fuel lines. Remove fuel lines and retainers from rear crossmember. Remove rear crossmember. Move wiring harness away from transmission oil pan. 6. Lower transmission enough to gain access to top of transmission. Remove wiring harness from front Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

crossmember. Remove engine block ground. Remove transmission mounting bolts as necessary. Pull transmission straight back on clutch hub splines, and remove transmission. Installation

To install, reverse removal procedure. On 4WD, install NEW transmission adapter gasket. Adjust transfer case shift cable. See TRANSFER CASE CABLE under ADJUSTMENTS. Lightly coat input shaft splines with high-temperature grease. Tighten bolts to specifications. See TORQUE SPECIFICATIONS (S/T SERIES) table. Fill transmission with fluid. See TRANSMISSION/TRANSFER CASE LUBRICATION FLUID table under LUBRICATION.

Fig. 4: Hydraulic Clutch Line Separator (Quick Connect Disconnect Tool) Courtesy of GENERAL MOTORS CORP. CLUTCH ASSEMBLY & PILOT BEARING WARNING: DO NOT use compressed air to clean clutch parts. Clutch plate contains asbestos and is harmful when inhaled. Removal (C/K & P Series)

1. Remove transmission. See TRANSMISSION . Install Clutch Alignment Tool (J-5824-01) to support clutch plate. Mark flywheel and pressure plate for reassembly reference. See Fig. 5 . 2. Evenly loosen pressure plate bolts 1-2 turns at a time until pressure plate spring tension is released. Remove clutch plate and pressure plate. Remove clutch aligner. Remove pilot bearing, if worn or damaged, using Pilot Bearing Puller (J-23907). Remove concentric slave cylinder and release bearing. See CONCENTRIC SLAVE (ACTUATOR) CYLINDER . Inspection Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

1. Clean all components with water-dampened cloth to remove asbestos fibers. Clean flywheel housing with solvent. Release bearing is permanently packed with lubricant and should not be cleaned with solvent. 2. Inspect all components for wear or damage. Inspect all contact surfaces for scoring, warping and damage. Clutch plate runout must not exceed .20" (.508 mm). Inspect friction surfaces for excessive oil. Inspect splines for nicks, burrs and sliding fit. Bellhousing transmission pilot hole runout should not exceed .015" (.38 mm). Installation

1. On 4.3L, 5.0L and 5.7L, use brass drift to install NEW pilot bearing into flywheel, if removed. On 6.5L diesel, use Pilot Bearing Driver (J-34140) to install NEW pilot bearing into flywheel, if removed. On 4.3L, 5.0L and 5.7L, lubricate pilot bearing with machine oil. On 6.5L diesel, pilot bearing is sealed and does not require lubrication. 2. Install clutch aligner to support clutch plate. Install clutch plate and pressure plate to flywheel. Ensure reference marks are aligned. If installing NEW clutch plate and pressure plate, align lightest part of clutch cover, identified by a yellow dot, with heaviest part of flywheel part of flywheel, identified by an"X". Install and tighten NEW spring washers and bolts evenly to avoid distortion. Remove clutch aligner. 3. Lubricate O.D. groove and pack grease into I.D. recess of release bearing. To complete installation, reverse removal procedure. Tighten bolts to specifications. See TORQUE SPECIFICATIONS (C/K SERIES) or TORQUE SPECIFICATIONS (P SERIES) table. Fill reservoir with fluid. See TRANSMISSION/TRANSFER CASE LUBRICATION FLUID table under LUBRICATION. Bleed system. See BLEEDING CLUTCH SYSTEM . Removal (S/T Series)

1. Remove transmission. See TRANSMISSION . Remove slave cylinder and release bearing. Install Clutch Aligner (J-33169) to support clutch plate. Mark flywheel, clutch plate and pressure plate for reassembly reference. 2. Evenly loosen pressure plate bolts 1-2 turns at a time until clutch plate spring tension is released. Remove clutch plate and pressure plate. Remove clutch aligner. Remove pilot bearing if worn or damaged using Pilot Bearing Puller (J-23907). Inspection

1. Clean all components with water-dampened cloth to remove asbestos fibers. Clean clutch fork, bellhousing and ball stud with solvent. Release bearing is permanently packed with lubricant and should not be cleaned with solvent. 2. Inspect all components for wear or damage. Inspect all contact surfaces for scoring, warping and damage. Clutch plate runout must not exceed .20" (.508 mm). Inspect friction surfaces for excessive oil. Inspect splines for nicks, burrs and sliding fit. Installation

1. Use Pilot Bearing Installer (J-26516-A) with Driver Handle (J-8092) to install NEW pilot bearing into flywheel, if removed. See Fig. 1 . Lubricate pilot bearing with machine oil. Install Clutch Aligner (J33169) to support clutch plate. Install clutch plate and pressure plate to flywheel. Ensure reference marks Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

are aligned. 2. Install and tighten NEW spring washers and bolts evenly to avoid distortion. Remove clutch aligner. Lubricate O.D. groove and pack grease into I.D. recess of release bearing. 3. To complete installation, reverse removal procedure. Tighten bolts to specifications. See TORQUE SPECIFICATIONS (S/T SERIES) table. Fill reservoir with fluid. See TRANSMISSION/TRANSFER CASE LUBRICATION FLUID under LUBRICATION. Bleed system. See BLEEDING CLUTCH SYSTEM .

Fig. 5: Exploded View Of Clutch Assembly Courtesy of GENERAL MOTORS CORP. MASTER CYLINDER & RESERVOIR WARNING: Vehicles are equipped with air bag supplemental restraint system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in the appropriate AIR BAG RESTRAINT SYSTEMS article. NOTE:

Master cylinder is serviced as an assembly along with master cylinder reservoir and tubing. Replacement of individual components cannot be performed. A complete pre-filled, pre-bled master cylinder assembly must be installed.

Removal

Disconnect negative battery cable. Separate push rod from clutch pedal. Using Quick Connect Disengagement Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

Tool (J-36221), remove hydraulic line from concentric slave cylinder at transmission. Remove line clips from wiring harness bracket and sheet metal. Rotate master cylinder body 45 degrees clockwise and remove from cowl panel. See Fig. 6 . Installation

To complete installation, reverse removal procedure. Tighten bolts to specifications. See TORQUE SPECIFICATIONS . Top off reservoir with fluid. See TRANSMISSION/TRANSFER CASE LUBRICATION FLUID table under LUBRICATION. Bleed system. See BLEEDING CLUTCH SYSTEM .

Fig. 6: Master Cylinder Removal Courtesy of GENERAL MOTORS CORP. CONCENTRIC SLAVE (ACTUATOR) CYLINDER Removal & Installation

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

Using Hydraulic Clutch Line Separator (J-36221), depress the White plastic sleeve to separate coupling. See Fig. 4 . Protect both halves of coupling to prevent contamination. Remove transmission. See TRANSMISSION . Remove bolts securing concentric slave cylinder to clutch housing shaft. Remove slave cylinder assembly from transmission input shaft. Remove release bearing from slave cylinder. For installation, reverse removal procedure.

OVERHAUL NOTE:

All master and concentric slave (actuator) cylinders are serviced as an assembly. Rebuilding or overhaul is not possible.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS (C/K SERIES) Application Bellhousing-To-Engine Bolts Bellhousing-To-Transmission Bolts Crossmember Bolts Lower PTO Cover Bolt (Oil Drain On NV4500) Oil Fill Plug (NV4500) Oil Fill & Drain Plugs (NV3500) Parking Brake Drum To Yoke Bolts Parking Brake Yoke Shaft Nut Pressure Plate-To-Flywheel Bolts Gasoline engine Diesel engine Shift Housing Bolts Transfer Case-To-Transmission Bolts

Ft. Lbs. (N.m) 35 (47) 74 (100) 38 (51) 27 (37) 30 (41) 44 (60) 27 (37) 350 (475) 29 (40) 25 (34) 11 (15) 24 (33) INCH Lbs. (N.m) 89 (10) 71 (8)

Clutch Housing Cover Bolts Slave Cylinder Bolts TORQUE SPECIFICATIONS (P SERIES) Application Lower PTO Cover Bolt (Oil Drain On NV4500) Oil Fill Plug (NV4500) Parking Brake Drum To Transmission Parking Brake Yoke Shaft Nut Shift Lever Nut Transmission To Engine Studs

Ft. Lbs. (N.m) 30 (41) 30 (41) 65 (88) 325 (441) 15 (20) 23 (31) INCH Lbs. (N.m) 89 (10)

Clutch Housing Cover Bolts Microsoft Saturday, August 29, 2009 11:55:17 AM

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1997 Chevrolet S10 Pickup 1996-97 CLUTCHES General Motors Corp. Trucks

Shift Housing Bolts

89 (10)

TORQUE SPECIFICATIONS (S/T SERIES) Application Adapter-To-Transmission Bolts Bellhousing-To-Engine Bolts Pressure Plate-To-Flywheel Bolts Rear Crossmember Bolts Skid Plate Bolts Support Brace Bolts Transfer Case Oil Drain & Fill Plugs Transfer Case-To-Transmission Bolts Transmission Brace To Engine Bolts Transmission Brace To Engine Studs Transmission Oil Fill & Drain Plugs (NV3500) Transmission Oil Fill Plug (NV1500)

Ft. Lbs. (N.m) 31 (42) 35 (47) 29 (40) 34 (46) 25 (34) 35 (47) 18 (25) 41 (55) 37 (50) 35 (47) 44 (60) 17 (24) INCH Lbs. (N.m) 62 (7) 80 (9) 27 (3)

Clutch Housing Cover Bolts Concentric Slave Cylinder Bolts Reservoir Bolts

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1997 Chevrolet S10 Pickup 1996 GENERAL INFORMATION Computer Relearn Procedures - General Motors Corp.

1996 GENERAL INFORMATION Computer Relearn Procedures - General Motors Corp.

INTRODUCTION Vehicles equipped with engine or transmission computers may require a relearn procedure after the vehicle battery is disconnected. Vehicle computers memorize and store vehicle operation patterns for optimum driveability and performance. When the vehicle battery is disconnected, this memory is lost. Default data is used until new data from each key start is stored. As the computer restores its memory from each new key start, driveability is restored. Driveability problems may occur during the relearn stage. Depending on the vehicle and how it is equipped, the following driveability problems may exist:     

Rough or unstable idle. Hesitation or stumble. Rich or lean running. Poor fuel mileage. Harsh or poor transmission shift quality.

To accelerate relearn process after battery removal and installation, vehicle should be road tested in the following manner:    

Vehicle at normal operating temperature (cooling fan cycles). Accelerate at normal throttle position (20-50%). Cruise at light to medium throttle. Decelerate to a stop, downshifting and using brakes normally.

Manufacturers identify specific relearn procedures. See RELEARN PROCEDURES . Always complete the procedure before returning the vehicle to the customer.

RELEARN PROCEDURES VEHICLE DRIVEABILITY RELEARN PROCEDURE General Motors does not provide a specific procedure for driveability relearn. If a vehicle battery was disconnected for facilitating repairs or a Powertrain Control Module (PCM) was replaced, driving the vehicle will enable the PCM to relearn driveability. Inform your customer that he/she may experience driveability different from what they are accustomed to until the PCM completes it's relearn function. TP SENSOR LEARN (CADILLAC) If a NEW TP sensor or throttle body is installed, EBTCM must learn new TP sensor idle position voltage. This procedure is necessary to ensure effective engine management. If an improper TP sensor offset is maintained by Microsoft Saturday, August 29, 2009 11:36:11 11:36:07 AM

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1997 Chevrolet S10 Pickup 1996 GENERAL INFORMATION Computer Relearn Procedures - General Motors Corp.

the PCM, a high idle at closed throttle or stall condition may occur. 1. Turn ignition on (engine off). Wait for 30 seconds. 2. Turn ignition to LOCK position. Wait for 30 seconds. NOTE:

Ensure accelerator and brake pedals are free from any obstructions while performing TP sensor/idle learn procedure. Ensure that cruise control cable is not holding throttle open. PCM will not perform learn function with accelerator pedal or brake pedal obstructions.

TP SENSOR LEARN (CORVETTE) If a NEW TP sensor or throttle body is installed, EBTCM must learn new TP sensor idle position voltage. This procedure is necessary to ensure effective engine torque reduction during ASR operations. TP sensor learn procedure requires a Tech-1 scan tester or T-100 (CAMS) unit. 1. Turn ignition off. Connect Tech-1 scan tester with a Mass Storage cartridge. Turn ignition on. Select ABS/ASR feature from menu. 2. Select F5 (TP SENSR LEARN). Press up arrow to begin learn procedure. Wait for Tech-1 scan tester to indicate COMPLETE. Turn ignition off. Disconnect Tech-1 scan tester. NOTE:

Ensure accelerator and brake pedals are free from any obstructions while performing TP sensor/idle learn procedure. PCM will not perform learn function with accelerator pedal or brake pedal obstructions.

Microsoft Saturday, August 29, 2009 11:36:07 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

DESCRIPTION All FWD and some RWD vehicles use an electric cooling fan. The electric cooling fan is used for radiator and A/C condenser cooling. Cooling fan operates when A/C is on and when engine coolant temperature exceeds a specific value. One or more cooling fan relays may be used.

TROUBLE SHOOTING PRELIMINARY INFORMATION This article contains only the text required to test electric cooling fans. Other diagnostic information may be referenced while performing electric cooling fan diagnosis. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section for complete information on engine control systems. Some truck models are equipped with an auxiliary electric cooling fan. The auxiliary electric cooling fan is not controlled by Powertrain Control Module (PCM). Trouble shoot cooling fan using appropriate diagnostic information provided. For cooling fan relay location, see COOLING FAN RELAY LOCATION table. COOLING FAN RELAY LOCATION Application "C" & "K" Series

Location (1) In Engine Compartment Fuse/Relay

Block, Near Anti-Lock Brake Control Module "P" Series Diesel

Under Battery Junction Block, On Engine Bulkhead Relay Bracket At Main Support Bracket, Behind Steering Column Inside Electrical Center, At Right Front Of Engine Compartment

Gasoline "U" Series (1) See Fig. 1 .

To help save diagnostic time, ALWAYS check for blown fuses or fusible links before proceeding with any testing. If fuses are blown, locate and repair short circuit before replacing fuses. Ensure all related relay and wire harness connections are clean and tight. Repair as necessary. See WIRING DIAGRAMS for component, terminal and wire color identification. WARNING: Vehicles may be equipped with a PCM/VCM using an Electronically Microsoft Saturday, August 29, 2009 11:33:06 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

Erasable Programmable Read Only Memory (EEPROM). When replacing PCM/VCM, the new PCM/VCM must be programmed.

Fig. 1: Auxiliary Cooling Fan Relay Location ("C" & "K" Series) Courtesy of GENERAL MOTORS CORP.

SCAN TOOL A variety of information is transmitted through Data Link Connector (DLC). This data is transmitted at a high frequency which requires the use of Tech 1 Scan Tool (94-00101A), appropriate cartridge kit and vehicle interface module kit. Other types of scan tools are available and may function and provide adequate information for diagnostic work. Always refer to scan tool manufacturer's instructions.

ELECTRIC COOLING FAN CIRCUIT DIAGNOSIS 3.4L ("U" SERIES) Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

NOTE:

Cooling fan circuit utilizes 3 cooling fan relays. Relays directly controlling fan motors are 4-pin type and are referred to as No. 1 and No. 2. Relay determining cooling fan motor low speed or high speed operation is referred to as 5-pin relay in this test. See WIRING DIAGRAMS .

Description

Power for cooling fan motors is supplied through COOL FAN 1 Maxi-fuse (30-amp) and COOL FAN 2 Maxifuse (30-amp) in underhood electrical center. Cooling fan relays are energized when current flows from Maxifuses through relay coils, then to ground through Powertrain Control Module (PCM). No. 1 cooling fan relay control circuit is grounded for low speed operation. Both fan control circuits and all 3 relays are grounded for high speed fan operation. During low speed cooling fan operation, PCM supplies a ground path for No. 1 cooling fan relay. As a result, relay contacts close, allowing current to flow from COOL FAN 1 Maxi-fuse through relay coil to cooling fan No. 1 (left side). During low speed cooling fan operation, ground path for cooling fan No. 1 is through cooling fan relay (5-pin) and cooling fan motor No. 2 (right side). This results in a series circuit with both fans operating at low speed. During high speed cooling fan operation, PCM supplies 2 ground paths for all 3 cooling fan relays. As a result, relay contacts close in all relays, allowing both cooling fan motors to operate at high speed. Both cooling fans are supplied current from both COOL FAN Maxi-fuses. Each cooling fan motor has a separate ground path when operating in high speed mode. Cooling Fan Circuit Diagnosis

1. If Powertrain On-Board Diagnostic (OBD) System Check has not been performed, see appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. If OBD SYSTEM CHECK has been performed, go to next step. 2. Check for PCM Diagnostic Trouble Codes (DTCs). If any DTCs are present, perform testing for applicable DTC. Repair all DTCs that are set before proceeding with testing. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. If no DTCs are present, go to next step. 3. Ensure engine coolant temperature is less than 212°F (100°C). Turn A/C off. Turn ignition on. If cooling fans go off, go to next step. If cooling fans do not go off, go to step 32). 4. Using scan tool, select RELAY CONTROL function. Command low speed fans on. If cooling fans operate at low speed, go to next step. If cooling fans do not operate as specified, go to step 8). 5. Command high speed fans on. Wait 6 seconds. If cooling fans operate at high speed, go to next step. If cooling fans do not operate as specified, go to step 58). NOTE:

Ensure ambient temperature is greater than 48°F (9°C) before proceeding.

6. Exit scan tool OUTPUT TESTS. Start engine. Turn A/C on. If cooling fans come on, go to DIAGNOSTIC AIDS . If cooling fans do not come on, go to next step. 7. Using scan tool, view A/C REQUEST display. If YES is displayed, go to step 77). If YES is not displayed, go to appropriate A/C CLUTCH CIRCUIT DIAGNOSIS TEST in A/C COMPRESSOR Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

8. 9. 10.

11. 12. 13. 14.

15. 16.

17.

CLUTCH CONTROLS article. If either cooling fan is running, go to next step. If neither cooling fan runs, go to step 16). If cooling fan No. 1 runs, go to next step. If cooling fan No. 1 does not run, go to step 14). Turn ignition off. Disconnect cooling fan No. 2 harness connector. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command low speed fans on. If cooling fan No. 1 runs, go to next step. If cooling fan No. 1 does not run, go to step 80). Remove cooling fan relay (5-pin) from underhood electrical center. If cooling fan No. 1 runs, go to next step. If cooling fan No. 1 does not run, go to step 13). Locate and repair short to ground in circuit No. 532 (Gray wire). After repairs, go to step 81). Check circuit No. 409, and/or circuit No. 473 for a short to ground. Repair as necessary and go to step 81). If no problem was found, go to step 70). Turn ignition off. Disconnect cooling fan No. 1 harness connector. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command low speed fans on. If cooling fan No. 2 runs, go to next step. If cooling fan No. 2 does not run, go to step 71). Replace cooling fan No. 1 diode. After replacing cooling fan diode, go to step 81). Turn ignition on. Remove No. 1 cooling fan relay from underhood electrical center. Using a test light connected to ground, probe No. 1 cooling fan relay cavity No. 87. If test light illuminates, go to step 18). If test light does not illuminate, go to next step. Check for blown Maxi-fuse that supplies power to No. 1 cooling fan relay. If fuse is blown, locate and repair short circuit. Possible causes for short circuit are:  Seized cooling fan motors.  Shorted cooling fan motor windings.  Short to ground in circuit No. 504.  Short to ground in power feed circuit between fuse and No. 1 cooling fan relay. If fuse is not blown, check for an open in power feed circuit between fuse and No. 1 cooling fan relay. Repair as necessary. After repairs, go to step 81).

18. Using a test light connected to ground, probe No. 1 cooling fan relay cavity No. 86. If test light illuminates, go to step 20). If test light does not illuminate, go to next step. 19. Check for blown Maxi-fuse that supplies power to No. 1 cooling fan relay. If fuse is blown, locate and repair short circuit. Possible causes for short circuit are:  Seized cooling fan motors.  Shorted cooling fan motor windings.  Short to ground in circuit No. 504.  Shorted relay coil in cooling fan relay.  Short to ground in power feed circuit between fuse and No. 1 cooling fan relay. If fuse is not blown, check for an open in power feed circuit between fuse and No. 1 cooling fan relay. Repair as necessary. After repairs, go to step 81). 20. Turn ignition off. Disconnect both cooling fan harness connectors. Using fused jumper wires, jumper Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

21.

22.

23. 24. 25.

26. 27.

28. 29.

30. 31.

32.

33. 34. 35. 36.

terminals "A" and "B" together at both harness connectors. Turn ignition on. Connect a test light between No. 1 cooling fan relay cavities No. 30 and 87. If test light illuminates, go to next step. If test light does not illuminate, go to step 27). Connect a test light between No. 1 cooling fan relay cavities No. 85 and 86. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command low speed fans on. If test light illuminates, go to next step. If test light does not illuminate, go to step 25). Turn ignition off. Remove jumper wires and reconnect cooling fan harness connectors. Connect a fused jumper wire between No. 1 cooling fan relay cavities No. 30 and 87. Turn ignition on. If both cooling fans run, go to next step. If not, go to step 24). Check for poor connections at No. 1 cooling fan relay in underhood electrical center. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 37). Check for poor connections at both cooling fan motors. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 63). Turn ignition off. Disconnect PCM harness connector C1. Install a fused jumper wire between No. 1 cooling fan relay cavities No. 85 and 86. Turn ignition on. Using a test light connected to ground, probe PCM harness connector C1, terminal No. 32 (Dark Green wire). If test light illuminates, go to step 77). If test light does not illuminate, go to next step. Locate and repair open in circuit No. 335 (Dark Green wire) between No. 1 cooling fan relay and PCM harness connector C1, terminal No. 32. After repairs, go to step 81). Turn ignition off. Remove jumper wires and reconnect cooling fan harness connectors. Connect a fused jumper wire between No. 1 cooling fan relay cavities No. 30 and 87. Remove cooling fan relay (5-pin) from underhood electrical center. Using a test light connected to ground, probe cooling fan relay (5-pin) cavity No. 30. If test light illuminates, go to next step. If test light does not illuminate, go to step 31). Connect a test light between cooling fan relay (5-pin) cavities No. 30 and 87A. If test light illuminates, go to step 30). If test light does not illuminate, go to next step. Check for open in circuit No. 409 between cooling fan relay (5-pin) cavity No. 87A and harness connector terminal "B" at cooling fan motor No. 2. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 57). Check for poor connections at cooling fan relay (5-pin) cavitiesNo. 30 and 87A in underhood electrical center. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 76). Check for an open in circuit No. 504 between No. 1 cooling fan relay cavity No. 30 and harness connector terminal "B" at cooling fan motor No. 1. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 56). Using scan tool, view A/C REQUEST. If YES is displayed, go to appropriate A/C CLUTCH CIRCUIT DIAGNOSIS TEST in A/C COMPRESSOR CLUTCH CONTROLS article. If YES is not displayed, go to next step. If both cooling fans are operating at low speed, go to next step. If both cooling fans do not operate at low speed, go to step 40). Remove No. 1 cooling fan relay from underhood electrical center. If both cooling fans run, go to next step. If both cooling fans do not run, go to step 36). Locate and repair short to power in circuit No. 504 (White wire). After repairs, go to step 81). Using a test light connected to battery positive, probe No. 1 cooling fan relay cavity No. 85. If test light illuminates, go to step 38). If test light does not illuminate, go to next step.

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

37. Replace No. 1 cooling fan relay. After replacing cooling fan relay, go to step 81). 38. Turn ignition off. Disconnect PCM harness connector C1. Using a test light connected to battery positive, probe No. 1 cooling fan relay cavity No. 85. If test light come on, go to next step. If test light does not illuminate, go to step 77). 39. Locate and repair short to ground in circuit No. 335 (Dark Green wire) between No. 1 cooling fan relay and PCM harness connector C1, terminal No. 32. After repairs, go to step 81). 40. If both cooling fans operate at high speed, go to next step. If both cooling fans do not operate at high speed, go to step 42). 41. Using scan tool, view A/C PRESSURE on display. If reading is less than 1.2 volts, go to step 77). If reading is 1.2 volts or greater, go tostep 44). 42. Turn ignition off. Disconnect PCM harness connector C1. Turn ignition on. If cooling fan No. 2 operates at high speed, go to next step. If cooling fan No. 2 does not operate at high speed, go to step 77). 43. Check for a short to ground in circuit No. 473 to cooling fan relay (5-pin) and relay No. 2 control circuit (Dark Blue wire). Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 52). 44. Turn ignition off. Disconnect A/C pressure sensor harness connector. Turn ignition on. Using scan tool, view A/C PRESSURE on display. If reading is near zero volts, go to step 46). If reading is not as specified, go to next step. 45. Using a voltmeter, check voltage between A/C pressure sensor signal and ground circuits. If reading is near zero volts, go to step 77). If reading is not as specified, go to step 51). 46. Using a test light connected to battery positive, probe A/C pressure sensor ground circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 49). 47. Using a voltmeter, check voltage between A/C pressure sensor 5-volt reference and sensor ground. If reading is near 5 volts, go to next step. If reading is not as specified, go to step 50). 48. Replace A/C pressure sensor. After replacing pressure sensor, go to step 81). 49. Locate and repair open or short to power in A/C pressure sensor ground circuit. After repairs, go to step 81). 50. Locate and repair open or short to ground in A/C pressure sensor 5-volt reference circuit. After repairs, go to step 81). 51. Locate and repair short to power in A/C pressure sensor signal circuit. After repairs, go to step 81). 52. Remove No. 2 cooling fan relay from underhood electrical center. If cooling fan No. 2 operates at high speed, go to next step. If cooling fan No. 2 does not operate at high speed, go to step 70). 53. Remove cooling fan relay (5-pin) from underhood electrical center. If cooling fan No. 2 operates at high speed, go to next step. If cooling fan No. 2 does not operate at high speed, go to step 55). 54. Locate and repair short to power in circuit No. 409 (Light Blue wire) between No. 2 cooling fan relay and cooling fan motor No. 2. After repairs, go to step 81). 55. Locate and repair short to power in circuit No. 532 (Dark Blue wire) between cooling fan relay (5-pin) and cooling fan motor No. 1. After repairs, go to step 81). 56. Check for an open in circuit No. 532 (Dark Blue wire) between cooling fan relay (5-pin) cavity No. 30 and terminal "A" of cooling fan motor No. 1 harness connector. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 79). 57. Check for an open in circuit No. 1050 (Black wire) between cooling fan motor No. 2 harness connector Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

58.

59.

60.

61.

62. 63. 64.

65. 66. 67. 68.

69. 70. 71.

72. 73.

terminal "A" and ground. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 80). Turn ignition on. Remove No. 2 cooling fan relay from underhood electrical center. Connect a test light between No. 2 cooling fan relay cavity No. 86 and battery positive. Using scan tool, select RELAY CONTROL function. Command high speed fans on. Wait 6 seconds. If test light illuminates, go to step 61). If test light does not illuminate, go to next step. Remove cooling fan relay (5-pin) from underhood electrical center. Connect a test light between cooling fan relay (5-pin) cavity No. 86 and battery positive. Using scan tool, select RELAY CONTROL function. Command high speed fans on. Wait 6 seconds. If test light illuminates, go to step 78). If test light does not illuminate, go to next step. Turn ignition off. Disconnect PCM harness connector C1. Check circuit No. 473 (Dark Blue wire) for an open or short to power. Repair as necessary. After repairs, go to step 81). If no problem is found, go to step 77). Turn ignition off. Reinstall No. 2 cooling fan relay. Disconnect both cooling fan motor harness connectors. Turn ignition on. Using scan tool, select RELAY CONTROL function. Command high speed fans on. Wait 6 seconds. Using a test light connected to ground, probe terminal "B" of cooling fan motor No. 2 harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 64). Using a test light connected to battery positive, probe terminal "A" of cooling fan motor No. 1 harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 71). Check for a seized cooling fan motor or open motor winding. Replace appropriate cooling fan motor. After replacing motor, go to step 81). Turn ignition off. Remove No. 2 cooling fan relay from underhood electrical center. Turn ignition on. Using a test light connected to ground, probe No. 2 cooling fan relay cavity No. 85. If test light illuminates, go to step 66). If test light does not illuminate, go to next step. Locate and repair open in battery voltage circuit to No. 2 cooling fan relay. Check for blown Maxi-fuse (30-amp). Repair short to ground if blown. Replace fuse. After replacing fuse, go to step 81). Using a test light connected to ground, probe No. 2 cooling fan relay cavity No. 30. If test light illuminates, go to step 68). If test light does not illuminate, go to next step. Locate and repair open in battery voltage circuit to No. 2 cooling fan relay cavity No. 30. After repairs, go to step 81). Check for open in circuit No. 409 (Light Blue wire) between cooling fan motor No. 2 harness connector terminal "B" and No. 2 cooling fan relay cavity No. 87. Repair as necessary. After repairs, go to step 81). If no problem was found, go to next step. Check for poor connections at No. 2 cooling fan relay in underhood electrical center. Repair as necessary. After repairs, go to step 81). If no problem was found, go to next step. Replace No. 2 cooling fan relay. After replacing cooling fan relay, go to step 81). Turn ignition off. Remove cooling fan relay (5-pin) from underhood electrical center. Turn ignition on. Using a test light connected to ground, probe cooling fan relay (5-pin) cavity No. 85. If test light illuminates, go to step 73). If test light does not illuminate, go to next step. Locate and repair open in battery voltage circuit to cooling fan relay (5-pin) cavity No. 85. After repairs, go to step 81). Using a test light connected to battery positive, probe cooling fan relay (5-pin) cavity No. 87. If test light

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

74. 75. 76. 77. 78. 79. 80. 81. 82. 83.

illuminates, go to step 75). If test light does not illuminate, go to next step. Locate and repair open in circuit No. 1050 (Black wire) between cooling fan relay (5-pin) cavity No. 87 and ground. After repairs, go to step 81). Check for poor connections at cooling fan relay (5-pin) in underhood electrical center. Repair as necessary. After repairs, go to step 81). If no problem was found, go to step 76). Replace cooling fan relay (5-pin). After replacing cooling fan relay, go to step 81). Replace PCM. After replacing PCM, go to step 81). Repair open in circuit No. 473 (Dark Blue wire) between PCM harness connector C1, terminal No. 31 and cooling fan relays (5-pin and No. 2) cavity No. 86. After repairs, go to step 81). Replace cooling fan motor No. 1. After replacing cooling fan motor, go to step 81). Replace cooling fan motor No. 2. After replacing motor, go to next step. Ensure coolant temperature is less than 212°F (100°C). Turn A/C off. Start engine and let idle. If cooling fans are running, go to step 32). If cooling fans are not running, go to next step. Using scan tool, select RELAY CONTROL function. Command low speed fans on. If both cooling fans operate at low speed, go to next step. If both cooling fans do not operate at low speed, go to step 8). Command high speed cooling fans on. Wait 6 seconds. If both cooling fans operate at high speed, system is okay at this time. If both cooling fans do not operate at high speed, go to step 58).

Diagnostic Aids

Check for poor connections at PCM, cooling fan relays and cooling fan motors. Inspect harness connectors for damaged, corroded or backed-out terminal pins. Inspect related wiring harnesses for damage or improper routing. 4.3L, 5.0L, 5.7L & 7.4L ("C" & "K" SERIES) Description

Auxiliary cooling fan is controlled by VCM based on various inputs. Battery voltage is supplied to the auxiliary cooling fan relay. If ignition voltage is supplied to auxiliary fan relay (coil side). VCM controls cooling fan by relay by providing a ground path. NOTE:

Check VCM Diagnostic Trouble Codes (DTCs) that may affect system. If any DTCs are present, perform testing for applicable DTC. Some DTCs may cause auxiliary cooling fan to stay on at all times. Repair all DTCs that are set before proceeding with testing. See appropriate ENGINE PERFORMANCE article.

Cooling Fan Circuit Diagnosis

1. Perform Powertrain On-Board Diagnostic (OBD) Sytem Check. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. After performing OBM system check, go to next step. 2. Turn ignition on. Using scan tool, check if any Diagnostic Trouble Codes (DTCs) are present. If DTCs are present, perform testing for applicable DTC. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. If no DTCs are present, go to next step. Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

3. Ensure engine coolant temperature is less than 212°F (100°C) when diagnosing cooling fan system. Turn ignition on, with engine off. If cooling fan is off, go to next step. If cooling fan is on, go to step 5). 4. Using scan tool, command cooling fan relay on, then off. If cooling fan turns on and off with each command, system is okay. See DIAGNOSTIC AIDS . If cooling fan does not turn on and off with each command, go to step 6). 5. Disconnect cooling fan relay. If cooling fan stops, go to step 10). If cooling fan does not stop, go to step 16). 6. Turn ignition off. Disconnect cooling fan relay. Turn ignition on. Using a test light connected to ground, probe battery feed circuits at relay harness connector terminals. If test light illuminates on both circuits, go to next step. If not, go to step 19). 7. Connect test light between battery feed circuit and auxiliary fan relay circuit at relay harness connector. Using scan tool, command fan on and then off. If test light turn on and off with each command, go to next step. If not, go to step 11). 8. Turn ignition off. Reconnect cooling fan relay. Disconnect VCM harness connector containing the relay control circuit. Turn ignition on. Using DVOM on 10-amp. scale, check current draw on relay control circuit from VCM harness connector to ground. If current draw is less than 0.75 amp within 2 minutes, go to step 22). If not, go to step 11). 9. Disconnect cooling fan harness connector. Connect test light across cooling fan harness connector terminals. If test light illuminates, go to step 16). If test light does not illuminate, go to next step. 10. Turn ignition off. Disconnect VCM harness connector. Using DVOM, check resistance between ground and cooling fan relay control circuit at VCM harness connector. If resistance is infinite, go to step 24). If not, go to step 20). 11. Connect a fused jumper wire between battery feed circuit and circuit leading to cooling fan motor. If cooling fan operates, go to next step. If not, go to step 15). 12. Turn ignition off. Reconnect cooling fan relay. Disconect VCM harness connector containing the fan relay control circuit. Turn ignition on. Connect a fused jumper wire to ground and probe fan relay control circuit terminal at VCM harness connector. If relay operates, go to step 14). If not, go to next step. 13. Check connections at cooling fan relay connector. Repair as necessary. If connections are okay, go to next step. 14. Check connections at VCM harness connector. Repair as necessary. If connections are okay, go to step 21). 15. Check connections at cooling fan harness connector. Repair as necessary. If connections are okay, go to step 17). 16. Repair short to voltage in power feed circuit between cooling fan relay and fan motor. 17. Check for open in power feed circuit between cooling fan relay and cooling fan motor. Repair as necessary. If circuit is okay, go to next step. 18. Check for open in cooling fan motor ground circuit. Repair as necessary. If circuit is okay, go to step 23). 19. Repair open in battery feed circuit that did not illuminate test light. 20. Check for short to ground in relay control circuit. Repair as necessary. If circuit is okay, go to step 22). 21. Check for open in cooling fan relay control circuit. Repair as necessary. If circuit is okay, go to next step. 22. Replace auxiliary cooling fan relay. If cooling fan still does not operate, go to step 24). 23. Replace auxiliary cooling fan motor. Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

24. Replace VCM. Program replacement VCM using required equipment. Diagnostic Aids

Whenever owner complains of an overheating problem, determine if complaint was due to an actual boilover, or TEMP light or gauge indicated overheating. Whenever gauge or light indicates overheating, but no boilover is detected, gauge or light circuit should be checked. Gauge accuracy can also be checked by comparing engine coolant temperature sensor reading with gauge reading. If engine is actually overheating, and gauge indicates overheating, but cooling fan is not coming on, ECT sensor has probably shifted out of calibration and should be replaced. Whenever engine is overheating, and cooling fan is on, cooling system should be checked. 6.5L - VIN F DIESEL ("P" SERIES W/O AUX FAN CONTROL SWITCH) Description

With ignition switch in ON position, ENG 1 fuse (20-amp) located in instrument panel fuse block, supplies voltage to coil side of auxiliary cooling fan relay. During A/C compressor operation, A/C high pressure switch closes. This supplies a ground path for cooling fan relay. As a result, relay contacts close, allowing current to flow to cooling fan motor through relay, resulting in auxiliary cooling fan motor operation. NOTE:

A fully charged A/C system is required for proper auxiliary cooling fan operation.

Cooling Fan Circuit Diagnosis

1. If cooling fan does not run, go to next step. If cooling fan runs continuously, go to step 10). 2. Turn ignition off. Remove cooling fan relay. Turn ignition on. Using a test light connected to ground, probe cooling fan relay harness connector terminal No. 30. If test light illuminates, go to next step. If test light does not illuminate, locate and repair open in Red wire between fusible link at battery junction block and cooling fan relay. 3. Using a fused jumper wire, jumper cooling fan relay harness connector terminals No. 30 and 87. If cooling fan motor does not run, go to next step. If cooling fan motor runs, go to step 6). 4. Disconnect cooling fan motor harness connector. Using a test light connected to ground, probe cooling fan motor harness connector terminal "A". If test light illuminates, go to next step. If test light does not illuminate, Locate and repair open in Red wire between cooling fan relay and cooling fan motor. 5. Turn ignition off. Using an ohmmeter, check resistance between cooling fan motor harness connector terminal "B" and ground. If resistance is greater than 5 ohms, locate and repair open or poor connection between cooling fan motor and ground. If resistance is not as specified, replace cooling fan motor. 6. Turn ignition on. Using a test light connected to ground, probe cooling fan relay harness connector terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, locate and repair open in Pink wire between ENG 1 fuse and cooling fan relay. 7. Turn ignition off. Disconnect A/C high pressure switch. Using an ohmmeter, check resistance between A/C high pressure switch harness connector terminal "A" and cooling fan relay harness connector Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

10.

11.

12.

terminal No. 86. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, locate and repair open in Dark Green wire between cooling fan relay and A/C high pressure switch. Check resistance between A/C high pressure switch harness connector terminal "B" and ground. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, locate and repair open in Black wire between A/C high pressure switch and splice. Reconnect cooling fan relay. Turn ignition on. Using a fused jumper wire, jumper A/C high pressure switch harness connector terminal "A" to ground. If cooling fan motor runs, replace A/C high pressure switch. If cooling fan motor does not run, replace cooling fan relay. Turn ignition on. Disconnect cooling fan relay from harness connector. If cooling fan motor stops, go to next step. If cooling fan motor continues to operate, locate and repair short to power between cooling fan relay and cooling fan motor. Turn ignition off. Disconnect A/C high pressure switch harness connector. Using an ohmmeter, check resistance between A/C high pressure switch harness connector terminal "A" and ground. If resistance is greater than 5 ohms, go to next step. If not, locate and repair short to ground in Dark Green wire between cooling fan relay and A/C high pressure switch. Reconnect A/C high pressure switch harness connector. Turn ignition on. Using a test light connected to ground, probe cooling fan relay harness connector terminal No. 86. If test light illuminates, replace A/C high pressure switch. If test light does not illuminate, replace cooling fan relay.

6.5L - VIN F DIESEL ("P" SERIES W/AUX FAN CONTROL SWITCH) & 7.4L - VIN J DIESEL ("P" SERIES W/O AUX FAN CONTROL SWITCH) Description

On models not equipped with Vehicle Control Module (VCM), ENG 1 fuse (20-amp) located in instrument panel fuse block supplies voltage to coil side of auxiliary cooling fan relay with ignition switch in ON position. A ground path for cooling fan relay is supplied by A/C high pressure switch, or auxiliary fan control switch (if equipped). On models equipped with VCM, a ground path for fan control relay is supplied by VCM. As a result, relay contacts close, allowing current to flow to cooling fan motor through relay, resulting in auxiliary cooling fan motor operation. NOTE:

A fully charged A/C system is required for proper auxiliary cooling fan operation.

Cooling Fan Circuit Diagnosis

1. If cooling fan does not operate, or does not operate properly, go to next step. If cooling fan runs continuously with ignition off, go to step 12). If cooling fan runs continuously with ignition on, go to step 13). 2. If cooling fan motor never operates, go to next step. If cooling fan motor does not operate with high coolant temperature, go to step 9). If cooling fan motor does not operate with A/C on, go to step 10). 3. Turn ignition off. Disconnect fan control relay harness connector. Turn ignition on. Using a test light connected to ground, probe fan control relay harness connector terminal No. 30. If test light illuminates, go to next step. If test light does not illuminate, locate and repair open in Red wire between fan control relay and splice near fusible link. Microsoft Saturday, August 29, 2009 11:33:02 AM

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

4. Using a fused jumper wire, jumper fan control relay harness connector terminals No. 30 and 87 together. If cooling fan motor runs, go to next step. If cooling fan motor does not run, go to step 6). 5. Disconnect jumper wire. Using a test light connected to ground, probe fan control relay harness connector terminal No. 85. If test light illuminates, go to step 8). If test light does not illuminate, locate and repair open in Pink wire between ENG 1 fuse and fan control relay. 6. With jumper wire still in place, disconnect cooling fan motor harness connector. Using a test light connected to ground, probe cooling fan motor harness connector terminal "B". If test light illuminates, go to next step. If test light does not illuminate, locate and repair open in Red wire between fan control relay and cooling fan motor. 7. Using a test light connected to battery positive, probe cooling fan motor harness connector terminal "A". If test light illuminates, replace cooling fan motor. If test light does not illuminate, locate and repair open in Black wire between cooling fan motor and ground. 8. Reconnect fan control relay. Using a voltmeter, check voltage (backprobe) between fan control relay harness connector terminal No. 86 and ground. If reading is less than 10 volts, replace fan control relay. If reading is 10 volts or greater, locate and repair open in Dark Green wire between fan control relay and splice. 9. Disconnect auxiliary fan control switch harness connector. Turn ignition on. Using a voltmeter, check voltage between auxiliary fan control switch harness connector terminal "A" and ground. If reading is less than 10 volts, locate and repair open in Dark Green wire between auxiliary fan control switch and splice. If reading is 10 volts or greater, replace auxiliary fan control switch. 10. Disconnect A/C high pressure switch harness connector. Using a voltmeter, check voltage between auxiliary fan control switch harness connector terminal "B" and ground. If reading is 10 volts or greater, go to next step. If reading is less than 10 volts, locate and repair open in Dark Green wire between A/C high pressure fan switch and splice. 11. Using a test light connected to battery positive, probe A/C high pressure switch harness connector terminal "A". If test light illuminates, replace A/C high pressure fan switch. If test light does not illuminate, locate and repair open in Black wire between A/C high pressure switch harness connector terminal "A" and splice. 12. With ignition on, disconnect fan control relay harness connector. If cooling fan motor stops, replace fan control relay. If cooling fan motor continues to run, locate and repair short to power in Red wire between fan control relay and cooling fan motor. 13. Turn ignition off. Disconnect fan control relay harness connector. Using a test light connected to battery positive, probe cooling fan relay harness connector terminal No. 86. If test light illuminates, go to next step. If test light does not illuminate, replace fan control relay. 14. With test light still connected, disconnect auxiliary fan control switch harness connector. If test light remains on, go to next step. If test light does not remain on, replace auxiliary fan control switch. 15. With test light still connected, disconnect A/C high pressure fan switch harness connector. If test light remains on, locate and repair short to ground in Dark Green wire between fan control relay and either A/C high pressure fan switch or auxiliary fan control switch.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

Fig. 2: Cooling Fan System Wiring Diagram ("C" & "K" Series)

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

Fig. 3: Cooling Fan System Wiring Diagram ("P" Series - 6.5L VIN Y Diesel Engine)

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

Fig. 4: Cooling Fan System Wiring Diagram ("P" Series 6.5L VIN F Diesel Engine - & 7.4L VIN N Engine)

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

Fig. 5: Cooling Fan System Wiring Diagram ("P" Series - 7.4L VIN J Engine)

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

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1997 Chevrolet S10 Pickup ENGINE COOLING FAN 1997 ENGINE COOLING General Motors Corp. - Electric Cooling Fan

Fig. 6: Cooling Fan System Wiring Diagram ("U" Series)

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

DESCRIPTION & OPERATION Description

Cruise control system components include: Powertrain Control Module (PCM) or Vehicle Control Module (VCM), cruise control module (electronic controller and electric stepper motor combined), cruise control switch, vehicle speed sensor, vehicle speed sensor buffer, and brake and clutch release switches. CRUISE CONTROL MODULE Cruise control module is mounted to master cylinder. Refer to Fig. 1 . Module incorporates an electronic controller and an electric stepper motor. Stepper motor regulates throttle position in response to control module commands. Module is not serviceable.

Fig. 1: Electric Motor Cruise Control Module (Typical) Courtesy of GENERAL MOTORS CORP. CRUISE CONTROL SWITCH Cruise control switch, mounted on end of multifunction (turn signal) lever, controls system operational modes. SET/COAST Microsoft Saturday, August 29, 2009 12:00:58 12:00:54 PM

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

To set vehicle speed, turn control switch to ON position. With vehicle speed at 25 MPH or more, press and release SET/COAST button. Vehicle will maintain set speed. To increase speed during engaged cruise, accelerate to desired speed. Press and release SET/COAST button. Vehicle will maintain new set speed. To decrease speed during engaged cruise, press and hold SET/COAST button. System will disengage. When vehicle has slowed to desired speed, release SET/COAST button. Vehicle will maintain new set speed. To decrease speed by one-MPH increments during engaged cruise, tap SET/COAST button (quickly press and release button; DO NOT hold button). Vehicle speed will decrease one MPH for each tap of button. RESUME/ACCEL

To resume set speed after system has been disengaged by braking, momentarily engage and release RESUME/ACCEL switch. Vehicle will return to set speed. If RESUME/ACCEL switch is engaged for more than one second, vehicle will begin to accelerate. To accelerate using cruise control system, engage and hold RESUME/ACCEL switch until desired speed is reached. To increase speed by one-MPH increments during engaged cruise, tap RESUME/ACCEL switch (quickly move to RESUME/ACCEL position and release). Vehicle speed will increase one MPH for each tap of switch. After 10 taps, system must be reset to a new speed to continue this function. BRAKE & CLUTCH RELEASE SWITCHES Brake and clutch release switches allow current flow to module when brakes and clutch are released. When brake or clutch pedal is depressed, voltage supply to cruise control circuit in PCM/VCM is interrupted. Brake switch may incorporate brakelight and torque converter clutch switch. VEHICLE SPEED SENSOR Vehicle Speed Sensor (VSS) is mounted in transmission (2WD) or transfer case (4WD). VSS produces an AC signal with a frequency proportional to speed at which transmission output shaft rotates, which is also proportional to vehicle speed. This signal is then sent to vehicle speed sensor buffer. VEHICLE SPEED SENSOR BUFFER Vehicle speed sensor buffer receives and converts AC voltage to a rate of 4000 pulses per mile. This signal is then sent to cruise control module, speedometer, and VCM/PCM. These components convert number of pulses per mile to pulses per second to determine speed of vehicle. Buffer is located on left side of instrument panel, near parking brake.

TROUBLE SHOOTING 1. Check fuses, and replace as necessary. Ensure cruise control cable and throttle linkage move freely. Some problems may be related to vehicle speed sensor circuit. Check for codes. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section. Refer to menu below. Microsoft Saturday, August 29, 2009 12:00:54 PM

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

TESTS W/CODES - 2.2L  TESTS W/CODES - 4.3L 2. Check for a broken or partially broken wire inside insulation which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Visually inspect for broken or open wires. Ensure any aftermarket electronic equipment is properly installed. 

TESTING NOTE:

Cruise control will be disabled if stoplights (including center high mounted stoplight) are not operating properly.

CRUISE CONTROL DOES NOT ENGAGE 1. Ensure BRAKE (10-amp) and STOP/HAZ (20-amp) fuses are okay. Turn ignition off. Disconnect cruise control module connector. Turn ignition on. Connect test light between cruise control module connector terminal "F" (Brown wire) and ground. If test light glows, go to next step. If test light does not glow, repair open or short to ground in Brown wire. 2. Connect test light between cruise control module connector terminals "F" (Brown wire) and "E" (Black/White wire). If test light glows, go to next step. If test light does not glow, repair open in Black/White wire. 3. Turn cruise control on. Connect test light between cruise control module connector terminal "B" (Dark Blue wire) and ground. If test light does not glow, go to next step. If test light glows, check for short to power in Dark Blue wire. If circuit is okay, replace cruise control switch. 4. Connect test light between cruise control module connector terminal "C" (Gray/Black wire) and ground. If test light does not glow, go to next step. If test light glows, check for short to power in Gray/Black wire. If circuit is okay, replace cruise control switch. 5. Connect test light between cruise control module connector terminal "A" (Gray wire) and ground. If test light glows, go to step 7). If test light does not glow, go to next step. 6. Connect test light between cruise control switch connector terminal A13 (Brown wire) and ground. If test light glows, check for open in Gray wire. If circuit is okay, replace cruise control switch. If test light does not glow, repair open in Brown wire. 7. Ensure ignition is on. Connect test light between cruise control module connector terminal "D" (Purple wire on A/T, Brown/White wire on M/T) and ground. If test light glows, go to step 10). If test light does not glow, go to next step (M/T) or step 9) (A/T). 8. Connect test light between clutch pedal position switch connector terminal "B" (Purple wire) and ground. If test light does not glow, go to next step. If test light glows, check for open in Brown/White wire. If circuit is okay, replace clutch pedal position switch. 9. Connect test light between brakelight switch connector terminal "D" (Brown wire) and ground. If test light glows, check for open in Purple wire. If test light does not glow, repair open in Brown wire. 10. Ensure ignition is on. Connect test light between cruise control module connector terminal "B" (Dark Blue wire) and ground. Press and hold SET/COAST button. If test light glows, go to next step. If test light does not glow, check for open in Dark Blue wire. If circuit is okay, replace cruise control switch. 11. Turn ignition switch to OFF position. Connect cruise control module. Disconnect PCM connector C2, or Microsoft Saturday, August 29, 2009 12:00:54 PM

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

VCM connector C4. Turn ignition switch to RUN position. Using a DVOM, measure voltage at PCM connector C2, terminal "K" (Brown Wire), or VCM connector C4, terminal No. 3 (Dark Green/White wire). If reading is about 7 volts, go to next step. If reading is not about 7 volts, check for short to ground or open in Brown or Dark Green/White wire. If circuit is okay, replace cruise control module. 12. Turn ignition off. Reconnect VCM/PCM connector. Set parking brake. Start engine. Turn cruise control off. Turn cruise control off. After 3 seconds, press and hold SET/COAST button. Press and hold RESUME/ACCEL switch. Fully depress and hold brake pedal. After 10 seconds, release brake pedal. If engine RPM momentarily increases, check for poor connections at VCM/PCM. If connections are okay, replace VCM/PCM. If engine RPM does not momentarily increase, replace cruise control module. CRUISE CONTROL DOES NOT RESUME, ACCELERATE, TAP-UP OR TAP-DOWN Ensure BRAKE and STOP/HAZ fuses are okay. Disconnect cruise control module. Turn ignition on. Turn cruise control on. Connect test light between cruise control module connector terminal "C" (Gray/Black wire) and ground. Press and hold RESUME/ACCEL switch. If test light glows, check for poor connection at cruise control module terminal "C". If connection is okay, replace cruise control module. If test light does not glow, check for open in Gray/Black wire. If circuit is okay, replace cruise control switch.

Remove electrical connectors from switch. Remove pedal bracket bolt. Remove switch from pedal bracket. To install, reverse removal procedure. Tighten pedal bracket bolt to 13 ft. lbs. (17 N.m). CRUISE CONTROL CABLE Removal & Installation (4.3L)

1. Remove and discard retainer. To install, attach cable bead to ribbon end fitting of cruise control module. Snap cable fitting over ferrule on end of conduit until snap is heard. Ensure cable is taut and ribbon is not twisted. Slide cable conduit over ribbon, and install in cruise control module. 2. Install cable fitting into rectangular slot in engine bracket. Snap cable fitting over throttle lever pin. Route cable over accelerator cable through retainer on right rear corner of engine. Flip adjuster lever down to lock cable. Ensure a 0-1 mm clearance exists. Removal & Installation (2.2L)

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

1. Remove and discard retainer. To install, attach cable bead to ribbon end fitting of cruise control module. Ensure cable is taut and ribbon is not twisted. Slide cable conduit over ribbon, and install in cruise control module. Route cable over refrigerant line (if equipped). 2. Rotate cam lever. Install cable slug into slot opening in throttle lever, and install wire into pulley groove. DO NOT twist or kink cable. Ensure cable slug is supported by sides of throttle cam lever. 3. Install cable fitting into rectangular slot in engine bracket. Connect cable locator clip to top of routing bracket mounted on rocker cover. Flip adjuster lever (Natural) down to lock cable. Ensure a 0-1 mm clearance exists. CRUISE CONTROL MODULE Removal & Installation

Disconnect negative battery cable. Remove cruise control cable. See CRUISE CONTROL CABLE. Disconnect electrical connector from module assembly. Remove cruise control module. To install, reverse removal procedure. Tighten cruise control module fasteners to specification. See TORQUE SPECIFICATIONS . VEHICLE SPEED SENSOR (VSS) Removal (A/T Models)

Disconnect negative battery cable. Raise and support vehicle. Disconnect speed sensor electrical connector. Remove speed sensor retainer bolt. Using Speed Sensor Remover/Installer (J-38417), remove speed sensor. Remove speed sensor O-ring from speed sensor. Installation

To install, reverse removal procedure. Lubricate O-ring with transmission fluid. Tighten speed sensor retainer bolt to 97 INCH lbs. (11 N.m). Removal (M/T Models)

Disconnect negative battery cable. Raise and support vehicle. Disconnect speed sensor electrical connector. Remove speed sensor retainer bolt. Remove speed sensor. Remove speed sensor O-ring from speed sensor. Installation

To install, reverse removal procedure. Lubricate O-ring with transmission fluid. Tighten speed sensor bolt to 16 ft. lbs. (22 N.m).

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Pedal Bracket Bolt

Ft. Lbs. (N.m) 13 (18) INCH Lbs. (N.m)

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

Cruise Control Module Screws Vehicle Speed Sensor Bolt A/T M/T

40 (4.5) 97 (11) (1)

(1) Tighten bolt to 16 ft. lbs. (22 N.m).

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

Fig. 2: Cruise Control System Wiring Diagram (4.3L)

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

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1997 Chevrolet S10 Pickup CRUISE CONTROL SYSTEM 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Cruise Control System

Fig. 3: Cruise Control System Wiring Diagram (2.2L)

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

DESCRIPTION & OPERATION Rear window defogger system consists of rear window defogger switch on instrument panel, timer relay, rear defogger grid and heated mirrors (if equipped). Timer relay is incorporated in rear window defogger switch, located on left side of instrument panel. Grid is bonded to inside surface of rear window. Current enters grid on left side and is grounded on right side of cab. Ignition switch must be on to operate system rear window defogger system. When rear window defogger switch is pressed, timer relay allows current to flow to grid for 10 minutes, then stops current flow to grid. Each time rear window defogger switch is activated after initially activation, timer relay will allow current flow to grid for 5 minutes. If ignition switch is turned off then back on, timer relay resets to 10-minute cycle. Any time rear window defogger switch or ignition switch is turned off, current stops flowing to grid.

ON-VEHICLE SERVICE GRID FILAMENT REPAIR 1. Turn system off. Disconnect negative battery cable. Gently clean area to be repaired with steel wool. Wipe area clean with denatured alcohol. Be sure to clean 1/4" (6 mm) beyond each side of break. 2. With glass at room temperature of 70-90°F (20-32°C), position masking tape along both side of grid line at damaged area. See Fig. 1 . Apply grid repair material to grid and remove masking tape. Holding heat gun 1-2" (25-50 mm) from repair area, apply heat at 500-700°F (260-370°C) for 2-3 minutes. If heat gun is not available, allow repair area to air dry for at least 24 hours. 3. Test defogger operation to verify repair. If repair appears discolored, apply a coating of tincture of iodine. Allow iodine to dry for 30 seconds and carefully wipe off excess.

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

Fig. 1: Repairing Grid Line

TESTING NOTE:

Before testing, ensure fuses and circuit breakers are okay and ground connections are clean and tight. Leave electrical connectors attached and backprobe terminals unless specified otherwise. For references to connectors and terminals see appropriate wiring diagram. See WIRING DIAGRAMS .

GRID FILAMENT TEST 1. Start engine. Turn defogger system on. Ground test light and lightly probe each grid line. Move test light from feed wire side of grid to ground side. See Fig. 2 . 2. Test light should gradually dim as it is moved across grid. Be sure to check each grid in at least 2 places to avoid the possibility of bridging a gap with test light. 3. If test light shows full brilliance at both ends of grid, check for loose ground wire contact at cab body. If test light goes out as it is moved across grid, a break has been detected. Use a grease pencil to mark break (s) on outside of window. Go to GRID FILAMENT REPAIR under ON-VEHICLE SERVICE.

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

Fig. 2: Examining Grid Brilliance Test Patterns (Typical) Courtesy of GENERAL MOTORS CORP. REAR WINDOW DEFOGGER Indicator Illuminates, But Rear Window Does Not Clear

1. Connect test light between ground and rear window defogger switch terminal "A" (Orange wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire between rear window defogger switch and instrument panel fuse block. 2. Turn rear window defogger switch on. Connect test light between ground and rear window defogger switch terminal "B" (Purple wire). If test light illuminates, go to next step. If test light does not illuminate, replace rear window defogger switch. Microsoft Saturday, August 29, 2009 12:03:13 PM

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

3. Connect test light between ground and connector C432 (body harness-to-rear defogger grid pigtail) terminal "A" (Purple wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Purple wire between connector C432 and rear window defogger switch. 4. Connect test light between connector C432 terminal "A" (Purple wire) and connector C433 (body harness-to-rear defogger grid pigtail) terminal "A" (Black wire). If test light illuminates, repair rear defogger grid as necessary. If test light does not illuminate, repair open in Black wire between connector C433 and ground. Rear Window Defogger Does Not Operate

1. Turn ignition on. Connect test light between ground and rear window defogger switch terminal "E" (Pink wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Pink wire between rear window defogger switch and instrument panel fuse block. 2. Connect test light between rear window defogger switch terminals "E" (Pink wire) and "D" (Black wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Black wire between rear window defogger switch and ground. 3. Connect test light between ground and rear window defogger switch terminal "A" (Orange wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire between rear window defogger switch and instrument panel fuse block. 4. Turn rear window defogger switch on. Connect test light between ground and rear window defogger switch terminal "B" (Purple wire). If test light illuminates, go to next step. If test light does not illuminate, replace rear window defogger switch. 5. Connect test light between ground and connector C432 (body harness-to-rear defogger grid pigtail) terminal "A" (Purple wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Purple wire between connector C432 and rear window defogger switch. 6. Connect test light between connector C432 terminal "A" (Purple wire) and connector C433 (body harness-to-rear defogger grid pigtail) terminal "A" (Black wire). If test light illuminates, repair rear defogger grid as necessary. If test light does not illuminate, repair open in Black wire between connector C433 and ground. Indicator Inoperative

Turn headlights on. Turn dimmer control to full intensity. Connect test light between ground and rear window defogger switch terminal "C" (Gray wire). If test light illuminates, replace indicator bulb. If test light does not illuminate, repair open in Gray wire between rear window defogger switch and instrument panel fuse block.

REMOVAL & INSTALLATION WARNING: Before servicing instrument panel components on vehicles with Supplemental Inflatable Restraint (SIR) system, disable SIR system. See DISABLING & ACTIVATING AIR BAG SYSTEM in AIR BAG RESTRAINT SYSTEM article. NOTE:

For removal and installation procedures for mirrors, see MIRRORS - POWER article.

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

A/C-HEATER CONTROL Removal & Installation

Disconnect negative battery cable. Remove instrument panel trim panel. Remove A/C-heater control mounting screws. Disconnect electrical and vacuum harnesses. Remove A/C-heater control from vehicle. To install, reverse removal procedure.

WIRING DIAGRAMS NOTE:

For pickup models, see SYSTEM WIRING DIAGRAMS article in WIRING DIAGRAMS section.

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

Microsoft Saturday, August 29, 2009 12:03:13 PM

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1997 Chevrolet S10 Pickup DEFOGGER - MIRROR & REAR WINDOW 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Rear Window & Mirror Defoggers

Fig. 3: Rear Window Defogger System Wiring Diagram (Blazer, Bravada & Jimmy)

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

MODEL IDENTIFICATION Vehicle model can be identified by fifth character of Vehicle Identification Number (VIN), stamped on metal pad on top of left end of instrument panel, near windshield. See MODEL IDENTIFICATION table. MODEL IDENTIFICATION Series (1) "C" "G" "K" "L" "M" "P" "S" "T" (1) Fifth character of VIN.

Model 2WD Pickup, Sierra, Silverado, Suburban, Tahoe & Yukon (2) RWD Van

Escalade, 4WD Pickup, Sierra, Silverado, Suburban, Tahoe & Yukon AWD Astro & Safari 2WD Astro & Safari Forward Control & Motorhome 2WD Blazer, Jimmy, Pickup & Sonoma Bravada, Envoy, 4WD Blazer, Jimmy, Pickup & Sonoma

(2) Includes Express, G-Van and Savana.

DESCRIPTION This article covers 2 similar locking differentials: those with a 2-piece case (axles with a 10 1/2" ring gear) and those with a 1-piece case (all other axles). The 1-piece case has 2 pinion gears. The 2-piece case has 3-pinion gears. Both types have a clutch disc pack behind each of the side gears.

AXLE RATIO & IDENTIFICATION Rear axle identification is stamped on forward side of right axle tube. The first 3 digits indicate rear axle ratio, the next digit indicates axle assembly build source code, the next 3 digits indicate the day built in Julian Date form and the last digit identifies the shift build (first or second). Front axle identification is located on tag attached near axle tube.

REMOVAL & INSTALLATION See appropriate article in DRIVE AXLES.

OVERHAUL Microsoft Saturday, August 29, 2009 11:28:07 11:28:03 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

1-PIECE CASE Disassembly (Differential)

1. Using Governor Remover (J-26252), remove governor bushing. Remove "E" clips holding latching bracket in position on governor shaft. Move latching bracket down shaft. 2. Using governor remover, remove latching bracket bushing. See Fig. 1 . Remove latching bracket, shaft and spring from case. Remove governor. Remove lock screw and pinion shaft. Remove pinion gear and thrust washer. Rotate side gear and roll gears out of case.

Fig. 1: Exploded View Of 1-Piece Case Locking Differential Courtesy of GENERAL MOTORS CORP. 3. Remove thrust block and right side gear. Remove right clutch plates and side thrust washer. Remove left side gear, cam plate and clutch plates (cam unit) as an assembly. Remove side gear thrust washer. Microsoft Saturday, August 29, 2009 11:28:03 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

Disassembly (Cam Unit)

Remove retaining ring with snap ring pliers. Remove clutch plates, guide clips and wave washer. Remove cam plate and left side gear. Inspection

NOTE:

If side gears or thrust block are replaced, adjust differential. Check side gear backlash and thrust block clearance. See 1-PIECE CASE under ADJUSTMENTS.

Clean all parts in solvent. Inspect all gears for cracks and scoring. Inspect all clutch components and thrust washers for damage. Check fit of side gears on axle shafts. Inspect thrust sleeve for wear. Replace components as necessary. Reassembly (Cam Unit)

Install cam plate on side gear. Install wave washer. Install clutch plates in alternating sequence (8 on 7 5/8" ring gear and 10 on 8 1/2" ring gear). See Fig. 1 . Install retaining ring. Use grease to hold guide clips in place. Install guide clips on clutch plates. Reassembly (Differential)

1. Install thrust washer and left side gear (cam unit) in tocase. Install thrust washer for right side gear into case. Install clutch pack for right side gear. Install clutch plates in alternating sequence. See Fig. 1 . 2. Use grease to hold guide clips in place. Install guide clips onto clutch plates. Install right side gear, thrust block, thrust washers and pinion gears. Install pinion gears into case, 180 degrees apart. 3. Rotate pinion gears and thrust block into case. Ensure open side of thrust block faces small window opening. Install pinion shaft and NEW lock screw. DO NOT tighten lock screw to specification at this time. NOTE:

Once unit is installed into differential housing, tighten lock screw to specification.

4. Place governor assembly and latching bracket into case. Place straight end of latching bracket spring over and outside governor assembly shaft. See Fig. 2 . 5. Install governor assembly and latching bracket bushing. Latching bracket bushing has a tapered hole; governor bushing has a straight hole. Press governor bushing into case to set shaft end play at .004.020" (.10-.51 mm). Press latching bracket bushing into case so no shaft end play exists. Once unit is installed, tighten lock screw to 37 ft. lbs. (51 N.m) on 9 1/2" ring gear, or 27 ft. lbs. (37 N.m) on all others.

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

Fig. 2: Installing Governor & Latching Bracket Courtesy of GENERAL MOTORS CORP. 2-PIECE CASE Disassembly (Differential)

1. With differential removed from housing, remove ring gear and side bearings. Remove screws from front face of ring gear flange. Place differential on right half. 2. Using a screwdriver, gently pry differential case halves apart at yoke hole locations. Remove left half. Hold thumb against inside of gear hub when separating differential case halves to prevent left side gear from falling out. 3. Remove governor and latching bracket assemblies. See Fig. 3 . Remove left side gear, clutch plates, guide clips and thrust washer. Remove reaction blocks, pinion yoke, pinion gears and pinion thrust washers.

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

Fig. 3: Exploded View Of 2-Piece Case Locking Differential Courtesy of GENERAL MOTORS CORP. Disassembly (Cam Unit)

1. Remove right side gear and side gear thrust washer. Measure and record overall length of gear assembly from front of gear to back of thrust sleeve, including side gear thrust washer. See Fig. 3 . 2. Using press and Bearing Remover (J 22912-01), press thrust sleeve from right side gear. Separate clutch plates, guide clips, wave spring and cam plate from right side gear. See Fig. 4 .

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

Fig. 4: Exploded View Of Right Side Gear (Cam Unit) & Components Courtesy of GENERAL MOTORS CORP. Inspection

NOTE:

If side gears or reaction blocks were replaced, adjust differential. Check side gear backlash and reaction block clearance. See 2-PIECE CASE under ADJUSTMENTS.

1. Install cam plate onto right side gear. Install wave spring and clutch plates. Install clutch plates in alternating sequence. See Fig. 4 . 2. Press thrust sleeve on right side gear until sleeve is even with surface of right side gear disc splines. 3. Use grease to hold guide clips in place. Install guide clips onto clutch plates. If side gear or thrust sleeve were replaced, measure and record overall length of gear assembly from front of gear to back of thrust sleeve, including side gear thrust washer. Microsoft Saturday, August 29, 2009 11:28:03 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

4. Compare new measurement with original measurement taken during disassembly. If difference between measurements is .003" (.07 mm) or more, install NEW side gear thrust washer to obtain reading nearest original measurement. Reassembly (Differential)

1. Install right thrust washer and right cam unit. Install reaction blocks, reaction block thrust washer, pinion yoke, pinion gears and pinion thrust washers. 2. Install left thrust washer and clutch plates in differential case half. Ensure clutch plates are installed in alternating sequence. See Fig. 3 . Install left side gear and latching bracket assembly. 3. Install governor assembly. Ensure straight end of latching bracket spring is over and outside governor assembly shaft. See Fig. 2 . Hold left side gear in differential case half, and install case halves together. Install and tighten retaining bolts. Install ring gear and differential side bearings.

ADJUSTMENTS 1-PIECE CASE NOTE:

If side gears have been replaced, adjust differential. Adjust clearance using correct thickness of selective thrust washers. Left and right side gear backlash must also be adjusted.

Gear Backlash

1. Install cam unit and thrust washer into flange end of case. Install pinion gears and thrust washer into differential. Ensure thrust washers are aligned with pinion shaft hole. 2. Press side gear downward, and install pinion shaft and lock screw. If side gear cannot be pressed down enough to install pinion shaft, install thinner thrust washer. 3. Rotate pinion gear closest to lock screw so one tooth is pointing downward (perpendicular to ring gear flange). Insert a screwdriver firmly between side gear and pinion shaft. 4. Install dial indicator on ring gear flange, with indicator stem positioned on tooth of pinion gear closest to lock screw. Zero dial indicator. 5. Pull pinion gear against case, rotate pinion gear back and forth, and note backlash reading. Repeat procedure on opposite pinion gear. Backlash should be .002-.010" (.05-.25 mm). 6. Change thrust washer thickness to obtain correct backlash. If backlash is greater than specification, use thicker thrust washer. If backlash is less than specification, use thinner thrust washer. Repeat procedure for other side gear. 2-PIECE CASE NOTE:

If cam gear, side gears or reaction block have been replaced, adjust differential clearance. Adjust clearance using correct thickness of selective thrust block and selective side gear thrust washers. Left and right side gear backlash and thrust block clearance must also be adjusted.

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

Right Side Gear Backlash

1. Install right side gear (cam unit) and side gear thrust washer into differential case right half. Using washers, long bolt and nut, clamp right side gear unit into differential case. 2. Install pinion gears and thrust washers onto pinion yoke. Install pinion yoke into differential case half. Loosen nut on bolt. Position one pinion gear tooth facing downward (perpendicular to ring gear flange), and tighten nut. 3. Install dial indicator onto ring gear flange, with indicator stem positioned on one tooth of pinion gear. Pull pinion gear against differential case half. Rotate pinion gear back and forth, and note backlash reading. 4. Ensure pinion yoke remains seated while checking backlash. Repeat procedure on remaining pinion gears. Backlash should be .010-.018" (.25-.46 mm). 5. Change thrust washer thickness to obtain correct backlash. If backlash is greater than specification, use thicker thrust washer. If backlash is less than specification, use thinner thrust washer. Left Side Gear Backlash

1. Assemble clutch plates in alternating sequence. See Fig. 3 . Use grease to hold guide clips in place, and install guide clips onto clutch plates. 2. Install thrust washer, clutch plates and left side gear into differential case half. Using washers, long bolt and nut, clamp left side gear into differential case. 3. Install pinion gears and thrust washers onto pinion yoke. Install pinion yoke into differential case half. Loosen nut on bolt. Position one pinion gear tooth facing downward (perpendicular to ring gear flange), and tighten nut. 4. Install dial indicator on ring gear flange, with indicator stem positioned on one tooth of pinion gear. Pull pinion gear against differential case. Rotate pinion gear back and forth, and note backlash reading. 5. Ensure pinion yoke remains seated while checking backlash. Repeat procedure on remaining pinion gears. Backlash should be .002-.010" (.05-.25 mm). 6. Change thrust washer thickness to obtain correct backlash. If backlash is greater than specification, use thicker thrust washer. If backlash is less than specification, use thinner thrust washer. Reaction Block Clearance

1. Install left thrust washer, clutch plates and side gear into differential case. Using washers, long bolt and nut, clamp side gear into differential case. Install right thrust washer and cam pack. Using washers, long bolt and nut, clamp side gear into differential case. 2. Place straightedge across top of both side gears. Using depth micrometer, measure distance from face of straightedge to surface of differential case half. Subtract straightedge thickness from this measurement. 3. Add measurement of both sides together. This is the side gear spread. Assemble both original reaction blocks together and measure thickness of both reaction blocks. 4. Reaction block thickness should be 0-.006" (0-.15 mm) less than side gear spread. To adjust clearance, select reaction block with different thickness, or reshim left or right clutch pack. Ensure side gear backlash remains within specification. Microsoft Saturday, August 29, 2009 11:28:03 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES Differentials - Eaton Locking - Trucks

AXLE ASSEMBLY SPECIFICATIONS AXLE ASSEMBLY SPECIFICATIONS Application Governor Shaft End Play (1-Piece Case) Pinion Gear Backlash 1-Piece Case 2-Piece Case Left Side Gear Right Side Gear Reaction Block Clearance (2-Piece Case)

In. (mm) .004-.020 (.10-.51) .002-.010 (.05-.25). .002-.010 (.05-.25) .010-.018 (.25-.46) 0-.006 (0-.15)

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Pinion Shaft Lock Screw 7 5/8", 8 1/2" & 8 5/8" Ring Gear 9 1/2" Ring Gear

Ft. Lbs. (N.m) 27 (37) 37 (51)

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

1996-97 DRIVE AXLES "T" Series Front Axle

AXLE RATIO & IDENTIFICATION Front axle identification is located on tag attached near axle tube.

DESCRIPTION & OPERATION Front axle assembly on "T" Series models uses a 7 1/4" ring gear. Front axle assembly has an electric 4WD engage/disengage feature which allows shifting in or out of 4WD while vehicle is moving (under most conditions). The 4WD feature is shifted by a vacuum actuation system. See Fig. 1 . The vacuum actuation system consists of a vacuum switch and vacuum actuator. Shift mechanism in transfer case triggers vacuum switch to apply engine vacuum to vacuum actuator after about a 3-second delay. The vacuum actuator, in turn, pulls on shift cable which pulls on shift fork in axle. This connects the right axle output shaft to the front axle differential. Torque is now available to front wheels. Right side of axle assembly consists of a solid axle shaft which rides inside of a stationary axle tube. A short stub shaft with CV joint attached is bolted to right inner axle shaft flange. Left drive axle shaft consists of a flexible drive shaft using an inner tripod joint and outer CV joint. Left axle tripod joint housing is bolted to axle carrier output shaft drive flange. CV joint splined/threaded shaft on outer end of drive axle shaft slips through steering knuckle/hub assembly. See Fig. 3 . Front axle assembly differential uses a conventional ring and pinion gear set to transmit driving force of engine to the front wheels. Ring and pinion gear set transfers driving force at a 90-degree angle from front drive shaft to drive axle shafts/CV joints.

Microsoft Saturday, August 29, 2009 11:26:59 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 1: Vacuum Actuation System Courtesy of GENERAL MOTORS CORP.

LUBRICATION Fill differential with 80W or 80W-90 GL-5 gear lubricant to edge of filler hole (warm differential), or to 1/2" (12 mm) below edge of filler hole (cold differential).

TROUBLE SHOOTING Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

NOTE:

See TROUBLE SHOOTING - BASIC PROCEDURES article in GENERAL INFORMATION.

Remove front axle assembly. See FRONT AXLE ASSEMBLY . Using Carrier Bushing Remover/Installer (J33791), press bushing out of carrier housing. See Fig. 2 . To install, reverse tool and press NEW bushing into housing. Repeat procedure for other mounting bushing.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 2: Removing/Installing Carrier Case Bushing Courtesy of GENERAL MOTORS CORP. FRONT AXLE ASSEMBLY Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Removal & Installation

1. Disconnect negative battery cable. Remove shift cable from vacuum actuator by disengaging lock spring. Push in actuator diaphragm to release cable. 2. Unlock steering wheel. Raise and support vehicle. Remove engine drive belt shield and front axle skid plate (if equipped). Remove wheels. Remove lower shock absorber bolt, and compress shock to gain access to output shaft flange bolts. 3. Disconnect 4WD indicator light connector from switch. Remove 3 bolts securing cable and switch housing. Pull housing away to gain access to cable locking spring. DO NOT unscrew cable coupling nut unless cable is being replaced. See SHIFT CABLE . 4. Disconnect shift cable from shift fork shaft by lifting spring over slot in shift fork. Disconnect axle vent hose. Disconnect steering relay rod from idler arm and pitman arm, and pull steering linkage forward. Support axle assembly using appropriate transmission jack. 5. Remove 6 right stub shaft-to-output shaft flange bolts, and 6 left drive axle-to-output shaft flange bolts. Wire left drive axle and right stub shaft aside. Mark front of drive shaft to ensure proper installation. Remove bolts and clamps. Wire drive shaft aside. 6. Remove bolts securing right axle tube to frame rail. Remove mounting bolts from axle assembly. Tip axle assembly counterclockwise while lifting to gain clearance from mounting ears and remove axle assembly. To install, reverse removal procedure. Tighten all bolts and nuts to specification. See TORQUE SPECIFICATIONS . LEFT DRIVE AXLE SHAFT Removal

1. Raise and support vehicle. Remove engine drive belt shield and front axle skid plate (if equipped). Remove wheel. Remove stabilizer bar from lower control arm. If both ends of stabilizer bar are being removed, DO NOT mix left and right stabilizer bar components. CAUTION: DO NOT use wedge type remover tool on tie rod end. Damage to tie rod end will result. 2. Disconnect left outer tie rod end from steering knuckle using Steering Linkage Puller (J-24319-01). Wire tie rod end aside. Insert a long drift through caliper and into disc rotor vanes to prevent rotation. Remove cotter pin, retainer, axle hub nut and washer from drive axle shaft CV joint. See Fig. 3 . Loosen 6 drive axle shaft flange bolts retaining tripod joint housing to axle carrier output shaft drive flange.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 3: Left Drive Axle Shaft With Tripod & CV Joints Courtesy of GENERAL MOTORS CORP. 3. Remove brakeline bracket from upper control arm. Remove shock absorber from lower control arm mounting bracket. Install floor stand or jack under lower control arm near ball joint to maintain spring tension and lower control arm position. 4. Remove upper control arm ball joint-to-steering knuckle nut. Separate upper control arm ball joint stud from knuckle. Using shop towel, cover lower shock mount ears on lower control arm to prevent CV joint boot damage when removing axle shaft. Install Puller (J-28733) to rotor to push CV joint splined shaft through hub splines. 5. Remove 6 drive axle shaft flange bolts securing tripod joint housing to axle carrier output shaft drive flange. DO NOT allow drive axle shaft to hang free. Pull slightly outward on top of steering knuckle to enable drive axle shaft removal. DO NOT stretch brake hose. Remove drive axle shaft. Installation

1. Before installing drive axle shaft, inspect inner wheel bearing seal on rear of knuckle. Replace, if required, using Seal Installer (J-28574). Lube seal lip. 2. To install drive axle shaft, reverse removal procedure. Tighten all bolts and nuts to specification. See TORQUE SPECIFICATIONS . PINION FLANGE & OIL SEAL Removal Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

1. Remove bolts and retainers from pinion flange. Mark position of drive shaft to pinion flange to ensure correct installation. Remove drive shaft from pinion flange, and wire shaft aside. 2. Mark pinion flange, pinion shaft and pinion nut to ensure alignment and bearing preload are maintained on installation. Using Pinion Flange Remover Set (J-8614-01), hold pinion flange stationary and remove pinion flange nut and washer. Place drain pan under pinion area of differential carrier. Remove pinion flange and oil seal. See Fig. 4 . 3. Clean pinion flange in solvent and inspect seal surface of pinion flange for nicks, burrs or damage (such as a groove worn into pinion flange by oil seal). Repair or replace as necessary. Installation

1. Lubricate pinion flange surface and sealing lip of oil seal. Install oil seal using seal installer. Install pinion flange onto pinion shaft with marks aligned. Install pinion nut and tighten to position marked on pinion shaft. 2. Tighten nut 1/16" beyond alignment marks. Install drive shaft and tighten bolts to specification. See TORQUE SPECIFICATIONS . Check gear oil level.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 4: Removing Pinion Nut & Flange Courtesy of GENERAL MOTORS CORP. RIGHT AXLE TUBE & INNER AXLE SHAFT Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Removal

1. Disconnect negative battery cable. Remove shift cable from vacuum actuator by disengaging lock spring. Push in actuator diaphragm to release cable. 2. Unlock steering wheel. Raise and support vehicle. Remove engine drive belt shield and front axle skid plate (if equipped). Remove wheel. Remove stabilizer bar from both lower control arms. DO NOT mix left and right stabilizer bar components. 3. Place a support under right lower control arm, and disconnect right upper ball joint. Remove support so control arm can hang free. Remove stub axle shaft flange bolts from inner axle shaft flange. 4. Disconnect 4WD indicator light connector from switch. Remove 3 bolts securing cable and switch housing. Pull housing away to gain access to cable locking spring. DO NOT unscrew cable coupling nut unless cable is being replaced. See SHIFT CABLE . 5. Disconnect shift cable from shift fork shaft by lifting spring over slot in shift fork. Place drain pan under drive axle. Remove drain plug to drain lubricant. Remove bolts securing axle tube to right frame. Remove bolts securing axle tube assembly to carrier. 6. Remove tube assembly by working around drive axle. DO NOT allow sleeve, thrust washers, connector and output shaft to fall out of carrier while removing tube. See Fig. 5 . Installation

1. Install sleeve, thrust washers, connector and output shaft in carrier. Apply Sealant (GM 1052942 or Loctite 518) on axle tube to differential surface. Ensure thrust washer is installed with notch aligned with tab on washer. See Fig. 6 . Use wheel bearing grease to hold thrust washer in place. 2. Install tube and shaft assembly to differential and install one bolt at one o'clock position, but DO NOT tighten. Pull assembly down and install cable, switch housing and 4 remaining bolts. Tighten bolts to specification. See TORQUE SPECIFICATIONS . 3. Install 2 bolts securing tube to frame. Tighten bolts to specification. See TORQUE SPECIFICATIONS . Inspect shift mechanism operation. To complete installation, reverse removal procedure.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 5: Exploded View Of 4WD "T" Series Front Axle Assembly Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 6: Installing Axle Tube Thrust Washer Courtesy of GENERAL MOTORS CORP. RIGHT SIDE OUTPUT SHAFT PILOT BEARING Removal & Installation

Remove right axle tube and inner axle shaft assembly. See RIGHT AXLE TUBE & INNER AXLE SHAFT . Remove pilot bearing using Pilot Bearing Remover (J-34011). Lubricate NEW pilot bearing with wheel bearing grease. Install NEW pilot bearing using Pilot Bearing Installer (J-33842). To complete installation, reverse removal procedure. SHIFT CABLE Removal

1. Disengage shift cable from vacuum actuator by disengaging locking spring. Push actuator diaphragm in to release cable. Squeeze 2 locking fingers of cable with pliers. Pull cable out of bracket hole. 2. Raise and support vehicle. Remove bolts securing cable and switch housing to carrier. DO NOT unscrew coupling nut at this time. Remove shift cable housing from carrier assembly. Pull out about 3/4" (19 mm) of cable. Remove cable end from shift fork shaft. Bend tang of lock spring, then pull cable end from shift fork shaft. Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

3. Note cable routing for installation. Unscrew coupler nut and remove shift cable from shift cable housing. Remove cable from vehicle. Installation

1. Install cable and switch housing to carrier. Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS . 2. Guide cable though switch housing into fork shaft hole and push cable in. Cable will snap into place. Start coupling nut by hand to avoid cross threading. Tighten nut to specification. See TORQUE SPECIFICATIONS . DO NOT overtighten nut. 3. Connect shift cable to vacuum actuator by pressing cable into bracket hole. Cable and housing will snap into place. Check cable operation. VACUUM ACTUATOR Removal & Installation

Disconnect vacuum line from actuator. Remove shift cable. See SHIFT CABLE . Remove vacuum actuator bolts and actuator. To install, reverse removal procedure.

OVERHAUL RIGHT AXLE TUBE ASSEMBLY Disassembly

1. Place mounting flange of axle tube assembly in a vise. Remove springs, shift shaft/fork, and differential sleeve (No. 22). See Fig. 5 . Remove snap ring, connector gear and thrust washer from axle shaft. 2. Using a soft mallet, tap on flange end of axle shaft to remove axle shaft from tube. DO NOT hammer on pilot bearing stem end of axle shaft, severe damage will result. Using a screwdriver, pry out deflector and oil seal. 3. Using a Bearing Remover (J-29369-2) and slide hammer, remove axle bearing from tube. Cleaning & Inspection

Wash all parts in solvent. Dry using compressed air. Inspect all parts for excessive wear and scoring. Inspect connector gear and axle shaft splines for wear, cracks, and twisted splines. Reassembly

1. Clean gasket surfaces on axle tube and carrier housing. Lubricate NEW bearing using wheel bearing grease. Using Bearing Installer (J-33844), install axle bearing into tube. Lightly coat lip of NEW seal with grease. Install seal using Seal Installer (J-33893). 2. Install deflector to axle shaft (if removed) and insert axle shaft into axle tube. Install thrust washer, ensuring tube slots align with tabs on washer. See Fig. 6 . Use wheel bearing grease to hold thrust washer in place. Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

3. Drive connector gear onto end of axle using a plastic hammer. Install snap ring. Ensure snap ring seats properly in groove. Ensure axle tube and carrier case sealing surfaces are clean. Install springs on shift shaft/fork. Insert shift shaft/fork into groove in differential sleeve. Install shift shaft/fork assembly into tube assembly at same time sleeve is installed onto connector gear. 4. Apply a bead of Sealant (GM 1052942 or Loctite 518) to axle tube sealing surface. Assemble axle tube to carrier case. Install and tighten axle tube-to-carrier bolts to specification. See TORQUE SPECIFICATIONS . Inspect shift mechanism operation. FRONT AXLE ASSEMBLY Disassembly

1. Remove axle carrier. See FRONT AXLE ASSEMBLY under REMOVAL & INSTALLATION . Remove right axle tube and inner axle shaft assembly. See RIGHT AXLE TUBE & INNER AXLE SHAFT under REMOVAL & INSTALLATION. 2. Remove shift shaft/fork assembly consisting of sleeve, springs and seals. See Fig. 5 . Remove thrust washer and output shaft from right side of carrier assembly. Remove right output shaft bearing using Bearing Remover (J-34011). Remove washer from right side of carrier assembly. 3. Remove left output flange from carrier assembly by prying on one side with a screwdriver while simultaneously tapping outward on other side with a soft-faced hammer. Remove deflector from output flange. Remove 6 cover-to-carrier bolts securing left side cover. Tap cover to loosen and remove. Pry out left output flange seal with a screwdriver. 4. Remove 10 bolts holding carrier halves together. Insert screwdriver in slots provided (one next to fill plug, one 180 degrees from fill plug) and pry carrier halves apart. See Fig. 12 . 5. Remove differential assembly from carrier. See Fig. 5 . Remove both side bearing adjusting sleeve lock tabs. Using Side Bearing Adjusting Wrench (J-33792), rotate adjusting sleeve and push side bearings out of bores. Remove side bearings from adjusting sleeve using Bearing Remover (J-21551). 6. Using Pinion Flange Remover Set (J-8614-01), hold pinion flange stationary and remove pinion nut. See Fig. 4 . Mount left half of carrier in Holding Fixture (J-33837-1). Use bolts supplied with remover set to install carrier on fixture. See Fig. 7 . Remove pinion flange and deflector.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 7: Installing Pinion Holding Fixture Tool Courtesy of GENERAL MOTORS CORP. 7. Remove pinion with attached shim, inner bearing and spacer as an assembly. Remove collapsible spacer from pinion. Using Differential Side/Pinion Bearing Remover (J-22912-01), press inner bearing from pinion. Remove shim(s) from pinion, keeping shims in order. 8. Install Bearing Race Remover (J-33837-6) on Holding Fixture (J-33837-1) and remove outer pinion bearing, race and pinion seal. Remove inner pinion bearing race by pushing it out of carrier with bearing race remover installed on Pinion Bearing Remover/Installer Set (J-33837). See Fig. 8 .

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 8: Removing Inner Pinion Bearing Race Courtesy of GENERAL MOTORS CORP. 9. Using Differential Side/Pinion Bearing Remover (J-22912-01), remove side bearings from differential case assembly. Remove ring gear bolts. Ring gear uses left-hand thread bolts. Using a brass drift, drive ring gear from differential case. DO NOT pry ring gear from differential case or damage to ring gear and differential case will occur. 10. Remove bolt from differential pinion gear shaft. Remove pinion gear shaft. Roll pinion gears and thrust washers out of differential case. Remove side gears and thrust washers, marking side gears and differential case left and right for reassembly reference. Upper and lower carrier mounting bushings should be replaced using Bushing Remover (J-33791). Cleaning & Inspection

Clean all parts in cleaning solvent. Inspect all parts for excessive wear. Replace as required. Reassembly

1. Install pinion bearing races using Holding Fixture (J-33837-1) and Bearing Race Installer (J-33837-4) Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

until races are seated in carrier. See Fig. 9 . Lubricate inner and outer bearings, then set pinion depth. See DRIVE PINION DEPTH under ADJUSTMENTS.

Fig. 9: Installing Inner Pinion Bearing Race Courtesy of GENERAL MOTORS CORP. 2. Install appropriately sized shim onto pinion. Shim size was previously determined during pinion depth adjustment. Using Pinion Bearing Installer (J-33785), install inner pinion bearing onto pinion. Install NEW collapsible spacer onto pinion shaft. Lubricate outer pinion bearing, and install bearing and pinion seal into carrier case using Seal Installer (J-33782). Insert pinion, with attached inner bearing and collapsible spacer, into carrier case. 3. Install deflector and pinion flange. Apply GM PST sealant to area where pinion threads meet pinion flange. Install pinion washer and nut. Install same flange holder previously used to remove pinion flange. Hold flange while slowly tightening nut and checking pinion flange until no end play is present. DO NOT tighten nut any further. 4. Rotate pinion several times to ensure bearings have been seated. Recheck end play. Set final pinion preload to 15-25 INCH lbs. (1.7-2.8 N.m) by tightening pinion nut in small increments, rotating pinion between increments. Each increment increases preload by several INCH lbs. 5. If preload specification is exceeded, remove pinion and install NEW collapsible spacer. Once preload has been obtained, rotate pinion several times to ensure bearings have seated and recheck preload. 6. Install side gears and thrust washers into differential case. If old side gears are being reinstalled, ensure they are placed in their original locations as marked during disassembly. Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

7. Position one pinion gear between side gears and rotate gears until pinion gear is directly opposite opening in case. Place remaining pinion gear between side gears. Ensure holes in both pinion gears line up. Rotate pinion gears toward opening just enough to allow installation of thrust washers. 8. Install differential pinion gear shaft. Install pinion gear shaft bolt. Install ring gear onto differential assembly. Tighten NEW bolts alternately in progressive steps to 60 ft. lbs. (81 N.m). Ring gear uses lefthand thread bolts. 9. Press side bearings onto differential assembly using Side Bearing Installer (J-33790). Press bearings onto sleeves using Bearing Installer (J-33788). 10. Using same side bearing adjusting wrench used during disassembly, install sleeves into carrier case. Install side bearing races into carrier using Race Installer (J-23423-A). Place differential assembly into left carrier case half. Turn left sleeve inward until backlash is felt between ring and pinion. 11. Remove carrier case from holding fixture, and attach carrier halves together using 4 bolts. If halves DO NOT make complete contact, back out right sleeve. Install carrier case bolts and tighten to 35 ft. lbs. (47 N.m). Set ring gear backlash adjustment to specification. See RING GEAR BACKLASH under ADJUSTMENTS. 12. Install both side bearing adjusting sleeve lock tabs over left and right sleeves. Remove 4 bolts holding axle carrier halves together and separate carrier halves. Apply Sealant (GM 1052942 or Loctite 518) to one carrier housing surface. 13. Reconnect axle carrier housing halves. Install 10 attaching bolts and tighten to specification. See TORQUE SPECIFICATIONS . Install/drive seal into left side cover. Apply Sealant (GM 1052942 or Loctite 518) to left side cover. Install 6 cover-to-carrier bolts securing left side cover and tighten to specification. See TORQUE SPECIFICATIONS . 14. Install deflector onto left output shaft and insert shaft into left side of carrier. Drive shaft into place with a soft-faced (brass or plastic) hammer. Install NEW pilot bearing into right output shaft using Pilot Bearing Installer (J-33842). Install washer onto right output shaft, and insert right output shaft into right side of carrier. 15. Install right axle tube and inner axle shaft assembly. See RIGHT AXLE TUBE & INNER AXLE SHAFT under REMOVAL & INSTALLATION. To complete reassembly, reverse disassembly procedure. LEFT DRIVE AXLE SHAFT NOTE:

Use illustration for exploded view of left drive axle shaft. See Fig. 10 .

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 10: Exploded View Of Left Axle Shaft Courtesy of GENERAL MOTORS CORP.

ADJUSTMENTS Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

DRIVE PINION DEPTH 1. Lubricate inner and outer pinion bearings liberally with gear oil. Hold pinion bearings in position and install Pinion Shim Setting Gauge (J-33838). Install Dial Indicator (J-29763) onto gauge. See Fig. 11 . 2. With gauge installed, preload inner and outer pinion bearings to 9-14 INCH lbs. (1.0-1.6 N.m) by tightening shim setting gauge mounting bolt while holding end of gauge shaft with a wrench. Rotate shaft several times to ensure bearings have seated. Recheck preload. 3. Push dial indicator downward until needle rotates about 3/4 turn clockwise. Tighten dial indicator in this position. Set button of pinion shim setting gauge on differential bearing bore. See Fig. 11 . NOTE:

4WD front axle drive pinion gears are nominal or zero, and are not marked on pinion head surface. Shim thickness will equal dial indicator gauge reading.

4. Rotate gauge slowly back and forth until dial indicator reads lowest point of bore. Set dial indicator to zero. Repeat rocking action of gauge to verify zero setting. 5. After satisfactory zero setting is obtained and verified, move gauge button out of differential side bearing bore. Record dial indicator reading. Use a shim that is exactly the same size as this indicator reading. 6. Remove dial indicator and gauge from carrier. Position correct shim on drive pinion. Install drive pinion bearing. Continue at step 2) of REASSEMBLY under FRONT AXLE ASSEMBLY under OVERHAUL .

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 11: Pinion Shim Setting Gauge & Dial Indicator Installation & Measurement Courtesy of GENERAL MOTORS CORP. RING GEAR BACKLASH 1. Use Side Bearing Adjusting Wrench (J-33792) and torque wrench to tighten right adjusting sleeve until no backlash is present. This torque measurement should be about 100 ft. lbs. (136 N.m). 2. Using Side Bearing Adjusting Wrench (J-33792), tighten left adjusting sleeve until no backlash is present. This torque measurement should be about 100 ft. lbs. (136 N.m). 3. Mark location of adjusting sleeves in relation to carrier halves so notches can be counted when turned. See Fig. 12 . Turn right sleeve OUT 2 notches using side bearing adjusting wrench. Turn left sleeve IN one notch. Rotate pinion several times to seat bearings.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 12: Marking Adjusting Sleeve Location Courtesy of GENERAL MOTORS CORP. 4. Mount base clamp of Dial Indicator Set (J-8001) so gauge plunger button contact outer edge of pinion flange. Ensure plunger is at right angle to flange. See Fig. 13 . Move pinion flange through its free play travel while holding differential carrier and ring gear stationary. Record dial indicator reading. Divide dial indicator reading by 2 to obtain backlash reading.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

Fig. 13: Measuring Backlash At Pinion Flange Courtesy of GENERAL MOTORS CORP. 5. Gear backlash at pinion flange should be .003-.010" (.08-.25 mm), with a preferred measurement of .005.007" (.13-.18 mm). If backlash is not within specification, equally turn adjusting sleeves as necessary. 6. To increase backlash, turn left sleeve in and turn right sleeve out an equal amount. To decrease backlash, turn right sleeve in and turn left sleeve out an equal amount. Turning sleeve one notch will change backlash about .003" (.08 mm). DO NOT install sleeve locks yet. 7. When backlash is within specification, perform gear tooth contact pattern check. See GEAR TOOTH CONTACT PATTERNS article in GENERAL INFORMATION. When pattern is satisfactory, continue at step 12) of REASSEMBLY under FRONT AXLE ASSEMBLY under OVERHAUL .

AXLE ASSEMBLY SPECIFICATIONS Microsoft Saturday, August 29, 2009 11:26:56 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES "T" Series Front Axle

AXLE ASSEMBLY SPECIFICATIONS Application Ring Gear Backlash Preferred Allowed Ring Gear Runout (Maximum)

In. (mm) .005-.007 (.13-.18 mm) .003-.010 (.08-.25) .002 (.05) INCH Lbs. (N.m) 15-25 (1.7-2.8)

Pinion Bearing Preload

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Axle Assembly Mounting (Bushing) Bolts Axle Assembly Mounting (Bushing) Nuts Axle Hub Nut Ball Joint Nut (Upper) Cable Switch Housing Bolts Carrier Case Bolts Drain & Fill Plugs Drive Axle/Stub Shaft-To-Output Flange Bolts Front Drive Shaft Bolts Idler Arm-To-Steering Relay Rod Nut Left Output Shaft Cover Bolts Pitman Arm-To-Steering Relay Rod Nut Right Axle Tube-To-Carrier Bolts Right Axle Tube-To-Frame Bolts

Ft. Lbs. (N.m) 66 (90) 55 (75) 181 (245) 83 (113) 35 (48) 35 (47) 24 (33) 59 (80) 59 (80) 60 (82) 18 (25) 35 (47) 35 (48) 55 (75) 59 (80)

Ring Gear Bolts (1) Shock Absorber Lower Mounting Bolt Skid Plate Bolts Stabilizer Bar Bushing Bracket-To-Frame Bolts Stabilizer Bar-To-Lower Control Arm Bolts Tie Rod Nut Wheel Lug Nuts Adjusting Sleeve Lock Bolt Shift Cable Coupling Nut (1) Always use NEW bolts. Bolts are left-hand thread.

54 (73) 20 (27) 30 (40) 24 (33) 35 (47) 96 (130) INCH Lbs. (N.m) 71 (8) 89 (10)

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

Model 2WD Pickup, Sierra, Silverado, Suburban, Tahoe & Yukon Express, G-Van & Savana 4WD Pickup, Sierra, Silverado, Suburban, Tahoe & Yukon AWD Astro & Safari 2WD Astro & Safari 2WD Blazer, Jimmy, Pickup & Sonoma AWD Bravada, 4WD Blazer, Envoy, Jimmy, Pickup & Sonoma

DESCRIPTION NOTE:

8 1/2" ring gear differential is also used as front drive axle on K2 models. K2 models may also be equipped with a Dana front drive axle. Some models are equipped with a locking differential. For testing and overhaul procedures, see DIFFERENTIALS - EATON LOCKING article.

Drive axle assembly is hypoid gear type with integral carrier housing. This type assembly is used on light-duty emission vehicles with semi-floating axles. Differential side bearing preload adjustment and drive pinion depth adjustment are made by using shims. Pinion bearing preload is made with a collapsible spacer. A removable differential cover permits inspection and minor servicing of differential without removing axle assembly from vehicle.

AXLE RATIO & IDENTIFICATION Rear axle identification is stamped on forward side of axle tube. The first 3 digits indicate rear axle ratio, the next digit indicates axle assembly build source code and the next 3 digits indicate the day built.

LUBRICATION Fill differential with appropriate amount of 80W or 80W-90 GL-5 gear lubricant. See LUBRICATION SPECIFICATIONS table. On models with limited-slip or locking differential, add 4 ozs (.12 L) of limited slip additive. Microsoft Saturday, August 29, 2009 11:27:36 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

LUBRICATION SPECIFICATIONS Aplication "C" & "K" Series 8 1/2" & 8 5/8" Ring Gear 9 1/2" Ring Gear "G" Series 8 5/8" Ring Gear 9 1/2" Ring Gear "L" & "M" Series "S" & "T" Series 7 5/8" Ring Gear 8 5/8" Ring Gear

Specification 4.2 Pts. (2.0L) 5.5 Pts. (2.6L) 5.3 Pts. (2.5L) 5.9 Pts. (2.8L) 4.0 Pts. (1.9L) 3.8 Pts. (1.8L) 4.2 Pts. (2.0L)

TROUBLE SHOOTING See appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

REMOVAL & INSTALLATION AXLE SHAFT & BEARING Removal

1. Raise vehicle and support. Remove rear wheels and brake drums. Place drain pan below differential cover. Loosen, but DO NOT remove, differential cover bolts. Break cover loose. Allow lubricant to drain. Remove differential cover. Remove differential pinion shaft lock bolt. 2. On non-locking differential assemblies, remove differential pinion shaft. Push outer flanged end of axle shaft toward center of vehicle. Remove "C" lock from axle shaft groove and from counterbore recess in side gear. Remove axle shaft from axle housing. 3. On locking differential assemblies (with thrust block and clutch packs), move pinion shaft part way out. Rotate differential case to lock pinion shaft against carrier housing. See Fig. 1 .

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

Fig. 1: Removing Axle From Locking Differential Assembly Courtesy of GENERAL MOTORS CORP. 4. Using screwdriver, rotate "C" lock until its open end faces thrust block and "C" lock is aligned with thrust block sides. See Fig. 2 . Push axle shaft inward. Remove "C" lock from thrust block and axle shaft groove. Remove axle shaft from axle housing. See Fig. 2 . CAUTION: DO NOT hammer on axle shaft flange.

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

Fig. 2: Removing "C" Lock From Locking Differential Courtesy of GENERAL MOTORS CORP. 5. On all assemblies, insert Axle Bearing & Seal Remover into axle housing behind bearing. Attach Slide Hammer (J-2619) and Adapter (J-2619-10) to bearing remover. Remove axle bearing and axle seal. See Fig. 3 .

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

Fig. 3: Removing Axle Bearing & Seal Courtesy of GENERAL MOTORS CORP. Installation

1. Lubricate axle shaft cavity using gear oil. Using Bearing Installer (J-8092), install axle shaft bearing into housing until bearing installer bottoms against housing shoulder. 2. Using Seal Installer (J-21128) for 8 1/2 and 8 5/8 or (J-29713) for 9 1/2, install axle shaft seal into housing until seal bottoms against housing shoulder. Install axle shaft and "C" lock. Ensure not to damage seal. On non-locking differential assemblies, install "C" lock on bottom of axle shaft. On locking differential assemblies, install "C" lock so that ends are flush with thrust block. See Fig. 2 . On all assemblies, pull axle shaft outward to seat "C" lock. 3. Coat pinion shaft lock bolt threads with Loctite 242. Install pinion shaft and pinion shaft lock bolt. Tighten lock bolt to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure. Reseal differential cover using gasket or RTV sealant. Tighten differential cover bolts in a crisscross pattern to specification. Fill differential with lubricant. PINION FLANGE & OIL SEAL NOTE:

If replacing pinion and ring gear, discard original pinion flange after removal. Replacement pinion, ring gear and pinion flange are balanced as an assembly.

Removal

1. Raise and support vehicle. Remove rear wheels and brake drums. Mark drive shaft, axle shafts, pinion Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

flanges and output shafts for reassembly. Unbolt drive shaft, and wire aside. Using tape, secure "U" joint bearing caps. Using an INCH-lb. torque wrench, rotate pinion several revolutions. Stop and start rotation several times. Note and record pinion bearing preload. 2. Match mark pinion-to-nut and nut-to-pinion flange for reassembly purposes. Count and record number of exposed threads on pinion. 3. Hold pinion flange with Pinion Flange Holder (J-8614-01). See Fig. 4 . Remove nut and washer. Install Pinion Flange Remover (J-8614-1, J-8614-2 or J-8614-3) through pinion flange holder. Pry pinion seal from housing.

Fig. 4: Removing Pinion Flange Courtesy of GENERAL MOTORS CORP. Installation

1. Thoroughly clean contact area. Inspect pinion flange oil seal surface and drive splines. Replace pinion flange if damaged. Lubricate inside diameter of seal. Place pinion seal in housing bore. 2. Using Seal Installer (J-23911 for 7 5/8", J-22836 for 8 1/2" and 8 5/8", or J-22388 for 9 1/2"), install pinion seal. Apply a coat of high-temperature lubricant to pinion seal lip. CAUTION: DO NOT hammer flange onto pinion shaft to install. Ring gear and pinion will be damaged. 3. Align pinion flange marks with marks on pinion. Install pinion flange. Install washer and NEW nut to pinion. Tighten nut snug, taking note of scribe marks and number of exposed threads. Measure pinion preload. Using pinion flange holder and remover, tighten nut in small increments. Rotate flange after each increment. Tighten pinion nut until original preload. Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

4. On all models, except "S" and "T" series trucks, if original preload was less than 3 INCH lbs. (.3 N.m), set preload to 3-5 INCH lbs. (.3-.6 N.m). On "S" and "T" series trucks, set preload to 3-5 INCH lbs. (.3-.6 N.m) greater than original recorded specification. On all models, if rotating torque has been exceeded, a new collapsible spacer will have to be installed. Install drive shaft. Add lubricant as needed. REAR HUB & CARRIER ASSEMBLY Removal & Installation

1. Raise vehicle. Allow rear hub and carrier assembly to hang free. Drain lubricant. Remove rear wheels and brake drums. Remove parking brake cable. Disconnect drive shaft and brake lines. Disconnect vent hose from assembly. Support assembly. Disconnect height sensor, ABS sensor and brake proportional valve linkage (if equipped). 2. Disconnect shock absorbers at assembly. Remove stabilizer shaft (if equipped). Remove "U" bolt nuts, washers, spacers and spring plates. Lower and remove assembly from vehicle. 3. To install assembly, reverse removal procedure. Bleed brake system. Adjust height sensing and brake proportional valve linkage (if equipped).

OVERHAUL DIFFERENTIAL ASSEMBLY Disassembly

NOTE:

Check and record ring gear backlash and pinion bearing preload before disassembly.

1. Remove axle shafts. See AXLE SHAFT & BEARING under REMOVAL & INSTALLATION. Roll out differential pinions and thrust washers. Mark pinions and thrust washers (left and right). Remove side gears and thrust washers. Mark side gears and thrust washers (left and right). CAUTION: Differential case side bearings are preloaded. Differential case will fall free after being pried past a certain point. 2. Mark differential case side bearing caps and housing. Loosen bearing cap bolts. Remove caps, mark shims, spacers, and side bearing races. Using pry bar, pry against housing at window of differential case and remove case. 3. Place any loose shims with appropriate left and right bearing races. Using Differential Side Bearing Puller/Remover (J-22888) and Adapter (J-8107-2 for 7 5/8", J-8107-4 for 8 1/2" and 8 5/8", or J-8107-3 for 9 1/2"), remove differential case side bearings. DO NOT pull on bearing cage, pull on bearing cone. 4. Ring gear bolts have left-hand threads. Remove ring gear bolts. Tap ring gear off carrier using a soft drift and hammer. Using an INCH-lb. torque wrench and proper socket, check torque required to rotate drive pinion. If no preload reading is obtained, check for looseness of pinion assembly, bearings or weak collapsible sleeve. Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

CAUTION: DO NOT damage pinion bearings when removing pinion from differential housing. 5. Remove pinion flange. See PINION FLANGE & OIL SEAL under REMOVAL & INSTALLATION. Install pinion nut back onto pinion. Install rear differential cover using 2 bolts to keep pinion from falling out. Tap end of pinion (using soft drift and hammer) to remove pinion from front bearing. 6. Remove differential cover and pinion assembly. Remove pinion oil seal and front bearing from housing. Remove collapsible spacer from pinion. Remove inner bearing from pinion using a press and Bearing Remover Clamp (J-25320 for 7 5/8", J-8612-B for 8 1/2" and 8 5/8", or J-22912-01 for 9 1/2"). Press bearing from pinion, and remove shim. 7. Remove pinion bearing races from axle housing using hammer and punch. Inspect bearings and bearing races. Replace as required. Discard and replace pinion oil seal, pinion nut and collapsible spacer. Cleaning & Inspection

Clean all parts. Inspect all small gears, thrust washers, bearings and races for chipping, cracks or wear. Inspect axle shaft splines, ring gear and pinion teeth. Inspect pinion shaft for cracks or excessive wear. Inspect pinion flange oil seal surface, drive splines, flange ears and bearing contact surface. Replace components as required. Reassembly

1. If installing new ring gear and pinion, and/or pinion bearings, see DRIVE PINION DEPTH and SIDE BEARING PRELOAD under ADJUSTMENTS. After installing original pinion shims onto pinion, install inner pinion bearing onto pinion using Bearing Installer (J-5590). Drive bearing onto pinion until bearing is tightly seated against pinion shims. 2. Install a NEW collapsible spacer onto pinion. Lubricate pinion bearings. Install pinion into axle housing. Install outer bearing onto pinion using Bearing Installer (J-5590). Hold pinion in position from inside housing while driving bearing onto pinion. To install pinion oil seal and pinion flange, see PINION FLANGE & OIL SEAL under REMOVAL & INSTALLATION. 3. Install ring gear squarely onto differential case. Tighten ring gear bolts evenly and alternately to specification. Ring gear bolts are left-hand thread. See TORQUE SPECIFICATIONS table. 4. Lubricate pinion gears and side gears with gear oil. Install left and right gears and thrust washers into case as marked in disassembly. Install one pinion gear onto side gears and rotate gears until pinion gear is exactly opposite. Place second pinion gear onto side gears so that pinion gear holes are exactly opposite each other. 5. Verify pinion shaft fits through both pinion gears for alignment purposes. Install pinion gear thrust washers. Hold pinion gears in position and carefully remove pinion shaft. Rotate side gears to position pinion gears in alignment with differential case holes. Install pinion shaft and pinion shaft lock bolt. Temporarily snug tighten lock bolt. 6. If side bearings were removed, install side bearings to differential case using Press or Bearing Installer (J25299). Using Bearing Installer (J-25299), first install Adapter (J-8107-2) to opposite bearing end of differential case to protect case surface. Drive bearing onto case using hammer, Bearing Installer (J25299) and Adapter (J-8092). Repeat for opposite side. 7. Lubricate side bearings and install races. Install differential case into carrier housing. Install spacer between each bearing race and housing with chamfered edge of spacer against housing. Install right Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

bearing cap and loosely tighten bolts so that differential case is free to move but will not fall out of housing. To complete installation, see SIDE BEARING PRELOAD under ADJUSTMENTS.

ADJUSTMENTS DRIVE PINION DEPTH 1. Drive pinion rear bearing shim thickness must be determined whenever a new axle housing, ring gear and pinion, or pinion bearings is installed. Shim pack thickness is determined by using Pinion Setting Gauge Set (J-21777). See Fig. 5 . 2. Install pinion bearing races into housing (if previously removed). Install lubricated rear pinion bearing through rear of housing. Position Gauging Plate (J-23597-11 for 7 5/8", J-21777-29 for 8 1/2" and 8 5/8", or J-21777-85 for 9 1/2") to rear pinion bearing. Install stud bolt and washer through gauging plate and rear pinion bearing, pointing stud bolt toward front pinion bearing position. See Fig. 5 .

Fig. 5: Cross-Sectional View Of Pinion Setting Gauge Set Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

3. Install lubricated front pinion bearing into race. Install Bearing Disc (J-21777-42) to outside of front pinion bearing. Install and tighten stud bolt hex nut until snug. Rotate gauge plate and bearings to ensure proper seating, while snugging hex nut. Hold stud bolt head stationary with a wrench. Using INCH-lb. torque wrench, tighten hex nut in small increments until 20 INCH lbs. (2.2 N.m) of torque is required to rotate gauge plate and bearings. See Fig. 5 . 4. Mount side bearing Gauging Discs (J-21777-45 for 7 5/8", 8 1/2" and 8 5/8", or J-21777-86 for 9 1/2") on ends of arbor. Place arbor into carrier side bearing recesses making sure gauging discs are properly seated. Install side bearing caps and bolts. Snug tighten bolts to avoid arbor movement. 5. Position dial indicator on mounting post of arbor with contact button resting on top surface of plunger. Set dial indicator to zero. Push indicator down on indicator shaft until needle rotates 3/4 of a revolution to right, and then tighten in this position. 6. Place plunger onto gauging area of pinion gauge plate. Rock plunger rod slowly back and forth across gauging area until dial indicator reads greatest deflection. 7. At point of greatest deflection, set indicator to zero. Repeat rocking action several times to verify setting. Once zero reading is obtained, rotate gauge shaft to remove plunger from gauging area. 8. Dial indicator will now read required pinion shim thickness for nominal pinion setting. Record this reading. Check drive pinion for painted or stamped markings on pinion stems, or for a stamped code number on small end of pinion gear. NOTE:

If no markings are found on pinion, use dial indicator reading as shim thickness.

9. If marking is a plus (+), add that many thousandths of an inch to recorded indicator reading. If marking is a minus (-), subtract that many thousandths of an inch from indicator reading. This measurement will then be required thickness of rear pinion bearing shim pack. 10. Remove bearing caps and all gauging tools from housing. Place selected shim pack on pinion gear. Using a press, install lubricated pinion bearing onto pinion shaft. 11. Install a NEW collapsible spacer over pinion gear shaft. Install pinion assembly into position from rear of housing. While holding pinion in position, carefully drive front pinion bearing onto pinion gear shaft until a few threads are exposed. 12. Install pinion seal, pinion flange, washer and nut. Ensure pinion flange alignment mark is properly aligned with pinion shaft end mark. Using Companion Flange Holder/Remover (J-8614-01), tighten pinion self-locking nut until all end play is removed. Rotate pinion several times to seat bearings. Check preload using an INCH-lb. torque wrench. 13. Continue tightening nut and checking preload until specified preload is obtained. See AXLE ASSEMBLY SPECIFICATIONS table. DO NOT back off nut to lessen preload. 14. If preload is exceeded, install a NEW collapsible spacer and retighten self-locking nut until proper preload is obtained. SIDE BEARING PRELOAD NOTE:

Adjust drive pinion depth prior to performing side bearing preload adjustment.

7 5/8", 8 1/2" & 8 5/8" Ring Gears Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

1. Side bearing preload and backlash adjustment are adjusted by varying thickness of both left and right side bearing shims. Side bearings must be previously installed to differential case. Lubricate side bearings and install races. 2. Place differential case assembly into position in housing. Position ring gear tightly against pinion so backlash is .000-.001" (0-.025 mm). Hold assembly in place by hand temporarily. Install Bearing Strap (J22799-6) to left side bearing race. 3. Install Side Bearing Backlash Gauge (J-22779) between left side bearing race and carrier housing. See Fig. 6 . While moving gauge up and down, tighten gauge adjusting nut until a slight drag is felt. Tighten lock bolt on side of gauge, and leave gauge in position.

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

Fig. 6: Installing Side Bearing Backlash Gauge (J-22779) Courtesy of GENERAL MOTORS CORP. 4. Install service adjustment spacer and shim between right bearing race and carrier housing. Determine Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

bearing preload by inserting feeler gauges between carrier and shim. The point just before feeler gauge drag begins is the correct feeler gauge thickness. This is the zero setting without preload. 5. Remove gauge from left side. Using a micrometer, measure gauge in 3 places and average readings. Record measurements. 6. Add together measurements of right side shim, spacer and feeler gauge. Subtract .010" (.25 mm) from ring gear (left) side measurement and add .010" (.25 mm) to opposite (right) side measurement. This allows for initial backlash adjustment. 7. To obtain correct preload, add .004" (.10 mm) to both measurements. Total measurement is correct shim pack thickness for each side. See following example: Ring Gear Side (Left) Shim Pack .250" (Gauging Tool Measurement) -.010" (Backlash Adjustment) +.004" (Bearing Preload) =.244" (Ring Gear Side Shim Pack) Opposite Ring Gear Side (Right) Shim Pack .265" (Combined Measurement Total) +.010" (Backlash Adjustment) +.004" (Bearing Preload) =.279" (Opposite Ring Gear Side Shim Pack) NOTE:

If shim is not chamfered enough and scrapes spacer when it is installed, file or grind chamfer before installation.

8. Install ring gear side shim first, and wedge opposite side shim between bearing cup and spacer. Install shim so chamfered side is against spacer. If necessary, partially remove differential case to install right side shim. If necessary, carefully tap shim into place with a soft-face hammer. Tighten bearing cap bolts to specification. See TORQUE SPECIFICATIONS table. Check backlash. See BACKLASH & FINAL ASSEMBLY . 9 1/2" Ring Gear

1. Differential side bearing preload is adjusted by adjusting nut in right differential bearing bore and by adjusting shims in left bearing bore. Bore and bearing cap provide mating threads for preload adjusting nut. 2. Install bearing races to differential bearings. Install differential case into axle housing assembly and temporarily hold in position by hand. Install bearing shims so chamfered side is against spacer. 3. Push differential case away from pinion and install adjusting nut. Tighten right side preload adjusting nut using Spanner Wrench (J-24429). Turn pinion to seat differential case bearings. 4. Back off adjusting nut slightly. Install bearing caps and snug tighten bolts. Turn adjusting nut until nut contacts shim. Note nut position and tighten nut 3 additional slots. Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

5. Tighten bearing cap bolts to specification. Install adjusting nut lock bolt and tighten to specification. See TORQUE SPECIFICATIONS table. Check backlash adjustment. See BACKLASH & FINAL ASSEMBLY . BACKLASH & FINAL ASSEMBLY 1. Rotate pinion and differential case several times to seat bearings. Using a dial indicator mounted to axle housing, check ring gear backlash at 4 different teeth locations around ring gear. Install indicator in line with gear rotation and perpendicular to tooth angle. 2. Ensure pinion flange is locked in position or held rigid while taking each backlash reading. Four backlash readings should not vary more than .002" (.05 mm). NOTE:

DO NOT change total shim pack thickness for each side bearing. If a shim is removed from one side, add same thickness shim to other side.

3. Total backlash reading should be .005-.009" (.13-.23 mm). If backlash is incorrect, adjust side bearing shims as necessary. After backlash adjustment is completed, perform gear tooth contact pattern check. See GEAR TOOTH CONTACT PATTERNS article in GENERAL INFORMATION. 4. If pattern is incorrect, adjust pinion or ring gear as required. Install axle shafts, "C" locks, pinion shaft and lock bolt. Install rear housing cover and add gear oil. See Fig. 7 .

AXLE ASSEMBLY SPECIFICATIONS AXLE ASSEMBLY SPECIFICATIONS Application Ring Gear Backlash Side Bearing Preload 7 5/8", 8 1/2" & 8 5/8" 9 1/2"

In. (mm) .005-.009 (.13-.23) .008 (.20) Zero plus 3 Slots INCH Lbs. (N.m)

Pinion Bearing Preload (1) 7 5/8" Ring Gear New Bearings 24-32 (2.7-3.6) Used Bearings 8-12 (1.0-1.4) 8 1/2", 8 5/8" & 9 1/2" Ring Gear New Bearings 20-25 (2.3-2.8) Used Bearings 10-15 (1.1-1.7) (1) Preload measurement is torque needed to turn pinion in housing without differential case and ring gear installed.

TORQUE SPECIFICATIONS Microsoft Saturday, August 29, 2009 11:27:32 AM

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

TORQUE SPECIFICATIONS Application Differential Bearing Adjusting Nut Lock Bolt Differential Cover Bolts Drive Shaft-To-Pinion Flange Bolts Except C3500 Heavy Duty & "S" & "T" Series C3500 Heavy Duty "S" & "T" Series 2.2L 4.3L Pinion Shaft Lock Bolt

Ft. Lbs. (N.m) 25 (34) 20 (27) 15 (20) 27 (36) 15 (20) 33 (45) 27 (36)

Ring Gear-To-Differential Case Bolt (1) 7 5/8" Ring Gear 8 1/2" & 8 5/8" Ring Gear 9 1/2" Ring Gear Side Bearing Cap Bolt 8 1/2" & 8 5/8" Ring Gear 9 1/2" Ring Gear Side Bearing Preload Adjusting Nut Lock Bolt 9 1/2" Ring Gear Spring "U" Bolts ("S" & "T" Series) Inner Nuts Outer Nuts (1) Left-hand thread. Use NEW bolts.

90 (120) 90 (120) 105 (145) 60 (81) 60 (81) 22 (30) 41 (56) 48 (65)

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1997 Chevrolet S10 Pickup 1998-99 DRIVE AXLES 7 5/8", 8 1/2", 8 5/8" & 9 1/2" Ring Gears

Fig. 7: Axle Assembly (8 1/2" & 8 5/8" Shown; Others Similar) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

ENGINE COOLING Drive Belt Routing - Trucks

BELT ADJUSTMENT BELT ADJUSTMENT Application

(1) Lbs. (kg) (1)

All Models

(1) Serpentine belt tension is maintained automatically by a spring-tensioned idler pulley. No adjustment

is necessary.

SERPENTINE DRIVE BELT ROUTING NOTE:

For serpentine belt routing, see underhood label or Figs. Fig. 1 - Fig. 13 .

NOTE:

Diagram for 3.4L not available from manufacturer.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 1: Drive Belt Routing - 2.2L (With A/C & P/S) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 2: Drive Belt Routing - 2.2L (With A/C & Manual Steering) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 3: Drive Belt Routing - 2.2L (Without A/C, With P/S) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 4: Drive Belt Routing - 2.2L (Without A/C, With Manual Steering) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 5: Drive Belt Routing - 4.3L ("S" & "T" Series) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 6: Drive Belt Routing - 4.3L (Except "S" & "T" Series), 5.0L & 5.7L (With A/C) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 7: Drive Belt Routing - 4.3L (Except "S" & "T" Series), 5.0L & 5.7L (Without A/C) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 8: Drive Belt Routing - 6.5L Diesel (With Second Generator) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 9: Drive Belt Routing - 6.5L Diesel (Without Second Generator) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 10: Drive Belt Routing - 7.4L (With A/C & Secondary Air Injection) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 11: Drive Belt Routing - 7.4L (Without A/C, With Secondary Air Injection) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 12: Drive Belt Routing - 7.4L (With A/C, Without Secondary Air Injection) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Drive Belt Routing - Trucks

Fig. 13: Drive Belt Routing - 7.4L (Without A/C, Without Secondary Air Injection) Courtesy of GENERAL MOTORS CORP.

SPECIFICATIONS CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in the GENERAL INFORMATION before disconnecting battery.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Model 2WD Pickup, Sierra, Suburban, Tahoe & Yukon

"K" "L" "M" "P" "S" "T" "T" (1) Fifth character of VIN.

4WD Pickup, Sierra, Suburban, Tahoe & Yukon AWD Astro & Safari 2WD Astro & Safari Commercial Van & Motorhome 2WD Blazer, Jimmy, Pickup & Sonoma 4WD Blazer, Jimmy, Pickup & Sonoma AWD Bravada

(2) RWD Van

(2) Includes Express, G-Van and Savana.

DESCRIPTION CONSTANT VELOCITY JOINTS Constant Velocity (CV) joints are used on AWD "L" and "T" series and 4WD Tracker, "K" and "T" series vehicles. These joints are located at axle end of drive shaft. A cage contains 6 balls inside CV joint. See appropriate FRONT AXLE article. DRIVE SHAFTS Drive shafts may have one shaft, 2 shafts with a center bearing, or 3 shafts with slip joints. Three shafts are used on 4WD vehicles. Location of slip joints vary with model application. See Fig. 1 .

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Fig. 1: Identifying Commonly Used Drive Shaft Combinations UNIVERSAL JOINTS Universal joints compensate for the effects of vehicle loading and axle windup present during acceleration. When operated within designed angle variations, a universal joint will operate effectively. When the design angle is changed or exceeded, operational life of joint will decrease. On a driveline with a designed deep angle, a double cardan joint is used in place of a simple universal joint. A double cardan joint is composed of 2 universal joints, coupled by a yoke and phased for constant velocity. A ball socket between the 2 universal joints serves as a centering device. See Fig. 2 . This causes each of the 2 units to operate through half of the complete angle between drive shaft and differential carrier. Needle roller bearings are used in universal joints. Needles are held in place on the trunnions by round bearing cups. Bearing cups are held in the yokes either by snap rings or injected plastic retainers.

INSPECTION DRIVELINE If abnormal vibration or driveline noise is present, check these sources of possible vibration before overhauling Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

driveline: Drive Shaft

Check drive shaft for damage or dents. Check for undercoating adhering to shaft. If present, clean shaft thoroughly. Universal Joints

Check for foreign material stuck in joints. Check for loose bolts, worn bearings and rust showing lack of grease.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Fig. 2: Identifying Simple Universal Joint & Double Cardan Joint Courtesy of GENERAL MOTORS CORP. Center Bearing

Tighten drive shaft center bearing mounting bolts. If bearing insulator is deteriorated or oil-soaked, replace it. Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Engine & Transmission Mounts

Tighten mounting bolts. Replace deteriorated mounts. Tires & Wheels

Check tire inflation and wheel balance. Check for foreign objects in tread, damaged tread, mismatched tread patterns or incorrect tire size.

ADJUSTMENTS DRIVE SHAFT PHASING 1-Piece Shafts

Ensure flange on each end of drive shaft is in same plane. Check for arrows on slip joint and drive shaft to aid in alignment. If flanges are not in same plane, remove slip joint flange and realign. See Fig. 3 .

Fig. 3: Phase Alignment Of 1-Piece Drive Shaft 2-Piece Or 3-Piece Shafts

1. Rotate transmission until yoke ears are on a horizontal plane. If drive shaft is correctly installed, center line of yoke ears at each end of individual shafts will be parallel. If flanges are not in same plane, remove drive shaft. Install drive shaft with yokes aligned to a horizontal plane. See Fig. 4 . 2. On models with 2-piece shafts, rotate transmission yoke until trunnion is in horizontal plane. Install front drive shaft with "U" joint trunnion in vertical plane. Connect bearing support to crossmember. 3. Ensure that front face of bearing support is perpendicular (90 degrees) to centerline of drive shaft. Install rear drive shaft with "U" joint trunnion of slip joint in vertical plane. Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

4. Set differential pinion yoke trunnion in vertical plane. Connect rear drive shaft to pinion yoke. If 2-piece shaft is correctly installed, centerline of trunnions at each end of individual shafts will be parallel. See Fig. 4 .

Fig. 4: Phase Alignment Of 2-Piece Drive Shaft (3-Piece Shaft Is Similar) DRIVE SHAFT BALANCING Adjustment

NOTE:

DO NOT run engine without ram airflow across radiator for prolonged periods, as overheating of engine or transmission may occur.

1. Drive shaft imbalance may often be cured by disconnecting shaft and rotating it 180 degrees in relation to other components. Test by raising rear wheels off ground, and turning shaft with engine. 2. On most models, balance testing may be done by marking shaft in 4 positions, 90 degrees apart. Place marks about 6" (152 mm) forward of weld, at rear end of shaft. Number marks 1, 2, 3 and 4. 3. Place screw-type hose clamp so clamp head is in No. 1 position, and rotate shaft with engine. If there is little or no change, move clamp head to No. 2 position, and repeat test. 4. Continue procedure until vibration is at lowest level. If no difference is noted with clamp head moved to all 4 positions, vibrations may not be drive shaft imbalance. 5. If vibration is lessened but not completely gone, place 2 clamps at that point, and run test again. Combined weight of clamps in one position may increase vibration. If so, rotate clamps 1/2" apart, above and below best position, and repeat test. 6. Continue to rotate clamps as necessary, until vibration is at lowest point. If vibration level is still Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

unacceptable, leave rear clamp(s) in position and repeat procedure at front end of drive shaft. If vibration can be eliminated or reduced to acceptable levels using this test procedure, send drive shaft to balance shop for permanent balancing. FLANGE ALIGNMENT & RUNOUT Adjustment

1. All flanges must be perpendicular in both vertical and horizontal planes to engine crankshaft. Only exception is : "broken back" type driveline, which has flanges that are not perpendicular in vertical plane. See Fig. 5 .

Fig. 5: "Broken Back" Type Drive Shaft Alignment (Typical) 2. With non-parallel or "broken back" type installation, working angles of universal joints of a given drive shaft should be equal. Angle "A" = angle "B". 3. This is calculated as follows: angle of output shaft centerline is subtracted from angle of drive shaft. Difference should equal angle of drive shaft subtracted from pinion shaft angle. 4. Parallel type joints maintain constant velocity between output shaft and pinion shaft. Vibration is minimized and component life maximized when universal joints are parallel. 5. Using dial indicator, measure runout of transmission flange, center bearing flange and pinion flange. If runout exceeds .003-.005" (.08-.13 mm), replace flange. 6. If dial indicator cannot be used, push rod with snug fit through flange bearing bore. See if it aligns with opposite flange bore. If not, replace flange. See Fig. 6 .

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Fig. 6: Vertical Alignment Of Drive Shaft 7. Rotate transmission flange until it is vertical, measuring from side. Check center bearing and pinion flanges. They cannot be more than one degree off vertical. See DRIVE SHAFT PHASING . 8. Rotate transmission flange until it is vertical, measured from side. Measure angle from end and record it. Check all other flanges for same angle. They must be within 1/2 degree of each other. Adjust as required. 9. If difficulty is encountered when making these adjustments, horizontal alignment should be checked. Even though vertical alignment is correct, horizontal alignment can be badly out of adjustment. This is often found after major component replacement or repair of serious accident damage. See Fig. 7 .

Fig. 7: Horizontal Alignment Of Drive Shaft Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

10. To make horizontal alignment checks, set up straightedges. See Fig. 8 . Set transmission output flange horizontal and clamp straightedge to flange in a horizontal plane. Repeat procedure with drive pinion flange. Ensure that flanges are horizontal by checking angle of straightedge with spirit level.

Fig. 8: Checking Horizontal Alignment 11. Using straightedge that is 12" (305 mm) longer than width of rear wheel track at 90 degrees, clamp to frame side rails. Use large framing squares to align straightedge with side rails. 12. Measure distance "X" at each side. If both measurements are not within 1/16" (1.6 mm) of each other, transmission flange is horizontally misaligned. See Fig. 8 . 13. Measure distance "Y" (edge of straightedge to axle shaft centerline) at each side. If 2 dimensions are not within 1/8" (3.2 mm) of each other, axle housing is misaligned. 14. Measure distance "W" at each side. If both measurements are not within 1/16" (1.6 mm) of each other, pinion flange is horizontally misaligned. DRIVE SHAFT RUNOUT Raise vehicle so rear wheels can spin. Attach dial indicator to smooth place on vehicle underbody. A magnetic base dial gauge is recommended. DO NOT attach dial indicator base at a weld. With transmission in Neutral, Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

hand rotate axle pinion flange or transmission and take required dial indicator readings on drive shaft. See DRIVE SHAFT RUNOUT (IN.) table. 1-Piece Drive Shafts

If runout exceeds specifications, rotate drive shaft 180 degrees at pinion flange and install. Check runout again. 2-Piece Drive Shafts

Measure rear drive shaft runout. Reference mark position of rear drive shaft yoke to pinion flange. Remove rear drive shaft and measure front drive shaft runout, both on tube and at tapered hole on splined end. If runout exceeds specifications, rotate rear drive shaft 180 degrees at pinion flange and install. Check runout again. 3-Piece Drive Shafts

Check each shaft at its center and at both ends, approximately 3" (76 mm) from weld. If problem is found, disconnect each shaft, one at a time, and measure remaining shafts until problem shaft is found. Rotate shaft connected to problem shaft 180 degrees and install. Check runout again. If necessary, repeat procedure in an attempt to bring runout to specifications. If runout is still not within specifications, replace appropriate drive shaft. If runout still exceeds specifications, check for bent pinion. DRIVE SHAFT RUNOUT (IN.) Application 1-Piece Astro & Safari "C" & "K" Series Exc. Aluminum Graphite Aluminum Graphite "G" & "P" Series "S" & "T" Series 2-Piece "C" & "K" Series Front With Slip Yoke

Front Check

Center Check

.024

.040 .040 .040 .024

.050 ..... .050 .024

.055 .040 .055 .024

.025

.....

.040

.....

(1) .004 (1) .007

Rear

(2) .030

.040

"G" Series "P" Series Front

.030

.035

.020

.....

(3) .008

Rear

(2) (4) .030

.030

.035

.025

.040

With Fixed Yoke

3-Piece "C" & "K" Series Pickup

Rear Check

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Suburban .015 .010 "P" Series .015 .010 (1) Measured on ground surface near spine, with drive shaft removed.

.015 .015

(2) Measured with rear shaft connected to front shaft. Runout of front drive shaft must be within

specification. (3) Measured at tapered hole in end of splined shaft, with rear drive shaft removed. (4) Measured with front drive shaft disconnected. Runout of front drive shaft must be within

specification. UNIVERSAL JOINT MAINTENANCE Lubrication

1. Whenever drive shaft is removed or slip yoke sticks in extension housing seal, clean yoke with solvent. Lubricate inside diameter of seal with synthetic oil seal lubricant and outside diameter of seal with transmission fluid. 2. Ball socket on double cardan joint requires periodic lubrication through provided fitting. Special Lubricant (1050679) is recommended by manufacturer. If lubrication fitting cannot be seen from beneath vehicle, double cardan joint may be lubricated from above using Adapter (J-25512-2) attached to end of a flex hose. See Fig. 9 .

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Fig. 9: Lubricating Ball Socket Of Double Cardan Joint Courtesy of GENERAL MOTORS CORP.

OVERHAUL NOTE:

DO NOT disassemble universal joints unless external leakage or damage has occurred.

Before disassembly, scribe alignment marks on yoke and shaft for reassembly. If joints are rusted or corroded, apply penetrating oil before pressing out bearing cups or trunnion pin. CROSS SHAFT & ROLLER TYPE UNIVERSAL JOINTS Snap rings or injected plastic retainers may be used to retain bearing cups. Joints with snap rings may be disassembled and reassembled using same cross shaft and bearings. Joints with nylon retainers are disassembled by breaking nylon retainers; install NEW nylon retainers after service, or replace joints with joints that use snap rings. Removal & Disassembly

1. Disconnect yoke or flange attaching bolts and remove drive shaft from vehicle. DO NOT use a pry bar to Microsoft Saturday, August 29, 2009 11:28:43 AM

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

hold drive shaft while loosening bolts, or damage to bearing seals may result. Scribe marks on yoke and shaft for reassembly reference. 2. Remove retaining strap (if equipped). Remove bushing retainers/snap rings from yoke. Press out bearing cups. Remove last bearing cup by pressing on end of cross shaft. 3. Remove cross shaft assembly from yoke. DO NOT remove seal retainers from cross shaft. Cross shaft and retainers are serviced as an assembly. Reassembly & Installation

1. Coat roller bearings with lubricant. Fill bearing cups with grease. Place cross assembly in drive shaft yoke. Place bearing cups in position. 2. Press both bearing cups into yoke until retainers/snap rings can be installed. Ensure cross stays aligned in center of bearing cups while pressing into place. Install retainers/snap rings. Repeat procedure for remaining bearing caps. Install strap (if equipped). Install drive shaft in vehicle. Ensure scribed marks on yoke and shaft are aligned. DOUBLE CARDAN TYPE UNIVERSAL JOINTS Removal & Disassembly

1. Disconnect yoke and flange attaching bolts. Remove drive shaft from vehicle. Index mark joint, yoke flange and cross shafts for reassembly. See Fig. 10 . 2. Pry out all snap rings and press bearing out far enough to allow bearing cup end to be clamped in vise. Tap on yoke until free of bearing cup. 3. Repeat procedure for remaining bearings. Remove remaining parts from center yoke assembly.

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1997 Chevrolet S10 Pickup 1996-97 DRIVE AXLES Drive Shafts & Universal Joints - Trucks

Fig. 10: Exploded View Of Double Cardan Type Universal Joint Courtesy of GENERAL MOTORS CORP. Reassembly

1. Pack all bearings with Lubricant (1050679). Assemble center yoke components in reverse order of disassembly. 2. Using arbor press or vise, press 2 opposing bearing cups into position at same time until all bearing cups are installed. Ensure cross shafts and yokes remain aligned during this process. 3. Check for free movement of joint. If bind exists, seat bearings by sharply rapping yokes with brass hammer. DO NOT hammer directly on bearings. Installation

1. Before installing drive shaft, clean yoke and inspect machined surface for scratches, nicks or burrs. 2. Provide support for drive shaft during installation to prevent damage to universal joints. Position front end of shaft and align marks made during removal. 3. Install and attach 2 clamps to pinion yoke. Install 4 screws and lock washer assemblies on CV joint at transfer case. Use press bar to prevent assembly from rotating while attaching screw assemblies.

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

BUZZERS, RELAYS & TIMERS BUZZERS, RELAYS & TIMERS Component A/C Compressor Relay (2.2L VIN 4) A/C Compressor Relay (4.3L VIN W, X) Blower Motor Relay Daytime Running Lamps (DRL) Relay Door Lock Relay Fog Lamp Relay Fuel Pump Relay (2.2L VIN 4) Fuel Pump Relay (4.3L VIN W, X) Hazard Flasher Horn Relay Map/Dome Lamp Relay Starter Relay Turn Signal Lamp Flasher

Component Location On center rear of engine compartment. See Fig. 1. On center rear of engine compartment. See Fig. 2. On center rear of engine compartment. Behind glove box, on relay center. Behind right side of dash, above blower plenum. Behind glove box, on relay center. Behind glove box, on relay center. See Fig. 1. Behind glove box, on relay center. See Fig. 2. In power distribution center. Behind glove box, on relay center. Behind dash, right of steering column. Center rear of engine compartment. In power distribution center.

CIRCUIT PROTECTION DEVICES CIRCUIT PROTECTION DEVICES Component Battery Junction Block Diode, A/C Compressor Clutch Dash Fuse Block (2.2L VIN 4) Dash Fuse Block (4.3L VIN W, X) Power Distribution Center Relay Center

Component Location On left rear of engine compartment. At A/C compressor. On left side of dash. See Fig. 1. On left side of dash. See Fig. 2. In I/P below and in front of radio. Behind glove box.

CONTROL UNITS CONTROL UNITS Component Alarm Module Chime Module Cruise Control Module Daytime Running Lamps (DRL) Module

Component Location In power distribution center. In power distribution center. On left side of firewall. Between HVAC module & glove box.

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

Inflatable Restraint Diagnostic Energy Reserve Module Electronic Ignition Control Module (2.2L VIN 4) Electronic Ignition Control Module (Electronic Spark Control) (4.3L VIN W, X) Fuel Level Buffer Module Heater & A/C Controller Interior Lamp Control Module Powertrain Control Module (PCM) (2.2L VIN 4) Remote Keyless Entry Module Sun Roof Express Module Transfer Case Control Module Vehicle Control Module (VCM) (4.3L VIN W, X) Windshield Wiper Pulse Control Module

Behind right kick panel. On right side of engine, near camshaft position sensor. See Fig. 1. On top right side of engine. See Fig. 2. Under glove box. Under center of dash. Behind left side of dash. On right front of engine compartment. See Fig. 1. Behind lower left side of dash, near park brake. Part of sun roof assembly. Behind center of dash. On right front of engine compartment. See Fig. 2. On center of firewall.

MOTORS MOTORS Component Blower Motor Power Door Lock Motors (4) Power Seat Motors (3) Power Window Motors (4) Liftgate Lock Actuator Mode Door Vacuum Actuator (Lower) Mode Door Vacuum Actuator (Upper) Washer Pump Motor (Front) Washer Pump Motor (Rear) Wiper Motor (Front) Wiper Motor (Rear)

Component Location On right rear of engine compartment. In bottom rear of each door. Under each front seat. In each door. In endgate, below glass. On left side of air distributor module. On right side of air distributor module. In washer fluid reservoir, on left front of engine compartment. In washer fluid reservoir, on left front of engine compartment. Part of windshield wiper pulse control module. On top center of rear endgate.

SENDING UNITS & SENSORS SENDING UNITS & SENSORS Component A/C Refrigerant Pressure Sensor (2.2L VIN 4) ABS Wheel Speed Sensors (2) Arming Sensor (2WD) Arming Sensor (4WD)

Component Location On right rear of engine compartment. See Fig. 1. Inside of respective front wheel. Inside left frame rail. On second crossmember, near left frame rail.

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

Ambient Air Temperature Sensor Camshaft Position Sensor (2.2L VIN 4) Camshaft Position Sensor (4.3L VIN W, X) Crankshaft Position Sensor (2.2L VIN 4) Crankshaft Position Sensor (4.3L VIN W, X) Discriminating Sensors (2)

In front center of vehicle, near hood latch. In right side of engine, near spark plug wires. See Fig. 1. In distributor. See Fig. 2. Lower right front of engine. See Fig. 1. On front of engine, near crankshaft pulley. On frame rail on respective sides of engine compartment. On lower left side of engine.

Engine Coolant Temperature Gauge Sensor (4.3L VIN W, X) Engine Coolant Temperature (ECT) Sensor Near thermostat housing, on front of engine. See (w/Engine Coolant Temperature Gauge Sensor) Fig. 1. (2.2L VIN 4) Engine Coolant Temperature (ECT) Sensor (4.3L In lower left side of engine. See Fig. 2. VIN W, X) Fuel Level Sensor (w/Fuel Pump) On top of fuel tank. Fuel Pump Switch & Engine Oil Pressure Gauge On right side of engine. See Fig. 1. Sensor (2.2L VIN 4) Fuel Pump Switch & Engine Oil Pressure Gauge On top rear of engine, near distributor. See Fig. 2. Sensor (4.3L VIN W, X) Fuel Pump Sender In top of fuel tank. Fuel Tank Vapor Pressure Sensor (2.2L VIN 4) Top of fuel tank. See Fig. 1. Fuel Tank Vapor Pressure Sensor (4.3L VIN W, X) Top of fuel tank. See Fig. 2. Heated Oxygen Sensor (HO2S) (Left Front) (4.3L In left exhaust manifold. See Fig. 2. VIN W, X) Heated Oxygen Sensor (HO2S) (Post-Converter) In exhaust system, after catalytic converter. (2.2L VIN 4) Heated Oxygen Sensor (HO2S) (Pre-Converter) In exhaust system, before catalytic converter. See (4.3L VIN W, X) Fig. 2. Heated Oxygen Sensor (HO2S) (Post-Converter) In exhaust system, after catalytic converter. See Fig. (4.3L VIN W, X) 2. Heated Oxygen Sensor (HO2S) (Right Front) (4.3L In right exhaust manifold. See Fig. 2. VIN W, X) Intake Air Temperature (IAT) Sensor (2.2L VIN 4) In fresh air intake duct. See Fig. 1. Intake Air Temperature (IAT) Sensor (4.3L VIN W, In fresh air intake duct. See Fig. 2. X) Knock Sensor (KS) (2.2L VIN 4) On lower right side of engine. See Fig. 1. Knock Sensor (KS) (4.3L VIN W, X) On top center of engine. See Fig. 2. Manifold Absolute Pressure (MAP) Sensor (2.2L On top center of engine. See Fig. 1. VIN 4) Manifold Absolute Pressure (MAP) Sensor (4.3L On top center of engine. See Fig. 2. VIN W, X) Mass Air Flow (MAF) Sensor (4.3L VIN W, X) On air intake assembly. See Fig. 2. Microsoft Saturday, August 29, 2009 11:29:46 AM

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

Oxygen Sensor (O2S) (Pre-Converter) (2.2L VIN 4) Throttle Position (TP) Sensor (2.2L VIN 4) Throttle Position (TP) Sensor (4.3L VIN W, X) Vehicle Speed Sensor (VSS) (2.2L VIN 4) Vehicle Speed Sensor (VSS) (4.3L VIN W, X)

In exhaust manifold. See Fig. 1. On throttle body assembly. See Fig. 1. On throttle body assembly. See Fig. 2. On left rear of transmission or transfer case. See Fig. 1. On left rear of transmission or transfer case. See Fig. 2.

SOLENOIDS & SOLENOID VALVES SOLENOIDS & SOLENOID VALVES Component 1-2 Shift Solenoid Valve 2-3 Shift Solenoid Valve 3-2 Shift Solenoid Valve Air Inlet Valve Actuator Air Temperature Valve Electric Actuator Brake Pressure Modulator Valve (BPMV) Brake Transmission Shift Interlock Solenoid (Bravada) Brake Transmission Shift Interlock Solenoid (except Bravada) Evaporative Emissions (EVAP) Canister Purge Solenoid (2.2L VIN 4) Evaporative Emissions (EVAP) Canister Purge Solenoid (4.3L VIN W, X) Evaporative Emissions (EVAP) Canister Vent Solenoid (2.2L VIN 4) Idle Air Control (IAC) Valve (2.2L VIN 4) Idle Air Control (IAC) Valve (4.3L VIN W, X) Linear EGR Solenoid Valve (2.2L VIN 4) Linear EGR Solenoid Valve (4.3L VIN W, X) Pressure Control Solenoid Valve Torque Converter Clutch Pulse Width Modulation Solenoid Valve Window Release Solenoid (Rear)

Component Location Inside transmission. Inside transmission. Inside transmission. On blower plenum, near right kick panel. On top of blower plenum. In left rear of engine compartment. On center floor, near shift lever. On steering column, near shift lever. On lower right side of engine. See Fig. 1. On top right rear of engine. See Fig. 2. On crossmember, rear of fuel tank. Near throttle body assembly. See Fig. 1. On throttle body assembly. See Fig. 2. On top rear of engine. See Fig. 1. On top front of engine. See Fig. 2. Inside automatic transmission. Inside automatic transmission. In center of tailgate.

SWITCHES SWITCHES Component A/C Compressor Cycling Switch (4.3L VIN W, X)

Component Location On right rear of engine compartment, near

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

A/C High Pressure Cut-Off Switch (4.3L VIN W, X) Automatic Transmission Fluid Pressure Manual Valve Position Switch Back-Up Lamp Switch (2.2L VIN 4 A/T) Back-Up Lamp Switch (2.2L VIN 4 M/T) Back-Up Lamp Switch (4.3L VIN W, X) Brake Pressure Warning Switch Clutch Pedal Position & Cruise Control Shutoff Switch Front Axle Switch Park Brake Warning Switch Park/Neutral Position (PNP) Switch Safety Belt Retractor Switch TCC Brake & Cruise Control Release Switch Transmission Range (TR) Switch Wiper Cutout Switch (Rear)

accumulator. See Fig. 2. On rear of A/C compressor. See Fig. 2. Inside transmission. On left side of transmission. On right side of transmission. On left side of transmission. On left side of engine compartment, part of BPMV. On clutch pedal support bracket. On front axle, right of differential. On base of park brake assembly. On left side of transmission. Under driver's seat. On brake pedal support bracket. On left side of transmission. Inside endgate.

MISCELLANEOUS MISCELLANEOUS Component Auxiliary Power Outlet (2) Blower Motor Resistor Data Link Connector (DLC) (2.2L VIN 4) Data Link Connector (DLC) (4.3L VIN W, X) Distributor (4.3L VIN W, X) Diode Module Fuel Injectors (2.2L VIN 4) Fuel Injectors (4.3L VIN W, X) Fuel Pump Prime Connector (2.2L VIN 4) Fuel Pump Prime Connector (4.3L VIN W, X) Ignition Coil (4.3L VIN W, X) Resistor, A/C Request Voltage Drop Transfer Case Connector (Electric Shift 4WD)

Component Location On center of dash. On right rear of engine compartment, on blower module. Under left side of dash. See Fig. 1. Under left side of dash. See Fig. 2. Top rear of engine. See Fig. 2. Between HVAC module & glove box. On top of engine, at intake ports. See Fig. 1. On top of engine, at intake ports. See Fig. 2. On left rear side of engine compartment. On left rear side of engine compartment. See Fig. 2. On top right side of engine. See Fig. 2. In dash harness, near relay center. On left side of transfer case.

CONNECTORS CONNECTORS Microsoft Saturday, August 29, 2009 11:29:46 AM

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

Component C100 (Black, 8 Pin) C101 (Black, 7 Pin) C102 (Black, 15 Pin) C104 (Black, 6 Pin) C105 (Black, 4 Pin) C108 (Black, 7 Pin) C109 (Yellow, 4 Pin) C111 (2.2L VIN 4) (White, 5 Pin) C111 (4.3L VIN W) (Black, 12 Pin) C111 (4.3L VIN X) (Black, 12 Pin) C114 (Black, 2 Pin) C117 (Black, 4 Pin) C120 (Black, 15 Pin) C175 (Gray, 20 Pin) C203 (Black, 56 Pin) C207 (Black, 2 Pin) C209 (Black, 10 Pin) C211 (Black, 48 Pin) C218 (Black, 1 Pin) C219 (Black, 8 Pin) C220 (Black, 6 Pin) C300 (Black, 2 Pin)

Component Location Engine harness to oxygen sensor extension harness, rear of VCM, near blower motor. Engine harness to body harness, right of engine compartment, near VCM. Left rear of engine compartment, above brake booster. Chassis to engine harness, forward of lower evaporator housing. Engine harness to oxygen sensor extension harness, left frame rail, near VSS. Left rear of engine compartment, near battery junction box. Left rear of engine compartment, near battery junction box. Fuel injector harness connector, top center of engine. Fuel injector harness connector, top center of engine. Fuel injector harness connector, top center of engine. Left side of engine compartment, near cruise control module. Engine harness to oxygen sensor, right rear of automatic transmission. Right side of engine compartment, near powertrain control module. Engine harness to A/T connector, on right side of A/T. Body harness to dash harness, behind right side of dash. Dash harness to safety belt retractor switch, under driver's seat. Body harness to dome harness, at left front of dash, at left front window. Body harness to steering column harness, near steering column. Dash to crossbody harness, behind top center of dash. Dash to crossbody harness, behind top center of dash. Dash harness to foglight switch & relay harness, behind dash, left of steering column. Dome harness to sun roof overhead harness, near

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

C317 (Black, 2 Pin) C401 (Black, 4 Pin) C402 (Black, 4 Pin) C403 (Black, 4 pin) C410 (Black, 4 Pin) C415 (Black, 6 Pin) C425 (Black, 3 Pin) C426 (Black, 8 Pin) C427 (Black, 1 Pin) C428 (Black, 8 Pin) C429 (Black, 1 Pin) C430 (Black, 2 Pin) C432 (Black, 1 Pin) C433 (Gray, 1 Pin) C500 (Black, 13 Pin) C501 (Black, 16 Pin) C601 (Black, 16 Pin)

sun roof module. Body harness to left front seat belt switch & power seats, under left front seat. Chassis to taillight harness, near G402. Body harness to taillight harness, at left rear of vehicle. Body harness to taillight harness, to right rear of vehicle. Body harness to tailgate harness, center rear of body, at tailgate. Body harness to tailgate harness, center rear of body, at tailgate. Body harness to tailgate harness, center rear of body, at tailgate. Body harness to left liftgate harness. Body harness to left liftgate harness. Body harness to right liftgate harness. Body harness to right liftgate harness. Chassis harness to license light harness, inside rear crossmember, in front of license plate. Body harness to rear defogger grid. Body harness to rear defogger grid. Crossbody harness to left front door harness, in left front door. Crossbody harness to left front door harness, in left front door. Crossbody harness to right front door harness, in right front door.

GROUNDS GROUNDS Component G100 G101 (2.2L VIN 4) G101 (4.3L VIN W) G101 (4.3L VIN X) G102 (2.2L VIN 4) G102 (4.3L VIN W) G102 (4.3L VIN X)

Component Location Lower right front of engine block. Lower right radiator support. Left rear of engine compartment, left side of A/C compressor relay. Left rear of engine compartment, left side of A/C compressor relay. Left side of engine, below exhaust manifold. Rear of right cylinder head. Rear of right cylinder head.

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

G103 G104 G105 G106 G107 (2.2L VIN 4) G107 (4.3L VIN W) G107 (4.3L VIN X) G108 G109 G110 G111 G112 G113 G114 G115 G116 G118 G125 G126 G130 G132 G180 (2.2L VIN 4) G180 (4.3L VIN W) G180 (4.3L VIN X) G402 G410 (Pickup) G410 (Utility) G420 G452 (Pickup) G452 (Utility)

Rear of right cylinder head. Left rear portion of cylinder head. Left rear portion of cylinder head. Battery negative harness, right side frame rail, near wheel speed sensor connector. Battery negative harness, right front of engine. On front of engine, below water pump. On front of engine, below water pump. Battery negative harness, right side of radiator support. Left side of radiator support. Right side of radiator support. Right side of radiator support. Left side of radiator support. Left rear of engine compartment, left side of A/C compressor relay. Right rear of engine, below crankshaft position sensor. Left rear of engine, below crankshaft position sensor. Left side of engine, below exhaust manifold. Left side of engine, below exhaust manifold. Left side of radiator support. Right side of radiator support. Left side of radiator support. Left side of engine, below exhaust manifold. Lower left side of radiator support. Lower right side of radiator support. Lower right side of radiator support. Left rear of frame, on crossmember. Near trailer wiring provision. In left rear frame rail, on crossmember. Body harness, right "D" pillar. Near trailer wiring provision. Left "D" pillar, near taillights.

SPLICES SPLICES Component S100

Component Location Engine harness, 30 cm from VCM connector breakout.

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

S101 (2.2L VIN 4) S101 (4.3L VIN W) S101 (4.3L VIN X) S102 (2.2L VIN 4) S102 (4.3L VIN W) S102 (4.3L VIN X) S103 (2.2L VIN 4) S103 (4.3L VIN W) S103 (4.3L VIN X) S104 (2.2L VIN 4) S104 (4.3L VIN W) S104 (4.3L VIN X) S106 (2.2L VIN 4) S106 (4.3L VIN W) S106 (4.3L VIN X) S107 (2.2L VIN 4) S107 (4.3L VIN W) S107 (4.3L VIN X) S109 (2.2L VIN 4) S109 (4.3L VIN W) S109 (4.3L VIN X) S110 S111 S112 S118 S119 S121 S122

Engine harness, 12 cm from A/C refrigerant pressure sensor breakout. Engine harness, 6.5 cm from generator breakout. Engine harness, 6.5 cm from generator breakout. Engine harness, 19 cm from injector harness breakout. Engine harness, 8 cm left of generator breakout. Engine harness, 8 cm left of generator breakout. Engine harness, 20 cm from A/C compressor connector. Engine harness, 7.5 cm from A/C compressor breakout. Engine harness, 7.5 cm from A/C compressor breakout. Engine harness, 20 cm from A/C compressor connector. Engine harness, 7.5 cm from A/C compressor breakout. Engine harness, 7.5 cm from A/C compressor breakout. Engine harness, 8 cm from breakouts to connector C102 & oxygen sensor. Engine harness, 4 cm from breakout to generator. Engine harness, 4 cm from breakout to generator. Engine harness, 15 cm from dash harness breakout. Engine harness, 4 cm from C104 breakout toward generator breakout. Engine harness, 4 cm from C104 breakout toward generator breakout. Engine harness, 6 cm from breakout to starter. Engine harness, 7 cm right of C102. Engine harness, 7 cm right of C102. In body harness, 16 cm from power distribution block ring terminal. Engine harness, 15 cm from VSS connector. Engine harness, 38 cm to left of C105 breakout. Dash extension harness, 40 cm from breakout to blower motor resistor. Body harness, 18 cm from positive battery terminal. Forward light harness, 4 cm right of front windshield washer pump breakout. Forward light harness, 6 cm right of left headlight breakout.

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

S123 S124 S139 S140 (2.2L VIN 4) S140 (4.3L VIN W) S140 (4.3L VIN X) S204 S205 S208 S209 S216 S224 S240 S267 S269 S282 S303 S306 S317 S318 S319 S400 S404 S405 (Pickup) S405 (Utility) S417 S418 S419

Forward light harness, 6 cm left of left headlight breakout. Forward light harness, 13 cm right of left headlight breakout. Fog lamp harness, 4 cm from left fog lamp breakout. Engine harness, 17 cm from C175 breakout. Engine harness, 15 cm from C116 breakout. Engine harness, 15 cm from C116 breakout. Dash harness, 11 cm right of instrument cluster breakout. Dash harness, 18 cm right of instrument cluster breakout. Dash harness, 35 cm right of instrument cluster breakout. Dash harness, 39 cm right of instrument cluster breakout. Dash harness, 39 cm right of instrument cluster breakout. Dash harness, 7 cm to right relay center breakout. Front of dash harness, 4 cm into steering column breakout. Body harness, 67 cm from dash harness connectors. Dome light harness, 5 cm from inside rearview mirror breakout. Body harness, in pancake mold, in floorpan area. Body harness, 8 cm into left rear door breakout. Body harness, 26 cm rear of rear door breakout. Oxygen sensor jumper, 10 cm rear of C126 breakout. Oxygen sensor jumper, 16 cm forward of C127 breakout. Body harness, 6 cm forward of C406 breakout. Body harness, 6 cm from endgate harness breakout. Body harness, 10 cm left of dome light breakout. Chassis harness, 20 cm rear of EVAP vent valve breakout. Body harness, 10 cm left of dome light breakout. Rear light harness, 10 cm rear of pass-through on left side. Rear light harness, 10 cm rear of pass-through on right side. Rear light harness, 4 cm from breakout for left

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

back-up light. Rear light harness, 4 cm from breakout for right back-up light. Left front door harness, 13 cm from crossbody harness connector. Left front door harness, 17 cm from crossbody harness connector. Left front door harness, 11 cm from crossbody harness connector. Right front door harness, 17 cm from crossbody harness connector. Right front door harness, 13 cm from crossbody harness connector.

S420 S500 S501 S502 S601 S602

COMPONENT LOCATION GRAPHICS NOTE:

Figures may show multiple component locations. Refer to appropriate table for proper figure references.

Fig. 1: Engine Compartment (2.2L VIN 4)

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1997 Chevrolet S10 Pickup 1997 GENERAL MOTORS Blazer, Bravada, Jimmy, S10 Pickup & Sonoma

Fig. 2: Engine Compartment (4.3L VIN W & VIN X)

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

DESCRIPTION Independent front suspension consists of upper and lower control arms with steering knuckle mounted between ball joints. See Fig. 1 . Upper control arm is mounted on pivot shaft. Lower control arm is mounted directly to frame with pivot bolts. Coil springs are mounted between lower control arm and a formed seat in suspension crossmember. Shock absorbers fit between lower control arm and frame. A stabilizer bar is mounted to frame side rails and connected to lower control arms.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

Fig. 1: Exploded View Of Front Suspension (Typical) Courtesy of GENERAL MOTORS CORP.

ADJUSTMENTS & INSPECTION Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

WHEEL ALIGNMENT NOTE:

See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

FRONT WHEEL BEARINGS 1. Raise and support vehicle. Remove hub dust cap and cotter pin. Tighten spindle nut to 12 ft. lbs. (16 N.m) while turning wheel forward by hand. Back off nut until just loose. CAUTION: Never preload tapered roller bearings, or damage to bearings will result. Bearings are designed to have a slightly loose feel when properly adjusted. 2. Finger-tighten nut until snug. Loosen nut slightly until NEW cotter pin can be installed. DO NOT loosen nut more than 1/2 flat. Install cotter pin and measure hub end play. Hub end play (in and out movement) should be .001-.005" (.03-.13 mm). Install dust cap. RIDING HEIGHT NOTE:

See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

BALL JOINT CHECKING NOTE:

Ensure wheel bearings are properly adjusted before checking ball joints. Replace ball joint rubber grease seal if cut or damaged.

Upper Ball Joint

1. Raise and support vehicle with jackstand under lower control arm, near lower ball joint. Ensure upper control arm bumper does not contact frame. Place dial indicator against lower part of wheel rim. Push in on bottom of tire while pulling outward at top. Read dial indicator, then reverse push/pull procedure. 2. Lateral (horizontal) deflection should not exceed .125" (3.18 mm). If deflection is excessive, replace ball joint. With ball joint disconnected from steering knuckle, check to see if ball joint can be rotated by finger pressure. Replace if ball joint can be twisted. Lower Ball Joint

1. Wear indicator is built into ball joint. Wear is indicated by position of the 1/2" diameter round boss that grease fitting is threaded into. A new ball joint has a boss projection of .050" (1.27 mm) beyond cover surface. 2. With vehicle weight on wheels, ensure wear indicator protrudes beyond surface of ball joint cover. Replace ball joint if wear indicator is recessed or even with housing.

REMOVAL & INSTALLATION Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

WHEEL HUB/ROTOR & BEARINGS Removal

1. Raise and support vehicle. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove dust cap, cotter pin, spindle nut and washer. Carefully remove hub/rotor assembly to avoid damage to spindle threads. 2. Remove outer bearing, inner grease seal and inner bearing. Clean bearings, and inspect bearings and races for damage. If races require removal from hub, drive old races from hub using hammer and Wheel Bearing Race Remover (J-29117-A). Installation

1. To install, reverse removal procedure. Pack bearings with high-temperature bearing grease. Install NEW grease seal until seal is even with hub surface. Lubricate seal lip and hub cavity with wheel bearing grease. 2. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Adjust wheel bearings. See FRONT WHEEL BEARINGS under ADJUSTMENTS & INSPECTION. Lower vehicle and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. SHOCK ABSORBERS Removal

Raise and support vehicle. Remove wheel and tire assembly. Hold upper stem from turning while removing upper stem retaining nut, retainer and rubber grommet at top of shock absorber. Remove shock absorber-tolower control arm bolts and nuts. Lower shock absorber from vehicle. Inspection

NOTE:

Purging air from non-spiral groove shock is not required, as reservoir has gas-charged cell. Spiral groove shock has air-charged cell and air must be purged.

1. On spiral groove shock, purge air from pressure chamber by mounting shock in vise (top end up) and fully extending unit. Reverse position (top end down) and fully collapse unit. Repeat procedure several times. 2. Bench check shock unit by mounting in vise with top end up (top end down on gas-charged shocks). DO NOT clamp vise on reservoir tube or mounting threads. Check rubber grommets for deterioration and replace as necessary. 3. Operate shock by hand at various rates of speed and note resistance. Rebound force is normally stronger than compression force. If resistance is not smooth and constant, replace shock. Installation

To install, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

SPECIFICATIONS table. STABILIZER BAR Removal

Raise and support vehicle. Remove wheel and tire assembly. Remove stabilizer bar-to-frame retaining bolts and clamps. See Fig. 1 . Disconnect stabilizer bar from frame. Remove stabilizer bar-to-lower control arm retaining bolt, nut and washers. Disconnect stabilizer bar from lower control arm, and remove rubber grommets and bushing assembly. Remove stabilizer bar and bushings from vehicle. Check all rubber bushings for excessive wear, deterioration or damage. Replace as necessary. Installation

To install, reverse removal procedure. Bushings should be installed with slit area toward front of vehicle. Apply rubber lubricant to bushings to aid in installation. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. COIL SPRINGS Removal

1. Raise and support vehicle with jackstand under frame, with control arms hanging free. Remove wheel and tire assembly. Remove shock absorber. See SHOCK ABSORBERS . WARNING: Securely bolt Spring Remover (J-23028-01) to floor jack, and install safety chain through lower control arm and coil spring to prevent personal injury. 2. Install Spring Remover (J-23028-01) on floor jack. Position assembly under lower control arm so bushings seat in grooves of spring remover. 3. Remove stabilizer bar-to-lower control arm retaining bolt, nut and washers. Disconnect stabilizer bar from lower control arm, and remove rubber grommets and bushing assembly. Raise floor jack to release spring tension on lower control arm pivot bolts. Install safety chain around coil spring and through lower control arm. CAUTION: DO NOT apply force on lower control arm and ball joint to remove coil spring. Coil spring can easily be removed by maneuvering spring. 4. Remove lower control arm pivot bolts and nuts (rear bolt and nut first). Carefully lower floor jack until all tension is released from coil spring. Remove safety chain and coil spring from vehicle. Installation

NOTE:

Coil spring must be positioned with tape at lowest position. Bottom of

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

spring is coiled helical, and top is coiled flat with a gripper notch near end of spring coil. 1. Position coil spring onto lower control arm. Ensure spring insulator is in place. Raise control arm with spring remover and floor jack. Ensure coil spring is properly positioned, with end of lower spring coil covering one drain hole in lower control arm, and clear of or partially covering other drain hole. 2. Install lower control arm pivot bolts and nuts (front bolt and nut first). Pivot bolts must be installed with nuts toward rear of vehicle. To complete installation, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. STEERING KNUCKLE Removal

NOTE:

DO NOT place jackstand under lower control arm. Spring tension is needed to break loose ball joint stud.

1. Raise and support vehicle with jackstand under frame, with control arms hanging free. 2. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove speed sensor (if equipped). Remove hub/rotor assembly. Remove splash shield. Remove cotter pin and nut from tie rod end. Use Tie Rod Remover (J-6627-A) to separate tie rod end from steering knuckle. CAUTION: Support lower control arm with floor jack during removal and installation of steering knuckle. 3. If replacing steering knuckle, carefully remove steering knuckle grease seal. Position floor jack under lower control arm between ball joint and spring seat. Raise floor jack until lower control arm is just supported. 4. Remove cotter pins and nuts from upper and lower ball joints. Using Ball Joint Separator (J-23742), separate ball joint studs from steering knuckle. See Fig. 2 . Raise upper control arm to disengage ball joint stud from steering knuckle. Remove steering knuckle. Inspection

Inspect tapered holes in steering knuckle for out-of-round, deformation or damage. Inspect spindle for worn or damaged threads. Replace steering knuckle as necessary. Installation

CAUTION: When installing upper and lower ball joint stud nuts, DO NOT loosen nut to install cotter pin.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

1. To install, reverse removal procedure. Install NEW grease seal on steering knuckle (if removed). Tighten ball joint stud nuts to align cotter pin holes as necessary. Install tie rod end stud into steering knuckle. 2. Install Steering Linkage Installer (J-29193) or (J-29194). Tighten steering linkage installer to 40 ft. lbs. (54 N.m) to seat tie rod taper. Remove steering linkage installer and install tie rod end stud nut. 3. To complete installation, reverse removal procedure. Adjust wheel bearings. See FRONT WHEEL BEARINGS under ADJUSTMENTS & INSPECTION. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

Fig. 2: Separating Upper & Lower Ball Joints From Steering Knuckle Courtesy of GENERAL MOTORS CORP. UPPER BALL JOINT Removal

1. Raise and support vehicle with jackstand under lower control arm, between ball joint and spring seat. Jackstand must remain under lower control arm during upper ball joint servicing to maintain lower Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

control arm and coil spring positioning. 2. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove nut securing speed sensor harness (if equipped). Remove grease fitting and cotter pin from upper ball joint stud. Remove upper ball joint stud nut. 3. Install Ball Joint Separator (J-23742) between upper and lower ball studs. See Fig. 2 . Extend bolt on ball joint separator to loosen ball joint stud from steering knuckle. Remove ball joint separator. Separate ball joint from steering knuckle. 4. Using drill motor and 1/8" (3.18 mm) drill bit, drill 1/4" (6.35 mm) deep hole in ball joint retaining rivets. Using 1/2" (12.7 mm) drill bit, drill out rivet heads. Using a hammer and small punch, drive out rivets and remove upper ball joint from upper control arm. Installation

CAUTION: When installing upper and lower ball joint stud nuts, DO NOT loosen nut to install cotter pin. To install, reverse removal procedure. Use NEW nuts and bolts to install ball joint into upper control arm. Install grease fitting and lubricate NEW ball joint. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. LOWER BALL JOINT Removal

1. Raise and support vehicle with jackstand under lower control arm between ball joint and spring seat. Jackstand must remain under lower control arm during lower ball joint servicing to maintain lower control arm and coil spring positioning. 2. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove grease fitting, rubber grease seal and cotter pin from lower ball joint stud. Remove lower ball joint stud nut. 3. Install Ball Joint Separator (J-23742) between upper and lower ball studs. See Fig. 2 . Extend bolt on ball joint separator to loosen ball joint stud from steering knuckle. Remove ball joint separator. Separate ball joint from steering knuckle. 4. Place a wooden block between upper control arm and frame to keep steering knuckle assembly aside. Obtain "C" Clamp (J-9519-30) and Removers (J-9519-7 or J-9519-40 and J-9519-28) from Ball Joint Remover/Installer Set (J-9519-D), and assemble on lower control arm. See Fig. 3 . Remove ball joint from lower control arm. Installation

CAUTION: When installing upper and lower ball joint stud nuts, DO NOT loosen nut to install cotter pin.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

1. Obtain "C" Clamp (J-9519-30) and Installer (J-9519-16) from ball joint remover/installer set, and assemble on lower control arm. See Fig. 3 . Reverse removal procedure to install ball joint into lower control arm. Ensure bleed vent in rubber grease seal is facing inward. Install grease fitting and lubricate NEW ball joint. 2. To complete installation, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

Fig. 3: Removing & Installing Lower Control Arm Ball Joint Courtesy of GENERAL MOTORS CORP. UPPER CONTROL ARM Removal

1. Note location of alignment shims for reassembly. Remove upper control arm pivot shaft-to-frame nut and shim. See Fig. 1 . Raise and support vehicle with jackstand under lower control arm, between ball joint and spring seat. Ensure jackstand remains under lower control arm during upper control arm servicing to maintain lower control arm and coil spring positioning. Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

2. Remove wheel and tire assembly. Remove grease fitting and cotter pin from upper ball joint stud. Remove upper ball joint stud nut. Install Ball Joint Separator (J-23742) between upper and lower ball studs. See Fig. 2 . Extend bolt on ball joint separator to loosen ball joint stud from steering knuckle. Remove ball joint separator. Separate ball joint from steering knuckle. Lift upper control arm, and remove upper control arm pivot shaft-to-frame bolts. Remove upper control arm. Installation

1. To install, reverse removal procedure. 2. Ensure holes in upper control arm shaft align with holes in frame. Ensure alignment shims are installed in original position. 3. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle. Check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. UPPER CONTROL ARM BUSHINGS Pivot Shaft Bushing Replacement

1. Remove upper control arm from vehicle. See UPPER CONTROL ARM . Place upper control arm in soft-jawed vise. Remove nuts and retainers from ends of pivot shaft. 2. Using Bushing Remover/Installer (J-22269-1) and Receiver/Installer (J-21474-5), press bushing and pivot shaft from upper control arm. Repeat procedure for opposite bushing. 3. To install, place pivot shaft in upper control arm. Using Bushing Remover/Installer (J-22269-1) and small piece of pipe with the same outer diameter as bushing, press NEW bushing into upper control arm and onto pivot shaft. 4. Ensure each bushing is positioned .48-.52" (12.2-13.2 mm) from face of control arm to bushing outer sleeve. Repeat procedure for bushing on opposite end. Install nuts and retainers onto upper control arm pivot shaft ends. LOWER CONTROL ARM Removal

1. Raise and support vehicle with jackstand under frame, with control arms hanging free. Remove wheel and tire assembly. Remove coil spring. See COIL SPRINGS . Separate lower ball joint from steering knuckle. See LOWER BALL JOINT . 2. Separate lower control arm from steering knuckle and carefully maneuver out of opening in splash shield. Remove lower control arm-to-frame pivot bolts and nuts (rear bolt and nut first). Remove lower control from vehicle. Installation

1. To install, reverse removal procedure. Use NEW nuts on lower control arm pivot bolts. Install lower control arm pivot bolts and nuts (front bolt and nut first). Ensure lower control arm pivot bolts are installed with bolt heads facing toward front of vehicle, and are tightened to specification with vehicle at riding height. Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

2. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. LOWER CONTROL ARM BUSHINGS Front Bushing Replacement

1. Remove lower control arm from vehicle. See LOWER CONTROL ARM . Place lower control arm in soft-jawed vise. Using a blunt chisel, drive front bushing flare down even with rubber of bushing. Install appropriate lower control arm bushing service equipment. See CONTROL ARM BUSHING SERVICE EQUIPMENT table. 2. Tighten nut until front bushing is removed from lower control arm. To install front bushing, assemble appropriate control arm bushing service equipment. See Fig. 4 . 3. Position NEW front bushing into lower control arm with lip side of bushing on outside of lower control arm. Tighten nut until bushing is fully seated into lower control arm. Flare front bushings after installation. See Fig. 5 . Turn nut on flaring die until bushing is flared about 45 degrees. Remove bushing flaring die and other service equipment.

Fig. 4: Removing Lower Control Arm Front Bushing (Typical) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

Fig. 5: Flaring Lower Control Arm Front Bushing Courtesy of GENERAL MOTORS CORP. CONTROL ARM BUSHING SERVICE EQUIPMENT Application Bolt & Thrust Washer Bushing Installer Nut Receiver/Installer

Tool Number J-21474-3 J-21474-13 J-21474-4 J-21474-5 Or J-21474-6

Rear Bushing Replacement

1. Remove lower control arm from vehicle. See LOWER CONTROL ARM . Place lower control arm in soft-jawed vise. 2. Install appropriate receiver, remover, spacer, nut and bolt as indicated. See Fig. 6 . See CONTROL ARM BUSHING SERVICE EQUIPMENT table. Tighten nut until rear bushing is removed from lower control arm. 3. Assemble control arm bushing service set. Install nut, bolt, spacer and receiver. Position NEW rear bushing into lower control arm with lip side of bushing on outside of lower control arm. Tighten nut until bushing is fully seated into lower control arm. Microsoft Saturday, August 29, 2009 11:51:52 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

Fig. 6: Removing Lower Control Arm Rear Bushing Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Ball Joint-To-Steering Knuckle Nut Lower Upper Lower Control Arm-To-Frame Pivot Bolt Nuts Front Bolt

Ft. Lbs. (N.m) 79 (107) 61 (83) (1) 85 (115) (1) 72 (98)

Rear Bolt

(2)

Shock Absorber-To-Frame Nut Shock Absorber-To-Lower Control Arm Bolts Splash Shield Bolts Stabilizer Bar To-Frame Bolts Stabilizer Bar To-Lower Control Arm Nut

22 (30) 19 (26) 13 (18)

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front - 2WD Coil Spring - "S" Series Trucks

(3) 13 (18)

Tie Rod End-To-Steering Knuckle Nut Upper Ball Joint-To-Control Arm Nuts Upper Control Arm Pivot Shaft Nuts Upper Control Arm Pivot Shaft-To-Frame Nuts Wheel Lug Nut (1) Tighten with suspension loaded (weight of vehicle on wheels).

39 (53) 17 (23) 85 (115) 66 (89) 95 (130)

(2) 97 INCH lbs. (11 N.m) (3) Obtain torque by running nut to unthreaded portion of bolt.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

1996-97 SUSPENSION Front 4WD - "T" Series Trucks

DESCRIPTION Independent front suspension consists of upper and lower control arms with steering knuckle mounted between ball joints. See Fig. 1. Shock absorbers fit between lower control arm and frame. A stabilizer bar is mounted to frame side rails and connected to lower control arms. Torsion bars are used in place of coil springs. Front of torsion bar attaches to lower control arm. Rear of torsion bar attaches to adjustable arm at torsion bar support crossmember. Adjustments to trim height are made here.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Fig. 1: Exploded View Of Front Suspension (Typical) Courtesy of GENERAL MOTORS CORP.

ADJUSTMENTS & INSPECTION Microsoft Saturday, August 29, 2009 11:52:26 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

WHEEL ALIGNMENT NOTE:

See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

FRONT WHEEL BEARINGS Front wheel bearings are sealed, pre-adjusted and require no maintenance unless wheel hub and bearing assembly is removed. See WHEEL HUB & BEARINGS under REMOVAL & INSTALLATION. RIDING HEIGHT NOTE:

See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

UPPER BALL JOINT CHECKING NOTE:

Replace ball joint rubber grease seal if cut or damaged.

1. Raise and support vehicle with jackstand under lower control arm, near lower ball joint. Ensure upper control arm bumper does not contact frame. Place dial indicator against lower part of wheel rim. Push in on bottom of tire while pulling outward at top. Read dial indicator, then reverse push/pull procedure. 2. If lateral (horizontal) deflection exceeds .125" (3.18 mm), replace ball joint. With ball joint disconnected from steering knuckle, try to rotate ball joint by finger pressure. If ball joint can be rotated by finger pressure, replace ball joint. LOWER BALL JOINT CHECKING NOTE:

Replace ball joint rubber grease seal if cut or damaged.

Raise and support vehicle with jackstand under lower control arm, near lower ball joint. Place a dial indicator on spindle hub. Pry wheel between lower control arm and outer race to measure vertical movement. Note dial indicator reading. If reading exceeds .125" (3.18 mm), replace loose ball joint.

1. Raise and support vehicle. Remove wheel and tire assembly. Install Axle Shaft Boot Seal Protector (JMicrosoft Saturday, August 29, 2009 11:52:26 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

28712) to drive axle shaft boot to protect drive axle during repair. Depress brake caliper piston, detach brake caliper and wire aside. Remove brake rotor. See Fig. 1. Remove drive axle shaft nut cotter pin, retainer, drive axle shaft nut and washer. Pull hub and bearing assembly off drive axle shaft. NOTE:

Darkened areas on bearing assembly are caused by heat treatment process and DO NOT indicate a need for replacement.

2. Inspect steering knuckle grease seal for cuts, distortion and wear. Inspect steering knuckle, hub and bearing for damage. Replace as necessary. If wheel hub stud must be replaced, use Wheel Stud Remover (J-6627-A). Installation

1. To install NEW wheel hub stud, lubricate hub bore and install stud. Place 4 washers on stud and install stud nut with flat side to washers. Tighten stud nut to draw stud into hub bore. Remove nut and washers. Install hub and bearing assembly onto drive axle shaft. 2. To complete installation, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Depress brake pedal several times to extend caliper piston after installation. STEERING KNUCKLE Removal

1. Raise and support vehicle. Unload torsion bar tension. See Fig. 2. Count exact number of tool turns for reassembly reference. Slide, but DO NOT remove, torsion bar forward. 2. Remove wheel and tire assembly. Install Axle Shaft Boot Seal Protector (J-28712) to drive axle shaft boot to protect drive axle during repair. Depress brake caliper piston, detach brake caliper and wire aside. Remove brake rotor. 3. Remove drive axle shaft nut cotter pin, retainer, drive axle shaft nut and washer. Pull hub and bearing assembly off drive axle shaft. Remove splash shield. Remove cotter pin and tie rod end stud nut. Using Universal Steering Linkage Puller (J-24319-01), separate tie rod end from steering knuckle. 4. Remove upper and lower ball joint stud cotter pins. Place Ball Joint Separator (J-34026) over upper ball joint stud. Loosen ball joint stud nut. See Fig. 3. Back off nut until nut contacts tool. Continue backing off nut until nut forces ball stud out of steering knuckle. Remove spacer. Repeat procedure to separate lower ball joint from steering knuckle. 5. Remove steering knuckle from vehicle. Inspect steering knuckle grease seal for cuts, distortion and wear. Inspect steering knuckle, hub and bearing for damage. Replace as necessary. Installation

1. Using hammer and Steering Knuckle Seal Installer (J-28574), install NEW steering knuckle grease seal into steering knuckle. Install spacer (if equipped). Install steering knuckle onto upper and lower ball joint studs.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

CAUTION: When installing upper and lower ball joint stud nuts, tighten nut to align cotter pin hole. DO NOT tighten ball joint stud nuts more than an additional 1/6 turn to align cotter pin hole. Complete tightening of ball joint stud nuts with vehicle at proper riding height specification. 2. Install ball joint stud nuts and cotter pins. Install drive axle (if removed). Install tie rod end onto steering knuckle. Install tie rod end stud nut and cotter pin. Install splash shield. Install hub and bearing assembly onto drive axle shaft and into steering knuckle. 3. To complete installation, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle. Check wheel alignment and adjust ride height. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

Fig. 2: Unloading Torsion Bar Tension Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Fig. 3: Separating Ball Joint From Steering Knuckle Courtesy of GENERAL MOTORS CORP. SHOCK ABSORBERS Removal

Raise and support vehicle. Remove wheel and tire assembly. Remove shock absorber retaining bolt and nut from lower control arm. Remove shock absorber retaining bolt and nut from frame. Remove shock absorber from vehicle. Inspection

NOTE:

Purging air from non-spiral groove shock is not required, as reservoir has

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

gas-charged cell. Spiral groove shock has air-charged cell and air must be purged. 1. On spiral groove shock, purge air from pressure chamber by mounting shock in vise (top end up) and fully extending unit. Reverse position (top end down) and fully collapse unit. Repeat procedure several times. 2. Bench check shock unit by mounting in vise with top end up (top end down on gas-charged shocks). DO NOT clamp vise on reservoir tube or mounting threads. Check rubber grommets for deterioration and replace as needed. 3. Operate shock by hand at various rates of speed and note resistance. Rebound force is normally stronger than compression force. If resistance is not smooth and constant, replace shock. Installation

To install, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. STABILIZER BAR Removal

NOTE:

Keep right and left side stabilizer bar components separate for installation in original locations.

Raise and support vehicle. Remove wheel and tire assembly. Remove fasteners and separate stabilizer bar from lower control arm. Remove stabilizer bar. Remove stabilizer bar bushings. Replace bushings if deformed or deteriorated. Replace stabilizer bar and clamps if excessive worn or damaged. Installation

Unload torsion bar tension. See Fig. 2. Count exact number of tool turns for reassembly reference. To install, reverse removal procedure. Ensure split in bushing faces toward front of vehicle. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle. Adjust ride height and check wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. UPPER BALL JOINT Removal

1. Raise and support vehicle under lower control arms. Remove wheel and tire assembly. Remove upper ball joint stud nut and separate upper ball joint stud from steering knuckle using Ball Joint Separator (J36607). Remove brakeline and brackets from upper control arm (if equipped). 2. Drill a 1/8" (3.18 mm) diameter by 1/4" (6.35 mm) deep hole in ball joint retaining rivets. Drill off rivet heads with a 1/2" (12.7 mm) drill bit. Drive out rivets with a hammer and small punch. Remove ball joint. Installation Microsoft Saturday, August 29, 2009 11:52:26 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

CAUTION: When installing upper ball joint stud nut, tighten nut to align cotter pin hole. DO NOT tighten ball joint stud nut more than an additional 1/6 turn to align cotter pin hole. Complete tightening of upper ball joint stud nut with vehicle at proper riding height specification. To install, reverse removal procedure. Use NEW nuts and bolts to install ball joint to upper control arm. Lubricate NEW ball joint. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle. Check ride height and adjust wheel alignment. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. LOWER BALL JOINT Removal

1. Raise and support vehicle under lower control arms. Remove wheel. Remove steering knuckle. See STEERING KNUCKLE. Remove brakeline and brackets from lower control arm. 2. Drill a 1/8" (3.18 mm) diameter by 1/4" (6.35 mm) deep hole in ball joint retaining rivets. Drill off rivet heads with a 1/2" (12.7 mm) drill bit. Using a 5/16" (8 mm) drill bit, drill through 2/3 of the length of rivet shank. Drive out rivet with a 5/16" (8 mm) punch. Remove ball joint. Installation

CAUTION: When installing lower ball joint stud nut, tighten nut to align cotter pin hole. DO NOT tighten ball joint stud nut more than an additional 1/6 turn to align cotter pin hole. Complete tightening of lower ball joint stud nut with vehicle at proper riding height specification. To install, reverse removal procedure. Use NEW nuts and bolts to install ball joints to lower control arm. Lubricate NEW ball joint. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle. Check wheel alignment and adjust ride height. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. UPPER CONTROL ARM Removal

1. Raise and support vehicle under lower control arms. Remove wheel. Remove upper ball joint stud cotter pin. Place Ball Joint Separator (J-34026) over upper ball joint stud. Loosen ball joint stud nut. See Fig. 3. Back off nut until nut contacts tool. Continue backing off nut until nut forces ball stud out of steering knuckle. Remove spacer. 2. Mark alignment adjustment cams for reassembly reference. Remove upper control arm pivot bolts, cams/washers and nuts. Remove upper control arm from vehicle. See Fig. 4. Replace bushings and/or bumper as necessary. Installation

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

1. If upper control arm bumper is deteriorated or damaged, install NEW bumper. Mount upper control arm on vehicle. Install pivot bolts, alignment adjustment cams and NEW pivot bolt nuts. CAUTION: When installing upper ball joint stud nut, tighten nut to align cotter pin hole. DO NOT tighten ball joint stud nut more than an additional 1/6 turn to align cotter pin hole. Complete tightening of upper ball joint stud nut with vehicle at proper riding height specification. 2. Ensure pivot bolt heads are facing inward. Connect steering knuckle to upper ball joint studs. To complete installation, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. 3. Lower vehicle. Check wheel alignment and adjust ride height. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. Complete tightening of upper control arm pivot bolts and nuts with vehicle at proper riding height.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Fig. 4: Exploded View Of Upper Control Arm Courtesy of GENERAL MOTORS CORP. UPPER CONTROL ARM BUSHINGS Bushing Replacement

1. Remove upper control arm from vehicle. See UPPER CONTROL ARM. Place upper control arm in soft-jawed vise. 2. Press bushings out of upper control arm using Nut (J-21474-18), Bolt (J-21474-19), washer, bearing and Microsoft Saturday, August 29, 2009 11:52:26 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Control Arm Bushing Service Set (J-33793). See Fig. 5. 3. Install NEW bushings into upper control arm using Nut (J-21474-18), Bolt (J-21474-19), washer, bearing and Control Arm Bushing Service Set (J-33793). See Fig. 5. 4. Ensure bushings are properly seated in upper control arm. Install upper control arm. See UPPER CONTROL ARM.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Fig. 5: Replacing Upper Control Arm Bushings Courtesy of GENERAL MOTORS CORP. LOWER CONTROL ARM Removal Microsoft Saturday, August 29, 2009 11:52:26 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

1. Raise and support vehicle. Unload torsion bar tension. See Fig. 2. Count exact number of tool turns for reassembly reference. Slide torsion bar forward to remove adjuster arm. Remove wheel and tire assembly. 2. Remove drive axle nut. Remove stabilizer bar from vehicle. See STABILIZER BAR. Remove shock absorber from vehicle. See SHOCK ABSORBERS. Separate lower ball joint from steering knuckle. See LOWER BALL JOINT. 3. Remove lower control arm pivot bolts, nuts and washers. Remove lower control arm from vehicle. See Fig. 1. Replace bushings and/or bumper as necessary. Installation

1. To install, reverse removal procedure. Install front leg of lower control arm onto vehicle, then rear leg. Install lower control arm pivot bolts, washers and NEW nuts, with bolt heads facing rearward. CAUTION: When installing upper ball joint stud nut, tighten nut to align cotter pin hole. DO NOT tighten ball joint stud nut more than an additional 1/6 turn to align cotter pin hole. Complete tightening of upper ball joint stud nut with vehicle at proper riding height specification. 2. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. Lower vehicle. Check wheel alignment and adjust ride height. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT. Complete tightening of lower control arm pivot bolts and nuts with vehicle at proper riding height specification. LOWER CONTROL ARM BUSHINGS Removal

Remove lower control arm. See LOWER CONTROL ARM. Place lower control arm in a soft-jawed vise. Press bushings out of lower control arm using a washer, bearing and Control Arm Bushing Service Set (J21474). See Fig. 6. Installation

To install, reverse removal procedure. Press in bushings until properly seated. Install lower control arm. See LOWER CONTROL ARM.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Fig. 6: Replacing Lower Control Arm Bushings Courtesy of GENERAL MOTORS CORP. TORSION BARS & SUPPORT Microsoft Saturday, August 29, 2009 11:52:26 AM

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Removal

1. Raise and support vehicle. Remove wheel and tire assembly. Unload torsion bar tension. See Fig. 2. Mark adjusting bolt setting. Using Torsion Bar Unloading Tool (J-36202), increase tension on adjusting arm. Remove torsion bar adjusting bolt, counting number of turns for reassembly reference. 2. Remove torsion bar adjusting nut. Slowly relieve torsion bar tension. Remove unloading tool. Slide torsion bar forward. Remove torsion bar adjusting arm. Remove support mounting bolts, nuts and washers. Remove support retainer, spacer and rubber insulator. See Fig. 7. 3. Disconnect muffler flange from catalytic converter. Loosen rear exhaust hanger and lower rear exhaust. Remove torsion bar support. Slide torsion bar rearward and remove from lower control arm. 4. Inspect torsion bars, adjusting arms, retainers, rubber insulators and support for bend, cracks, deterioration or damage. Check adjusting bolt and nut for damage or stripped threads. Replace as necessary. Installation

1. Install torsion bar rubber insulators, spacer and support retainer onto support. Install support assembly onto frame, slightly behind mounting holes. Install rear exhaust and rear exhaust hanger. Connect muffler flange to catalytic converter. 2. Install adjusting arm and seal onto torsion bar. Slide torsion bar into lower control arm in original position. Slide torsion bar support forward, engaging rear of torsion bar in support. Install support mounting bolts, nuts and washers. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS table. 3. Install adjusting bolt and nut on each torsion bar. Add tension to torsion bar with Torsion Bar Unloading Tool (J-36202). Ensure adjusting bolt is positioned to setting marked before removal. Release tension on unloading tool until tension is taken up by adjusting bolt. Remove unloading tool. Lower vehicle. Check wheel alignment and adjust ride height. See SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT.

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Fig. 7: Exploded View Of Torsion Bar & Support Assembly Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application

Ft. Lbs. (N.m) 17 (23)

Ball Joint-To-Control Arm Nut (1) Ball Joint-To-Steering Knuckle Nut (1) (2) Lower Upper Drive Axle Shaft Nut Hub & Bearing/Shield-To-Steering Knuckle Bolt

79 (107) 61 (83) 181 (245) 77 (105) 81 (110)

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1997 Chevrolet S10 Pickup 1996-97 SUSPENSION Front 4WD - "T" Series Trucks

Lower Control Arm-To-Frame Pivot Bolt (1) (5) Lower Control Arm-To-Frame Pivot Bolt Nut (1) (3) (5)

81 (110)

Shock Absorber Nut (4) Stabilizer Bar Clamp-To-Frame Bolt Stabilizer Bar-To-Lower Control Arm Bolt Tie Rod End-To-Steering Knuckle Nut Torsion Bar Retainer-To-Support Link Nut Lower Upper

54 (73) 26 (35) 11 (15) 39 (53) 50 (68) 33 (48)

Upper Control Arm-To-Frame Pivot Bolt Nut (1) Front Rear Wheel Lug Nut (1) Complete tightening of bolts and/or nuts with vehicle at proper riding height specification.

85 (115) 72 (98) 95 (129)

(2) Tighten nut to align cotter pin hole. DO NOT tighten nut more than an additional 1/6 turn to align

cotter pin hole. (3) Use NEW nuts during reassembly. (4) Install both bolts with nuts facing rear of vehicle. (5) Install upper/rear bolt with nut facing rear of vehicle. Install lower/front bolt with nut facing front of

vehicle.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL Fuses & Circuit Breakers - Blazer, Bravada, S10 Pickup & Sonoma

1997 ELECTRICAL Fuses & Circuit Breakers - Blazer, Bravada, S10 Pickup & Sonoma

IDENTIFICATION CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. FUSE BLOCK Fuse block is located at driver's end of instrument panel.

Fig. 1: Fuse Block View Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL Fuses & Circuit Breakers - Blazer, Bravada, S10 Pickup & Sonoma

Fig. 2: Fuse Block Identification Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

DESCRIPTION WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG article in the ACCESSORIES/SAFETY EQUIPMENT Section. SYSTEM DESCRIPTION System blends heated outside air with cooler outside air to obtain desired temperature. Major components of the system are blower motor, air inlet assembly, heater air distributor assembly, and heater control panel. Temperature control door is controlled by an actuator motor. Vacuum actuators control mode valves to regulate flow of air through heater unit.

OPERATION AUXILIARY HEATER BLOWER SWITCH A 3-speed blower switch (if equipped) is located on instrument panel, to right of steering column. When switch is in OFF position, auxiliary system does not operate. BLOWER SPEED SWITCH The blower speed switch selects low, medium-low, medium-high or high blower speed. MODE SELECTOR The mode selector directs discharge air to windshield, floor, or dash outputs, as desired by driver. TEMPERATURE CONTROL SELECTOR The temperature control lever or knob controls discharge air temperature in all mode positions. Full hot position provides maximum heat. Full cold position provides unheated air. OPERATING MODES NOTE:

To identify heater vacuum selector valve operation, see Fig. 3 .

VENT Mode

Air is directed to instrument panel outlets. Microsoft Saturday, August 29, 2009 11:42:43 11:42:39 AM

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

BI-LEV Mode

Air is directed to instrument panel and floor outlets. A slight amount of air is directed to defroster and side window defogger outlets. HEAT Mode

Air is diverted to floor outlets to heat passenger compartment. A slight amount of air is directed to windshield and side window defogger outlets. BLEND Mode

Air is divided between instrument panel and floor outlets, with a slight amount of air going to defroster outlets. DEF Mode

Air is directed to windshield defroster outlets. A slight amount of air is diverted to floor outlets and side window defogger outlets.

ADJUSTMENTS NOTE:

Information on temperature control cable adjustment not available at time of publication

TROUBLE SHOOTING NOTE:

For Heater System trouble shooting information, see the HEATER SYSTEM TROUBLE SHOOTING article. For front (and rear) blower motor trouble shooting information, see the A/C-HEATER SYSTEM - MANUAL article.

TEMPERATURE DOOR MALFUNCTIONING 1. Turn ignition on. Using DVOM, backprobe terminal "B" (Light Blue wire) of heater control module connector C2 to ground. Move temperature control knob from HOT setting to COLD setting, and then from COLD setting to HOT setting. If voltage varies between approximately 1-12 volts, go to step 3). 2. If voltage does not vary as indicated, check for poor connection at heater control module connector C2 (terminal "B") or short to ground/voltage in Light Blue wire. Also check for open Brown wire between heater control module connector C2 and fuse block. If connection and wires are okay, replace heater control module. 3. Using DVOM, backprobe temperature door motor terminal No. 10 (Brown wire) to ground. If battery voltage exists, go to next step. If voltage does not exist, repair open Brown wire between temperature door motor and fuse block. 4. Using DVOM, backprobe between temperature door motor terminal No. 7 (Black/White wire) and terminal No. 10 (Brown wire). If battery voltage exists, go to next step. If voltage does not exist, repair open Black/White wire. Microsoft Saturday, August 29, 2009 11:42:39 AM

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

5. Using DVOM, backprobe temperature door motor terminal No. 8 (Light Blue wire) to ground while moving temperature control knob. If voltage does not vary between approximately 1-12 volts, repair open Light Blue wire. If voltage varies between 1-12 volts, check for binding door or poor connections at temperature door motor. If okay, replace temperature door motor.

REMOVAL & INSTALLATION WARNING: To avoid injury from accidental air bag deployment, read and follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section. ACTUATOR MOTOR Removal & Installation

Actuator motor is located on top of heater case. Remove instrument panel. Unplug electrical connectors. Remove actuator motor. To install, reverse removal procedure. BLOWER MOTOR Removal & Installation

Disconnect negative battery cable. Remove vehicle control module (if equipped). Remove coolant reservoir. Remove cooling tube. Unplug connector. Remove blower motor. To install, reverse removal procedure. CONTROL ASSEMBLY Removal & Installation

Remove accessory trim plate. Remove heater control unit retaining screws. Remove heater control unit. Unplug vacuum connectors. Unplug electrical connectors. To install, reverse removal procedure. HEATER CORE WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in the AIR BAG RESTRAINT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section. CAUTION: Heater core can be damaged if too much force is applied to heater core pipes during hose removal. Removal & Installation

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

Disconnect negative battery cable. Drain engine coolant. Disconnect heater hoses at core, and plug core openings. See Fig. 1 . Remove instrument panel. See INSTRUMENT PANEL . Remove rear case screws and rear case. Remove straps. Remove heater core. Remove seals. To install, reverse removal procedure. Fill cooling system. Start engine and check for leaks.

Fig. 1: Exploded View Of Heater System Components Courtesy of GENERAL MOTORS CORP. INSTRUMENT PANEL Removal & Installation

1. Disable air bag system. See AIR BAG RESTRAINT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section. 2. Remove instrument cluster trim plate. Move tilt steering column down (if equipped), set parking brake and move automatic transmission gear selector to low (if equipped). Microsoft Saturday, August 29, 2009 11:42:39 AM

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

3. Remove left underdash hush panel. See Fig. 2 . Remove Data Link Connector (DLC) and Remote Keyless Entry (RKE) module connectors. Remove center underdash hush panel. Disconnect park brake release cable from instrument panel. Disconnect park brake cable from ratchet mechanism. 4. Remove right underdash hush panel. Remove lighter and accessory outlets, if equipped. Remove courtesy light. Remove knee bolster. Partially pull A/C-heater control panel and radio to disconnect connectors on back of A/C-heater control panel and radio. 5. Remove 4 steering column retaining bolts and lower steering column. Remove speaker and defroster grilles. Remove 9 instrument panel support bolts, including brake pedal bracket support bolt. Remove electrical connectors. Remove instrument panel. To install, reverse removal procedure.

Fig. 2: Locating Instrument Panel Components Courtesy of GENERAL MOTORS CORP. AUXILIARY HEATER COMPONENTS NOTE:

Information not available.

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Auxiliary Heater Bolts Blower Motor Bolts Heater Case Bolts

INCH Lbs. (N.m) 13 (1.5) 12 (1.4) 97 (11)

VACUUM DIAGRAM

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

Fig. 3: Heater System Vacuum Diagram Courtesy of GENERAL MOTORS CORP.

WIRING DIAGRAM

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

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1997 Chevrolet S10 Pickup HEATER SYSTEM 1997 A/C-HEATER SYSTEMS General Motors Corp. - Heater System

Fig. 4: Heater System Wiring Diagram

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

1997 AIR CONDITIONING & HEAT Manual A/C

A/C SYSTEM SPECIFICATIONS A/C SYSTEM SPECIFICATIONS Application Compressor Type 2.2L 4.3L Compressor Belt Tension

Specification Harrison V5 5-Cyl. Harrison HT6 6-Cyl. (1)

System Oil Capacity (2) 2.2L 4.3L Refrigerant (R-134a) Capacity

9 ozs. 8 ozs. 32 ozs.

System Operating Pressures (3) High Side

299 psi (21 kg/cm2 )

26 psi (1.8 kg/cm2 ) (1) Tighten serpentine belt until indicator mark on movable portion of belt tensioner is within limits of slotted area on stationary portion of belt tensioner. (2) Use PAG Oil. Low Side

(3) Specification is with ambient temp at 80°F (27°C), relative humidity at 60 percent and engine speed

at 1500 RPM.

DESCRIPTION WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG article in the ACCESSORIES/SAFETY EQUIPMENT Section. CAUTION: When discharging air conditioning system, use only approved refrigerant recovery/recycling equipment. Make every attempt to avoid discharging refrigerant into the atmosphere. CAUTION: When battery is disconnected, radio will go into anti-theft protection mode. Obtain radio anti-theft protection code from owner prior to servicing vehicle. SYSTEM DESCRIPTION Microsoft Saturday, August 29, 2009 11:43:21 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

A/C-heater system is a blend-air system. Air entering vehicle must pass through evaporator core and through and/or around heater core to obtain desired temperature. Compressor operation on 6-cylinder compressor is controlled by a pressure cycling switch located on top of accumulator. Compressor operation on 5-cylinder compressor is controlled by Powertrain Control Module (PCM) through A/C compressor clutch relay based on A/C related inputs to PCM.

OPERATION A/C-HEATER CONTROL PANEL Temperature Control Knob

An electric motor controls the temperature door based on the temperature knob position. When temperature knob is in the Blue (cold) position, air delivered by system is unheated. When temperature knob is in Red (hot) position, all air passing through heater module is heated before it is discharged. Intermediate position of temperature knob results in a mixture of heated and unheated air to provide more moderate air temperatures. Mode Selector Knob

Mode selector knob positions are OFF, MAX A/C, NORM A/C, BI-LEV A/C, VENT, HEAT, BLEND and DEFROST. Mode selector knob operates a rotary vacuum switch that routes engine vacuum to specific hoses in the vacuum harness. These hoses control various vacuum actuators on A/C-heater system. Each actuator operates an air valve (a door-like hinged deflector) that routes airflow to various outlets through the system. Blower Switch

Blower switch provides a choice of various blower speeds. Blower switch receives power through a fuse in fuse block when ignition is on. In various speed positions, circuit continues through wiring harness to blower motor resistor, near blower motor. There are 4-positions: LO, HI and 2 intermediate positions. Blower operates in any mode position except OFF.

TROUBLE SHOOTING WARNING: To avoid injury from accidental air bag deployment, read and follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section. NOTE:

Also see the A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL article.

A/C COMPRESSOR CLUTCH CONTROLS See the A/C COMPRESSOR CLUTCH CONTROLS article. BLOWER MOTOR INOPERATIVE Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

1. Turn ignition switch to RUN position. Place mode selector in VENT position. Place blower switch in LO position. Connect test light from Purple wire at blower motor relay connector to ground. If test light does not glow, go to next step. If test light glows, check for poor connection at blower motor and relay connectors. If connections are okay, check for open Purple wire or Black wire between blower motor relay connector and blower motor connector. If wires are okay, replace blower motor. 2. Disconnect blower motor relay connector. Connect test light from Dark Blue wire at blower motor relay connector to ground. If test light does not glow, go to next step. If test light glows, check for poor connection at blower motor relay connector. If connection is okay, replace blower motor relay. 3. Connect test light from Brown wire (mode selector control to fuse block wire) at mode selector control to ground. If test light does not glow, repair open Brown wire between mode selector control and fuse block. If test light glows, check for poor connections at blower motor relay connector and mode selector control connector. If connections are okay, replace control panel. BLOWER MOTOR DOES NOT OPERATE IN HIGH SPEED 1. Turn ignition switch to RUN position. Place mode selector in VENT position. Place blower switch in HIGH position. Connect test light from Orange wire at blower motor relay connector to ground. If test light glows, go to next step. If test light does not glow, check for poor connection at blower switch connector of control panel. If connection is okay, replace control panel. 2. Connect test light from Red wire at blower motor relay connector to ground. If test light does not glow, repair open Red wire between blower motor relay connector and battery junction block. If test light glows, check for poor connection at blower motor relay connector or open Black wire between blower motor relay connector and ground. If connection and wire are okay, replace blower motor relay. BLOWER MOTOR DOES NOT OPERATE IN MEDIUM SPEEDS 1. Turn ignition switch to RUN position. Place mode selector in VENT position. Place blower switch in medium-low (M1) position. Connect test light from Tan wire at blower motor resistor connector to ground. If test light glows, go to next step. If test light does not glow, check for poor connection at blower switch connector of control panel or open Tan wire. If connection and wire are okay, replace control panel. 2. Place blower switch in medium-high (M2) position. Connect test light from Light Blue wire at blower motor resistor connector to ground. If test light does not glow, check for poor connection at blower switch connector or open Light Blue wire. If connection and wire are okay, replace blower switch. If test light glows, check for poor connection at blower motor resistor connector. If connection is okay, replace blower motor resistor. BLOWER MOTOR DOES NOT OPERATE IN LOW SPEED Turn ignition switch to RUN position. Place mode selector in VENT position. Place blower switch in LO position. Disconnect blower motor resistor. Connect test light from Brown wire at blower motor resistor connector to ground. If test light does not glow, check Brown wire for high resistance or open. If wire is okay, replace control panel. If test light glows, check for poor connections at blower motor resistor. If connections are okay, replace blower motor resistor. BLOWER MOTOR OPERATES IN HIGH SPEED ONLY Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

1. Turn ignition switch to RUN position. Place mode selector in VENT position. Place blower switch in LO position. Using a DVOM, measure voltage between Dark Blue wire at blower motor relay connector and ground. If voltage is less than 4 volts, go to next step. If voltage is greater than 4 volts, check for poor connection at blower motor relay connector. If connection is okay, replace blower motor relay. 2. Disconnect blower motor resistor connector. Connect test light from Brown wire at blower motor resistor connector to ground. If test light does not glow, check for open Brown wire or for poor connection at blower switch connector of control panel. If wire and connection are okay, replace control panel. If test light glows, check Dark Blue wire for high resistance or open. If wire is okay, replace blower motor resistor.

TESTING A/C SYSTEM PERFORMANCE 1. Park vehicle out of direct sunlight. Open windows or door to ventilate interior. Vent engine exhaust, if necessary. Install manifold gauge set. Note ambient temperature and humidity. 2. Close all windows and doors. Place mode selector lever in MAX A/C position, blower switch lever in HIGH position, and temperature control lever in full cold position. 3. Insert thermometer into right center vent. Place transmission in Park or Neutral. Start engine and allow it to run at 1500 RPM until temperature tester reaches lowest temperature (approximately 3 minutes). See A/C SYSTEM PERFORMANCE SPECIFICATIONS . A/C SYSTEM PERFORMANCE SPECIFICATIONS (1) Ambient Temp. °F (°C) Low Side psi (kg/cm2 ) High Side psi (kg/cm2 ) 70 (21) 21 (1.5) 261 (18) 80 (27) 26 (1.8) 299 (21) 90 (32) 35 (2.5) 385 (27) (1) Specifications are with relative humidity at 60 percent.

Outlet Temp. °F (°C) 40 (4) 45 (7) 56 (13)

For removal and installation procedures not covered in this article, see the HEATER SYSTEM TROUBLE SHOOTING article.

ACCUMULATOR Removal & Installation Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

1. Disconnect negative battery cable. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Disconnect electrical connections (if necessary). Disconnect accumulator lines, and plug openings. On 4.3L engines, remove accumulator bracket screws and accumulator. On 2.2L engines, remove clamp bolt remove accumulator from clamp. See Fig. 1 . 2. To install, reverse removal procedure. Add 3 ounces of clean refrigerant oil to NEW accumulator before installation. Lubricate NEW "O" rings with clean refrigerant oil before installation. Evacuate, charge, and leak test system.

Fig. 1: Exploded View Of Accumulator Assembly Courtesy of GENERAL MOTORS CORP. BLOWER MOTOR & FAN Removal & Installation

1. Disconnect negative battery cable. Disconnect blower motor electrical connections. Remove Vehicle Control Module (VCM), if necessary. Remove coolant recovery reservoir and blower motor cooling tube. Remove blower motor mounting screws. 2. Cut access cover along dotted lines. See Fig. 2 . Remove upper half of access cover, tearing remaining portion of access cover. Remove blower motor. Remove nut attaching blower fan to blower motor shaft, and remove fan. 3. To install, reverse removal procedure. Apply a bead of Black weatherstrip adhesive to cut and tear lines for access cover. Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

Fig. 2: Blower Motor & Evaporator Housing Assembly Courtesy of GENERAL MOTORS CORP. COMPRESSOR Removal & Installation

1. Disconnect negative battery cable. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove electrical connections, as necessary. 2. Remove drive belt. Remove refrigerant hoses from compressor, and cap openings. Remove compressor from bracket (if equipped). 3. To install, reverse removal procedure. Drain and measure oil from old compressor. If less than one ounce is drained, add 2 ounces of refrigerant oil to NEW compressor. If more than one ounce is drained, add the same amount to NEW compressor. Evacuate, charge, and leak test system. CONDENSER Removal & Installation

1. Disconnect negative battery cable. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove upper fan shroud. Drain engine coolant. Remove radiator. Disconnect inlet and outlet lines at condenser, and cap openings. Remove condenser from vehicle. 2. To install, reverse removal procedure. Lubricate NEW "O" rings with clean refrigerant oil before Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

installation. Add one ounce of clean refrigerant oil to condenser. Fill cooling system, and check for leaks. Evacuate, charge, and leak test A/C system. CONTROL PANEL Removal & Installation

Disconnect negative battery cable. Remove instrument panel center bezel. Remove control panel screws. Remove control cable. Disconnect vacuum and electrical connectors at control panel. Remove control panel. To install, reverse removal procedure. EVAPORATOR CORE Removal

1. Disconnect both negative and positive battery cables. Recover the refrigerant from the A/C system. See Fig. 2 . Disconnect blower motor resistor connector. Remove the battery and battery tray. 2. Disconnect condenser-to-evaporator line. Disconnect hose from accumulator. See ACCUMULATOR . Remove coolant recovery reservoir. 3. Remove the VCM, or PCM. Raise the vehicle. Remove the right front wheel, and right front wheel house panel. Remove evaporator and blower motor assembly screws and nuts. Remove acoustic barrier (if equipped). Remove evaporator and blower module from vehicle. Remove case screws and nuts. Separate case sections, and remove evaporator core. See Fig. 2 . Installation

1. Install the evaporator core. Install the case sections and screws. Install the evaporator and blower module assembly in the vehicle. Install the acoustic barrier (if equipped). 2. Install the evaporator and blower module screws and nuts. Tighten the bolts and stud to 40 INCH lbs. (4.5 N.m). Tighten screws and nuts to 22 INCH lbs. (2.5 N.m). 3. Install right front wheel and right front wheel house panel. Lower the vehicle. Install the VCM, or PCM. Install the coolant recovery reservoir. Install the accumulator. 4. Install the evaporator tube to evaporator. Install the electrical connectors, as necessary. Install battery and battery tray. Connect the blower motor resistor. 5. Replace refrigerant to the system. Install the battery cables. Check the system for leaks. HEATER CORE CAUTION: Heater core can be damaged if too much force is applied to heater core pipes during hose removal. Removal & Installation

1. Disable air bag system. See the AIR BAG RESTRAINT SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section. Drain engine coolant. Remove heater hoses at core, Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

2. 3.

and plug core openings. Remove instrument cluster trim plate. Move tilt steering column down (if equipped), set parking brake and move automatic transmission gear selector to low (if equipped). Remove left underdash hush panel. Remove Data Link Connector (DLC) and Remote Keyless Entry (RKE) module connectors. Remove center underdash hush panel. Disconnect park brake release cable from instrument panel. Disconnect park brake cable from ratchet mechanism. Remove right underdash hush panel. Remove lighter and accessory outlets, if equipped. Remove courtesy light. Remove knee bolster. Partially pull A/C-heater control panel and radio to disconnect connectors on back of A/C-heater control panel and radio. Remove 4 steering column retaining bolts and lower steering column. Remove speaker and defroster grilles. Remove 9 instrument panel support bolts, including brake pedal bracket support bolt. See Fig. 3 . Remove electrical connectors. Remove instrument panel. Remove core cover attaching screws. Remove retainers at end of core. Remove heater core. To install, reverse removal procedure. Fill cooling system, and check for leaks.

Fig. 3: Locating Instrument Panel Support Bolts Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:43:17 AM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Accumulator Inlet Fitting Compressor Bolts 2.2L 4.3L

Ft. Lbs. (N.m) 30 (41) 37 (50) 24 (33) 24 (33)

Compressor Hose Assembly Bolt (1) Compressor-To-Bracket Bolt Condenser Inlet Fitting Evaporator-To-Accumulator Fitting Evaporator-To-Condenser Line Fittings (1) Use NEW sealing washers.

23 (31) 18 (24) 30 (41) 13 (18)

VACUUM DIAGRAM

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

Fig. 4: Manual A/C-Heater System Vacuum Diagram Courtesy of GENERAL MOTORS CORP.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

Fig. 5: Manual A/C-Heater System Wiring Diagram (2.2L)

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

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1997 Chevrolet S10 Pickup 1997 AIR CONDITIONING & HEAT Manual A/C

Fig. 6: Manual A/C-Heater System Wiring Diagram (4.3L)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

MODEL IDENTIFICATION BODY DESIGNATIONS Body Code

Models

Cars (1) "F" "H"

Camaro, Firebird Boneville, Eighty Eight, LeSabre, LSS, Regency Cavalier, Sunfire Achieva, Cutlass, Grand Am, Malibu, Skylark Century, Cutlass Supreme, Grand Prix Lumina, Monte Carlo, Regal Corvette

"J" "L/N" "W" "W" "Y" Trucks/Vans (2) "C"

2WD Pickup, Sierra, Suburban, Tahoe & Yukon Express, Savanna & Van 4WD Pickup, Sierra, Suburban, Tahoe & Yukon AWD Astro & Safari 2WD Astro & Safari Commercial Van/Motorhome 2WD Blazer, Jimmy, Pickup & Sonoma 4WD Blazer, Bravada, Jimmy, Pickup & Sonoma Silhouette, Trans Sport & Venture

"G" "K" "L" "M" "P" "S" "T" "U" (1) Body codes determined by fourth character of VIN code. (2) Vehicle series is fifth character of VIN code.

COMPRESSOR APPLICATIONS COMPRESSOR APPLICATIONS Application (1)

Compressor

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

"C" Body "E" Body "K" Body "F" Body 3.8L V6 5.7L V8 "G" Body "H" Body "J" Body "L/N" Body "V" Body "W" Body "Y" Body "Z" Body (Saturn) (1) Body codes determined by fourth character of VIN code.

Harrison V5 5-Cyl. Harrison HD6/HR-6HE 6-Cyl. Harrison HD6/HR-6HE 6-Cyl. Harrison V5 5-Cyl. Harrison HD6/HT6 6-Cyl. Harrison HD6/HT6 6-Cyl. Harrison HD6/HT6 6-Cyl. Harrison V5 5-Cyl. Harrison V5 5-Cyl. Harrison V5 5-Cyl. Harrison V5 5-Cyl. Harrison V5/V7 Zexel Rotary Vane

COMPRESSOR APPLICATIONS Application (1) "C" & "K" Series "G" Series "L" & "M" Series "P" Series "S" & "T" Series 2.2L 4.3L "U" Series (1) Series codes determined by fifth character of VIN code.

Compressor Harrison HD6/HT6 6-Cyl. Harrison HD6/HT6 6-Cyl. Harrison HD6/HT6 6-Cyl. Harrison HD6/HT6 6-Cyl. Harrison V5 5-Cyl. Harrison HD6/HT6 6-Cyl. Harrison V5 5-Cyl.

OPERATIONAL TESTING When trouble shooting and diagnosing an air conditioning system, always refer to appropriate vacuum and wiring diagrams for the system involved. See appropriate A/C-HEATER SYSTEM - MANUAL article. If blower operates at all speeds and compressor clutch engages, electrical circuits are functioning properly. If evaporator inlet pipe and accumulator surface appear to be the same temperature when felt by hand, system is properly charged with refrigerant. Ensure vacuum and diaphragm function properly when moving selector control.

ELECTRICAL TROUBLE SHOOTING BLOWER MOTOR WILL NOT RUN Microsoft Saturday, August 29, 2009 11:43:59 AM

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Check fuses. Turn ignition switch to RUN position. Check for voltage at function control switch. Switch blower switch to HI position. Check for voltage at switch and at high-speed blower relay. Ground blower motor with ignition switch in RUN position. If blower operates, motor is okay. BLOWER DOES NOT OPERATE IN HI Check for voltage at high-speed blower relay with ignition switch in RUN position and blower switch in HI position. If voltage is not present, check for voltage at blower switch. BLOWER OPERATES ONLY IN HI Check blower resistors for open condition. Check blower switch for voltage at each position. A/C DOES NOT WORK With engine running and function control switch at NORM position, check for voltage at pressure cycling switch. Check for voltage between pressure cycling switch and compressor clutch. Ground compressor clutch circuit. If clutch engages, check wide-open throttle cut-out switch and A/C compressor cut-off switch.

REFRIGERANT SYSTEM DIAGNOSIS INSUFFICIENT COOLING NOTE:

Quick check procedure may be used to check for proper refrigerant charge, provided ambient temperature is more than 70°F (21°C). On vehicles with Cycling Clutch Orifice Tube (CCOT) system, compressor will cycle on and off to meet system requirements.

Quick Check Procedure

1. Engine must be at normal operating temperature. Open vehicle doors and hood. Select MAX A/C or RECIRC mode. Move temperature lever to COLD position. Blower switch in HIGH position. Engine should be at normal idle speed. 2. While compressor is engaged, feel temperature of accumulator surface and evaporator inlet pipe. If temperature of both components is the same, system is normal. If evaporator inlet pipe is frosted or feels cooler than accumulator surface, refrigerant charge is low. 3. Add refrigerant in 4-ounce increments, allowing system to stabilize between additions, until accumulator and inlet pipe are the same temperature. Add an additional 14 ounces of refrigerant. Thorough Check Procedures

Begin diagnosis at V5/TXV SYSTEM DIAGNOSIS (STEP 1) or V5/VDOT SYSTEM DIAGNOSIS (STEP 1) . For further diagnosis, go to appropriate trouble shooting chart. See TROUBLE SHOOTING CHART DIRECTORY . V5/TXV SYSTEM DIAGNOSIS (STEP 1) Microsoft Saturday, August 29, 2009 11:43:59 AM

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Preliminary Checks

Check and repair the following: 

  

     

Connect Tech 1 Scan Tool. Check for stored trouble codes. If codes are found, see the TESTS W/CODES article in the ENGINE PERFORMANCE section. Check A/C fuse. Check A/C blower operation. On vehicles with cable operated temperature door, move temperature lever rapidly from cold to hot. Listen for temperature door hitting travel stops at each end. Adjust as necessary. Check A/C compressor clutch coil connection. Check A/C pressure transducer connection. Check compressor belt condition. Adjust or replace as necessary. Check cooling fan operation. Check for restricted airflow across condenser. Check Technical Service Bulletins (TSBs) for A/C system updates.

V5/VDOT SYSTEM DIAGNOSIS (STEP 1) Preliminary Checks

Check and repair the following:   

    

Check A/C fuse. Check A/C blower operation. On vehicles with cable operated temperature door, move temperature lever rapidly from cold to hot. Listen for temperature door hitting travel stops at each end. Adjust as necessary. Check clutch coil and connections at rear head switch(es). Check compressor belt condition. Adjust or replace as necessary. Check cooling fan operation. Check for restricted airflow across condenser. Check Technical Service Bulletins (TSBs) for A/C system updates.

If discharge air temperature with A/C on is normal after making repairs, system is operating properly. If further trouble shooting is required, go to appropriate trouble shooting chart. See TROUBLE SHOOTING CHART DIRECTORY . TROUBLE SHOOTING CHART DIRECTORY (1) Application CCOT System V5/TXV System V5/VDOT System

Figures Fig. 1 -Fig. 5 Fig. 6 -Fig. 12 Fig. 13 -Fig. 19

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

(1) Vehicles with Harrison V5 5-cylinder compressor use a Variable Displacement Orifice Tube (VDOT)

or Thermal Expansion Valve (TXV) system, referred to as V5/VDOT and V5/TXV systems. Vehicles with any other compressor use the Cycling Clutch Orifice Tube (CCOT) system.

INSUFFICIENT COOLING DIAGNOSIS CHARTS - (CCOT)

Fig. 1: Insufficient Cooling Chart "A" (CCOT) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:43:59 AM

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 2: Insufficient Cooling Chart "B" (CCOT) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 3: Insufficient Cooling Chart "C" (CCOT) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 4: Insufficient Cooling Chart "D" (CCOT) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 5: Insufficient Cooling Chart "E" (CCOT) Courtesy of GENERAL MOTORS CORP.

CHECKING REFRIGERANT CHARGE - STEP 2 - (V5/TXV)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 6: Checking Refrigerant Charge - Step 2 (V5/TXV) Courtesy of GENERAL MOTORS CORP.

CHECKING COMPRESSOR CLUTCH ENGAGEMENT - STEP 3 - (V5/TXV)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 7: Checking Compressor Clutch Engagement - Step 3 (V5/TXV) Courtesy of GENERAL MOTORS CORP.

CHECKING PERFORMANCE - STEP 4 - (V5/TXV)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 8: Checking Performance - Step 4 (V5/TXV) Courtesy of GENERAL MOTORS CORP.

PERFORMANCE DIAGNOSTIC CHART - STEP 5 - (V5/TXV)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 9: Performance Diagnostic Chart - Step 5 (V5/TXV) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:43:59 AM

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

DIAGNOSTIC CODE PROCEDURES - STEP 6 - (V5/TXV)

Fig. 10: Diagnostic Code Procedures - Step 6 (V5/TXV) Courtesy of GENERAL MOTORS CORP.

CHECKING FOR NO STROKE COMPRESSOR - STEP 7 - (V5/TXV) Microsoft Saturday, August 29, 2009 11:43:59 AM

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 11: Checking For No Stroke Compressor - Step 7 (V5/TXV) Courtesy of GENERAL MOTORS CORP.

CONTROL VALVE DIAGNOSIS - STEP 8 - (V5/TXV) Microsoft Saturday, August 29, 2009 11:43:59 AM

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 12: Control Valve Diagnosis - Step 8 (V5/TXV) Courtesy of GENERAL MOTORS CORP.

CHECKING REFRIGERANT CHARGE - STEP 2 - (V5/VDOT)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 13: Checking Refrigerant Charge - Step 2 (V5/VDOT) Courtesy of GENERAL MOTORS CORP.

CHECKING COMPRESSOR CLUTCH ENGAGEMENT - STEP 3 - (V5/VDOT)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 14: Checking Compressor Clutch Engagement - Step 3 (V5/VDOT) Courtesy of GENERAL MOTORS CORP.

CHECKING PERFORMANCE - STEP 4 - (V5/VDOT)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 15: Checking Performance - Step 4 (V5/VDOT - 1 Of 2) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 16: Checking Performance - Step 4 (V5/VDOT - 2 Of 2) Courtesy of GENERAL MOTORS CORP.

RIGHT AREA DIAGNOSIS & SERVICE - STEP 5 - (V5/VDOT)

Fig. 17: Right Area Diagnosis & Service - Step 5 (V5/VDOT) Courtesy of GENERAL MOTORS CORP.

LEFT AREA DIAGNOSIS & SERVICE - STEP 6 - (V5/VDOT)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 18: Left Area Diagnosis & Service - Step 6 (V5/VDOT) Courtesy of GENERAL MOTORS CORP.

CONTROL VALVE DIAGNOSIS - STEP 7 - (V5/VDOT)

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1997 Chevrolet S10 Pickup A/C-HEATER SYSTEM TROUBLE SHOOTING - MANUAL 1997 A/C-HEATER SYSTEMS General Motors - Manual A/C-Heater System Trouble Shooting

Fig. 19: Control Valve Diagnosis - Step 7 (V5/VDOT) Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:44:00 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

DESCRIPTION Instrument cluster uses analog speedometer and gauges. See Fig. 1 . Indicator lights, plugged into back of cluster, are serviceable, but no other components on cluster are serviceable. If any component on cluster is faulty, replace cluster.

Fig. 1: Identifying Instrument Components Courtesy of GENERAL MOTORS CORP. WARNING: If BRAKE light is on, ensure brake hydraulic system is okay before driving vehicle. BRAKE When one or more of the following conditions exists, BRAKE light is grounded, turning on light:  

Parking brake switch is closed. Brake pressure differential switch is closed (detects loss of hydraulic pressure).

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.



BPMV detects problem in hydraulic part of ABS system. Light also comes on for 2 seconds after ignition is turned on, and engine is off (BPMV turns on light for 2-second system check).

CHARGING SYSTEM One side of battery symbol light bulb is connected to alternator field circuit, and other side to ignition power circuit. When ignition is turned on, bulb is grounded through field circuit. When engine is started, field output equalizes voltage across bulb, turning off light. If charging system output is insufficient, light comes on. CHECK GAUGES If coolant temperature is too high or oil pressure is too low, light comes on to alert driver of condition indicated by gauges. A CHECK GAUGES light driver (part of coolant temperature gauge) monitors signals from temperature gauge sending unit and oil pressure sending unit. If CHECK GAUGES light driver receives a signal from either sending unit, it grounds light. COOLANT TEMPERATURE See CHECK GAUGES . OIL PRESSURE See CHECK GAUGES . SEAT BELT LIGHT Seat belt warning light works in conjunction with a buzzer. If seat belt is not fastened when key is turned to run, buzzer will sound for 8 seconds and light will illuminate solid for 20 seconds and flash for 55 seconds. Buzzer will stop if belt is fastened during 8 second interval. If seat belt is fastened when key is turned to run, no buzzer will sound and light will illuminate solid for 75 seconds. If seat belt is unfastened during 8 second interval, buzzer will sound for remainder of 8 second interval. SERVICE ENGINE SOON If a problem occurs in engine control system, PCM/VCM grounds light. Light should come on when ignition is turned on, then go out when engine starts if no problems exist in engine control system. SHIFT (M/T) Light comes on to tell driver when to upshift for best fuel economy. PCM/VCM monitors engine speed, load and throttle position for light control. PCM/VCM grounds light if parameters are met.

AIR BAG PRECAUTIONS Observe following precautions when working with vehicles equipped with Supplemental Inflatable Restraint (SIR) system: Microsoft Saturday, August 29, 2009 12:04:21 PM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.



Before performing any instrument panel testing, diagnosis or repair, disable SIR system by disconnecting negative battery cable and Yellow 2-pin connector at base of steering column. Wait 2 minutes before making SIR repairs. SIR system retains enough voltage to deploy air bag after power is disconnected. To prevent accidental air bag deployment, avoid SIR wiring harness when trouble shooting instrument panel components. All SIR wires are color-coded Yellow.

SPEEDOMETER & ODOMETER Vehicle Speed Sensor (VSS) produces voltage pulses of frequency proportional to vehicle speed. This signal is processed by PCM/VCM to produce a voltage pulse signal to speedometer and odometer. NOTE:

Incorrect VSS calibrator calibration may adversely affect operation of ABS, engine control system and cruise control system.

TRIPMETER Pressing button on cluster resets trip mileage to zero.

TESTING CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. CAUTION: Static electricity can destroy integrated circuits in instrument cluster and VSS calibrator. Before servicing these components, ground yourself and work area to discharge static electricity. NOTE:

Check GAUGES or IGN/GAU fuse in passenger compartment fuse block before testing. If all components in cluster are inoperative, check instrument cluster power and ground circuits. If power and ground circuits are okay, replace instrument cluster.

COOLANT TEMPERATURE GAUGE Gauge Indicates Cold When Engine Is Hot

Disconnect temperature gauge sending unit connector. Connect jumper between ground and Dark Green wire terminal of sending unit connector. Turn ignition on. If gauge indicates hot, replace sending unit. If gauge does not indicate hot, check Dark Green wire between sending unit and cluster. If wire is okay, replace instrument cluster. Microsoft Saturday, August 29, 2009 12:04:21 PM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Gauge Indicates Hot When Engine Is Cold

Disconnect temperature gauge sending unit connector. Turn ignition on. If gauge indicates cold, replace sending unit. If gauge still indicates hot, check Dark Green wire between sending unit and cluster. If wire is okay, replace instrument cluster. FUEL GAUGE Gauge Stays At EMPTY

Disconnect fuel tank sending unit connector. Turn ignition on. If gauge indicates FULL, replace sending unit. If gauge indicates EMPTY, check for short to ground in Purple wire. If wire is okay, replace instrument cluster. Gauge Stays At FULL

Disconnect fuel tank sending unit connector. Turn ignition on. Connect fused jumper wire between ground and Purple wire terminal of sending unit connector. If gauge indicates EMPTY, replace sending unit. If gauge indicates FULL, check Purple wire between sending unit and instrument cluster for an open circuit. If wire is okay, replace instrument cluster. Gauge Is Inaccurate

1. Disconnect fuel tank sending unit connector. Connect Red lead of Instrument Panel Tester (J-33431) to sending unit harness connector terminal (Purple wire), and connect other Red lead to ground. Turn ignition on. 2. Set tester dial to zero ohms, then 90 ohms. If fuel gauge indicates EMPTY at zero ohms and FULL at 90 ohms, check sending unit ground. If ground is okay, replace sending unit. If fuel gauge does not indicate as specified, check Purple wire between sending unit and cluster. If wire is okay, fuel gauge. INDICATOR LIGHTS Brake Warning Light Inoperative

Disconnect instrument cluster connector. Set parking brake. Connect self-powered test light between instrument cluster connector Tan/White wire and ground. If test light comes on, check for poor connection at instrument cluster connector. If connection is okay, replace instrument cluster. If test light does not light, repair open circuit in Tan/White wire. Ignition Switch Does Not Activate Brake Warning Light

1. Turn ignition on. Set parking brake. If brake warning light comes on, go to next step. If brake warning light does not come on, go to BRAKE WARNING LIGHT INOPERATIVE. 2. Release parking brake. Connect fused jumper wire between ground and Light Blue wire at 48-pin connector between ignition switch and parking brake warning switch. Turn ignition on. If brake warning light comes on, go to next step. If brake warning light does not come on, repair open circuit in Light Blue wire. 3. Connect fused jumper wire between Light Blue and Black wires at 48-pin connector. Turn ignition on. If Microsoft Saturday, August 29, 2009 12:04:21 PM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

brake warning light comes on, replace ignition switch. If brake warning light does not come on, repair open circuit in Black wire between 48-pin connector and ground. Parking Brake Will Not Activate Brake Warning Light

1. Disconnect parking brake warning switch connector. Connect fused jumper wire between Light Blue wire at parking brake warning switch connector and ground. Turn ignition on. If brake warning light does not come on, go to next step. If brake warning light does come on, check for poor connection at parking brake warning switch. If connection is okay, replace parking brake warning switch. 2. Remove fused jumper wire. Connect fused jumper wire between instrument cluster connector Tan/White wire and ground. If brake warning light comes on, go to next step. If brake warning light does not come on, check for poor connection at instrument cluster connector. If connection is okay, replace instrument cluster. 3. Connect test light between diode module Light Blue wire and ground. If test light comes on, repair open circuit in Light Blue wire. If test light does not come on, repair open circuit in Tan/White wire between instrument cluster and diode module. If circuit is okay, replace diode module. Brake Warning Light Remains On With Ignition On & Parking Brake Released

1. Disconnect parking brake warning switch connector. If brake warning light remains on, go to next step. If brake warning light does not remain on, replace parking brake warning switch. 2. Disconnect brake pressure warning switch connector (Brake Pressure Modulator Valve (BPMV) front connector). BPMV is located in engine compartment, on left inner fender panel and connector is on front side of BPMV. If brake pressure warning light remains on, go to next step. If brake pressure warning light does not remain on, replace brake pressure warning switch. 3. Disconnect 48-pin connector between ignition switch and parking brake warning switch. Check continuity between terminals B5 (Tan/White wire) and B2 (Black wire). If no continuity is present, reconnect connector and go to next step. If continuity is present, replace ignition switch. 4. Disconnect brake pressure modulator valve 10-pin connector. If brake warning light remains on, check Purple or Tan/White wires for a short to ground. If wires are okay, replace instrument cluster. If brake warning light does not remain on, diagnose brake system. See ANTI-LOCK BRAKE SYSTEM article in BRAKES section. CHECK GAUGES Or Temperature Indicator Does Not Light With Ignition Switch In Run Or Start

Disconnect ignition switch connector. Connect fused jumper wire between Dark Green wire at ignition switch connector and ground. Turn ignition on. If temperature or CHECK GAUGES indicator lights, replace ignition switch. If temperature or CHECK GAUGES indicator does not light, repair open circuit in Dark Green wire between ignition switch connector and instrument cluster connector. CHECK GAUGES Light Inoperative With High Coolant Temperature

Inspect CHECK GAUGES bulb and replace if faulty. If bulb is okay, replace instrument cluster. CHECK GAUGES Light Inoperative With Low Oil Pressure

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Inspect CHECK GAUGES bulb and replace if faulty. If bulb is okay, replace instrument cluster. OIL PRESSURE GAUGE NOTE:

If procedure specifies replacing oil pressure sending unit, replace with revised sending unit. Some older version sending units may cause gauge to indicate oil pressure higher than actual pressure, or may cause gauge fluctuations. Check with manufacturer for latest part number.

Gauge Is Inaccurate

1. Disconnect oil pressure sending unit connector. Connect one Red wire lead of Instrument Panel Tester (J33431) to Tan wire terminal of temperature sending unit connector, and connect other Red lead to ground. Turn ignition on. 2. Adjust tester dial to zero ohms, then 90 ohms. If gauge indicates LOW at zero ohms and HIGH at 90 ohms, replace sending unit. If gauge does not indicate as specified, check for open in Tan wire between sending unit and instrument cluster. If wire is okay, replace instrument cluster. SPEEDOMETER & ODOMETER NOTE:

Speedometer and odometer testing for is not available from manufacturer.

TACHOMETER Tachometer Inoperative

Connect Tech 1 scan tool to data link connector. Start engine. Read engine RPM from Tech 1 scan tool. If Tech 1 scan tool displays engine RPM, repair open or short to ground in White wire between ignition coil and instrument cluster terminal No. 8. See Fig. 2 . If wire is okay, replace instrument cluster. If Tech 1 displays zero for engine RPM, repair open or short to ground in White wire. If wire is okay, replace ignition coil or Powertrain Control Module (PCM).

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Fig. 2: Instrument Cluster Connector Courtesy of GENERAL MOTORS CORP. VOLTMETER Microsoft Saturday, August 29, 2009 12:04:21 PM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Voltmeter Inaccurate

Turn ignition on. Check voltage across battery terminals. If battery voltage matches vehicle voltmeter, voltmeter is accurate. If battery voltage does not match vehicle voltmeter, check for open or high resistance in Pink or Black wires at instrument cluster. If wires are okay, replace instrument cluster.

REMOVAL & INSTALLATION CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. CAUTION: Static electricity can destroy integrated circuits in instrument cluster and VSS calibrator. Before servicing these components, ground yourself and work area to discharge static electricity. INSTRUMENT CLUSTER Removal & Installation

Disconnect negative battery cable. Disable SIR system. See AIR BAG PRECAUTIONS . Remove sound insulation. Remove steering column cover nuts. Remove steering column cover. Remove instrument cluster bezel. Remove 4 cluster-to-instrument panel screws. Disconnect electrical connector. Remove cluster. See Fig. 3 . To install, reverse removal procedure.

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Fig. 3: Exploded View Of Instrument Cluster Courtesy of GENERAL MOTORS CORP.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Fig. 4: Analog Instrument Panel Wiring Diagram (1 Of 2)

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES/SAFETY EQUIP Analog Instrument Panels - General Motors Corp.

Fig. 5: Analog Instrument Panel Wiring Diagram (2 Of 2)

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

MODEL IDENTIFICATION VIN LOCATION The Vehicle Identification Number (VIN) is located on the left side of the dash panel at the base of the windshield. The VIN chart explains the code characters. SERVICE PARTS IDENTIFICATION LABEL Label is located inside glove box door and has the vehicle's VIN, wheelbase, paint information, and a list of all production options and special equipment. VIN CODE ID EXPLANATION Numbers preceding the explanations in the legend below refer to the sequence of characters as listed on VIN identification label. See VIN example below.

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

Fig. 1: VIN Code ID Explanation

MAINTENANCE SERVICE INTERVAL DEFINITIONS Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

SHORT TRIP/CITY & LONG TRIP/HIGHWAY SERVICE DEFINITIONS NOTE:

Starting in the 1996 model year, General Motors has renamed their maintenance schedules; One is referred to as the Short-Trip/City and the other is the Long Trip/Highway schedule. These schedule requirements are similar to the familiar Severe Service and Normal schedules and can be used in place of one another.

SEVERE & NORMAL SERVICE DEFINITIONS NOTE:

Use the Severe Service schedule if the vehicle to be serviced is operated under ANY (one or more) of these conditions:

Service is recommended at mileage intervals based on vehicle operation, emission classification, and Gross Vehicle Weight Rating (GVWR, VIN Position 4). Emission classification is identified by engine VIN code (except diesel-powered vehicles). Manufacturer's Schedules identify items to be serviced based on type of operation. Service schedules are based on the following primary operating conditions: Severe Service      

Short Trips (4 Miles Or Less) Freezing Temperatures Towing Or Heavily Loaded Severe Dust Conditions Hot Weather, Stop-And-Go Driving Extensive Idling Conditions (Taxi Or Delivery Type Service)

Normal Service 

No Severe Service Operating Conditions

SERVICE POINT LOCATIONS

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

Fig. 2: Service Point Locations (4.3L V-6 Typical) Courtesy of GENERAL MOTORS CORP.

Fig. 3: Borg-Warner Clutch Service Points Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

Courtesy of GENERAL MOTORS CORP.

Fig. 4: Lift Point Locations Courtesy of GENERAL MOTORS CORP. NOTE:

For more information regarding jacking or hoisting the vehicle, refer to the JACKING & HOISTING article in the WHEEL ALIGNMENT section.

SERVICE LABOR TIMES NOTE:

Labor times are provided, where available, within appropriate SERVICE INTERVAL table in SCHEDULED SERVICES article.

WHEEL & TIRE SPECIFICATIONS Wheel and tire information can be found on the Certification/Tire label attached to rear of driver's door or door pillar. NOTE:

DO NOT use chains with P235/75R15 size tires. Vehicle damage may result.

WHEEL SIZE Replacement wheels should match originals in load limit, diameter, width, offset, and mounting configuration. The wrong wheel can cause difficulty with bearing life, brake cooling, speedometer/odometer calibration, stopping ability, headlight aim, bumper height, vehicle ground clearance and tire or tire chain clearance to body Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

and chassis. WHEEL TIGHTENING Tighten lug nuts to 95 ft. lbs. (130 N.m).

BATTERY SPECIFICATIONS CAUTION: When battery is disconnected, vehicles equipped with computers may lose memory data. When battery power is restored, driveability problems may exist on some vehicles. These vehicles may require a relearn procedure. See COMPUTER RELEARN PROCEDURES article in the GENERAL INFORMATION section.

CAUTIONS & WARNINGS SUPPLEMENTAL RESTRAINT SYSTEM (AIR BAG) NOTE:

See the AIR BAGS article in the ACCESSORIES/SAFETY EQUIPMENT Section.

Modifications or improper maintenance, including incorrect removal and installation of the Supplemental Restraint System (SRS), can adversely affect system performance. DO NOT cover, obstruct or change the steering wheel horn pad in any way, as such action could cause improper function of the system. Use only plain water when cleaning the horn pad. Solvents or cleaners could adversely affect the air bag cover and cause improper deployment of the system. WARNING: To avoid injury from accidental air bag deployment, read and carefully follow all warnings and service precautions. See appropriate AIR BAGS article in ACCESSORIES/SAFETY EQUIPMENT. Modification to the air bag system component or wiring can adversely affect system performance and possibly cause injury. CAUTION: The Diagnostic Energy Reserve Module (DERM) can maintain enough voltage to cause a deployment of the inflator module for up to 10 minutes after the ignition switch is turned off and the battery is disconnected. Many of the service procedures require disconnection of the inflator module to avoid an accidental deployment. CAUTION: Disconnect negative battery cable before servicing any air bag system, steering column or passenger side dash component. After any repair, turn ignition key to the ON position from passenger's side of vehicle in case of accidental air bag inflation AIR CONDITIONING SERVICING Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

CAUTION: Avoid breathing R-134a refrigerant and PAG lubricant vapors, exposure may irritate eyes, nose and throat. To remove R-134a from system use R134a recycling equipment that meets SAE J2210 specifications. If accidental system discharge occurs, ventilate work area before resuming service. WARNING: R-134a service equipment or vehicle A/C systems SHOULD NOT be pressure tested or leak tested with compressed air. Some mixtures of air/R134a have shown to be combustible at elevated pressures. These mixtures are dangerous and may cause fire and/or explosions. See AIR CONDITIONING SERVICE article in GENERAL INFORMATION section. ANTI-LOCK BRAKE SYSTEM The anti-lock brake system contains electronic equipment that can be susceptible to interference caused by improperly installed or high output radio transmitting equipment. Since this interference could cause the possible loss of the anti-lock braking capability, such equipment should be installed by qualified professionals. On models equipped with anti-lock brake systems, ALWAYS observe the following cautions: 



DO NOT attempt to bleed hydraulic system without first referring to the appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES Section. DO NOT mix tire sizes. As long as tires remain close to the original diameter, increasing the width is acceptable. Rolling diameter must be identical for all 4 tires. Some manufacturers recommend tires of the same brand, style and type. Failure to follow this precaution may cause inaccurate wheel speed readings. Use ONLY recommended brake fluids. DO NOT use silicone brake fluids in an ABS-equipped vehicle.

AXLE LUBRICANTS CAUTION: Axle lube quantities must be replaced if the axle has been submerged in water. REPLACING BLOWN FUSES CAUTION: Before replacing a blown fuse, remove ignition key, turn off all lights and accessories to avoid damaging the electrical system. Be sure to use fuse with the correct indicated amperage rating. The use of an incorrect amperage rating fuse may result in a dangerous electrical system overload. BATTERY WARNING WARNING: When battery is disconnected, vehicles equipped with computers may lose memory data. When battery power is restored, driveability problems Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

may exist on some vehicles. These vehicles may require a relearn procedure. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION section. BRAKE PAD WEAR INDICATOR CAUTION: Indicator will cause a squealing or scraping noise, warning that brake pads need replacement. CATALYTIC CONVERTER CAUTION: To prevent catalytic converter overheating, DO NOT allow engine to idle for more than 20 minutes. COOLANT (DEX-COOL 1995-96 MODELS) CAUTION: Some 1995 build-out and all 1996 models have DEX-COOL engine coolant installed at the factory. DEX-COOL coolant is a silicate-free coolant that is orange in color. It should not be mixed with regular ethylene-glycol coolant. To avoid possible damage to vehicle cooling system, visually check engine coolant color before adding and/or changing engine coolant. Vehicle should have an identification label placed under the hood stating what type coolant is installed. COOLANT (PROPYLENE-GLYCOL FORMULATIONS) CAUTION: To avoid possible damage to vehicle use only ethylene-glycol based coolants with a mixture ratio from 44-68% anti-freeze. DO NOT use 100% anti-freeze as it will cause the formation of cooling system deposits. This results in coolant temperatures of over 300° F (149°C) which can melt plastics. 100% anti-freeze has a freeze point of only -8° F (-22°C). CAUTION: Propylene-Glycol Mixtures has a smaller temperature range than EthyleneGlycol. The temperature range (freeze-boil) of a 50/50 Anti-Freeze/Water Mix is as follows: Propylene-Glycol -26° F (-32°C) - 257° F (125°C); Ethylene-Glycol -35° F (-37°C) - 263° F (128°C). CAUTION: Propylene-Glycol/Ethylene-Glycol Mixtures can cause the destabilization of various corrosion inhibitors. Also Propylene-Glycol/Ethylene-Glycol has a different specific gravity than Ethylene-Glycol coolant, which will result in inaccurate freeze point calculations. ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

WARNING: Many solid state electrical components can be damaged by static electricity (ESD). Some will display a warning label, but many will not. Discharge personal static electricity by touching a metal ground point on the vehicle prior to servicing any ESD sensitive component. FUEL SYSTEM SERVICE WARNING: Relieve fuel system pressure prior to servicing any fuel system component. HALOGEN BULBS WARNING: Halogen bulbs contain pressurized gas which may explode if overheated. DO NOT touch glass portion of bulb with bare hands. Eye protection should be worn when handling or working around halogen bulbs. METHANOL GASOLINE CAUTION: Fuel that is more than 5% methanol should not be used in this vehicle. It can corrode metal parts in the fuel system, and damage plastic and rubber parts. Even at 5% methanol or less, solvents and corrosion preventers must be used with this fuel to avoid these problems. RADIATOR CAP CAUTION: Always disconnect the fan motor when working near the radiator fan. The fan is temperature controlled and could start at any time even when the ignition key is in the OFF position. DO NOT loosen or remove radiator cap when cooling system is hot. RADIATOR FAN WARNING: Keep hands away from radiator fan.

SPARK PLUGS - 2.2L NOTE:

Allow engine to cool before removing spark plugs from aluminum cylinder heads.

WARRANTY INFORMATION CAUTION: Due to the different warranties offered in various regions and the variety of Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

after-market extended warranties available, please refer to the warranty package that came with the vehicle to verify all warranty options. BUMPER-TO-BUMPER PLUS COVERAGE LIMITED WARRANTY Entire vehicle (except battery) is covered for 3 years or 50,000 miles, whichever occurs first. Covered by this warranty are any repairs to vehicle components which have proven defective in material and workmanship under normal use (tires excluded). Warranty repairs (parts and labor) will be made by the Dealer at no charge using new or remanufactured parts. This warranty is subject to a 100 deductible for each repair visit after the first year or 12,000 miles, whichever occurs first. BATTERY COVERAGE Covers replacement cost of battery for 3 years or 50,000 miles, whichever occurs first. A prorated charge applies after first 12 months or 12,000 miles, whichever occurs first. CORROSION COVERAGE Covers any body sheet metal panel that is perforated due to corrosion. Coverage is for 6 years or 100,000 miles, whichever occurs first. EMISSIONS "DEFECT" & "PERFORMANCE" WARRANTIES (FEDERAL) Defect Warranty ensures vehicle meets applicable EPA regulations and that emission control system is free from defects in materials and workmanship. Coverage is for a period of 5 years or 50,000 miles, whichever occurs first. Performance Warranty covers all costs of repairing or adjusting any components or parts as needed in order for the vehicle to pass a federally-required state or local emissions test. Other emission control parts related to these components are covered by the Performance Warranty, where applicable. If another part fails due to the failure of one of these components, both parts are covered. See customer's copy of warranty information for specific items covered. EMISSION "PERFORMANCE" WARRANTY (CALIFORNIA) If vehicle fails a Smog Check inspection, all necessary repairs and adjustments will be made by manufacturer to ensure vehicle passes inspection. Coverage is for 3 years or 50,000 miles, whichever occurs first. EMISSION "DEFECT" WARRANTY (CALIFORNIA) If any emission-related part on the vehicle is defective, the part will be repaired or replaced by manufacturer. Coverage is for 3 years or 50,000 miles, whichever occurs first. Some emission-related parts are covered for 7 years or 70,000 miles, whichever occurs first, and will be repaired or replaced by manufacturer if found to be defective in material or workmanship. See customer's copy of warranty information for specific items covered. Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

FUSES & CIRCUIT BREAKERS FUSE PANEL LOCATIONS The fuse block is located under the instrument panel to the left of the steering column. FUSE PANEL ID (1994 S-SERIES PICKUP)

Fig. 5: Fuse Panel ID (1994 S-Series Pickup) Courtesy of GENERAL MOTORS CORP. Fuse & Circuit Breaker Identification Microsoft Saturday, August 29, 2009 11:44:57 AM

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

   

 

         

A - Pwr-Accy 20 Amp (Circuit Breaker) Power Door Locks B - Pwr-Wdo 30 Amp (Circuit Breaker) Power Windows 1 - Stop-Haz 20 Amp Stoplights & Hazard Warning Lights, Chime Module 2 - Horn-Dim 20 Amp Dome & Glove Box Lights, Lighted Visor Mirror, Horn, I/P Courtesy Light, Power Mirror 3 - T/L-Ctsy 20 Amp Electric Shift Transfer Case Module, Parking Lights, Liscense Plate Light 4 - Gauges 20 Amp Auto Trans., Alternator Field, Variable Throttle Control, A/C Compressor, Cluster, Chime Module, 4WD Indicator Light, Heated O2 Sensor, Daytime Running Lights Module 5 - Not Used 6 - Htr-A/C 25 Amp Blower Motor, Temp. Door Motor 7 - Pwr Aux 25 Amp Power Auxiliary Outlets 8 - Not Used 9 - ECM Batt 15 Amp Engine Computer (Battery), ABS Battery, Fuel Pump 10 - ECM Ign 10 Amp Engine Computer (Ignition), Injectors, Engine Sensors 11 - Radio 20 Amp Radio, Inside Rearview Mirror Map Lights 12 - Not Used 13 - Rdo/Batt 15 Amp Clock, Radio Battery, CD Player 14 - Illum 5 Amp Cluster Illumination, Ash Tray Lamp, Radio Illumination, Heater Lamp, 4WD Illumination, Chime Module, Fog Lamp Sw. Illumination, Daytime Running Lights 15 - DRL 10 Amp Daytime Running Lights (Canada) 16 - Turn-B/U 15 Amp Turn Signal & Back-Up Lights 17 - Wiper 25 Amp Windshield Washers, Windshield Wiper Motor 18 - Brake 15 Amp Speedometer, ABS System, Cruise Control 19 - 4WD 20 Amp Four-Wheel Drive 20 - Not Used 21 - Fog 20 Amp Fog Lamps 22 - Not Used 23 - Not Used 24 - Not Used

RELAY CENTER (1994 S-SERIES PICKUP)

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

Fig. 6: Fuse Panel ID (1995 S-Series Pickup) Courtesy of GENERAL MOTORS CORP. Relay Identification    

1 - Relay Center 2 - Fuel Pump Relay 3 - Horn Relay 4 - Fog Lamp Relay (If Equipped)

FUSE PANEL ID (1995 S-SERIES PICKUP)

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

Fig. 7: Fuse Panel ID (1995 S-Series Pickup) Courtesy of GENERAL MOTORS CORP. Fuse & Circuit Breaker Identification    

 



        

         

A - Pwr-Accy 20 Amp (Circuit Breaker) Power Door Locks B - Pwr-Wdo 30 Amp (Circuit Breaker) Power Windows 1 - Stop-Haz 20 Amp Stoplights & Hazard Warning Lights, Chime Module 2 - Horn-Dim 20 Amp Dome & Glove Box Lights, Lighted Visor Mirror, Horn, I/P Courtesy Light, Power Mirror 3 - T/L-Ctsy 20 Amp Electric Shift Transfer Case Module, Parking Lights, Liscense Plate Light 4 - Gauges 20 Amp Auto Trans., Alternator Field, Variable Throttle Control, A/C Compressor, Cluster, Chime Module, 4WD Indicator Light, Heated O2 Sensor, Daytime Running Lights Module 5 - ENG1 20 Amp Linear EGR Valve, Evaporative Emissions Canister Purge Solenoid, Heated O2 Sensor #1, Heated O2 Sensor #2, Camshaft Position Sensor, Vehicle Control Module, Powertrain Control Module 6 - Htr-A/C 25 Amp HVAC Select Switch, Air Valve Actuator Motor 7 - Pwr Aux 25 Amp Power Auxiliary Outlets, Data Link Connector 8 - Not Used 9 - ECM Batt 15 Amp Engine Computer (Battery), ABS Battery, Fuel Pump 10 - ECM Ign 10 Amp Engine Computer (Ignition), Injectors, Engine Sensors 11 - Radio 20 Amp Radio, Inside Rearview Mirror Map Lights 12 - Not Used 13 - Rdo/Batt 15 Amp Clock, Radio Battery, CD Player 14 - Illum 5 Amp Cluster Illumination, Ash Tray Lamp, Radio Illumination, Heater Lamp, 4WD Illumination, Chime Module, Fog Lamp Sw. Illumination, Daytime Running Lights 15 - DRL 10 Amp Daytime Running Lights (Canada) 16 - Turn-B/U 15 Amp Turn Signal & Back-Up Lights 17 - Wiper 25 Amp Windshield Washers, Windshield Wiper Motor 18 - Brake 15 Amp Speedometer, ABS System, Cruise Control 19 - 4WD 20 Amp Transfer Case Control Module (Four-Wheel Drive) 20 - CRANK 10 Amp Diagnostic Energy Reserve Module (DERM) 21 - Fog 20 Amp Fog Lamps Relay 22 - Air Bag 10 Amp Air Bag Diagnostic Energy Reserve Module (DERM), Arming Sensor 23 - TRANS 10 Amp Automatic Transmission 24 - PRNDL 10 Amp Instrument Cluster

RELAY CENTER (1995-98 S-SERIES PICKUP)

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1997 Chevrolet S10 Pickup MAINTENANCE INFORMATION 1994-99 MAINTENANCE General Motors Corp. Maintenance Information

Fig. 8: Fuse Panel ID (1995-98 S-Series Pickup) Courtesy of GENERAL MOTORS CORP. Relay Identification    

1 - Relay Center 2 - Fuel Pump Relay 3 - Horn Relay 4 - Fog Lamp Relay (If Equipped)

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

GENERAL INFORMATION Service Reminder Indicators - Chevrolet

OIL CHANGE REMINDERS NOTE:

This article is only to be used for resetting maintenance reminder lights (when applicable). Some models (not all) may be equipped with one or more resettable maintenance reminder lights indicating maintenance is required. Once required maintenance services are performed, resetting of lights may be required. Information is provided to reset these lights where applicable.

NOTE:

Most vehicles are equipped with a Malfunction Indicator Light (MIL) or check engine light. If light comes on and remains on while driving, the vehicle requires some type of repair. See appropriate service and repair information. After repairing fault(s) and clearing fault code(s), the MIL or check engine light should go out. Some models may use a dual-function indicator light, which is also used to indicate emission component service is due. After performing required service, reset indicator light.

NOTE:

Most General Motors 1981-88 vehicles do not use a Service Reminder Indicator (SRI).

CHANGE ENGINE OIL LIGHT (PASSENGER CARS) 1990-91 CORVETTE

1. Engine oil life monitor calculates engine oil temperature and RPM. It indicates when the oil is nearly worn out. A CHANGE OIL light on left side of instrument cluster is illuminated when it is time to change oil. 2. To reset oil life monitor, turn ignition on. Depress ENG MET button on trip monitor and release. Within 5 seconds, depress and release ENG MET button again. Within 5 seconds, depress and hold the RANGE button on trip monitor. The CHANGE OIL light should flash. 3. Hold the RANGE button depressed until the CHANGE OIL light stops flashing and goes out. When the light goes out, the engine oil life monitor is reset. This should take about 10 seconds. If the light does not reset, turn the ignition off and repeat the procedure. 1992-96 CORVETTE

1. The CHANGE OIL light, located on left side of instrument cluster is illuminated when its time to change oil. When engine oil is changed, reset CHANGE OIL indicator even if indicator did not illuminate. This ensures indicator accuracy for next oil change. 2. To reset oil life monitor, turn ignition on. Ensure DLC terminal No. 12 is not grounded. Press ENG MET button, located on the trip monitor, and release. Within 5 seconds, press and release ENG MET button again. Within another 5 seconds, press and hold the GAUGES button located on the trip monitor. Microsoft Saturday, August 29, 2009 11:45:42 11:45:37 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

3. CHANGE OIL light will begin flashing. Hold GAUGES button depressed until CHANGE OIL light goes out. When light goes out, engine oil life monitor is reset. This should take about 10 seconds. If light does not reset, turn ignition off and repeat procedure. 1994 CAPRICE

1. Engine oil life monitor calculates engine oil temperature and RPM. It indicates when the engine oil is nearly worn out. A CHANGE OIL light on the instrument cluster is illuminated when it is time to change the engine oil. 2. To reset CHANGE OIL light, press reset switch located behind fuse block access door. 1995-96 CAPRICE

1. Engine oil life monitor calculates engine oil temperature and RPM. It indicates when the engine oil is nearly worn out. A CHANGE OIL light on the instrument cluster is illuminated when it is time to change the engine oil. 2. To reset oil life monitor and turn off CHANGE OIL light, turn ignition switch to ON position with engine off. Depress accelerator pedal to wide open throttle 3 times within 5 seconds. This throttle signal will inform the PCM to reset the oil life monitor and turn off the light. If light does not turn off, turn ignition off and repeat procedure. 1997-2000 CORVETTE

1. The CHANGE OIL light is illuminated when its time to change engine oil, usually between 3000 and 10,000 miles since last oil change. The Driver Information Center (DIC) will display CHANGE OIL NOW when an oil change is due. 2. To reset oil life monitor, turn ignition switch to RUN position, with engine off. Press TRIP button, located on DIC switch to display OIL LIFE. Message will display percentage of oil life remaining. 3. Press and hold RESET button on DIC for at least 2 seconds. Word RESET will appear, then OIL LIFE 99. Turn ignition off. 1997-2001 LUMINA

1. Engine oil life monitor calculates engine oil temperature and engine revolutions. It indicates when the engine oil is nearly worn out. CHANGE OIL or CHANGE OIL SOON light on the instrument cluster is illuminated when it is time to change the engine oil. 2. To reset oil life monitor on a vehicle with a Driver Information Center, go to step 4. To reset the oil life monitor on a vehicle NOT equipped with a Driver Information Center, turn ignition switch to ON or RUN position with engine off. Depress accelerator pedal slowly to wide open throttle 3 times within 5 seconds. 3. On 1997-98 vehicles, if the CHANGE OIL or CHANGE OIL SOON light flashes 2 times, the system is reset. However, if light comes on for 5 seconds, system did not reset. Repeat reset procedure. On 19992001 vehicles, if the CHANGE OIL or CHANGE OIL SOON light flashes, the system is resetting. Turn ignition off. Start vehicle. If oil light comes back on and stays on, the oil life monitor has not reset. Repeat reset procedure. 4. If vehicle is equipped with a Driver Information Center (DIC), reset oil life monitor by pressing the Driver Information Center RESET button for 5 seconds while viewing the oil life display. Microsoft Saturday, August 29, 2009 11:45:37 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

1997-99 MONTE CARLO

1. Engine oil life monitor calculates engine oil temperature and engine revolutions. It indicates when the engine oil is nearly worn out. CHANGE OIL or CHANGE OIL SOON light on the instrument cluster is illuminated when it is time to change the engine oil. 2. To reset oil life monitor on a vehicle with a Driver Information Center, go to step 4. To reset the oil life monitor on a vehicle NOT equipped with a Driver Information Center, turn ignition switch to ON or RUN position with engine off. Depress accelerator pedal slowly to wide open throttle 3 times within 5 seconds. 3. On 1997 vehicles, if the CHANGE OIL or CHANGE OIL SOON light flashes 2 times, the system is reset. However, if light comes on for 5 seconds, system did not reset. Repeat reset procedure. On 1999 vehicles, if the CHANGE OIL or CHANGE OIL SOON light flashes, the system is resetting. Turn ignition off. Start vehicle. If oil light comes back on and stays on, the oil life monitor has not reset. Repeat reset procedure. 4. If vehicle is equipped with a Driver Information Center (DIC), reset oil life monitor by pressing the Driver Information Center RESET button for 5 seconds while viewing the oil life display. 1998-2002 CAMARO

1. The CHANGE OIL (or CHANGE ENGINE OIL) message is displayed when its time to change engine oil, usually between 3000 and 7500 miles since last oil change. 2. To reset the oil life monitor, turn the ignition switch to RUN position, with engine off. Press the TRIP/OIL RESET button on the instrument panel for 12 seconds. The OIL CHANGE light will start to flash to confirm that system is reset. Reset is complete when OIL CHANGE light goes out. 2000-01 IMPALA & MONTE CARLO

1. The CHANGE ENGINE OIL message is displayed when its time to change engine oil, usually between 3000 and 7500 miles since last oil change. The oil change interval is not based on mileage, but on engine revolutions and engine operating temperature. 2. There are 2 ways to reset the engine oil life monitor. To reset the engine oil life monitor using the accelerator pedal, go to step 5. To reset the engine oil life monitor using the radio, turn the radio off. Turn ignition to ACC or ON, with the engine off. Press and hold the DISP button on the radio for at least 5 seconds until SETTINGS is displayed. 3. Press the SEEK up or down arrow to scroll through the main menu. Scroll until OIL LIFE appears on the display. Press the PREV or NEXT button to enter the sub-menu. RESET will be displayed. 4. Press the DISP button to reset. A chime will sound to verify the new setting and DONE will be displayed for one second. Once the message indicator has been reset, scroll through the menu until EXIT appears on the display. Press the DISP button to exit the program. A chime will sound to verify the exit. 5. To reset the engine oil life monitor using the accelerator pedal, turn ignition on with engine off. Fully depress and release the accelerator pedal slowly 3 times within 5 seconds. If CHANGE ENGINE OIL light flashes, oil life monitor is reset. If the CHANGE ENGINE OIL light comes back on and stays on, oil life monitor has not reset. Repeat reset procedure. 2001-04 CORVETTE

1. The CHANGE OIL SOON light is illuminated when its time to change engine oil, usually between 3000 Microsoft Saturday, August 29, 2009 11:45:37 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

and 10,000 miles since last oil change. See Fig. 1. The Driver Information Center (DIC) will display CHANGE OIL NOW when an oil change is due. 2. To reset oil life monitor, turn ignition switch to ON or RUN position, with engine off. Press TRIP button, located on DIC switch to display OIL LIFE. Message will display percentage of oil life remaining. 3. Press and hold RESET button on DIC for at least 2 seconds. OIL LIFE REMAIN 100 percent will appear. Turn ignition off.

Fig. 1: Identifying Instrument Cluster (2002-04 Corvette) Courtesy of GENERAL MOTORS CORP. 2002-04 IMPALA & MONTE CARLO

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

2. There are 2 ways to reset the engine oil life monitor. To reset the engine oil life monitor using the accelerator pedal, go to step 5. To reset the engine oil life monitor using the radio, turn the radio off. Turn ignition to ACC or ON, with the engine off. Press and hold the TUNE DISP button on the radio for at least 5 seconds until SETTINGS is displayed. 3. On Impala, press the SEEK PTYPE up or down arrow to scroll through the main menu. On Monte Carlo, press the SEEK PSCAN up or down arrow to scroll through the main menu. On all models, scroll until OIL LIFE appears on the display. Press the 1 PREV or 2 NEXT button to enter the sub-menu. RESET will be displayed. 4. Press the TUNE DISP button to reset. A chime will sound to verify the new setting and DONE will be displayed for one second. Once the message indicator has been reset, scroll through the menu until EXIT appears on the display. Press the TUNE DISP button to exit the program. A chime will sound to verify the exit. 5. To reset the engine oil life monitor using the accelerator pedal, turn ignition on with engine off. Fully depress and release the accelerator pedal slowly 3 times within 5 seconds. If CHANGE ENGINE OIL light flashes, oil life monitor is reset. If the CHANGE ENGINE OIL light comes back on and stays on, oil life monitor has not reset. Repeat reset procedure.

Fig. 2: Identifying Instrument Cluster (Impala & Monte Carlo V6) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

Fig. 3: Identifying Instrument Cluster (Impala V6) Courtesy of GENERAL MOTORS CORP.

Fig. 4: Identifying Instrument Cluster (Monte Carlo V6) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

Fig. 5: Identifying Instrument Cluster (Impala & Monte Carlo Supercharged V6) Courtesy of GENERAL MOTORS CORP. 2004 MALIBU

GM Oil Life System calculates when to change your engine oil and filter based on vehicle use. See Fig. 6. Anytime your oil is changed, reset the system so it can calculate when the next oil change is required. If a situation occurs where you change your oil prior to a Change Oil Soon message being turned on, reset the system. After changing the engine oil, reset the system. 1. Display OIL LIFE RESET on the DIC. 2. Press and hold ENTER button for at least one second. An ACKNOWLEDGED display message will appear for 3 seconds or until the next button is pressed. This will tell you the system has been reset. 3. Turn key to OFF. 4. If Change Oil Soon message comes back on when you start your vehicle, engine oil life system has not reset. Repeat the procedure.

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

Fig. 6: Identifying Instrument Cluster (2004 Malibu) Courtesy of GENERAL MOTORS CORP. 2005 CLASSIC

GM Oil Life System calculates when to change your engine oil and filter based on vehicle use. Anytime your oil is changed, reset the system so it can calculate when the next oil change is required. If a situation occurs where you change your oil prior to a Change Oil Soon message being turned on, reset the system. After changing the engine oil, reset the system. 1. Display OIL LIFE RESET on the DIC. 2. Press and hold ENTER button for at least one second. An ACKNOWLEDGED display message will appear for 3 seconds or until the next button is pressed. This will tell you the system has been reset. 3. Turn key to OFF. 4. If Change Oil Soon message comes back on when you start your vehicle, engine oil life system has not reset. Repeat the procedure. 2005-08 COBALT

NOTE:

On 2007 LS models, the SELECT and RESET buttons are located on steering wheel.

After changing the engine oil, the system must be reset as follows: 1. Turn the ignition to RUN, with engine off. 2. Press the information and reset buttons on the DIC at the same time to enter the personalization menu. 3. Press the information button to scroll through the available personalization menu modes until the DIC display shows OIL-LIFE RESET. 4. Press and hold the reset button until the DIC display shows ACKNOWLEDGED. This will tell you the system has been reset. Microsoft Saturday, August 29, 2009 11:45:38 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

5. Turn the key to LOCK. If the CHANGE OIL SOON message comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the reset procedure. 2005-08 CORVETTE

To reset the CHANGE ENGINE OIL message after an oil change, do the following: 1. Press the TRIP button so the OIL LIFE percentage is displayed. 2. Press RESET and hold for two seconds. OIL LIFE REMAINING 100% will appear. If the CHANGE ENGINE OIL message comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure. 2005-06 IMPALA & MONTE CARLO

To reset the CHANGE ENGINE OIL message, use one of the following procedures: Using The Radio

1. 2. 3. 4. 5. 6.

Turn the ignition to ACC or ON, with the radio off. Press and hold the TUNE DISP knob on the radio for at least five seconds until SETTINGS is displayed. Press the SEEK PSCAN up or down arrow to scroll through the main menu. Scroll until OIL LIFE appears on the display. Press the 1 PREV or 2 NEXT buttons to enter the sub-menu. RESET will be displayed. Press the TUNE DISP knob to reset. A chime will be heard to verify the new setting and DONE will be displayed for one second. 7. Once the indicator has been reset, scroll until EXIT appears on the display. 8. Press the TUNE DISP knob to exit programming. A chime will be heard to verify the exit. 9. Turn the key to OFF. If the CHANGE ENGINE OIL message comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure. Using the Accelerator Pedal

1. Turn the ignition to ON, with the engine off. 2. Fully press and release the accelerator pedal slowly three times within five seconds. If the CHANGE ENGINE OIL message flashes, the system is reset. 3. However, if it stays on, it did not reset. Repeat the procedure. 4. Turn the key to OFF. If the CHANGE ENGINE OIL message comes back on when you start your vehicle, the engine oil life system Microsoft Saturday, August 29, 2009 11:45:38 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

has not reset. Repeat the procedure. 2005-06 MALIBU

After changing the engine oil, reset the system by performing the following steps: 1. Display OIL LIFE RESET on the DIC. 2. Press and hold the ENTER button for at least one second. An ACKNOWLEDGED display message will appear for three seconds or until the next button is pressed. This will tell you the system has been reset. 3. Turn the key to OFF. 2007-08 IMPALA & MONTE CARLO

After changing the engine oil, reset the system by performing the following steps: 1. Press the option button on the DIC until OIL LIFE REMAINING appears on the DIC screen. 2. Press the SET/RESET button on DIC for more than 5 seconds. The oil life will change to 100%. 3. Turn the key to OFF. If the light or message comes back on when you start your vehicle, the oil life system has not reset. Repeat the procedure. 2007-08 MALIBU

After changing the engine oil, reset the system by performing the following steps: 1. Display OIL LIFE RESET appears on the DIC screen. 2. Press hold the ENTER button on DIC for at least 3 seconds. An ACKNOWLEDGE display message will appear for 3 seconds or until the next button is pressed. The oil life will change to 100%. 3. Turn the key to OFF. If the light or message comes back on when you start your vehicle, the oil life system has not reset. Repeat the procedure. CHANGE ENGINE OIL LIGHT (LIGHT TRUCKS, VANS & SUVS) 1996-98 C/K SERIES

NOTE:

These models may or may not be equipped with an CHANGE OIL SOON (or CHANGE ENGINE OIL) light.

1. To reset oil life monitor, turn ignition switch to RUN position, with engine off. Cycle accelerator pedal from closed throttle to Wide Open Throttle (WOT) 3 times within 5 seconds. CHANGE OIL SOON light will flash for 2 seconds when system is reset. 2. If CHANGE OIL SOON light comes on and stays on for 5 seconds, the system did not reset. Repeat reset procedures. 1999-2000 C/K SERIES

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

1. The CHANGE OIL SOON (or CHANGE ENGINE OIL) light is illuminated when its time to change engine oil, usually between 3000 and 10,000 miles since last oil change. 2. To reset oil life monitor, turn ignition switch to RUN position, with engine off. Cycle accelerator pedal from closed throttle to Wide Open Throttle (WOT) 3 times within 5 seconds. CHANGE OIL SOON light will flash for 2 seconds when system is reset. 3. If CHANGE OIL SOON light comes on and stays on for 5 seconds, the system did not reset. Repeat reset procedures. 2000-01 VENTURE

The engine oil life monitor will indicate when to change the engine oil - usually between 3,000 miles (5,000 km) and 10,000 miles (16,000 km) since the last oil change. See Fig. 7. Under severe conditions, the CHANGE OIL SOON light may be displayed before 3,000 miles (5,000 km). The vehicle must not be driven more than 10,000 miles (16,000 km) or 12 months without an oil change. Reset the oil life monitor when the oil has been changed, use the following procedure. 1. 2. 3. 4. 5.

Turn the ignition key to the RUN position. Fully push and release the accelerator pedal slowly 3 times within 5 seconds. If the CHANGE OIL SOON or OIL LIFE RESET message flashes for 10 seconds, the system is resetting. Turn ignition key to LOCK position. If the CHANGE ENGINE OIL message comes back on when engine is started, the system has not reset. Repeat the procedure. If it still does not reset, see dealer for service

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Fig. 7: Identifying Instrument Cluster (2004 Avalanche, Silverado, Suburban & Tahoe) Courtesy of GENERAL MOTORS CORP. 2002-04 TRAILBLAZER

The CHANGE ENG OIL message is displayed when its time to change engine oil, usually between 3000 and 7500 miles since last oil change. See Fig. 8. Under severe conditions, the indicator may come on before 3000 miles. The oil change interval is not based on mileage, but on engine revolutions and engine operating temperature. Vehicle should not be driven more than 7500 miles or 12 months without an oil and oil filter change. System will not detect dust in the oil. So if vehicle is driven in a dusty area, be sure to change oil and oil filter every 3000 miles or sooner if CHANGE OIL SOON indicator comes on. Reset system when oil has been changed.

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Fig. 8: Identifying Instrument Panel Cluster Courtesy of GENERAL MOTORS CORP. Manually Resetting Oil Life System

To reset the oil life monitor, turn ignition switch to ON or RUN position with engine off. Depress accelerator pedal slowly to wide open throttle 3 times within 5 seconds. If CHANGE ENG OIL light flashes for 5 seconds, oil life monitor is reset. If the CHANGE ENG OIL light does not flash, oil life monitor has not reset. Repeat this step. Reset Oil Life System Using Driver Information Center

If vehicle is equipped with a Driver Information Center (DIC), reset oil life monitor by pressing the Driver Information Center SELECT button for 5 seconds while ENGINE OIL LIFE is displayed. 2002-04 VENTURE

1. The CHANGE ENGINE OIL message is displayed when its time to change engine oil, usually between 3000 and 7500 miles since last oil change. See Fig. 9 and Fig. 10 . The oil change interval is not based on mileage, but on engine revolutions and engine operating temperature. 2. To reset the oil life monitor, turn the ignition switch to RUN position with the engine off. Press trip/reset button repeatedly until OIL is displayed on Driver Information Center (DIC). Once OIL is displayed, press and hold trip/reset button for 5 seconds. When trip/reset button is released, 100 will be displayed (indicating 100 percent oil life remaining). Turn ignition off. If CHANGE ENGINE OIL message comes back on and stays on, oil life monitor has not reset. Repeat this procedure.

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

Fig. 9: Identifying Instrument Cluster Courtesy of GENERAL MOTORS CORP.

Fig. 10: Identifying Instrument Cluster With Tachometer Courtesy of GENERAL MOTORS CORP. 2003-04 EXPRESS, CUTAWAY & RV CUTAWAY

Engine oil life monitor will show when to change the engine oil and oil filter. This will usually occur between 3000 and 7500 miles since the last oil change. Under severe conditions, the indicator may come on before 3000 miles. See Fig. 11. Vehicle should not be driven more than 7500 miles or 12 months without an oil and oil filter change. The system will not detect dust in the oil. So if the vehicle is driven in a dusty area, be sure to change the oil and oil filter every 3000 miles or sooner if the CHANGE OIL SOON indicator comes on. Microsoft Saturday, August 29, 2009 11:45:38 AM

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1. To reset oil life monitor when the oil has been changed, turn ignition ON, with engine off. 2. Fully press and release accelerator pedal 3 times within 10 seconds. 3. If CHANGE OIL light flashes for 5 seconds, the system is reset. If light does not display for 5 seconds, you will need to reset the system again.

Fig. 11: Identifying Instrument Cluster (2004 Express, Cutaway & RV Cutaway) Courtesy of GENERAL MOTORS CORP. 2004-08 COLORADO

1. Turn ignition ON, with engine off. 2. Press and release reset stem on instrument panel while OIL LIFE message is displayed. 3. Once the alternating OIL LIFE and RESET messages appear, press and hold stem in until several beeps will sound. This confirms that oil life system has been reset. Turn ignition off or full LOCK position. If CHANGE OIL messages comes back after starting engine, repeat reset procedure.

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Fig. 12: Identifying Instrument Cluster (2004 Colorado) Courtesy of GENERAL MOTORS CORP. 2004 SSR

This vehicle has an engine oil life monitor. See Fig. 13. The GM Oil Life System™ will show when to change engine oil and oil filter. This will usually occur between 3000 miles and 7500 miles since the last oil change. Under severe conditions, the indicator may come on before 3000 miles. Vehicle should not be driven more than 7500 miles or 12 months without an oil and oil filter change. The system will not detect dust in the oil. So if the vehicle is driven in a dusty area, be sure to change the oil and oil filter every 3000 miles or sooner if the CHANGE OIL SOON indicator comes on. Reset the system when the oil has been changed. 1. Turn ignition to ON without starting the engine. 2. Fully push and release accelerator pedal slowly 3 times within 5 seconds. 3. If CHANGE ENG OIL light flashes for 5 seconds, the system is reset. If light does not flash, repeat the procedure.

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Fig. 13: Identifying Instrument Cluster (2004 SSR) Courtesy of GENERAL MOTORS CORP. 2005-06 EQUINOX

1. Turn the ignition key to RUN with the engine off. 2. Fully press and release the accelerator pedal three times within five seconds. The change engine oil light will flash while the system is resetting. 3. Turn the key to LOCK. 2005-06 EXPRESS, CUTAWAY & RV CUTAWAY

To reset the change engine oil light, do the following: 1. 2. 3. 4.

Turn the ignition key to RUN with the engine off. Fully press and release the accelerator pedal slowly three times within five seconds. If the Change Engine Oil light flashes for five seconds, the system is reset. Turn the key to LOCK.

If the change engine oil light comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure. If it still does not reset, see your dealer for service. 2005-08 SILVERADO & TRAILBLAZER

1. Turn ignition key to RUN position, with engine off. 2. Fully press and release the accelerator pedal slowly 3 times within 5 seconds. If the OIL LIFE RESET message flashes for 10 seconds, the system is resetting. 3. Turn the key to LOCK. If CHANGE ENGINE OIL message comes back after engine starts, repeat reset procedure. Microsoft Saturday, August 29, 2009 11:45:38 AM

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2005-06 SSR

Always reset the engine oil life system to 100% after every oil change. It will not reset itself. To reset the change engine oil light, do the following: 1. Press the fuel information button until ENGINE OIL LIFE appears on the Driver Information Center (DIC). See . 2. Press and hold the select button. The engine oil life percentage will change to 100. 3. Turn the key to OFF. If the change engine oil light comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure.

Fig. 14: Identifying DIC Steering Wheel Buttons (Chevrolet SSR) Courtesy of GENERAL MOTORS CORP. 2005-06 TRAILBLAZER

To reset the change engine oil light, do the following: 1. Turn the ignition key to RUN with the engine off. 2. Fully press and release the accelerator pedal slowly three times within five seconds. 3. Turn the key to LOCK. Microsoft Saturday, August 29, 2009 11:45:38 AM

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If the change engine oil light comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure. For vehicles with the Driver Information Center (DIC), see Fig. 15 to identify DIC steering wheel buttons.

Fig. 15: Identifying Driver Information Center (DIC) Steering Wheel Buttons (Some Models) Courtesy of GENERAL MOTORS CORP. 2005-08 UPLANDER

1. Turn ignition key to RUN position, with engine off. Repeatedly push the SET/RESET button until OIL is displayed on the Driver Information Center (DIC). 2. Once OIL is displayed, push and hold the SET/RESET button for 5 seconds. The number will disappear and be replaced by 100 (indicating 100% oil life remaining). 3. Turn key to LOCK position. If CHANGE OIL SOON message comes back after engine starts, repeat reset procedure. Microsoft Saturday, August 29, 2009 11:45:38 AM

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2005-06 VENTURE

1. With the ignition key in RUN but the engine off, repeatedly push the trip/reset button until OIL is displayed on the Driver Information Center (DIC). 2. Once OIL is displayed, push and hold the trip/reset button for five seconds. The number will disappear and be replaced by 100 (indicating 100% oil life remaining). 3. Turn the key to OFF. 2005-06 C/K SERIES

On vehicles equipped with the DIC, use the fuel button to reach the ENGINE OIL LIFE screen and then press and hold the select button for five seconds while ENGINE OIL LIFE is displayed. See Fig. 15. OIL LIFE RESET will appear on the display for 10 seconds to let you know the system is reset. On vehicles NOT equipped with the DIC, do the following: 1. Turn the ignition key to RUN with the engine off. 2. Fully press and release the accelerator pedal slowly three times within five seconds. If the OIL LIFE RESET message flashes for 10 seconds, the system is resetting. 3. Turn the key to LOCK. If the CHANGE ENGINE OIL message comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure. If it still does not reset, see your dealer for service. 2006-08 AVALANCHE

After changing the engine oil, reset the system by performing the following steps: 1. Display OIL LIFE REMAINING on DIC. 2. Press hold the SET/RESET button on DIC or trip odometer stem (if not equipped with DIC) for at more than 5 seconds. The oil life will change to 100%. 3. Turn the key to OFF. If the light or message comes back on when you start your vehicle, the oil life system has not reset. Repeat the procedure. 2006-08 HHR

1. Turn the ignition to RUN position, with engine off. 2. Press INFORMATION and RESET buttons on the DIC at the same time to enter personalization menu. 3. Press INFORMATION button to scroll through the available personalization menu modes until the DIC display shows OIL LIFE RESET. 4. Press and hold RESET button until the DIC display shows ACKNOWLEDGED. This indicates that system has been reset. 5. Turn ignition off. If CHANGE OIL SOON message comes back when engine is started, repeal reset procedure. Microsoft Saturday, August 29, 2009 11:45:38 AM

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2007-08 EQUINOX

1. Turn ignition ON, with engine off. 2. Fully press and release the accelerator pedal slowly 3 times within 5 seconds. The CHANGE OIL LIGHT will flash while system is resetting. 3. When light stops flashing, turn key to LOCK. If the CHANGE ENGINE OIL message comes back on when you start the engine, repeat the reset procedure. 2007-08 SUBURBAN

1. Turn ignition ON, with engine off. Display OIL LIFE REMAINING on DIC 2. Press and hold SET/RESET button on DIC or trip odometer reset stem (if not equipped with DIC) for more than 5 seconds. The oil life should change to 100%. Turn ignition off. If CHANGE ENGINE OIL SOON message comes back after starting engine, repeat reset procedure.

CHECK ENGINE LIGHT 1989-94 GEO TRACKER Federal

1. CHECK ENGINE light functions as a service reminder indicator and emission system service. CHECK ENGINE light will come on each 50,000 miles (PCV and EGR), each 80,000 miles (oxygen sensor) and each 100,000 miles (charcoal canister) to indicate needed emission system service. 2. After servicing and/or replacing components, reset CHECK ENGINE light by sliding cancel switch to its opposite position. See LIGHT RESET SWITCH LOCATION (GEO TRACKER) for switch location. LIGHT RESET SWITCH LOCATION (GEO TRACKER) Application Location 1989-91 Behind Access Panel, Directly Below Steering Column (1) Behind Instrument Panel, Next To Left Speaker 1992-94 (1) See Fig. 16.

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Fig. 16: Light Reset Switch Location (1992-94 Geo Tracker - Federal) Courtesy of GENERAL MOTORS CORP. California

CHECK ENGINE light indicates when it is necessary to have emission system serviced, regardless of mileage. CHECK ENGINE light comes on briefly when starting as a bulb check. If light does not come on or stays on continually, repair as necessary.

OXYGEN SENSOR REMINDER FLAG 1980 MODELS 1. Every 30,000 miles, a reminder flag appears in speedometer face, indicating service of oxygen sensor is necessary. See Fig. 17. Inspect and service oxygen sensor as necessary and reset flag. 2. To reset flag, remove instrument panel trim plate. Remove instrument cluster lens. Using pointed tool, apply light downward pressure on notches of flag until it is reset. An alignment mark will appear in left center of odometer window when flag is fully reset.

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

Fig. 17: Resetting Reminder Flag Courtesy of GENERAL MOTORS CORP.

OXYGEN SENSOR WARNING LIGHT 1985-86 SPRINT At 30,000 mile intervals, a SENSOR light in dash will start flashing, indicating oxygen sensor needs replacement. To reset mileage counter (after sensor replacement), locate SENSOR light cancel switch on right side of fuse box. Return cancel switch to OFF position. Start engine to ensure light remains off.

TIRE PRESSURE MONITOR SYSTEM 1987-96 CORVETTE Tire Pressure Monitor Warning Indicators

NOTE:

The LOW TIRE PRESSURE warning light may come on if the vehicle is close to another vehicle that has a similar warning system and a low tire.

When the LOW TIRE PRESSURE warning light illuminates, immediately check air pressure of all tires and adjust to the specified pressure. This warning light will remain illuminated until ignition is turned off, even if tires are inflated while vehicle is running. If SERVICE LTPWS warning light illuminates, there is a problem in the TPM system. See appropriate manufacturer service information. Microsoft Saturday, August 29, 2009 11:45:38 AM

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1997-2004 CORVETTE NOTE:

If the wheels have been rotated, or tire pressure sensor or RCDLR is replaced, the TPM system needs to relearn tire pressure sensor IDs. See TIRE PRESSURE SENSOR RELEARN in appropriate manufacturer service information.

2000 IMPALA & MONTE CARLO LOW TIRE PRESSURE light comes on if air pressure in one tire drops to 12 psi (kPa) less than the other 3 tires, if tires are rotated, if tire(s) are repaired or replaced, if air pressure is adjusted or when vehicle battery is disconnected. Light will stay on until ignition is turned off or RESET button is pressed. Check and adjust air pressure in all 4 tires before resetting system. 1. There are 2 ways to reset the tire inflation monitor. To reset the tire inflation monitor using the exterior or interior lamp controls, go to step 4. To reset tire inflation monitor using the radio, turn the radio off. Turn ignition to ACC or ON, with the engine off. Press and hold the TUNE DISP button on the radio for at least 5 seconds until settings is displayed. 2. On Impala, press the SEEK PTYPE up or down arrow to scroll through the main menu. On Monte Carlo, press the SEEK PSCAN up or down arrow to scroll through the main menu. On all models, scroll until TIRE MON appears on the display. Press the 1 PREV or 2 NEXT button to enter the sub-menu. RESET will be displayed. 3. Press the TUNE DISP button to reset. A chime will sound to verify the new setting and DONE will be displayed for one second. Once the message has been reset, scroll through the menu until EXIT appears on the display. Press the TUNE DISP button to exit the program. A chime will sound to verify the exit. 4. On Impala, to reset the tire inflation monitor using the interior lamp controls, turn the interior lamp controls from OFF to ON position 3 times with ignition switch in ON position. On Monte Carlo, to reset the tire inflation monitor using the exterior lamp controls, turn exterior lamp controls from OFF to parking lamps 3 times with ignition switch in ON position. 2001-03 CORVETTE NOTE:

When the wheels have been rotated or a tire pressure sensor has been replaced, retrain tire pressure sensor. See TIRE PRESSURE SENSOR RELEARN in appropriate manufacturer service information.

2001-05 IMPALA & MONTE CARLO NOTE:

When a wheel is replaced or rotated, tire pressure has been adjusted, or vehicle's battery has been disconnected, TPM system will need to be recalibrated. See TIRE PRESSURE SENSOR RELEARN in appropriate manufacturer service information.

2003-04 IMPALA & MONTE CARLO 1. There are 3 different ways to reset the TPM system. If using the exterior lamp switch, go to next step. If Microsoft Saturday, August 29, 2009 11:45:38 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

3. 4. 5.

6. 7.

using the RDS radio, go to step 3. If using a scan tool, go to step 6. Adjust all tire pressures to the recommended Psi (kPa). Refer to tire placard located on the inside of the rear trunk lid. Turn ignition ON, with engine OFF. Cycle exterior lamp switch from OFF to parking lamps 3 times within 5 seconds. Using scan tool, clear the TPM DTC. Adjust all tire pressures to the recommended Psi (kPa). Refer to tire placard located on the inside of the rear trunk lid. Turn ignition to ACC or ON, with engine OFF. Turn radio OFF. Press and hold the DISP button until SETTINGS is displayed. Press SEEK up or down arrows until TIRE MON is displayed. Press the PREV or NEXT button to enter the sub-menu. RESET will be displayed. Press the DISP button, a chime will sound and DONE will be displayed. Scroll until EXIT is displayed. Press the DISP button to exit the TPM reset mode. A chime will sound to verify exit. Using scan tool, clear TPM DTC. Adjust all tire pressures to the recommended Psi (kPa). Refer to tire placard located on the inside of the rear trunk lid. Install the scan tool. Turn ignition ON, with engine OFF. With the scan tool select SPECIAL FUNCTIONS. Select TIM Reset. Press the RESET soft key. Using scan tool, clear TPM DTC.

2004-06 AVALANCHE, SILVERADO, SUBURBAN & TAHOE NOTE:

When the wheels have been rotated, or a tire pressure sensor or PDM/RCDLR has been replaced, retrain tire pressure sensor. See TIRE PRESSURE SENSOR RELEARN in appropriate manufacturer service information.

2004 CORVETTE 1. Turn ON ignition, with engine OFF. Press DIC RESET button in order to clear any warning messages. 2. Press and release OPTIONS button until display is blank. 3. Press and hold RESET button for 3 seconds. NOTE:

If the DIC does not display TIRE TRAINING message, ensure TPM option is enabled in the RCDLR. Check TPM option and Set Options/TPM. The scan tool can be used to enable, or disable TPM option in the RCDLR. Check TPM DTC display and Set Options/TPM DTC. The scan tool can be used to enable or disable TPM DTC displaying option on the DIC.

4. Press and release OPTIONS button until TIRE TRAINING is displayed. 5. Press and release RESET button and LEARN L FRONT TIRE is displayed, verifying learn mode has been enabled. NOTE:

If a horn chirp does not sound after 15 seconds, remove then reinstall sensor activating tool.

6. Starting at left front sensor, hold Tire Pressure Sensor Activating Tool (J-41760) over valve stem until a horn chirp sounds. Microsoft Saturday, August 29, 2009 11:45:38 AM

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7. After horn chirp sounds, proceed as in step 6 for the next 3 sensors in the following order of right front, right rear and left rear. 8. Turn ignition OFF to exit learn mode. 2004 AVALANCHE, SUBURBAN & TAHOE NOTE:

2005-08 AVALANCHE, SILVERADO, SUBURBAN & TAHOE NOTE:

When the wheels have been rotated or a tire pressure sensor has been replaced, retrain tire pressure sensor.

1. Turn ignition switch to ON position, with engine off. Apply parking brake. NOTE:

If learn mode cannot be enabled, TPM system is not enabled in PDM/RCDLR. See appropriate manufacturer service information.

2. Turn headlight switch from OFF to parking lamps 4 times within 4 seconds. A double horn chirp will sound and the low tire pressure indicator will begin to flash to indicate the learn mode has been enabled (the low tire pressure indicator should continue flashing throughout the matching procedure, and "SERVICE TIRE MONITOR" message will be displayed on the DIC). WARNING: Overinflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure, do not exceed the maximum inflation pressure as noted on the tire sidewall. NOTE:

If a horn chirp does not sound after 35 seconds for any of the 4 sensors, turn ignition switch to OFF position to exit the learn mode. Repeat procedure from step 1.

3. Starting with left front tire, increase or decrease the pressure for 8-10 seconds, or until a horn chirp sounds. Horn chirp may occur before the 8-10 second pressure increase/decrease time period has been reached, or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached. 4. After horn chirp has sounded, proceed as in step 3 for the next 3 sensors in the following order: right front, right rear and left rear. 5. After left rear sensor has been learned, check to see if the low tire pressure indicator is still flashing. If it is, turn ignition switch to OFF position to exit relearn procedure. Adjust all tire pressures to specification. If the low tire pressure indicator is not flashing, repeat procedure from step 1. 6. On some models, the DIC may list all 4 of the tire pressures at 0 psi after tire pressure sensor relearn procedure has been performed (although PDM/RCDLR reads correct learn value of the tires). To Microsoft Saturday, August 29, 2009 11:45:38 AM

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complete the relearn procedure on these models, drive the vehicle at highway speeds for 5 minutes. 2005-08 CORVETTE NOTE:

In the following procedure, a TPM Sensor Activation Tool (J-46079) must be used.

NOTE:

If the tire pressure sensor or RCDLR is replaced, the TPM system needs to relearn tire pressure sensor IDs.

The TPM system will cancel the learn mode if more then 2 minutes have passed and no sensors have been learned, or if the RCDLR has been in learn mode for more than 5 minutes. If the learn mode is canceled before any IDs are learned, the RCDLR will remember all previously stored IDs and their locations. As soon as the first sensor ID is learned, all other IDs are erased from the RCDLR's memory. 1. Turn ignition switch to ACC position. Apply parking brake. 2. Simultaneously press the keyless entry transmitter's lock and unlock buttons until a horn chirp sounds, indicating the learn mode has been enabled. 3. Starting with left front tire, hold antenna of TPM Sensor Activation Tool (J-46079) against the tire sidewall close to the wheel rim at the valve stem location, then press and release the ACTIVATE button and wait for a horn chirp. 4. After horn chirp has sounded, proceed as in step 3 for the next 3 sensors in the following order: right front, right rear and left rear. 5. After left rear sensor has been learned, a double horn chirp will sound, indicating all 4 sensor IDs have been learned. Turn ignition switch to OFF position. 2005 IMPALA & MONTE CARLO NOTE:

There are 3 different ways to reset the Tire Pressure Monitor (TPM) system. After resetting, the TPM system requires up to 30 minutes of straight line driving in each of the 3 speed ranges to complete the calibration process.

Using Exterior Lamp Switch

1. 2. 3. 4.

Adjust all tire pressures to the recommended kPa/psi. Turn ON the ignition, with the engine OFF. Cycle the exterior lamp switch from OFF to parking lamps 3 times within 5 seconds. Use the scan tool in order to clear the TPM DTC.

Using RDS Radio, If Equipped

1. Adjust all tire pressures to the recommended kPa/psi. 2. Turn the ignition to ACC or ON, with the engine OFF. 3. Turn the radio OFF. Microsoft Saturday, August 29, 2009 11:45:38 AM

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4. 5. 6. 7. 8. 9. 10.

Press and hold the DISP button until SETTINGS is displayed. Press the SEEK up or down arrows until TIRE MON is displayed. Press the PREV or NEXT button to enter the sub-menu. RESET will be displayed. Press the DISP button, A chime will sound and DONE will be displayed. Scroll until EXIT is displayed. Press the DISP button to exit the TPM reset mode. A chime will sound to verify exit. Use the scan tool in order to clear the TPM DTC.

Using Scan Tool

1. 2. 3. 4. 5. 6. 7.

Adjust all tire pressures to the recommended kPa/psi. Install the scan tool. Turn ON the ignition, with the engine OFF. With the scan tool select Special Functions. Select TIM Reset. Press the Reset soft key. Use the scan tool in order to clear the TPM DTC.

2006-08 COLORADO NOTE:

When the wheels have been rotated, or a tire pressure sensor has been replaced, retrain tire pressure sensor.

NOTE:

Learn Mode Cancellation The learn mode will cancel if the ignition is cycled to OFF or if more than 2 minutes has elapsed for any sensor that has not been learned. If the learn mode is cancelled before the first sensor is learned, the original sensor IDs will be maintained. If the learn mode is canceled for any reason after the first sensor is learned, all IDs are erased from the BCM memory and if equipped, the DIC will display dashes for tire pressures. WARNING: Stray signals from other TPM equipped vehicles just driving by can be inadvertently learned. If any random horn chirps are heard from the vehicle while performing the learn procedure, most likely a stray sensor has been learned and the procedure will need to be cancelled and repeated. Under these circumstances, performing the TPM Learn Procedure away from other vehicles would be highly recommended. In the event a particular sensor activation does not cause the horn to chirp, it may be necessary to rotate the wheel valve stem to a different position due to the sensor signal is being blocked by another component. Before proceeding with the steps below, verify the following: No other sensor learn procedure is being performed simultaneously within close proximity. Tire pressures are not being adjusted on another TPM equipped vehicle within close proximity. Park Brake and Headlamp Switch

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

input parameters are functioning correctly. 1. Turn ON the ignition, with the engine OFF. 2. Apply the parking brake. 3. Turn the exterior lamp switch from OFF to parking lamps 4 times within 4 seconds. A horn chirp will sound and the low tire pressure indicator will begin to flash indicating the learn mode has been enabled. 4. Starting with the left front tire, learn the tire pressure using one of the following methods: Method 1: Hold the antenna of the tool against the tire sidewall close to the wheel rim at the valve stem location then press and release the activate button and wait for a horn chirp. Method 2: Increase/decrease the tire pressure for 8-10 seconds then wait for a horn chirp. The horn chirp may occur before or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached. WARNING: Over inflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure do not exceed the maximum inflation pressure as noted on the tire sidewall. 5. After the horn chirp has sounded, repeat step 4 for the remaining 3 sensors in the following order: Right front, Right rear, Left rear. 6. After the LR sensor has been learned, a horn chirp will sound indicating all sensors have been learned. 7. Turn OFF the ignition to exit the learn mode. 8. After the learn mode has been exited, adjust all tires to the recommended pressures. 2006-08 EQUINOX NOTE:

When the wheels have been rotated, or a tire pressure sensor has been replaced, retrain tire pressure sensor.

NOTE:

Learn Mode Cancellation: The learn mode will cancel if the ignition is cycled to OFF or if more than 2 minutes has elapsed for any sensor that has not been learned. If the learn mode is cancelled before the first sensor is learned, the original sensor IDs will be maintained. If the learn mode is canceled for any reason after the first sensor is learned, all IDs are erased from the BCM memory and if equipped, the DIC will display dashes for tire pressures. WARNING: Stray signals from other TPM equipped vehicles just driving by can be inadvertently learned. If any random horn chirps are heard from the vehicle while performing the learn procedure, most likely a stray sensor has been learned and the procedure will need to be cancelled and repeated. Under these circumstances, performing the TPM Learn Procedure away from other vehicles would be highly recommended. In the event a particular sensor activation does not cause the horn to chirp, it may be necessary to rotate the wheel valve stem to a different position due to the sensor signal is being blocked by another component. Before proceeding with the steps below, verify the following: No other sensor

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

learn procedure is being performed simultaneously within close proximity. Tire pressures are not being adjusted on another TPM equipped vehicle within close proximity. Park Brake and Headlamp Switch input parameters are functioning correctly. 1. Turn ON the ignition, with the engine OFF. 2. Apply the parking brake. 3. Turn the exterior lamp switch from OFF to parking lamps 4 times within 4 seconds. A horn chirp will sound and the low tire pressure indicator will begin to flash indicating the learn mode has been enabled. 4. Starting with the left front tire, learn the tire pressure using one of the following methods:  Method 1: Hold the antenna of the tool against the tire sidewall close to the wheel rim at the valve stem location then press and release the activate button and wait for a horn chirp.  Method 2: Increase/decrease the tire pressure for 8-10 seconds then wait for a horn chirp. The horn chirp may occur before or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached. WARNING: Over inflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure do not exceed the maximum inflation pressure as noted on the tire sidewall. 5. After the horn chirp has sounded, repeat step 4 for the remaining 3 sensors in the following order: Right front, Right rear, Left rear. 6. After the LR sensor has been learned, a horn chirp will sound indicating all sensors have been learned. 7. Turn OFF the ignition to exit the learn mode. 8. After the learn mode has been exited, adjust all tires to the recommended pressures. 2006-08 IMPALA & MONTE CARLO NOTE:

If a tire pressure sensor or the RCDLR is replaced, or if wheels have been rotated, tire pressure sensor must be retrained.

Before proceeding with the steps below, ensure that no other sensor learn procedure is being performed simultaneously, or that no tire pressures are being adjusted on another TPM equipped vehicle within close proximity.

NOTE:

In the following procedures, a TPM Sensor Activation Tool (J-46079) may be used in place of increasing/decreasing pressures to enable sensor. To use, place activator antenna against the tire sidewall close to the wheel rim at the

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

valve stem location, then press and release the ACTIVATE button. NOTE:

If TPM Sensor Activation Tool (J-46079) is used, and vehicle is having trouble entering relearn mode, check batteries in activation tool. Low batteries may allow some functions to work, but not allow vehicle to perform learn function. When the internal battery is fresh (fully charged), the indicator is "full" or is all dark. When the battery is depleted, the indicator shows "empty" or is all light.

Relearn Procedure Using Keyless Entry System

1. Turn ignition switch to ACC position. Apply parking brake. 2. Simultaneously press the keyless entry transmitter's lock and unlock buttons until a horn chirp sounds, indicating the learn mode has been enabled. WARNING: Overinflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure, DO NOT exceed the maximum inflation pressure as noted on the tire sidewall. 3. Starting with left front tire, increase or decrease the pressure for 5-8 seconds, or until a horn chirp sounds. The horn chirp may occur before the 5-8 second pressure increase/decrease time period has been reached, or up to 30 seconds after the 5-8 second pressure increase/decrease time period has been reached. 4. After horn chirp has sounded, proceed as in step 3 for the next 3 sensors in the following order: right front, right rear and left rear. 5. After left rear sensor has been learned, a double horn chirp will sound, indicating all 4 sensor IDs have been learned. Turn ignition switch to OFF position. Adjust all tire pressures to specification. Relearn Procedure Using Scan Tool

NOTE:

1. 2. 3. 4.

Connect scan tool. Turn ignition switch to ACC position. Apply parking brake. Using scan tool, select "SPECIAL FUNCTIONS". Select "SENSOR LEARN MODE ENABLE", and press ENTER key. Press ON soft key. A horn chirp will sound, indicating the learn mode has been enabled. WARNING: Overinflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure, DO NOT exceed the maximum inflation pressure as noted on the tire sidewall.

5. Starting with left front tire, increase or decrease pressure for 5-8 seconds, or until a horn chirp sounds. The horn chirp may occur before the 5-8 second pressure increase/decrease time period has been reached, or up to 30 seconds after the 5-8 second pressure increase/decrease time period has been reached. Microsoft Saturday, August 29, 2009 11:45:38 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

6. After horn chirp has sounded, proceed as in step 5 for the next 3 sensors in the following order: right front, right rear and left rear. 7. After left rear sensor has been learned, a double horn chirp will sound, indicating all 4 sensor IDs have been learned. Turn ignition switch to OFF position. Adjust all tire pressures to specification. 2006-08 TRAILBLAZER NOTE:

When the wheels have been rotated, or a tire pressure sensor or EGM/LGM has been replaced, retrain tire pressure sensor.

NOTE:

If this procedure is performed following replacement and reprogramming of the Liftgate Module (LGM), DIC may display a low tire pressure fault and all tire pressures read 0 psi. If this problem occurs, contact vehicle manufacturer for repair procedure.

The TPM system will cancel the learn mode if more than 2 minutes have passed and no sensors have been learned, or if the system has been in learn mode for more than 5 minutes. If the learn mode is canceled before any sensor has been learned, the EGM/LGM will remember all current sensor IDs and their locations. As soon as the first sensor ID code is learned, all other IDs are erased from the EGM/LGM's memory. On models that display the individual tire pressure on DIC, updated tire pressures will not be displayed until EGM/LGM receives 2 more valid transmissions from each sensor. After performing the procedure below, always test drive the vehicle above 25 mph for at least 2 minutes before viewing tire pressures on DIC. NOTE:

Before proceeding with the steps below, ensure that no other sensor learn procedure is being performed simultaneously, or that tire pressures are not being adjusted on a TPM equipped vehicle within close proximity.

NOTE:

In the following procedure, a TPM Sensor Activation Tool (J-46079) may be used in place of increasing/decreasing pressures to enable sensor. To use, place activator antenna against the tire sidewall close to the wheel rim at the valve stem location, then press and release the ACTIVATE button.

NOTE:

If TPM Sensor Activation Tool (J-46079) is used, and vehicle is having trouble entering relearn mode, check batteries in activation tool. Low batteries may allow some functions to work, but not allow vehicle to perform learn function. When the internal battery is fresh (fully charged), the indicator is "full" or all dark. When the battery is depleted, the indicator shows "empty" or all light.

1. Turn ignition switch to ON position, with engine off. Apply parking brake. NOTE:

If learn mode cannot be enabled, TPM system is not enabled in EGM/LGM. See appropriate manufacturer service information.

2. Turn headlight switch from OFF to parking lamps 4 times within 4 seconds. A double horn chirp will Microsoft Saturday, August 29, 2009 11:45:38 AM

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1997 Chevrolet S10 Pickup GENERAL INFORMATION Service Reminder Indicators - Chevrolet

sound and the low tire pressure indicator will begin to flash to indicate the learn mode has been enabled. WARNING: Overinflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure, do not exceed the maximum inflation pressure as noted on the tire sidewall. 3. Starting with left front tire, increase or decrease the pressure for 8-10 seconds, or until a horn chirp sounds. Horn chirp may occur before the 8-10 second pressure increase/decrease time period has been reached, or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached. 4. After horn chirp has sounded, proceed as in step 3 for the next 3 sensors in the following order: right front, right rear and left rear. 5. After left rear sensor has been learned, turn ignition switch to OFF position to exit the learn mode. Adjust all tire pressures to specification.

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

IDENTIFICATION Transmission identification code is stamped on left side of transmission at front and rear housing joint. Manufacturer identifies it as NV 1500. Manufacturer RPO code is MW2.

LUBRICATION & ADJUSTMENTS See TRANSMISSION SERVICING - M/T article in MANUAL TRANS SERVICE section.

TROUBLE SHOOTING See TROUBLE SHOOTING - BASIC PROCEDURES article in GENERAL TROUBLE SHOOTING section.

ON-VEHICLE SERVICE REAR HOUSING OIL SEAL Removal

Raise and support vehicle. Drain transmission fluid. Remove drive shaft. Use oil seal remover to remove oil seal. See Fig. 1 .

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Fig. 1: Removing Rear Oil Seal Courtesy of GENERAL MOTORS CORP. Installation

Apply sealant on outside area of NEW seal. Fill lip of oil seal with chassis grease. Install seal using appropriate oil seal installer. Install drive shaft. Tighten drive shaft bolts to specification. See TORQUE SPECIFICATIONS . Fill transmission and lower vehicle. VEHICLE SPEED SENSOR Removal & Installation

Raise and support vehicle. Remove harness connector and bolt holding sensor in case. Remove vehicle speed sensor. Install NEW "O" ring onto speed sensor. Coat "O" ring with thin film of transmission fluid. Install speed sensor and bolt. Install harness connector. SHIFT LEVER Removal & Installation

Remove 10 screws securing shift lever boot to floor panel and insulator. Loosen nut and unscrew shift lever from housing assembly. To install, reverse removal procedure. Ensure shift pattern on lever knob is horizontal. SHIFT LEVER HOUSING Microsoft Saturday, August 29, 2009 11:56:42 AM

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Removal & Installation

Shift transmission into 3rd or 4th gear. Remove shift lever. When removing shift lever housing, remove 4 bolts at base of housing. See Fig. 3 . DO NOT remove bolts under boot located at top of shift lever housing. DO NOT disassemble shift lever housing. If housing requires repair, replace complete assembly. Internal components are not available from manufacturer. When installing shift lever housing, ensure transmission is in 3rd or 4th gear.

REMOVAL & INSTALLATION See TRANSMISSION REMOVAL & INSTALLATION - M/T article in MANUAL TRANS SERVICE section.

TRANSMISSION DISASSEMBLY 1. Remove 2 bolts securing idler shaft support and collar to rear housing. Remove back-up light switch and vehicle speed sensor. Remove shift rail block-out bushing bolt, located on top of front housing near breather assembly. 2. Using Detent Plug Remover (J-36509) and slide hammer, remove detent plug, spring and plunger from front housing. See Fig. 2 . Remove output shaft oil seal. With transmission in vertical position, remove input shaft bearing retainer. Remove snap ring. Position transmission horizontally and remove 9 front housing-to-rear housing bolts. See Fig. 3 . 3. Remove countershaft roller bearing from countershaft or bearing shell. Remove roll pin from shift lever. DO NOT lose plunger and spring. Support shift rail end while driving out shift lever roll pin. Using 3/16" (5 mm) punch and air gun, remove shift rail socket roll pin. DO NOT apply excessive force, or pin will peen shift rail and damage rear housing shift rail bushing. 4. Remove shift rail, shift rail socket, shift lever and shift rail block-out bushing. See Fig. 3 . Rotate 3rd-4th shift fork counterclockwise and remove shift fork. 5. Remove 5 bolts from center of rear housing securing output shaft bearing retainer. Remove rear housing from gear assemblies. Remove reverse idler gear and output shaft bearing retainer. Remove shift forks. Remove countershaft, countershaft bearing snap ring, and bearing. Press countershaft bearing off countershaft, if necessary. Remove output shaft assembly, input shaft and pilot bearing. See Fig. 4 .

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Fig. 2: Removing Detent Plug, Spring & Plunger Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Fig. 3: Identifying Transmission Shift Mechanism & Case Components Courtesy of GENERAL MOTORS CORP.

COMPONENT DISASSEMBLY & REASSEMBLY MAINSHAFT Disassembly

1. Remove 5th countergear from countershaft. Remove and discard speed sensor rotor. Remove snap ring from output shaft. Using gear puller adapter and puller, remove output shaft bearing from output shaft. Remove 5th gear from output shaft. 2. Remove snap ring, 5th-reverse synchronizer assembly, synchronizer rings and reverse gear from output shaft. See Fig. 4 . Scribe marks on hub and sleeve for installation reference. NOTE:

Leave synchronizer rings on all synchronizer assemblies to prevent synchronizer detent balls from popping out.

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

3. Remove input shaft and pilot bearing from output shaft. Remove snap ring. Remove 3rd-4th synchronizer assembly and 3rd gear using hydraulic press. Remove retainer ring, pin and 2-piece thrust washer. Remove 2nd gear and inner and middle cones from output shaft. Remove snap ring. Using gear and bearing separator plate and hydraulic press, remove 1st gear and 1st-2nd synchronizer assembly with inner and middle cones from output shaft. Scribe marks on hub and sleeve for installation reference. 4. Place 1st-2nd, 3rd-4th and 5th-reverse gear synchronizers in separate shop towels. Wrap assemblies and press against inner hub. Disassemble synchronizer assemblies. DO NOT mix parts. Cleaning & Inspection

1. Wash all parts in solvent and air dry. DO NOT spin dry bearings. Check gears and synchronizers for cracks, chipped teeth, excess wear and other damage. 2. Check bearings and bearing surfaces for nicks, burrs, bent cages and wear. Lubricate all bearings and check for rough rotation. Lubricate all components during reassembly. Reassembly

1. Assemble 1st-2nd, 3rd-4th and 5th-reverse gear synchronizer assemblies. Synchronizer sleeves must be assembled with offset teeth toward 2nd, 3rd and 5th gear. Install 1st-2nd synchronizer sleeve with groove facing 1st gear. Install 3rd-4th synchronizer sleeve with 2 grooves facing 3rd gear. Install 5th-reverse synchronizer sleeve with 2 grooves facing 5th gear and one groove facing reverse gear. 2. Install reverse gear on output shaft. Check hub and sleeve scribe marks for correct position. Align and engage splines of 5th-reverse synchronizer assembly and output shaft. See Fig. 4 . 3. Using press tube, reducer, separator plate and hydraulic press, press 5th-reverse synchronizer assembly with synchronizer ring onto output shaft until seated. Install NEW snap ring. Install 5th gear and bearing assembly on output shaft. Install NEW snap ring. Position NEW speed sensor rotor on output shaft 2" from bearing assembly. 4. Align and engage splines of 1st-2nd synchronizer assembly and output shaft. Using press tube, reducer, separator plate and hydraulic press, press 1st-2nd synchronizer assembly with both synchronizer rings onto output shaft. Check hub and sleeve scribe marks for correct position. 5. Stop press before tangs engage. Lift and rotate 1st gear to engage synchronizer ring. Continue to press until synchronizer assembly is seated. Install NEW snap ring. Install middle and inner cone, and 2nd gear. Install 2-piece thrust washer and pin with NEW retainer ring. Install 3rd gear. Align and engage splines of 3rd-4th synchronizer assembly and output shaft. 6. Using press tube, reducer, separator plate and hydraulic press, press 3rd-4th synchronizer assembly with both synchronizer rings onto output shaft. Stop press before tangs engage. Lift and rotate 3rd gear to engage synchronizer ring. Continue to press until synchronizer assembly is seated. Install NEW snap ring.

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Fig. 4: Exploded View Of Transmission Components Courtesy of GENERAL MOTORS CORP. REVERSE IDLER GEAR Disassembly & Reassembly

Remove reverse idler shaft support, gear, bearing assembly and collar. Remove 2 "O" rings from reverse idler shaft. See Fig. 4 . Clean all parts in solvent and air dry. Check gear teeth, bearing assembly and idler shaft for damage. Replace as necessary. To reassemble, reverse disassembly procedure. Lubricate all components during reassembly. Microsoft Saturday, August 29, 2009 11:56:42 AM

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

FRONT HOUSING ASSEMBLY Disassembly

Press out input shaft bearing from front housing using press tube, reducer and hydraulic press. Remove front housing shift rail bushing with shift rail bushing remover and slide hammer with pilot bearing puller. Remove breather assembly. See Fig. 3 . DO NOT remove metal tube from case. Remove oil fill plug. Cleaning & Inspection

Remove gasket material from case with liquid gasket remover. Clean all parts in solvent and air dry. Inspect all parts for damage, wear and cracks. Check mating surfaces for flatness. If scratches, grooves or scoring cannot be removed, replace component. Reassembly

Press in input shaft bearing using press tube, reducer and hydraulic press. Install front housing shift rail bushing flush to housing, and stake bushing using bushing installer. DO NOT stake tabs on bushing. Install breather assembly. Apply sealant to threads of oil fill plug and install plug. See Fig. 3 . REAR HOUSING ASSEMBLY Disassembly

Remove snap ring and shift rail support. Remove rear housing shift rail bushing using slide hammer. See Fig. 3 . Remove oil drain plug. Remove oil seal. Cleaning & Inspection

Remove gasket material from case with liquid gasket remover. Wash parts in solvent and air dry. Inspect bushing for scores, burrs, roundness or evidence of overheating. Check extension bushing for wear or damage. Replace as necessary. Using straightedge, check machined mating surfaces for flatness. Reassembly

Install rear housing shift rail bushing with writing on bushing lip facing down and flush in bore. Install shift rail support and snap ring. Install oil seal using oil seal installer. Fill seal lips with chassis grease. Apply sealant around edge of plug, and install oil drain plug.

TRANSMISSION REASSEMBLY 1. Install pilot bearing on input shaft with smaller diameter of bearing cage facing toward input shaft. Retain bearing on shaft with petroleum jelly. Install input shaft and pilot bearing on output shaft. Turn mainshaft over and position on Assembly Pallet (J-41663). See Fig. 5 . Install 5th countergear on countershaft. Press countershaft rear bearing onto countershaft. Install NEW snap ring on countershaft. Position countershaft on assembly pallet. 2. Install 2 "O" rings onto reverse idler shaft. Install shaft support, needle bearing, reverse idler gear and Microsoft Saturday, August 29, 2009 11:56:42 AM

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

idler shaft support collar on reverse idler shaft. See Fig. 4 . Ensure chamfer on idler shaft support and collar are facing up toward rear of transmission. Ensure groove on idler gear is facing collar. 3. Install reverse idler shaft assembly onto assembly pallet. Install output shaft bearing retainer onto mainshaft and countershaft. Ensure output shaft bearing retainer is positioned properly. Retainer should be positioned with hooked end under and behind mainshaft bearing, and forked end under and behind countershaft bearing. Install 5th-reverse shift fork onto 1st-2nd shift fork. 4. Install fork assemblies onto 1st-2nd and 5th-reverse synchronizer sleeves. Install rear housing over mainshaft, countershaft and reverse idler shaft assembly. Ensure reverse idler shaft assembly is lined up with holes in rear housing. Install 2 bolts securing reverse idler shaft assembly to rear housing. Short bolt goes in idler shaft assembly front hole. See Fig. 4 . Tighten bolts to specification. See TORQUE SPECIFICATIONS . 5. Install 5 output shaft bearing retainer bolts. Tighten bolts to specification in a crisscross pattern starting at bottom bolt located at 7 o'clock position. Tighten bolt above 5 o'clock position last. Remove rear housing assembly from assembly pallet and position horizontal. Install 3rd-4th shift fork onto 3rd-4th synchronizer sleeve.

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Fig. 5: Positioning Components On Assembly Pallet Microsoft Saturday, August 29, 2009 11:56:42 AM

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1997 Chevrolet S10 Pickup MANUAL TRANS OVERHAUL - NEW VENTURE 1500 (MW2) 1997 MANUAL TRANSMISSIONS New Venture 1500 (MW2) 5-Speed

Courtesy of GENERAL MOTORS CORP. 6. Install shift rail into 3rd-4th shift fork. Install shift lever and block-out bushing onto shift rail. Install shift rail through 1st-2nd and 5th-reverse shift forks. Install shift rail socket on shift rail. See Fig. 3 . Slide shift rail into rear housing. 7. Install NEW 22 mm roll pin into shift lever until pin is flush with shift lever. Install shift rail socket to shift rail 30 mm roll pin. See Fig. 3 . Drive in roll pin until it is flush with bottom of shift rail socket. Install detent spring and plunger into shift lever. Shift transmission into 3rd gear by pushing shift rail all the way to rear of rear housing. Apply Loctite 518 sealant to mating surfaces of rear housing. 8. Install input shaft bearing into front housing using press tube, reducer and hydraulic press. Install bearing shell and countershaft roller bearing into front housing with smaller diameter of bearing cage facing housing. Retain with petroleum jelly. Install front housing onto rear housing. 9. Install block-out bushing pin into top of front housing and tighten to specification. Ensure pin installs into shift lever and shift rail bushing. Install 9 bolts securing front housing to rear housing. Tighten bolts to specification. Install shift rail detent plunger, detent spring and plug. 10. Install snap ring on input shaft bearing. Install silicone sealant to input shaft bearing retainer mating surface. Install retainer to transmission. Install 5 retainer bolts and tighten to specification. Install back-up light assembly into rear housing and tighten to specification. Install shift housing.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Block-Out Bushing Pin Back-Up Light Switch Drive Shaft Bolts Front-To-Rear Housing Bolt Idler Shaft Support Bolt Front Rear Input Shaft Retainer Bolt Oil Drain Plug Oil Fill Plug Output Shaft Bearing Retainer Bolt Transmission-To-Engine Bolt Vehicle Speed Sensor Bolt

Ft. Lbs. (N.m) 24 (33) 28 (38) 15 (20) 24 (33) 33 (45) 16 (22) 21 (29) 27 (37) 17 (23) 16 (22) 35 (47) 16 (22) INCH Lbs. (N.m) 89 (10)

Shift Lever Housing Assembly Bolt

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1997 Chevrolet S10 Pickup 1996-97 MANUAL TRANSMISSION SERVICING General Motors

1996-97 MANUAL TRANSMISSION SERVICING General Motors

MODEL IDENTIFICATION MODEL IDENTIFICATION - TRUCKS Series (1) "C" "K" "P" "S" "T" (1) Vehicle series is fifth character of VIN.

Model 2WD Pickup, Sierra, Suburban, Tahoe & Yukon 4WD Pickup, Sierra, Suburban, Tahoe & Yukon Commercial Van/Motorhome 2WD Blazer, Jimmy, Pickup & Sonoma 4WD Blazer, Jimmy, Pickup & Sonoma & AWD Bravada

LUBRICATION SERVICE INTERVALS NOTE:

There are 2 light truck emission control classifications: Light Duty and Heavy Duty. Light Duty refers to vehicles weighing up to 8600 lbs. (GVW); Heavy Duty refers to vehicles weighing over 8600 lbs. (GVW).

Transmission

On all Light Duty vehicles, check transmission fluid every 12 months or 7500 miles. On Heavy Duty vehicles, check fluid level every 12 months or 6000 miles. Periodic draining and refilling is not required. Transfer Case

Check transfer case lubricant every oil change or 12 months. Under severe conditions, check it more frequently. CHECKING FLUID LEVEL Transmission

Check lubricant level at transmission filler plug hole. Lubricant should be level with bottom of filler hole. Transfer Case

Remove filler plug. Check oil level. Lubricant should be level with bottom of filler hole. RECOMMENDED FLUID Microsoft Saturday, August 29, 2009 11:55:54 11:55:50 AM

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1997 Chevrolet S10 Pickup 1996-97 MANUAL TRANSMISSION SERVICING General Motors

TRANSMISSION RECOMMENDED FLUID Application T5 5-Speed (77-mm) NV 1500 5-Speed (85-mm)

Fluid Type Dexron-III ATF (1) GM Synchromesh Fluid (9985648)

NV 3500 5-Speed (85-mm) NV 4500 5-Speed (109-mm) (1) With 5 percent Friction Modifier (12380672)

GM Synchromesh Fluid (12345349) GM GL-4 Transmission Fluid (12345871)

TRANSFER CASE RECOMMENDED FLUID Application Transfer Cases

Fluid Type Dexron-III ATF

FLUID CAPACITY NOTE:

Capacities listed in the following chart are approximations only. Correct fluid level should be determined by level at filler plug hole rather than by amount added.

TRANSMISSION REFILL CAPACITIES Application T5 5-Speed (77-mm) NV 1500 5-Speed (85-mm) NV 3500 5-Speed (85-mm) NV 4500 5-Speed (109-mm)

Pts. (L) 4.8 (2.4) 5.7 (2.7) 4.2 (2.0) 8.4 (4.0)

TRANSFER CASE REFILL CAPACITIES Application Model 231 & 233 Model 241 & 243 Model 4401 Model 4470

Pts. (L) 2.5 (1.2) 4.6 (2.2) 2.9 (1.4) 6.6 (3.1)

ADJUSTMENTS NOTE:

Manual transmissions have no shift rods. Shift lever mounts directly to top of transmission and is not adjustable.

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

DESCRIPTION & OPERATION When door lock switch is operated, all doors will lock or unlock. Each lock can also be operated manually. Locks are operated by reversible motors. Door lock switches operate to turn motors on by supplying battery voltage to one terminal and ground to the other terminal. When either door lock switch is moved to LOCK position, it completes a circuit to the motors. Motor in each door runs to operate door locks. When door lock switch is released, circuit is opened and motors turn off. When door lock switch is moved to UNLOCK position, polarity of voltage to motors is reversed. Door lock switches are usually closed for just a moment. If door lock switches are held closed, a circuit breaker in each motor will open to protect against damage. Circuit breakers close automatically when they cool.

TROUBLE SHOOTING Before proceeding to TESTING , perform the following visual inspections: 

 



Check appropriate circuit breakers and fuses. If circuit breakers or fuses are blown, service and repair source of overload. Replace circuit breakers and fuses. Check for mechanical failures or binding linkage. Check for broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. These circuits may be intermittent or resistive when loaded. Check by monitoring voltage drop with system under load. Check for proper installation of aftermarket electronic equipment.

See appropriate wiring diagram under WIRING DIAGRAMS to assist in testing procedures.

DOOR LOCKS DO NOT OPERATE FROM EITHER SWITCH (EXCEPT PICKUP) 1. Disconnect left door lock switch connector. Connect a test light between connector Orange wire and ground. If test light illuminates, go to next step. If test light does not illuminate, repair openin Orange wire. Microsoft Saturday, August 29, 2009 12:01:35 12:01:31 PM

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

2. Disconnect door lock relay. Connect test light between door lock relay socket Orange wire and ground. If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire. 3. Connect self-powered test light between door lock relay socket Black wire and ground. If test light illuminates, replace door lock relay. If test light does not illuminate, repair open in Black wire. DOOR LOCKS DO NOT OPERATE FROM EITHER SWITCH (PICKUP) Disconnect left door lock switch. Connect test light between door lock switch connector Orange wire and ground. If test light illuminates, repair open in Black wire. If test light does not illuminate, repair openin Orange wire. DOOR LOCKS LOCK & UNLOCK FROM ONE SWITCH ONLY (EXCEPT PICKUP) 1. Disconnect inoperative door lock switch. Connect test light between inoperative door lock switch connector Orange wire and ground. If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire. 2. Connect fused jumper wire between inoperative door lock switch connector Orange and Light Blue wires, and then between Orange and White wires. If doors lock and unlock, replace switch. If doors do not lock and unlock, check White and Light Blue wires for an open. Repair as necessary. DOOR LOCKS LOCK & UNLOCK FROM ONE SWITCH ONLY (PICKUP) Disconnect inoperative door lock switch. Connect test light between Orange wire at inoperative switch and ground. If test light illuminates, replace inoperative door lock switch. If test light does not illuminate, repair open in Orange wire. DOOR LOCKS DO NOT LOCK (EXCEPT PICKUP) Disconnect door lock relay. Connect fused jumper wire between door lock relay socket Light Blue and Gray wires. Connect another jumper wire between door lock relay socket Tan wire and ground. If doors lock, replace relay. If doors do not lock, repair open in Light Blue wire. DOOR LOCKS DO NOT UNLOCK (EXCEPT PICKUP) Disconnect door lock relay. Connect fused jumper wire between door lock relay socket White and Tan wires. Connect another jumper wire between Gray wire and ground. If doors unlock, replace relay. If doors do not unlock, repair open in White wire. DOOR LOCKS DO NOT LOCK OR UNLOCK FROM ENDGATE PUSH BUTTON SWITCH (EXCEPT PICKUP) 1. Disconnect endgate push button switch. Connect test light between switch Orange wire and ground. If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire. 2. Connect fused jumper wire between endgate lock switch connector Orange and White wires. If doors lock, replace endgate lock switch. If doors do not lock, repair open in Light Blue wire. 3. Connect fused jumper wire between endgate lock switch connector Orange and Light Blue wires. If doors Microsoft Saturday, August 29, 2009 12:01:31 PM

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

lock, replace endgate lock switch. If doors do not lock, repair open in White wire.

1. Disconnect negative battery cable. Remove 2 screws and armrest cover. Remove window crank handle (if equipped). Starting with front edge, pull out lock lever trim. Remove upper corner trim by pulling out at top edge and pivoting down to clear tab at trim panel. Remove 2 caps covering 2 assist handle screws. Remove 2 screws retaining handle to door. 2. Remove screw at front edge of accessory switch mount plate (if equipped). Remove plate from trim panel. Remove electrical connectors from switches on plate. Remove door courtesy light assembly from door panel. Remove trim panel retainers from door. Remove trim panel. See Fig. 1 . Remove lock rods from door lock motor. Remove screws or drill out rivets and remove door lock motor. See Fig. 2 and Fig. 3 . To install, reverse removal procedure.

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

Fig. 1: Removing Switch Mount Plate & Door Panel (Typical) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

Fig. 2: Removing Front Door Lock Motor (Typical) Courtesy of GENERAL MOTORS CORP.

Fig. 3: Removing Side Door Lock Motor (Typical) Courtesy of GENERAL MOTORS CORP. DOOR LOCK SWITCH Microsoft Saturday, August 29, 2009 12:01:31 PM

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

Removal & Installation

Disconnect negative battery cable. Remove screw at front edge of accessory switch mount plate (if equipped). Using a flat-blade screwdriver, remove plate from trim panel. Press tabs and remove front door switch mount plate. Carefully bend retaining tabs outward while pushing switch out of bezel. Disconnect power door lock switch wiring connector. Remove power door lock switch. To install, reverse removal procedures.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

Fig. 4: Power Door Lock System Wiring Diagram (Blazer, Bravada & Jimmy)

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

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1997 Chevrolet S10 Pickup DOOR LOCKS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Door Locks

Fig. 5: Power Door Lock System Wiring Diagram (Sonoma & S10)

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1997 Chevrolet S10 Pickup MIRRORS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Mirrors

MIRRORS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Mirrors

DESCRIPTION & OPERATION Power mirror assemblies contain 2 motors each. One motor positions the mirror up and down, and the other positions mirror right and left. Reversing polarity of motors will move power mirrors in opposite directions. The power mirror switch is located on the left door trim panel.

TROUBLE SHOOTING Before proceeding with specific testing, check the following for proper operation:    



Check courtesy light and CTSY (15-amp or 20-amp) fuse for proper operation. Check power seat system operation. Ensure power accessory circuit breaker is okay. Check and ensure grounds are clean and tight. Check for broken or partially broken wire inside insulation, which could cause system malfunction, but prove good in a continuity/voltage check with system disconnected. These circuits may be intermittent or have high resistance when loaded, and if possible, should be checked by monitoring voltage drop with system operational (under load). Check for proper installation of aftermarket electronic equipment.

TESTING BOTH POWER MIRRORS DO NOT OPERATE 1. Using test light, backprobe between power mirror switch connector terminal "H" (Orange wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire between power mirror switch and fuse block. 2. Backprobe between power mirror switch terminals "H" (Orange wire) and "A" (Black wire). If test light illuminates, check for poor connection at power mirror switch connector. If connection is okay, replace switch. If test light does not illuminate, repair poor connection or open in Black wire to power mirror switch. LEFT POWER MIRROR DOES NOT OPERATE IN LEFT/RIGHT POSITIONS 1. Using test light, backprobe between power mirror switch terminals "D" (Yellow wire) and "B" (Light Blue wire). Move power mirror switch to left and right positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in one or both positions, replace power mirror switch. 2. Backprobe between power mirror connector terminals "A" (Yellow wire) and "D" (Light Blue wire). Move power mirror switch to left and right positions. If test light illuminates in both positions, replace power mirror. If test light does not illuminate in both positions, repair open in Yellow or Light Blue wire between power mirror switch connector and power mirror connector. Microsoft Saturday, August 29, 2009 12:02:43 12:02:40 PM

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1997 Chevrolet S10 Pickup MIRRORS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Mirrors

LEFT POWER MIRROR DOES NOT OPERATE IN UP/DOWN POSITIONS 1. Using test light, backprobe between power mirror switch terminals "D" (Yellow wire) and "E" (Light Green wire). Move power mirror switch to up and down positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in one or both positions, replace power mirror switch. 2. Backprobe between power mirror connector terminals "C" (Yellow wire) and "B" (Light Green wire). Move power mirror switch to up and down positions. If test light illuminates in both positions, replace power mirror. If test light does not illuminate in both positions, repair open in Yellow or Light Green wire between power mirror switch connector and power mirror connector. RIGHT POWER MIRROR DOES NOT OPERATE IN LEFT/RIGHT POSITIONS 1. Using test light, backprobe between power mirror switch terminals "D" (Yellow wire) and "F" (Purple/White wire). Move power mirror switch to left and right positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in one or both positions, replace power mirror switch. 2. Backprobe between power mirror connector terminals "C" (Yellow wire) and "B" (Purple/White wire). Move power mirror switch to left and right positions. If test light illuminates, replace power mirror. If test light does not illuminate, repair open in Yellow or Purple/White wire between power mirror switch connector and power mirror connector. RIGHT POWER MIRROR DOES NOT OPERATE IN UP/DOWN POSITIONS 1. Using test light, backprobe between power mirror switch terminals "D" (Yellow wire) and "C" (Gray wire). Move power mirror switch to up and down positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in one or both positions, replace power mirror switch. 2. Backprobe between power mirror connector terminals "A" (Yellow wire) and "D" (Gray wire). Move power mirror switch to up and down positions. If test light illuminates, replace power mirror. If test light does not illuminate, repair open in Yellow or Gray wire between power mirror switch connector and power mirror connector.

1. Disconnect negative battery cable. Remove door handle bezel screw. Prying at rear of bezel with lever in locked position, remove door handle bezel from trim panel. Microsoft Saturday, August 29, 2009 12:02:40 PM

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1997 Chevrolet S10 Pickup MIRRORS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Mirrors

2. If equipped with window regulator handle, insert Door Handle Remover (J-9886-01) between handle and bearing plate. Align tool parallel with door handle, and push to disengage clip. Pull handle from door. Remove bearing plate. 3. On all models, use flat-blade tool to carefully remove power accessory switch panel. Pry off cover, and remove armrest screw. Remove door trim panel screws. Using Trim Panel Remover (J-38778), remove trim panel. Remove mirror access hole plugs. Remove power mirror mounting nuts. Disconnect electrical connector from power mirror. Remove power mirror assembly. 4. To install, reverse removal procedure. Tighten power mirror mounting screws to 53 INCH lbs. (6 N.m). Tighten handle bezel and door trim panel screws to 17 INCH lbs. (1.9 N.m). POWER MIRROR GLASS Removal & Installation

1. Place tape over mirror glass. Cover mirror face with a cloth, and break mirror lens. Wearing gloves, clean broken glass from inside mirror frame. 2. To install, remove adhesive backing from back of new mirror lens. Firmly press mirror lens into mirror housing.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup MIRRORS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Mirrors

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1997 Chevrolet S10 Pickup MIRRORS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Mirrors

Fig. 1: Power Mirror System Wiring Diagram

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

DESCRIPTION & OPERATION A 6-way power seat is used on driver's seat (all models) and passenger seat (some models). System consists of 3 reversible motors attached to a seat drive rail. Each motor contains a self-resetting circuit breaker. Power seat switch is located on left side of driver's seat, or on right side of passenger's seat. Drive cables connect motor to gearnuts, which turn jack screws and adjusters at each side of seat.

TROUBLE SHOOTING Check power accessory circuit breaker. If motors operate but seat does not move, check for obstruction in seat drive rail or check for broken drive gear. If seat tilts forward and/or rearward but does not move up or down, replace power seat switch.

TESTING POWER SEAT DOES NOT OPERATE IN ANY DIRECTION 1. Disconnect power seat switch connector. Connect test light between power seat switch harness terminal "B" (Orange wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire between power seat switch and fuse block. 2. Connect self-powered test light between seat switch assembly terminal "A" (Black wire) and ground. If test light illuminates, replace power seat switch. If test light does not illuminate, repair open in Black wire. POWER SEAT DOES NOT TILT FORWARD 1. Disconnect power seat front height motor connector. Connect test light between front height motor harness terminals "A" (Dark Blue wire) and "B" (Dark Green wire). Operate front height switch. If test light does not illuminate, go to next step. If test light illuminates, check and repair any damaged wiring. If wiring is okay, replace front height motor. 2. Disconnect power seat switch connector. Connect self-powered test light between front height motor harness terminal "A" (Dark Blue wire) and power seat switch harness terminal "H" (Dark Blue wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Dark Blue wire between power seat switch and front height motor. 3. Connect self-powered test light between front height motor harness terminal "B" (Dark Green wire) and power seat switch harness terminal "G" (Dark Green wire). If test light illuminates, replace power seat switch. If test light does not illuminate, repair open in Dark Green wire between power seat switch and front height motor. POWER SEAT DOES NOT TILT REARWARD Microsoft Saturday, August 29, 2009 12:00:21 12:00:16 PM

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

1. Disconnect power seat rear height motor connector. Connect test light between rear height motor harness terminals "A" (Yellow wire) and "B" (Light Blue wire). Operate rear height switch. If test light does not illuminate, go to next step. If test light illuminates, check and repair any damaged wiring. If wiring is okay, replace rear height motor. 2. Disconnect power seat switch connector. Connect self-powered test light between rear height motor harness terminal "A" (Yellow wire) and power seat switch harness terminal "A" (Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire between power seat switch and rear height motor. 3. Connect self-powered test light between rear height motor harness terminal "B" (Light Blue wire) and power seat switch harness terminal "B" (Light Blue wire). If test light illuminates, replace power seat switch. If test light does not illuminate, repair open in Light Blue wire between power seat switch and rear height motor. POWER SEAT DOES NOT MOVE FORWARD OR REARWARD 1. Disconnect power seat forward/rearward motor connector. Connect a test light between forward/rearward motor harness terminals "A" (Tan wire) and "B" (Light Green wire). Operate forward/rearward switch. If test light does not illuminate, go to next step. If test light illuminates, replace forward/rearward motor. 2. Disconnect power seat switch connector. Connect self-powered test light between forward/rearward motor harness terminal "A" (Tan wire) and power seat switch harness terminal "E" (Tan wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Tan wire between power seat switch and forward/rearward motor. 3. Connect self-powered test light between forward/rearward motor harness terminal "B" (Light Green wire) and power seat switch harness terminal "C" (Light Green wire). If test light illuminates, replace power seat switch. If test light does not illuminate, repair open in Light Green wire between power seat switch and forward/rearward motor. POWER LUMBAR INOPERATIVE 1. Disconnect power lumbar support connector. Connect self-powered test light between ground and Black wire terminal at power lumbar support harness connector. If test light illuminates, go to next step. If test light does not illuminate, repair open in Black wire between power lumbar support and ground. 2. Connect test light between ground and Orange wire at power lumbar support harness connector. If test light illuminates, go to next step. If test light does not illuminate, repair open in Orange wire between power lumbar support and fuse block. 3. Disconnect lumbar support motor. Connect jumper wire between one end of motor and ground. Connect self-powered test light between other end of motor and ground. If test light illuminates, go to next step. If test light does not illuminate, replace lumbar support motor. 4. Reconnect power lumbar support connector. Connect test light between ground and Orange wire terminal at power lumbar support switch. If test light does not illuminate, go to next step. 5. Connect self-powered test light between ground and Black wire terminal at power lumbar switch. If test light illuminates, repair open in Orange wire between power lumbar support and lumbar support switch. If test light does not illuminate, replace power lumbar switch.

REMOVAL & INSTALLATION Microsoft Saturday, August 29, 2009 12:00:16 PM

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

NOTE:

Complete removal and installation procedures of components are not available from manufacturer.

Removal & Installation (Power Seat)

Disconnect negative battery cable. Remove seat adjuster trim cover screws. Remove seat adjuster trim covers. Disconnect power seat electrical connectors. Remove power seat assembly from vehicle. To install, reverse removal procedure. Tighten power seat adjuster-to-seat bolts and nuts to 33 ft. lbs. (45 N.m). Removal & Installation (Adjuster Motor & Drive Cables)

1. Adjust seat to full upward front and rear position. Disconnect negative battery cable. Remove power seat from vehicle. See POWER SEAT. Noting location and routing of cables, squeeze ends of motor-toadjuster cables to disconnect cables. 2. Disconnect electrical connector. Remove adjuster assembly bolts. Remove adjuster assembly from vehicle. Remove motor from adjuster assembly. To install, reverse removal procedure. Tighten power seat adjuster-to-seat bolts and nuts to 33 ft. lbs. (45 N.m). Removal & Installation (Power Lumbar Switch)

Remove front seat. See POWER SEAT. Remove bolts, and remove seat track from seat bottom. Remove "J" strip from outboard side of seat bottom frame. Pull seat bottom cover back to expose power lumbar switch. Remove power lumbar switch. Disconnect electrical connector. To install, reverse removal procedure.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

Fig. 1: Power Seats Wiring Diagram (Blazer, Bravada & Jimmy)

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

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1997 Chevrolet S10 Pickup SEATS - POWER 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Seats

Fig. 2: Power Lumbar Seats Wiring Diagram (Blazer, Bravada & Jimmy)

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

DESCRIPTION & OPERATION Steering gear is a variable ratio, recirculating ball-type which acts as a rolling thread between worm shaft and rack piston. The worm shaft is supported at lower end by a thrust bearing with 2 races. It is supported at upper end by a bearing assembly in the adjuster plug. Control valves, located inside steering gear housing, direct power steering fluid to either side of rack piston. See Fig. 1 . Steering linkage connects steering gear to front wheels through pitman arm. Steering linkage consists of pitman arm, idler arm, relay rod and tie rods. See Fig. 2 and Fig. 3 . Tie rod ends connect to relay rod by ball studs. Adjuster tubes between inner and outer tie rod ends are used to adjust toe. Some models have a shock absorber attached to relay rod. Two different types of vane-type power steering pumps are used. The Model "P" pump is mounted inside reservoir. See Fig. 9 . The Model "CB" pump is mounted below reservoir. See Fig. 11 . On both models, vanes are driven by a rotor and move fluid from intake to pressure cavities of pump ring.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 1: Exploded View Of Power Steering Gear Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 2: Exploded View Of Steering Linkage (2WD) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 3: Exploded View Of Steering Linkage (4WD) Courtesy of GENERAL MOTORS CORP.

TROUBLE SHOOTING NOTE:

See TROUBLE SHOOTING - BASIC PROCEDURES article in GENERAL TROUBLE SHOOTING section.

TESTING HYDRAULIC SYSTEM PRESSURE TEST 1. Ensure belt tension is correct. Disconnect high pressure line from power steering pump. Connect Power Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Steering Pressure Gauge (J-5176-D) hose to power steering pump fitting. Connect other hose from valve side of tester to steering gear inlet. 2. Open valve on pressure gauge. Check fluid level and add fluid as necessary. Check for possible leaks at pressure gauge connections. Bleed air from system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. Run engine until fluid reaches normal operating temperature of 150-170°F (66-77°C). Check fluid level and add fluid as necessary. 3. Note pressure reading with valve open and engine idling. Pressure should be 80-125 psi (6-9 kg/cm2 ). If pressure exceeds 200 psi (14 kg/cm2 ), check hoses for restrictions and poppet valve for proper assembly. CAUTION: To prevent pump damage, DO NOT hold gauge valve closed for more than 5 seconds. 4. Completely close and open valve 3 times. Record highest reading each time. Readings should be within specification. See PRESSURE TEST SPECIFICATIONS table. 5. If pressure readings are within specification and within 50 psi (4 kg/cm2 ) of each other, pump is operating properly. 6. If readings are within specification but not within 50 psi (4 kg/cm2 ) of each other, flow control valve in pump is sticking. Remove valve, but DO NOT disassemble it. Clean valve. Flush system if dirty. 7. If pressure is constant but more than 100 psi (7 kg/cm2 ) below specification, clean or replace flow control valve in pump. If readings are still low, replace pump. 8. If pressure readings are as specified, turn steering wheel from stop to stop with valve open. Record highest pressure with wheels at both stops. If highest pressure is not equal to highest pressure recorded in step 2), steering gear is leaking internally. Repair or replace assembly. 9. Turn engine off. Remove tester. Reconnect pressure hose. Check fluid level. Bleed hydraulic system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. PRESSURE TEST SPECIFICATIONS Idle Pressure psi (kg/cm2 ) 80-125 (6-9)

Relief Pressure psi (kg/cm2 ) 1100-1200 (77-84)

LUBRICATION FLUID TYPE Manufacturer recommends General Motors Power Steering Fluid (1050017) or an equivalent. Failure to use proper fluid will cause hose and seal damage. FLUID LEVEL CHECK To check fluid level, run engine until power steering fluid reaches normal operating temperature, about 170°F (77°C). Turn engine off. Remove fluid reservoir cap, and check level gauge. On models with remote reservoir, fluid level should be 1/2"-1" from top of reservoir with wheels turned fully left. Add fluid through fluid reservoir cap as necessary, and recheck fluid level. DO NOT overfill system. Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

HYDRAULIC SYSTEM BLEEDING 1. Fill reservoir to correct level. Allow fluid to settle for no less than 2 minutes. Start engine and run for 3060 seconds, then turn off. Check fluid level and add fluid (as necessary). Repeat procedure until fluid level in reservoir remains constant. 2. Raise and support vehicle with both front wheels off ground. Start engine. Turn wheels right and left, lightly contacting stops. Check fluid level and add fluid (as necessary). 3. Lower vehicle. Turn wheels right and left, slowly from lock to lock. Turn off engine. Check fluid level and add fluid (as necessary). If fluid is foamy, allow vehicle to sit for a few minutes and repeat bleeding procedure.

ADJUSTMENTS NOTE:

Adjust worm bearing preload before performing over-center preload adjustment.

POWER STEERING PUMP BELT BELT TENSION (1) Application Serpentine Belt "V" Belt (1) Tension in lbs. using V-belt tension gauge

New Belt

Used Belt

(2)

146

(2) Serpentine belts are equipped with self-tensioner; adjustment is not required.

WORM BEARING PRELOAD 1. Remove steering gear from vehicle and mount in vise before performing preload adjustments. See STEERING GEAR under REMOVAL & INSTALLATION. Remove worm bearing adjuster lock nut. See Fig. 1 . Using spanner wrench, turn adjuster plug clockwise until plug is seated in housing. Torque should be about 20 ft. lbs. (27 N.m). 2. Index mark housing even with one hole in adjuster plug. See Fig. 4 . Measure back 1/2" counterclockwise from first index mark. Mark housing with second index mark. Rotate adjuster plug back counterclockwise until hole in adjuster plug aligns with second index mark on housing. Install and tighten adjuster plug lock nut. Ensure adjuster plug remains in position.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 4: Measuring Worm Bearing Preload Courtesy of GENERAL MOTORS CORP. OVER-CENTER PRELOAD 1. With worm bearing preload adjusted, rotate stub shaft slowly from stop to stop while counting total number of turns. With stub shaft positioned at either stop, rotate stub shaft back 2/3 total number of turns counted. Stub shaft should be back to exact center position. Flat on stub shaft should be facing upward and parallel to side cover and master spline on pitman shaft should be aligned with adjuster screw. 2. Turn pitman shaft adjuster screw counterclockwise until extended, then back off one full turn. Place INCH-lb. torque wrench in vertical position on end of stub shaft. Measure gear over-center torque by rotating torque wrench attached to stub shaft in a 90 degree arc, 45 degrees on each side of center. See Fig. 5 . Record highest degree of arc on each side of center. Record highest reading. 3. Turn adjuster screw in until torque required to rotate stub shaft is 6-10 INCH lbs. (.6-1.1 N.m) greater than reading in step 2). Continue adjustment until over-center reading is within specification. See LASH ADJUSTMENT PRELOAD table. Tighten adjuster screw lock nut when reading is obtained. LASH ADJUSTMENT PRELOAD Application Over-Center INCH Lbs. (N.m) New Gears 6-10 (0.7-1.1) (2) 4-5 (.5-.6) Used Gears

(1) Total INCH Lbs. (N.m)

18 (2.0) 14 (1.6)

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

(1) Total preload is sum of worm bearing and over-center preload. (2) In service for more than 400 miles.

Fig. 5: Adjusting Over-Center Preload Courtesy of GENERAL MOTORS CORP.

REMOVAL & INSTALLATION STEERING GEAR Removal

1. Center steering gear. Raise and support vehicle. Place drain pan under steering gear assembly. Disconnect Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

return and feed lines from steering gear. Cap ends of lines and steering gear fittings. Remove flexible coupling-to-intermediate shaft retaining screw. Remove flexible coupling (if equipped). Remove shield from intermediate shaft (if equipped). 2. Mark alignment of lower clamp to steering shaft. Remove lower clamp bolt from steering shaft. Mark relationship of pitman arm-to-pitman shaft. Remove pitman arm nut and spring washer. Remove pitman arm using Puller (J-6632-01) or Remover (J-29107). Remove steering gear mounting bolts and washers. Remove steering gear. Installation

To install, reverse removal procedure. Ensure lower clamp bolt hole is aligned with groove in worm shaft (if equipped). Ensure pitman arm-to-pitman shaft reference marks are aligned. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS . Fill reservoir (if necessary). Bleed air from system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. POWER STEERING PUMP Removal

1. Place drain pan under steering pump assembly. Disconnect return and feed lines from steering pump. Cap ends of lines and steering pump fittings. 2. Unload power steering pump belt tensioner (if equipped). Remove power steering pump belt. Remove bracket mounting nuts, and remove bracket (if equipped). Using Pulley Remover (J-25034-B), remove pulley from pump shaft. Remove pump mounting bolts and remove pump. Installation (All Models)

To install, reverse removal procedure. Use Pulley Installer (J-25033-B) to install pulley. Install pulley flush with end of pump shaft plus or minus .010" (.25 mm). Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS . Fill reservoir (if necessary). Bleed air from system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. INNER & OUTER TIE ROD ENDS Removal

Raise and support vehicle. Remove cotter pins and outer tie rod end nuts. Remove inner tie rod end nuts. Using Wheel Stud and Tie Rod Remover (J-6627-A), remove outer tie rod ball studs from steering knuckle and inner tie rod ball studs from relay rod. On Commercial Van with I-Beam Axle, remove shock absorber from tie rod. On all models, loosen adjuster tube clamp bolts and clamps. Unscrew and remove tie rod ends from adjuster tube. Installation

1. Lubricate tie rod end threads with chassis lubricant before installing. Install inner and outer tie rod ends to adjuster tube. Inner and outer tie rod end threads must be adjusted equally within 3 threads. Install adjuster clamps and clamp bolts. Ensure clamps are positioned between locating dimples on ends of Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

adjuster tube. 2. Tie rod ends must rotate full travel and travel must be maintained during clamp tightening. Slot in adjuster tube and slot in clamp must be properly positioned. 3. Install inner tie rod ends to relay rod ensuring seal is on ball stud. Tighten Steering Linkage Installer (J29193 or J-29194) to 40 ft. lbs. (54 N.m) to seat tapers. Install and tighten inner tie rod end-to-relay rod nuts. Install outer tie rod end to steering knuckle. CAUTION: When installing outer tie rod end nut, tighten nut to align cotter pin hole. DO NOT tighten nut more than an additional 1/6 turn to align cotter pin hole. DO NOT back off nut to insert cotter pin. 4. Install and tighten outer tie rod end nut. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS . Adjust toe-in. See WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT section. RELAY ROD Removal

1. Raise and support vehicle. Remove inner tie rod end nuts. Remove inner tie rod ends from relay rod (if equipped). On models without inner tie rods, remove tie rod end-to-steering knuckle nuts. Separate tie rod ends from steering knuckle. 2. On all models, remove steering shock absorber nut from relay rod (if equipped). Using Steering Linkage Puller (J-24319-01), remove steering shock absorber from relay rod (if equipped). Remove connecting rod nut and remove connecting rod from relay rod (if equipped). 3. Remove relay rod end nuts from pitman arm and idler arm. Using Steering Linkage Puller (J-24319-01), remove pitman arm and idler arm from relay rod. Remove relay rod. See Fig. 2 and Fig. 3 . Installation

Reverse removal procedure. Ensure seals are on ball studs. Using Steering Linkage Installer (J-29193 or J29194), seat all tapers to 40 ft. lbs. (54 N.m). Tighten nuts to specification. See TORQUE SPECIFICATIONS . Adjust toe-in. See WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT section. IDLER ARM NOTE:

Replace idler arm assembly if an up and down force of 25 ft. lbs. (110 N.m), applied at relay rod end of idler arm, produces a lash of more than 1/8" (3 mm) for a total of 1/4" (6 mm) in straight-ahead position. See Fig. 6 .

Removal

Raise and support vehicle. Remove idler arm-to-frame nut and bolt. Remove idler arm nut and spring washer from relay rod. Using Steering Linkage Puller (J-24319-01), remove idler arm from relay rod. Remove idler arm. See Fig. 2 and Fig. 3 . Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Installation

To install, reverse removal procedure. Ensure seal is on ball stud. Using Steering Linkage Installer (J-29193 or J-29194), seat tapers to 40 ft. lbs. (54 N.m). Tighten nuts to specification. See TORQUE SPECIFICATIONS . Adjust toe-in. See WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article in WHEEL ALIGNMENT section.

Fig. 6: Checking Idler Arm Play Courtesy of GENERAL MOTORS CORP. PITMAN ARM Removal

1. Raise and support vehicle. Disconnect air induction assembly. Slide up intermediate shaft cover. Mark intermediate shaft for reassembly. Remove intermediate shaft. Disconnect oil filter lines at crossmember bracket. Remove splash shield. 2. Remove pitman arm nut and spring washer from relay rod. Using Steering Linkage Puller (J-24319-01), remove pitman arm from relay rod. 3. Remove lower steering gear bolts. LOOSEN upper steering gear bolt. Rotate steering gear for pitman arm clearance at crossmember, and support gear using block of wood. 4. Mark pitman arm-to-pitman shaft position. Remove pitman arm nut and spring washer from pitman shaft. Using Remover (J-6632-01) or Puller (J-29107), remove pitman arm from pitman shaft. See Fig. 2 and Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 3 . Installation

To install, reverse removal procedure. Ensure pitman arm-to-pitman shaft reference marks are aligned. Ensure seal is on ball stud. Using Steering Linkage Installer (J-29193 or J-29194), seat tapers to 40 ft. lbs. (54 N.m). Tighten nuts to specification. See TORQUE SPECIFICATIONS . CONNECTING ROD Removal

Raise and support vehicle. Remove connecting rod nuts from pitman arm and relay rod. Using Steering Linkage Puller (J-24319-01), remove connecting rod from pitman arm and relay rod. Installation

Remove steering shock absorber nut from relay rod. Using Steering Linkage Puller (J-24319-01), remove steering shock absorber from relay rod. Remove steering shock absorber-to-frame nut and bolt. Remove steering shock absorber. Installation

Reverse removal procedure. Ensure seal is on ball stud. Using Steering Linkage Installer (J-29193 or J-29194), seat tapers to 40 ft. lbs. (54 N.m). Tighten nuts to specification. See TORQUE SPECIFICATIONS .

OVERHAUL STEERING GEAR Disassembly

1. Mount steering gear in vise, clamping onto one mounting tab. Pitman shaft should be in a vertical position. Insert punch through housing access hole to unseat retaining ring. Pry retaining ring out of groove in housing. 2. Rotate stub shaft counterclockwise to force housing end plug from housing. Remove seals and ring. Using Rack Piston Arbor (J-21552) and socket, remove rack piston end plug from rack piston. 3. Remove side cover bolts. Remove pitman shaft nut and spring washer from lower end of shaft retaining pitman arm. Remove pitman shaft and side cover assembly. Remove pitman shaft adjuster screw lock nut. Remove pitman shaft cover. Remove gasket from side cover. Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

4. Remove pitman shaft lower dust seal and rubber boot (if equipped). Using snap-ring pliers, remove pitman shaft lower retaining ring. Remove pitman shaft lower seals and washer. Using Pitman Shaft Bearing Puller (J-6278), remove pitman shaft bearing from housing. 5. Insert Rack Piston Arbor (J-21552) into end of rack piston assembly until arbor seats into end of worm shaft. Threaded arbor will keep recirculating balls from falling out of rack piston. Rotate stub shaft counterclockwise, forcing rack piston onto arbor. Remove rack piston and arbor assembly. Ensure arbor is fully inserted so recirculating balls will not fall out. 6. Remove adjuster plug lock nut. Using spanner wrench, remove adjuster plug. Remove valve body, stub shaft, worm shaft, seal, bearing races and worm bearing assembly from housing. If further disassembly is required, see appropriate component under OVERHAUL . Inspection

Clean components using solvent, and blow dry. Avoid wiping valve components using cloth. Lint may cause binding of mechanism. DO NOT steam clean hydraulic parts. Reassembly

1. Lubricate components with power steering fluid before reassembly. Install valve body, stub shaft and worm shaft assembly into housing. 2. Place seal protector over stub shaft. Install adjuster plug until it seats against valve body. Remove seal protector from housing. Loosely install adjuster plug lock nut. Insert rack piston (with arbor to retain recirculating balls) into housing. Align worm shaft and rack piston. Turn stub shaft clockwise to engage worm shaft. Maintain pressure on arbor until worm shaft is fully engaged. Remove arbor. 3. Install NEW pitman shaft side cover gasket. Thread pitman shaft side cover onto adjuster screw until it bottoms. Back off 1/2 turn. Install pitman shaft so center sector gear tooth meshes with center groove in rack piston. Install side cover bolts. 4. Install adjuster screw lock nut halfway onto pitman shaft. Install rack piston end plug in rack piston. Install housing end plug seals, ring, end plug and retainer ring. Adjust worm shaft bearing preload and over-center preload. See WORM BEARING PRELOAD and OVER-CENTER PRELOAD under ADJUSTMENTS. ADJUSTER PLUG Disassembly

Using snap-ring pliers, remove adjuster plug retaining ring. Remove adjuster plug washer and seal. Using screwdriver, pry up bearing retainer at raised area. Using Bearing Remover (J-8524-1) and Driver (J-7079-2), remove bearing from adjuster plug. Inspection

Inspect bearings and races for scoring, pitting and wear. Inspect adjuster plug threads for damage. Reassembly Microsoft Saturday, August 29, 2009 11:48:34 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Using Bearing Remover (J-8524-1) and Driver (J-7079-2), install bearing into adjuster plug. Install bearing retainer. Lubricate seal with power steering fluid. Install adjuster plug seal, washer and retaining ring. NOTE:

Retainer projections must not extend beyond washer when retaining ring is seated. Adjuster plug washer must be free to rotate.

WORM SHAFT, STUB SHAFT & VALVE BODY Disassembly

1. Mark position of worm bearing races and bearing to worm shaft. Mark position of worm shaft notches to valve body. Remove worm shaft from valve body and stub shaft assembly. Remove stub shaft seal. Remove worm bearing races and bearing from worm shaft. 2. Lightly tap end of stub shaft against wood block until shaft cap is free of valve body. Pull stub shaft outward until drive pin hole is visible. See Fig. 7 . CAUTION: DO NOT pull shaft more than 1/4" (6 mm) or spool valve may become cocked in valve body. 3. Disengage drive pin. Remove stub shaft from valve body. Rotate and remove valve spool from valve body. If binding occurs, realign valves. CAUTION: DO NOT force stub shaft or valve spool out of valve body.

4. Remove spool valve seal. Remove valve body rings and seals.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 7: Removing Stub Shaft From Valve Body Courtesy of GENERAL MOTORS CORP. Inspection

1. Clean components using solvent, and blow dry. Inspect stub shaft for nicks and burrs. Remove nicks and burrs using crocus cloth if possible. Inspect shaft pin for wear and cracks. 2. Check valve spool fit in valve body. Remove nicks and burrs using crocus cloth if possible. Lubricate valve spool with power steering fluid. Rotate valve spool in valve body. If valve spool does not rotate freely, replace complete valve and stub shaft assembly. 3. Valve assembly is balanced during assembly. If replacing any components other than rings or seals, replace complete valve and stub shaft assembly. Reassembly

1. Lubricate valve body components with power steering fluid. Install NEW rings and seals. Lubricate spool valve seals with power steering fluid and install on valve spool. Carefully insert valve spool into valve body. 2. Push valve spool through valve body until locating pin hole is visible at opposite end of valve body, and valve spool is flush with notched end of valve body. Install stub shaft into valve spool and valve body. 3. Align stub shaft locating pin with valve spool locating hole. Align notch in stub shaft cap with pin in Microsoft Saturday, August 29, 2009 11:48:35 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

valve body. Install stub shaft seal into valve body. CAUTION: Before installing assembled valve body into gear housing, ensure valve body stub shaft locating pin is fully engaged in stub shaft cap notch. DO NOT allow stub shaft to disengage from valve body pin. 4. Install bearing and races on worm shaft, aligning marks made during disassembly. See Fig. 1 . Install worm shaft onto valve body and stub shaft assembly, aligning notches made during disassembly. RACK PISTON BALLS Disassembly

Remove ball guide clamp screws and clamps. Remove ball guides. Remove all recirculating balls from rack piston. See Fig. 1 . Inspection

Clean components using solvent, and blow dry. Inspect rack piston grooves for scoring. Inspect ball bearings for damage. If any ball bearings are damaged, replace entire set. Check ball guides for cracks or dented ends. Inspect rack piston teeth for chips, cracks, dents and scoring. If rack piston is damaged, replace rack piston and worm shaft as an assembly. Reassembly

1. Lubricate seals and ring with power steering fluid and carefully install onto rack piston. Install worm shaft into rack piston until worm shaft touches piston shoulder. While turning worm shaft counterclockwise, insert ball bearings into rack piston. NOTE:

Ensure light and dark colored balls are installed alternately; Black balls are .0005" (.013 mm) smaller than Silver balls.

2. Install 6 balls in ball guide, alternating ball colors. Bearings in guide must be in sequence with bearings in rack piston. Hold balls in place with chassis lubricant. Install return ball guide assembly into position. 3. Install clamp. Tighten clamp screws. See Fig. 8 . Insert Rack Piston Arbor (J-21552) into rack piston until it contacts worm shaft. Maintain pressure on arbor, and back worm shaft out of rack piston. DO NOT allow ball bearings to drop out.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 8: Installing Ball Bearing Into Rack Piston Courtesy of GENERAL MOTORS CORP. POWER STEERING PUMP Disassembly (Model "P")

1. Using Puller (J-29785-A), remove pulley from shaft if not previously removed. Remove union fitting and "O" ring. Remove reservoir retaining bolts. Remove reservoir and "O" rings from housing. 2. Using punch and screwdriver, remove end plate retaining ring. Remove end plate and pressure plate spring. See Fig. 9 . Remove "O" ring, flow control valve, and spring. Using soft-faced hammer, tap end of drive shaft to loosen pressure plate. Microsoft Saturday, August 29, 2009 11:48:35 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

3. Remove pressure plate, pump ring, vanes, retaining ring, rotor, and thrust plate assembly from housing. Remove drive shaft. Pry drive shaft seal from housing. Remove dowel pins and seals. Inspection

1. Clean all pump components with solvent and blow dry. Inspect flow control valve assembly for wear, scoring, burrs and other damage. Inspect seal bore for burrs, nicks and score marks. 2. Inspect machined surfaces of body for scratches or burrs. Check "O" ring mating surfaces. Inspect drive shaft for excessive wear. 3. Inspect pump ring for roughness. Check thrust plate and pressure plate for scoring and wear. Ensure vanes slide freely but fit snugly into slots. If vanes are loose in slots, replace rotor and/or vanes. Reassembly

1. Lubricate all "O" rings, seals, pump ring, rotor and vanes with power steering fluid. Using socket, press NEW drive shaft seal into housing. 2. Install dowel pins and all "O" rings. Install drive shaft and thrust plate. Install pump rotor into housing with counterbore facing drive shaft side of steering pump. 3. Install NEW drive shaft retaining ring, ensuring ring is seated in groove. Install vanes with rounded edges toward pump ring. Install pump ring and pressure plate. Install "O" ring, flow control valve, and spring. 4. Install pressure plate spring, end plate, and retaining ring. Install seals and reservoir. Install union fitting, "O" ring, and reservoir retaining bolts.

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 9: Exploded View Of Power Steering Pump (Model "P") Courtesy of GENERAL MOTORS CORP. Disassembly (Model "CB") Microsoft Saturday, August 29, 2009 11:48:35 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

1. Remove pump assembly from vehicle. Remove retaining clips between reservoir and housing and remove reservoir from housing. 2. Remove union fitting and "O" ring. Remove control valve assembly and flow control spring. 3. Protect drive shaft with shim stock and using a small chisel, cut drive shaft seal and remove. Using small drift punch, remove end cover retaining ring. See Fig. 10 .

Fig. 10: Removing Retaining Ring (Pump Model "CB") Courtesy of GENERAL MOTORS CORP. 4. Remove internal components of pump by gently pushing on drive shaft. See Fig. 11 . Microsoft Saturday, August 29, 2009 11:48:35 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 11: Exploded View Of Power Steering Pump (Model "CB") Courtesy of GENERAL MOTORS CORP. 5. Remove "O" ring from pump housing. Remove locating dowel pins. Remove drive shaft seal (if not Microsoft Saturday, August 29, 2009 11:48:35 AM

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

already removed). Remove end cover, pressure plate spring and "O" ring from pressure plate. 6. Remove pump ring and vanes from drive shaft subassembly. Remove retaining ring from drive shaft. Remove pump rotor and thrust plate from drive shaft. Inspection

Clean all parts in power steering fluid and dry with compressed air. Inspect pressure plate, pump ring, vanes, thrust plate and drive shaft for scoring, pitting or chatter marks. Replace any damaged parts. Reassembly

1. Lubricate NEW drive shaft seal with power steering fluid and drive seal into pump housing using Seal Driver (J-7728). See Fig. 12 .

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 12: Installing Drive Shaft Seal Courtesy of GENERAL MOTORS CORP. 2. Install pump ring dowel pins into pump housing. Assemble thrust plate and pump rotor onto drive shaft. Fit NEW retaining ring to shaft. See Fig. 13 .

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 13: Assembling Drive Shaft Subassembly Courtesy of GENERAL MOTORS CORP. 3. Install drive shaft subassembly into pump housing. install vanes into pump rotor. With holes positioned correctly onto dowel pins, install pump ring into pump housing. 4. Lubricate NEW "O" ring with power steering fluid and install into pump body. Install pressure plate and pressure plate spring. 5. Lubricate NEW "O" ring with power steering fluid and install into end cover. Lubricate outer edge of end cover with power steering fluid. Press end cover into pump housing. When installing retaining ring into groove, ensure opening of ring is near access hole in pump housing. See Fig. 14 .

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Fig. 14: Installing End Cover & Retaining Ring Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Adjuster Plug Lock Nut Idler Arm Mounting Bolts Idler Arm-To-Relay Rod Nut 2WD 4WD

Ft. Lbs. (N.m) 78-81 (106-110) 60 (81) 35 (47) 60 (81)

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1997 Chevrolet S10 Pickup STEERING SYSTEM - POWER RECIRCULATING BALL 1997 STEERING Power Recirculating Ball - General Motors Corp.

Intermediate Shaft-To-Stub Shaft Bolt Pitman Arm-To-Relay Rod Nut Pitman Shaft Adjuster Screw Lock Nut Rack Piston End Plug Shock Absorber-To-Frame Bolt Shock Absorber-To-Relay Rod Nut Side Cover Bolts Steering Gear Mounting Bolts Steering Pump Mounting Bolts 2.2L 4.3L Tie Rod Adjuster Clamp Nut Tie Rod-To-Relay Rod Nut Tie Rod-To-Steering Knuckle Nut Union Fitting

26 (35) 60 (81) 20 (27) 110 (149) 26 (35) 45-46 (61-62) 40 (54) 55 (75) 20 (27) 36 (49) 14 (19) 35 (47) 35 (47) 55 (75)

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

DESCRIPTION & OPERATION A permanent-magnet motor operates each power window. Each motor raises and lowers window when voltage is supplied. Motor direction depends on polarity of supply voltage. Switches control supply voltage polarity. Master door lock/power window switch assembly controls all motors. Individual window switches are located on each door panel. Each motor is protected by a built-in circuit breaker. If a window switch is held too long with window obstructed or after window is fully up or down, circuit breaker opens circuit. Circuit breaker resets automatically as it cools.

TROUBLE SHOOTING Before proceeding to TESTING , perform the following visual inspections:  

 



Check POWER WINDOW CIRCUIT BREAKER for damage. Replace if damaged. Check power window voltage supply fuse. If fuse is blown, service and repair source of overload. Replace fuse. Check for mechanical failures or binding linkage. If express down feature does not work, but window moves down with each switch depression, replace left window switch. Check for broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. These circuits may be intermittent or resistive when loaded. Check by monitoring voltage drop with system under load. Check for proper installation of aftermarket electronic equipment.

Before any testing is attempted, battery should be fully charged and all connections and pins cleaned and tightened to ensure proper continuity and ground.

NOTE:

See appropriate wiring diagram under WIRING DIAGRAMS to assist in testing procedures.

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

2-DOOR Windows Do Not Operate

1. Turn ignition switch to RUN position. Connect test light between ground and Yellow wire at left window switch 11-pin connector. If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire between left window switch and fuse block. 2. Connect test light between left window switch 11-pin connector Yellow and Black wires. If test light illuminates, check window switch for poor connection. If connection is okay, replace left window switch. If test light does not illuminate, repair open in Black wire between left window switch and ground. Left Window Inoperative/Right Window Operates Okay

1. Turn ignition switch to RUN position. Connect test light between left window switch 8-pin connector Dark Blue and Brown wires. Observe test light and operate switch between UP and DOWN positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in both positions, check left window switch for poor connection. If connection is okay, replace left window switch. 2. Connect test light between left window motor connector Dark Blue and Brown wires. Observe test light and operate switch between UP and DOWN positions. If test light illuminates in both positions, check left window motor connector for poor connection. If connection is okay, replace left window motor. If test light does not illuminate in both positions, repair open in Dark Blue or Brown wires between left window switch connector and left front window motor connector. Right Window Inoperative From Individual Window Switch/Operates Okay From Left Window Switch

1. Turn ignition switch to RUN position. Connect test light between ground and Yellow wire at right window switch 11-pin connector. If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire between right window switch and fuse block. 2. Connect test light between right window switch 11-pin connector Dark Blue and Brown wires. Operate window between UP and DOWN positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in both positions, check window switch for poor connection. If connection is okay, replace right window switch. 3. Connect test light between right window motor connector Dark Blue and Brown wires. Operate window switch between UP and DOWN positions. If test light illuminates in both positions, check right window motor for poor connection. If connection is okay, replace right window motor. If test light does not illuminate in both positions, repair open in Dark Blue or Brown wires between right window switch and right window motor. Right Window Inoperative From Both Left & Right Switch/Left Window Operates Okay

1. Turn ignition switch to RUN position. Connect test light between right window motor connector Brown and Dark Blue wires. Operate window switch between UP and DOWN positions. If test light does not illuminate in both positions, go to next step. If test light illuminates in both positions, check right window motor for poor connection. If connection is okay, replace right window motor. 2. Connect test light between right window switch 11-pin connector Light Blue and Tan wires. Operate right window switch (at left window switch) between UP and DOWN positions. If test light illuminates in both Microsoft Saturday, August 29, 2009 11:59:44 AM

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

directions, go to next step. If test light does not illuminate in both directions, go to step 4). 3. Connect test light between right window switch 11-pin connector Dark Blue and Brown wires. Operate right window switch between UP and DOWN positions. If test light illuminates in both positions, repair open in Dark Blue or Brown wires between right window switch and right window motor. If test light does not illuminate in both positions, check right window switch for poor connection. If connection is okay, replace right window switch. 4. Connect test light between left window switch 8-pin connector Light Blue and Tan wires. Operate switch for inoperative window at left window switch. If test light illuminates in both positions, repair open in Light Blue or Tan wires between left window switch and right window switch. If test light does not illuminate in both positions, replace left window switch. 4-DOOR All Windows Do Not Operate

1. Turn ignition switch to RUN position. Connect test light between ground and Yellow wire at left front window switch 11-pin connector. If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire. 2. Connect test light between left front window switch 11-pin connector Yellow and Black wires. If test light illuminates, check window switch for poor connection. If connection is okay, replace left front window switch. If test light does not illuminate, repair open in Black ground wire. Left Front Window Inoperative/All Others Okay

1. Turn ignition switch to RUN position. Connect test light between left front window switch 8-pin connector Dark Blue and Brown wires. Operate switch between UP and DOWN positions. If test light illuminates in both directions, go to next step. If test light does not illuminate in both directions, check left front window switch for poor connection. If connection is okay, replace left front window switch. 2. Connect test light between left front window motor Dark Blue and Brown wires. Observe test light and operate switch between UP and DOWN positions. If test light illuminates in both positions, check left front window motor connector for poor connection. If connection is okay, replace motor. If test light does not illuminate in both positions, repair open in Dark Blue or Brown wire between left front window switch and left front window motor. Right Front, Left Rear, Or Right Rear Window Inoperative From Individual Window Switch, But Operates Okay From Left Front Switch

1. Turn ignition switch to RUN position. Place window lock-out switch in OFF position. Connect test light between inoperative window switch connector Dark Blue wire (left rear and right rear), or Yellow wire (right front window switch) and ground. If test light illuminates, go to next step. If test light does not illuminate, repair open in Dark Blue or Yellow wires as necessary. 2. Connect test light between inoperative window switch connector Dark Blue and Brown wires. Operate window between UP and DOWN positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in both positions, check inoperative window switch for poor connection. If connection is okay, replace inoperative window switch. 3. Connect test light between inoperative window motor connector Dark Blue and Brown wires. Operate Microsoft Saturday, August 29, 2009 11:59:44 AM

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

window between UP and DOWN positions. If test light illuminates in both positions, check inoperative window motor for poor connection. If connection is okay, replace inoperative window motor. If test light does not illuminate in both positions, repair open in Dark Blue or Brown wires between inoperative window switch and window motor. One Window (Other Than Left Front) Is Inoperative From Left Front Window Switch & Individual Window Switch/All Other Windows Operate Okay

1. Turn ignition switch to RUN position. Connect test light between inoperative window motor connector terminals "A" (Brown wire) and "B" (Dark Blue wire). Operate window switch between UP and DOWN positions. If test light does not illuminate in both positions, go to next step. If test light illuminates in both positions, check inoperative window motor for poor connection. If connection is okay, replace window motor. 2. Connect test light between inoperative rear window switch connector terminals "A" (Dark Green or Light Green wire) and "D" (Purple wire), or between right front window switch connector terminals "J" (Light Blue wire) and "L" (Tan wire). Operate inoperative window switch (at left front switch) between UP and DOWN positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in both positions, go to step 4). 3. Connect test light between right front inoperative window switch 11-pin connector terminals "G" (Dark Blue wire) and "K" (Brown wire), or between rear inoperative window switch connector terminals "F" (Brown wire) and "C" (Dark Blue wire). Operate inoperative window switch between UP and DOWN positions. If test light illuminates in both positions, repair open in Dark Blue or Brown wires between inoperative window switch and window motor. If test light does not illuminate in both positions, check inoperative window switch for poor connection. If connection is okay, replace inoperative window switch. 4. Connect test light between left front window switch connectors. For right front, connect test light between terminals "B" (Light Blue wire) and "D" (Tan wire) at 8-pin connector. For left rear, connect test light between terminals "A" (Dark Green wire) and "D" (Purple wire). For right rear, connect test light between terminals "A" (Light Green wire) and "D" (Purple wire). If test light illuminates in all positions, repair poor connection or open in appropriate wiring. If test light does not illuminate in all positions, replace left front window switch. Lock-out Function Does Not Work But Windows Operate Okay

Turn ignition switch to RUN position. Put window lock-out switch in LOCK position. Using a test light, backprobe between lock-out switch connector terminal "B" (Dark Blue wire) and ground. If test light illuminates, replace lock-out switch. If test light does not illuminate, repair short to voltage in Dark Blue wire.

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

WINDOW MOTOR Removal & Installation

1. Disconnect negative battery cable. Raise window to fully closed position. Secure glass to door frame using cloth-backed tape. Remove door garnish molding. Remove armrest mounting screws and armrest. 2. Remove power window switch. See WINDOW SWITCH. Remove door trim panel retaining screws. Using Trim Panel Remover (J 38778) pry retainers from door frame, and remove door trim panel. Remove armrest bracket. Remove water protection shield. Disconnect electrical connectors from motor. CAUTION: Sector gear must be locked into position. Regulator lift arm is under tension from counterbalance spring and could cause personal injury if sector gear is not locked in position. 3. Drill hole through regulator sector gear and backplate. Install bolt and nut, locking sector gear into position. Drill out window motor mounting rivets. Remove motor from window regulator. To install, reverse removal procedure. Use 3/16" (4.8 mm) rivets to install motor and regulator. WINDOW SWITCH Removal & Installation

Disconnect negative battery cable. Using flat-blade screwdriver, pry power window switch from door trim panel. Disconnect electrical connector and remove power window switch. To install, reverse removal procedure.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

Fig. 1: Power Window System Wiring Diagram (2-Door)

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

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1997 Chevrolet S10 Pickup POWER WINDOWS 1997 ACCESSORIES/SAFETY EQUIP General Motors Corp. - Power Windows

Fig. 2: Power Window System Wiring Diagram (4-Door)

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

DESCRIPTION & OPERATION These vehicles use a leaf spring and solid rear axle suspension system. The rear axle assembly is attached to a multi-leaf springs by U-bolts. The front ends of the springs are attached to the frame at the front hangers, through rubber bushings. The rear ends of the springs are attached to the frame by the use of shackles which allow the springs to "change their length" while the vehicle is in motion. Ride control is provided by two identical direct double acting shock absorbers, angle mounted between the frame and brackets attached to the anchor plate.

ADJUSTMENT Manufacturer does not provide adjustment procedures.

TROUBLE SHOOTING To perform rear suspension troubleshooting diagnosis, see Fig. 1

Fig. 1: Rear Suspension Troubleshooting Courtesy of GENERAL MOTORS CORP.

REMOVAL & INSTALLATION SHOCK ABSORBER Microsoft Saturday, August 29, 2009 11:53:10 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Removal

1. 2. 3. 4.

Raise vehicle on a hoist. Remove shock absorber to frame bracket nuts and bolts. See Fig. 2, Fig. 3 or Fig. 4 . Remove shock absorber to anchor plate nut and washer. Remove shock absorber from the vehicle.

Fig. 2: Removing Shock Absorber Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 3: Removing Shock Absorber (4-Door Utility Models) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 4: Removing Shock Absorber (2-Door Utility Models) Courtesy of GENERAL MOTORS CORP. Installation

1. Install shock absorber to lower anchor plate. DO NOT attach the washer or nut. See Fig. 2, Fig. 3 or Fig. 4. 2. Install shock absorber to the frame bracket with the bolts and nuts. 3. Tighten the bolts and nuts. See TORQUE SPECIFICATIONS. 4. Install lower anchor plate washer and nut. 5. Tighten the nut. 6. Lower the vehicle. Microsoft Saturday, August 29, 2009 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

STABILIZER BAR Removal

1. 2. 3. 4. 5.

Raise vehicle on a hoist. Remove lower nuts, washer and bolts from stabilizer links. See Fig. 5 or Fig. 6 Remove the nuts from the U-bolts. See Fig. 7, Fig. 8 or Fig. 9 . Remove U-bolts, clamps, and insulators. Remove the stabilizer bar.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 5: Removing Stabilizer Link (2 Door Utility Model) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 6: Removing Stabilizer Link (4 Door Utility Model) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 7: Removing Stabilizer Bar to Axle Mounting (2 Door Utility Model) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 8: Removing Stabilizer Upper Link Bolt (RWD Pickup Models) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 9: Removing Stabilizer Bar to Axle Mounting (4 Door and AWD Utility Model) Courtesy of GENERAL MOTORS CORP. Installation

1. 2. 3. 4. 5. 6. 7. 8.

Install stabilizer bar to rear axle. See Fig. 7, Fig. 8 or Fig. 9 . Install insulators, clamps, and U-bolts. Install nuts to U-bolts. Tighten the nuts. See TORQUE SPECIFICATIONS. Install stabilizer bar to link mounting bolt (4 door Utility models only). See Fig. 6 Install stabilizer bar to link nut. Fig. 5, Fig. 6, Fig. 7, Fig. 8 or .Fig. 9 Tighten the nuts. See TORQUE SPECIFICATIONS. Lower the vehicle.

TRACK BAR (ZR2 MODELS) Removal Microsoft Saturday, August 29, 2009 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

1. Raise the vehicle on a hoist and support rear axle at curb height position. 2. Remove track bar mounting bolts, washer and nuts at axle bracket and at frame bracket. See Fig. 10, Fig. 11 or Fig. 12 3. Remove the track bar. See Fig. 10, Fig. 11 or Fig. 12 .

Fig. 10: Identifying Track Bar (ZR2 Models) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 11: Removing Track Bar Axle Mounting (ZR2 Models) Courtesy of GENERAL MOTORS CORP.

Fig. 12: Removing Track Bar To Frame Mounting Bolt (ZR2 Models) Courtesy of GENERAL MOTORS CORP. Installation

1. Install the position track bar in frame bracket and loosely install bolt, washers, and nut. See Fig. 10, Fig. 11 or Fig. 12 . 2. Install the position track bar in axle bracket and loosely install bolt, washers, and nut. 3. Tighten the axle nut and the frame bracket bolt head. See TORQUE SPECIFICATIONS. 4. Remove rear axle support and lower vehicle. SPRING ASSEMBLY Microsoft Saturday, August 29, 2009 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Removal

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Raise the vehicle on a hoist. Support the rear axle to relieve the tension on the leaf springs. Remove the shock absorber. See SHOCK ABSORBER Remove the U-bolt nuts, washers, anchor plate, and U-bolts. See Fig. 13 Remove the spare tire, if equipped. Remove the shackle to frame bolt, washers, and nut. See Fig. 14 Remove the fuel tank on utility models. Remove the front bracket nut, washers, and nut. See Fig. 15 Remove spring assembly from the vehicle. Remove shackle to spring nut, washers, and spring bolt. Remove the shackle.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 13: Removing U-Bolts & Anchor Plate Mounting Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 14: Removing Shackle to Frame Mounting Bolts & Bushing Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 15: Removing Front Bracket Mounting Bolt Courtesy of GENERAL MOTORS CORP. Installation

1. 2. 3. 4. 5. 6. 7. 8.

Install shackle to the rear spring eye. See Fig. 14 Install shackle to spring bolt, washers, and nut. DO NOT tighten. Install spring assembly to the vehicle. Install the front bracket bolt, washers, and nut. DO NOT tighten. See Fig. 15 Install the fuel tank. Install shackle to frame bolt, washers, and nut. DO NOT tighten. Remove the spring support. Install spare tire, if equipped.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

9. 10. 11. 12.

Install the U-bolts, anchor plate, washers, and U-bolt nuts. See Fig. 13 Tighten the U-bolts nuts in sequence. See Fig. 16. See TORQUE SPECIFICATIONS. Tighten the front bracket nut and rear shackle nuts. Install the shock absorber. See SHOCK ABSORBER.

Fig. 16: Installing U-Bolts & Torquing In Sequence Courtesy of GENERAL MOTORS CORP. SPRING BUSHING Removal

1. Remove the spring assembly. See SPRING ASSEMBLY. 2. Remove the bushing from the spring assembly. 3. Press the bushing from the spring in an arbor press. Cleaning Microsoft Saturday, August 29, 2009 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

1. Clean the spring eye of any remaining parts of the bushing. 2. Remove any burrs that would cause any the new bushing to bind when installed. Installation

1. Apply rubber lubricant to the bushing, and the spring eye. 2. Install the bushing to the spring assembly. See SPRING ASSEMBLY. 3. Install the spring assembly to the vehicle. SHACKLE Removal

1. 2. 3. 4.

Raise the vehicle on a hoist and support the rear axle. Remove the frame to shackle nut, washers, and frame bolt. See Fig. 14 Remove the shackle to spring nut, washers, and bolt. Remove the shackle from the vehicle.

Installation

1. Install the shackle to the vehicle. See Fig. 14. 2. Install the shackle to spring bolt, washers, and nut. DO NOT tighten. 3. Install the frame to shackle bolt, washers, and nut. DO NOT tighten. NOTE:

Support the axle in such a way that there is a distance of 170 mm plus or minus 6 mm (6.7 inch plus or minus 0.24 inch), between the axle tube and the bumper bracket metal surfaces.

4. Tighten the rear shackle nuts. See TORQUE SPECIFICATIONS. 5. Lower the vehicle. REAR SHACKLE BUSHING Removal

1. 2. 3. 4. 5. 6. 7.

Raise vehicle on a hoist. Disconnect the negative battery cable. On 2 Door Utility Models, remove the fuel tank. On all models, support the rear axle. Remove the upper shackle bolt, nut and flat washers. Loosen the lower shackle bolt at the spring and leave it attached. Lower the axle until there is enough clearance to remove the shackle bushing. Using a blunt punch, straighten out the bushing flange that comes through the inner frame.

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

8. On 2 Door Utility Models, it is recommended that both shackle bushings are replaced while the fuel tank is out. On all models, remove the shackle bushing using the Adapter (J 21058-14) and the Ball Joint Remover (J 9519-E). See SPECIAL TOOLS. See Fig. 17.

Fig. 17: Removing Spring Shackle Bushing Courtesy of GENERAL MOTORS CORP. Installation

1. Install shackle bushing using the 3/8 Inch Nut (J 21474-18), the Control Arm Bushing Installer (J 2147413), the 3/8 Inch Bolt (J 21474-19), and the Receiver (J 21474-5). See Fig. 18. See SPECIAL TOOLS 2. Assemble tools as shown and pull the bushing into the frame rail until the flanged portion of the bushing is flush with the rail. 3. Stake the shackle bushing inner flange. 4. Raise axle into position. 5. Install frame to shackle bolt, washers, and nut; DO NOT tighten. 6. Repeat steps 1-5 for the other bushings. Microsoft Saturday, August 29, 2009 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

NOTE:

7. 8. 9. 10.

Support the axle in such a way that there is a distance of 170 mm plus or minus 6 mm (6.7 inch plus or minus 0.24 inch) between the axle tube and the bumper bracket metal surfaces.

Tighten the rear shackle nuts. See TORQUE SPECIFICATIONS. On 2 Door Utility Models, install the fuel tank. On all models, connect the negative battery cable. Lower the vehicle.

Fig. 18: Installing Spring Shackle Bushing Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS (1995) Microsoft Saturday, August 29, 2009 11:53:06 AM

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Application Lug (Wheel) Nuts Shackle to Frame Nuts Shackle to Spring Nuts Shock Absorber Lower Nuts Shock Absorber Upper Nuts Spring to Front Bracket Nuts Spring U-Bolt Nuts Stabilizer Clamp U-Bolts Nuts Stabilizer Bar to Link Nut (2 Door Utility) Stabilizer Bar to Link Nut (4 Door Utility) Track Bar Axle Mount Nut Track Bar Frame Mount Bolt

Ft. Lbs. (N.m) 95 (130 N.m) 92 (125 N.m) 92 (125 N.m) 47 (64 N.m) 17 (23 N.m) 92 (125 N.m) 85 (115 N.m) 44 (60 N.m) 15 (20 N.m) 50 (68 N.m) 44 (60 N.m) 44 (60 N.m)

TORQUE SPECIFICATIONS (1996-97) Application Lug (Wheel) Nuts Shackle to Frame Nuts Shackle to Spring Nuts Shock Absorber Lower Nuts Shock Absorber Upper Nuts (1996) Bolts (1997) Shock Absorber Lower Nut (4 Door Utility - 1997) Spring to Front Bracket Nuts Spring U-Bolt Nuts Stabilizer Clamp U-Bolts Nuts Stabilizer Bar Upper Link Nut (2 Door Utility) Stabilizer Bar Lower Link Nut (2 Door Utility) Stabilizer Bar Upper Link Nut (4 Door Utility and Pickup) Stabilizer Bar Lower Link Nut (4 Door Utility and Pickup) Track Bar Axle Mount Nuts Track Bar Bolt to Axle Mount Nut Track Bar Tie to Frame Mount Nut

Ft. Lbs. (N.m) 95 (130 N.m) 89 (122 N.m) 89 (122 N.m) 62 (84 N.m) 22 (22 N.m) 18 (25 N.m) 73 (100 N.m) 89 (122 N.m) 73 (100 N.m) 44 (60 N.m) 25 (35 N.m) 50 (68 N.m) 25 (35 N.m) 50 (68 N.m) 39 (53 N.m) 45 (61 N.m) 45 (61 N.m)

SPECIAL TOOLS

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1997 Chevrolet S10 Pickup 1995-97 SUSPENSION Rear - Blazer, Bravada, S10 Pickup, Jimmy & Sonoma

Fig. 19: Identifying Rear Suspension Special Tools Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup ENGINE COOLING Cooling System Specifications - Trucks

ENGINE COOLING Cooling System Specifications - Trucks

SPECIFICATIONS CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. BELT ADJUSTMENT BELT ADJUSTMENT Application All Models

Lbs. (kg) (1)

(1) Serpentine belt tension is maintained automatically by a spring-tensioned idler pulley. No adjustment

is necessary. COOLING SYSTEM SPECIFICATIONS COOLING SYSTEM SPECIFICATIONS Application Coolant Replacement Interval 1996 1997

Specification 30,000 Miles (1)

Pressure Cap Thermostat Opens Starts Fully Open

15 psi 188°F (87°C) 206°F (97°C)

Coolant Capacity (2) 2.2L 3.4L With Rear Heater Without Rear Heater 4.3L "C" & "K" Series "G" & "P" Series With Rear Heater Without Rear Heater "L" & "M" Series

11.6 Qts. (11.0L) 12.4 Qts. (11.75L) 11.8 Qts. (11.25L) 12.7 Qts. (12.3L) 14.0 Qts. (13.2L) 11.0 Qts. (10.5L)

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1997 Chevrolet S10 Pickup ENGINE COOLING Cooling System Specifications - Trucks

With Rear Heater 16.5 Qts. (15.5L) Without Rear Heater 14.3 Qts. (13.5L) "P" Series 13.8 Qts. (13.1L) "S" & "T" Series A/T 11.7 Qts. (11.1L) M/T 11.9 Qts. (11.3L) 5.0L With A/C 18.0 Qts. (17.0L) Without A/C 17.5 Qts. (16.6L) 5.7L Except C 3500HD With A/C 20.0 Qts. (19.0L) Without A/C 17.5 Qts. (16.6L) C 3500HD With A/C 27.0 Qts. (25.5L) Without A/C 26.4 Qts. (25.0L) 6.5L 27.5 Qts. (26.0L) 7.4L Standard With A/C 27.5 Qts. (26.0L) Without A/C 25.0 Qts. (23.5L) Heavy Duty With A/C 28.5 Qts. (27.0L) Without A/C 26.4 Qts. (25.0L) (1) No scheduled replacement interval given by manufacturer. Check and replace as necessary. (2) Specification is approximate and includes heater capacity.

SERPENTINE BELT ROUTING & ALIGNMENT NOTE:

For serpentine belt routing, see SERPENTINE DRIVE BELT ROUTING .

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

1997 ELECTRICAL General Motors Corp. - Starters

DESCRIPTION When the ignition switch is turned to the START position, the Delco-Remy starter solenoid windings are energized. This causes the solenoid plunger to move the shift lever, which engages the pinion with the engine flywheel ring gear. The movement of the plunger also closes the main solenoid contacts, applying battery voltage to the starter motor. See Fig. 1 . When the engine starts, the pinion will overrun, protecting the armature from excessive speed and the flywheel from damage. When the ignition switch is released, the plunger return spring disengages the pinion. On starters with the SD designation, used on gasoline engines only, the pinion is driven directly by the armature shaft. Wound field coils energize pole pieces that are arranged around the armature. Starters with the PG designation, used on diesel or large displacement gasoline engines, have a pinion that is driven by a gear reduction system. These starters are easily identified by 3 Torx bolts that retain the solenoid. The PG starter should not be disassembled and is serviceable only by complete replacement.

Fig. 1: Typical Cranking Circuit Courtesy of GENERAL MOTORS CORP.

COMPONENT LOCATIONS COMPONENT LOCATIONS Microsoft Saturday, August 29, 2009 11:31:04 11:31:00 AM

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Component Battery Junction Block Clutch Pedal Position & Cruise Control Shutoff Switch Instrument Panel Fuse Block Transmission Range Switch Starter Relay Transfer Case Shift Control Module

Location Left Rear Of Engine Compartment On Clutch Pedal Support Bracket Left Side Of Instrument Panel Left Side Of Automatic Transmission Center Rear Of Engine Compartment Behind Center Of Instrument Panel

TROUBLE SHOOTING NOTE:

For information not covered in this article, see the TROUBLE SHOOTING BASIC PROCEDURES article in the GENERAL INFORMATION section.

TROUBLE SHOOTING HINTS Note condition of SECURITY indicator light. If indicator stays on or flashes continuously troubleshoot antitheft system. Check starter solenoid terminals and battery grounds. Check for proper installation of aftermarket electronic equipment. Perform self-diagnostic system test, to be certain no trouble codes are stored in PCM memory which may lead to misdiagnosis. See appropriate TESTS W/CODES - 2.2L or TESTS W/CODES 4.3L article in ENGINE PERFORMANCE section. Check Black fusible link located at generator, Blue fusible link located at battery and Black fusible link located at battery junction block. Check 10-amp CRANK No. 20 fuse, located in instrument panel fuse block. See COMPONENT LOCATIONS table. STARTER NOISE CAUTION: Never operate starter for periods of more than 15 seconds. Excessive cranking can cause starter to overheat. Allow starter to cool for at least 2 minutes after each time operated. NOTE:

Check flywheel ring gear for damage.

1. A high-pitched whine, heard while cranking (before engine starts), indicates excessive distance between starter pinion and flywheel. If high-pitched whine is heard after engine starts and key is released, distance between starter pinion and flywheel is too small. Locate high spot on flywheel before checking pinion-toflywheel clearance. Pinion-to-flywheel clearance should be .020" (0.5 mm). See Fig. 2 . 2. If loud, siren-like "whoop" sound is heard after the engine starts, drive assembly is likely defective. If "rumble", "growl" or "knock" is present as starter is coasting to a stop after starting engine, starter armature is bent or unbalanced. 3. If diagnosis indicates pinion should be closer to flywheel, ensure proper starter motor was installed. During initial starter motor installation, shim(s) are not used. If shim(s) are present, remove as necessary. 4. If diagnosis indicates starter should be moved away from flywheel, add shims as necessary. If Microsoft Saturday, August 29, 2009 11:31:01 AM

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

using .039" (1.0 mm) long shims, do not exceed 2 shims. If using .015" (.38 mm) long shims, do not exceed 3 shims. If condition is not corrected, and pinion-to-flywheel clearance has been reached, short shims may be added to outer side of starter motor bolt using .015" (.38 mm) shims. For starter removal, see STARTER under REMOVAL & INSTALLATION .

Fig. 2: Measuring Pinion-To-Flywheel Clearance Courtesy of GENERAL MOTORS CORP.

ON-VEHICLE TESTING WARNING: Vehicles are equipped with air bag supplemental restraint system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in the AIR BAG RESTRAINT SYSTEM article. NOTE:

The following tests assume that engine and battery are operating normally and are at operating temperatures, battery is charged, there are no engine problems that would cause a no-start condition, and no diagnostic trouble codes are present.

SLOW OR NO CRANK AFTER EXTENDED PERIODS OF VEHICLE NON-USE There may be a parasitic load on electrical system. See PARASITIC LOAD EXPLANATION & TEST PROCEDURES article in GENERAL INFORMATION section. ENGINE DOES NOT CRANK, STARTER SOLENOID DOES NOT CLICK 1. Place gear selector in Park (A/T) or depress clutch pedal (M/T). Place ignition switch to START position. Microsoft Saturday, August 29, 2009 11:31:01 AM

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

4. 5.

10.

Using a DVOM, measure voltage between starter solenoid connector terminal "S" (Purple wire) and engine ground. If voltage is 9.6 volts or greater, go to next step. If voltage is lower than 9.6 volts, clean starter motor mounting blots, starter motor and mounting surface, and repeat test. If starter still does not engage, replace starter. Remove starter relay from underhood fuse-relay center. See COMPONENT LOCATIONS table. Connect a test light, between starter relay connector terminal No. 30 and ground. If test light illuminates, check for an open in Purple wire between starter relay connector terminal No. 87 and starter solenoid terminal "S". If test light does not illuminate, check for open in Red wire along with Black fusible link between starter relay connector terminal No. 30 and generator. Also check for an open in Red wire along with Blue fusible link between battery positive terminal and generator. Connect a fused jumper between starter relay terminals No. 85 and 86. Place gear selector in Park (A/T) or depress clutch pedal (M/T). Connect test light between starter relay connector terminal No. 86 and ground. Turn ignition switch to START position. If test light does not illuminate, go to next step. If test light illuminates check for an open in Black wire between starter relay connector terminal No. 86 and engine ground(s). See WIRING DIAGRAMS . If Black wire is okay replace, starter relay. If vehicle is equipped with automatic transmission, go to next step. If vehicle is equipped with manual transmission, proceed to step 12). Place gear selector in Park (A/T) or depress clutch pedal (M/T). Turn ignition switch to START position. Connect a test light between transmission range switch connector C1 terminal "G" (Yellow wire) and ground. If test light does not illuminate go to next step. If test light illuminates, check for an open in Yellow wire between transmission range switch connector C1 terminal "G" and starter relay connector terminal No. 85. Turn ignition switch to START position. Connect a test light between transmission range switch connector C1 terminal "E" (Purple wire) and ground. If test light does not illuminate, go to next step. If test light illuminates, adjust or replace transmission switch. Locate in line 7-pin Medium Gray C103 connector, located at left rear of engine compartment above brake booster. Disconnect 7-pin Medium Gray connector C103. Turn ignition switch to START position. Connect test light between female side of connector C103 terminal "A" (Purple wire) and ground. Turn ignition switch to START position. If test light does not illuminate, go to next step. If test light illuminates, check for an open in Purple wire between male side of connector C103 terminal "A" and transmission range switch connector C1 terminal "E". Locate in line 56-pin Black C203 connector, located behind right side of instrument panel. Disconnect 56-pin Black connector C203. Turn ignition switch to START position. Connect test light between female side of connector C203 terminal A8 (Purple wire) and ground. Turn ignition switch to START position. If test light does not illuminate, go to next step. If test light illuminates, check for an open in Purple wire between male side of connector C203 terminal A8, female side of connector C103 terminal "A" and inflatable restraint diagnostic energy reserve module connector terminal B10. Turn ignition switch to START position. Connect a test light between instrument panel fuse block connector terminal E1 (Purple wire) and ground. If test light does not illuminates, go to next step. If test light illuminates, check for an open in Purple wire between instrument panel fuse block connector terminal E1 and female side of connector C203 terminal A8. If wire is okay. replace 10-amp CRANK fuse No. 20. Locate Black 48-pin connector C211, located at steering column harness. Backprobe Black 48-pin connector C211 terminal D1 (Yellow wire). See Fig. 3 . Turn ignition switch to START position. Connect a test light between connector C211 terminal D1 (Yellow wire) and ground. If test light does not

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

illuminate, go to next step. If test light illuminates, check for an open in Yellow wire between male side of connector C211 terminal D1 and instrument panel fuse block connector terminal D2.

Fig. 3: Identifying Black 48-pin C211 Connector ("S" & "T" Series) Courtesy of GENERAL MOTORS CORP. 11. Disconnect Black 48-pin connector C211. Turn ignition switch to START position. Connect test light between male side of connector C211 terminal D5 (Red wire) and ground. If test light does not illuminate, check for an open in Red wire between battery junction block Black fusible link and male side of connector C211 terminal D5. If Red wire is okay, replace battery junction block Black fusible link. If test light illuminates, replace ignition switch. 12. Locate Black 15-pin connector C102, located in at left rear of engine compartment above brake booster. Backprobe Black 15-pin connector C102 terminal "D" (Purple/White wire). See Fig. 4 . Depress clutch pedal. Turn ignition switch to START position. Connect test light between connector C102 terminal "D" (Purple/White wire) and ground. If test light does not illuminate, go to next step. If test light illuminates, check for an open in Purple/White wire between male side of connector C102 terminal "D" and starter relay connector terminal No. 85. 13. Turn ignition switch to START position. Depress clutch pedal. Connect test light between clutch pedal position and cruise control shutoff switch connector terminal "C" (Purple/White wire) and ground. If test light does not illuminate, go to next step. If test light illuminates, check for an open in Purple/White wire between clutch pedal position and cruise control shutoff switch connector terminal "C", inflatable restrain shift control module connector terminal D16 and female side of connector C102 terminal "D". 14. Turn ignition switch to START position. Connect test light between clutch pedal position and cruise control shutoff switch connector terminal "A" (Purple wire) and ground. If test light does not illuminate, go to next step. If test light illuminates, replace clutch pedal position and cruise control shutoff switch. Microsoft Saturday, August 29, 2009 11:31:01 AM

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

15. Locate 56-pin Black C203 connector, located behind right side of instrument panel. Disconnect 56-pin Black connector C203. See Fig. 5 . Turn ignition switch to START position. Connect test light betw een female side of connector C203 terminal A8 (Purple wire) and ground. If test light does not illuminate, go to step 9). If test light illuminates, check for an open in Purple wire between male side of connector C203 terminal A8, clutch pedal position and cruise control shutoff switch connector terminal "A" and transfer case shift control module D16.

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Fig. 4: Black 15-pin Connector C102 ("S" & "T" Series - M/T Only) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 5: Black 56-pin Connector C203 ("S" & "T" Series) Courtesy of GENERAL MOTORS CORP. SOLENOID CLICKS, ENGINE DOES NOT CRANK 1. Remove 20-amp ECM IGN fuse No. 10 from instrument panel fuse block. Turn ignition switch to START position and hold for 15 seconds. Using a DVOM, measure voltage between battery negative and positive terminals. If voltage is more than 9,5 volts, go to next step. If voltage is less 9.5 volts or less, perform battery load test. If battery is okay, go to next step. If battery fails load test, replace battery and recheck symptom. 2. Turn ignition switch to START position. Using a DVOM, measure voltage between generator terminal (Red wire) and engine ground. If voltage is more than .5 volts, replace Black wire between generator and starter relay connector terminal No. 30 including Black fusible link, and recheck symptom. If voltage is .5 volts or less, go to next step. 3. Turn ignition switch to START position. Using a DVOM, measure voltage between generator terminal (Red wire) and battery negative terminal. If voltage is more than .5 volts, replace negative battery cable. If voltage is .5 volts or less, go to next step. 4. Turn ignition switch to START position. Using a DVOM, measure voltage between battery positive terminal and ground. If voltage is more than .5 volts, replace positive battery cable. If voltage is .5 volts or less, clean starter motor mounting blots, starter motor and mounting surface, and repeat test. IF starter still does not engage, replace starter and recheck symptom.

BENCH TESTING PRELIMINARY TESTS NOTE:

On PG260 starter motor, starter is serviced as an assembly. If test values do not meet specifications, replace starter and solenoid as an assembly.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Remove starter from vehicle. See STARTER under REMOVAL & INSTALLATION . Check starter for damage such as broken or stripped electrical terminals, broken or cracked drive end housing, etc.. If no obvious damage is found, perform starter no-load test and pinion clearance check before disassembling starter motor. SOLENOID WINDINGS TESTS NOTE:

To prevent overheating, DO NOT allow solenoid pull-in current to flow for more than 15 seconds.

NOTE:

Current flow will decrease as windings heat up.

Hold-In Windings Test

1. If solenoid is not removed from starter motor assembly, disconnect field lead from terminal "M" on solenoid and insulate field lead from solenoid motor terminal. Connect an ammeter and switch in series with 12-volt battery and starter solenoid terminal "S" as illustrated. See Fig. 6 . Connect a voltmeter between solenoid terminal "S" and ground. Connect a carbon pile across battery. 2. Turn switch on and quickly adjust carbon pile load until voltage reads as specified. See PULL-IN WINDINGS SPECIFICATIONS table. Check ammeter reading. Turn off carbon pile and open switch. At 10 volts reading should be 10-20 amps. If amperage reading is not as specified, replace starter solenoid. Pull-In Windings Test

Connect test equipment as in hold-in windings test. See HOLD-IN WINDINGS TEST. See Fig. 6 . Ground starter solenoid terminal "M". Turn switch on and quickly adjust carbon pile load until voltage reads as specified. Check ammeter reading. Turn off carbon pile and open switch. At 10 volts reading should be 60-85 amps. If ammeter reading is not as specified, replace starter solenoid.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 6: Solenoid Winding Test Connections Courtesy of GENERAL MOTORS CORP. STARTER NO-LOAD TEST CAUTION: DO NOT apply more voltage than specified. Excessive voltage may cause armature to throw windings due to excessive speed. 1. Secure starter in vise. Turn carbon pile off and open switch. Connect test equipment to starter as illustrated. See Fig. 7 . Turn switch on and adjust carbon pile until voltage reads as specified. See STARTER NO-LOAD TEST SPECIFICATIONS table. Check ammeter reading and pinion speed on RPM indicator. Turn off carbon pile and open switch. Compare RPM and amperage readings with specifications. See STARTER NO-LOAD TEST SPECIFICATIONS table. 2. If amperage and RPM readings are as specified, starter motor is okay. If test indicates low free speed and/or high current draw, unit may have tight, dirty or worn bearings or bushings, shorted or grounded armature, or a grounded field. 3. High current draw with pinion moving into cranking position but no pinion rotation indicates a direct ground in field, or frozen bearings or bushings. No pinion movement and a normal current reading indicates plunger is unable to move into solenoid or drive is unable to move on armature shaft. No pinion movement and very low or no current draw indicates an open or ground in solenoid windings. 4. Pinion moving into cranking position but not turning and very low current draw indicates an open in field circuit or armature windings, or no current flow between solenoid battery and motor field terminals while motor is engaged. Connect a jumper wire between solenoid battery and motor field terminal "M". If motor now turns at specified RPM, replace solenoid. 5. Low no-load and low current draw indicates high internal resistance due to poor brush lead connections; a dirty commutator; an open in armature windings; broken, worn or weak brush springs; or worn, damaged or dirty brushes. High no-load speed and high current draw indicates shorted field coils or shorted armature windings. If starter vibrates or is noisy, armature may be rubbing against inside of frame and field.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 7: Starter No-Load Test Connections Courtesy of GENERAL MOTORS CORP. STARTER NO-LOAD TEST SPECIFICATIONS Application Starter RPM 2.2L SD205 52-76 (1) 50-62 4.3L PG260

(1) Amps

6,000-12,900 8,500-10,700

(1) At 10 volts.

PULL-IN WINDINGS SPECIFICATIONS Application Starter Motor 2.2L SD205 4.3L

PG260

Amps (1) 60-85 (2) 30-50

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

(1) At 10 volts. (2) At 11.5 volts.

ARMATURE TEST NOTE:

Any ball bearings that are removed from armature must be replaced with new bearings.

1. Inspect solder joints between armature windings and commutator bars. If any have come loose, replace armature. If commutator is rough or damaged, replace armature. DO NOT turn commutator in lathe or undercut spaces between bars. If commutator is dirty, clean with 400 grit emery cloth and blow away any copper dust. 2. Using growler, check armature for shorts. Hold a flat steel strip on armature parallel to armature core or shaft. Rotate armature in growler. Steel strip will vibrate on area of short circuit. 3. Using self-powered test light, place one lead on armature shaft and other lead on commutator. Test light should not illuminate. If test light illuminates, armature is shorted or grounded and must be replaced. 4. If no-load test indicated armature may be rubbing against inside of frame and field assembly, inspect outside of armature for signs of rubbing. If armature is scored only on one side of laminations, armature shaft may be bent and armature should be replaced. If scoring is all around armature laminations, check frame and field assembly for an out-of-position pole or for a foreign object lodged inside. Repair or replace frame and field assembly. CAUTION: Some starters have a molded-type commutator. DO NOT undercut insulation as it may cause serious damage to commutator. FIELD COIL OPEN TEST Remove armature from frame and field assembly. Using self-powered test light, place one lead on field lead connection and other lead on one insulated brush. See Fig. 8 . Test light should illuminate. If test light does not illuminate, field coil is open. Repair or replace field and frame assembly. Repeat test for each insulated brush.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 8: Testing Field Coil For Open Courtesy of GENERAL MOTORS CORP. FIELD COIL GROUND TEST Remove armature from field and frame assembly. On starters with shunt lead, separate field and shunt lead connections during test. Ensure field lead connection is NOT touching ground during test. Using self-powered test light, place one lead on grounded brush holder and other lead on one insulated brush. See Fig. 9 . Test light should not illuminate. If test light illuminates, field coil is grounded. Repair or replace field and frame assembly. Repeat test for each insulated brush.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 9: Testing Field Coil For Ground Courtesy of GENERAL MOTORS CORP. BRUSHES, SPRINGS & HOLDERS CHECK If any brushes are damaged (oil-soaked or pitted) or worn more than 90 percent, replace, frame and fields. If brushes are not damaged and still have more than 50 percent of brush material left, use a soft cloth to clean contact face of brushes. Check brush spring tension and replace springs if weak, discolored or distorted. Ensure brush holders are clean and brushes are not binding in holders. Ensure full surface of brush contacts commutator for proper performance. COMMUTATOR END FRAME & BEARING Replace armature assembly is commutator outer diameter is less than 1.378" (36 mm) or if undercut depth is Microsoft Saturday, August 29, 2009 11:31:01 AM

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

less than .008" (.2 mm). DO NOT undercut insulation. Ensure commutator end bearing has not spun in frame. If bearing has spun, replace frame and bearing. DO NOT lubricate bearing. If bearing is dry or damaged, replace bearing. Install new bearing no deeper then .080 in (2.1 mm). DRIVE END HOUSING & BEARING Ensure drive end bearing has not spun in housing. If bearing has spun, replace housing and bearing. DO NOT lubricate bearing. If bearing is dry or damaged, replace bearing. Install new bearing no deeper then .010 in (.4 mm). DRIVE ASSEMBLY CHECK 1. Check pinion teeth for chips, cracks or excessive wear. If pinion teeth are damaged, replace drive assembly. Also check flywheel for damage. Check drive assembly for slipping before disassembly from armature. With drive assembly attached to armature, cover armature with shop towels and secure in a vise. 2. Using a 12-point socket and a torque wrench, turn pinion counterclockwise. Pinion should lock and withstand a torque of 50 ft. lbs. (68 N.m) without slipping. If pinion slips before 50 ft. lbs. (68 N.m) is reached, replace drive assembly. 3. Using a 12-point socket and a torque wrench, turn pinion clockwise. Pinion should turn freely in overrunning direction (clockwise) only. If pinion does not turn freely in clockwise direction, replace drive assembly. PINION CLEARANCE CHECK NOTE:

Pinion clearance is not adjustable. If clearance is not within specification, disassemble and check starter motor for worn or damaged components.

1. Secure starter motor in vise with opening in housing accessible for measurement. Disconnect field lead at solenoid terminal "M" and insulate from solenoid field terminal "M". Connect battery negative terminal lead to starter frame. Connect 12 volts to starter solenoid terminal "S". Momentarily touch jumper lead from starter solenoid terminal "M" to starter frame, shifting pinion into cranking position. 2. Push pinion as far as possible away from retainer. Using a feeler gauge, ensure there is .010-.160" (.254.06 mm) clearance between pinion and retainer. See Fig. 10 .

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 10: Checking Pinion Clearance Courtesy of GENERAL MOTORS CORP.

Vehicles are designed for starter mounting without shims. A short shim or long shims may have been added to correct a noise or engagement condition. When installing starter any previously installed shims should be replaced in original location to ensure proper pinion to flywheel clearance.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

STARTER Removal

On all engines, disconnect negative battery cable. Raise and support vehicle. On 2.2L engine, remove front exhaust pipe. Remove brace rod from front of engine to clutch housing. Remove starter heat shield. Remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter. Remove brush end bracket attaching bolt. Remove starter mounting bolts. Remove shims and note arrangement for reassembly. If necessary remove brush end bracket from starter. On 4.3L engine, remove front exhaust pipe. Remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter. Remove starter mounting bolts. Remove shims and note arrangement for reassembly. On 4.3L 4WD, disconnect engine mounts. Raise and support engine. Remove transmission mount and support transmission assembly. Remove starter mounting bolts. Remove shims and note arrangement for reassembly. Remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter. On 4WD Utility, remove starter solenoid terminal "S" nut and battery cable nut. Separate wiring from starter. If equipped remove transfer case shield. Remove bolts and two brackets holding brake pipe to transmission crossmember. Remove transmission crossmember attaching bolts. Remove transmission mount bolts and support transmission assembly. Slide transmission crossmember out of way. Remove bracket that holds transmission fluid cooler lines to flywheel housing. Remove brace rod to flywheel housing and lower flywheel housing. Remove starter mounting bolts. Remove shims and note arrangement for reassembly. Installation

To install, reverse removal procedure. Ensure shims are installed in original location. Tighten starter mounting bolts to specification. See TORQUE SPECIFICATIONS .

OVERHAUL STARTER & SOLENOID CAUTION: DO NOT clean starter in digressing tank or with grease dissolving solvents. This will remove lubricant from clutch mechanism, and damage insulation on armature and field coil. NOTE:

When reassembleing starter and solenoid, use grease (10477431) for lubrication. Use of other greases may cause starter failure.

NOTE:

On PG260 starter motor, starter and solenoid are not overhauled and are replaced as a complete assembly.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

1. Remove solenoid by turning 90 degrees pulling solenoid out of starter. If shaft needs to be drilled out, a new shaft and retaining ring will be needed for reassembly. Check starter drive for slippage before removing from armature shaft. Pinion stop color ring is not re-used. See Fig. 11 and Fig. 12 . Assembly

1. Apply a small amount of lubricant to armature shaft and to starter drive contact points. Use 2 sets of pliers to snap pinion stop collar over retainer ring. Lubricate solenoid core with grease. Apply grease evenly around inside edge or solenoid core. Apply thickly to first 1/2 (13 mm) inside edge of core. Plunger movement will distribute grease properly. Soak new drive end bushing in oil, before installation, for at least 30 minutes. To install, reverse removal procedure.

Fig. 11: Exploded View Of Delco-Remy Starter Motor (SD205 & SD255) Courtesy of GENERAL MOTORS CORP.

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 12: Exploded View Of Delco-Remy Starter Motor (PG250) Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Starter Bracket-To-Engine Bolts (2.2L, 2WD) Starter Mounting Bolts "S" Series Pickup "S" & "T" Series Blazer "T" Series Pickup

Ft. Lbs. (N.m) 33 (45) 33 (45) 35 (47) 35 (47) In. Lbs. (N.m) 70 (7) 71 (8)

Solenoid To Starter Bolts & Screws Solenoid Terminals Inner Nuts

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup 1997 ELECTRICAL General Motors Corp. - Starters

Fig. 13: Starting System Schematic ("S" & "T" Series)

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

DESCRIPTION All models use a collapsible steering column with an integral ignition switch and locking device. Some models include tilt wheel, gear shift interlock device, and/or Supplemental Inflatable Restraint (SIR) system.

DISABLING & ACTIVATING AIR BAG SYSTEM 1. To disable air bag system, turn ignition switch to OFF position. Remove SIR fuse from fuse block. Disconnect Yellow SIR connector at base of steering column. On models equipped with passenger-side air bag, also disconnect Yellow connector under right side of instrument panel. INFLATABLE RESTRAINT indicator light will come on. This is normal. 2. Wait 10 minutes before working on vehicle. All connectors used on SIR system use Connector Position Assurance (CPA) clips to ensure connector retention. 3. To activate air bag system, turn ignition switch to OFF position. Connect Yellow 2-pin connector and CPA clip at base of steering column and/or under right side of instrument panel. Install SIR fuse. Turn ignition switch to RUN position. INFLATABLE RESTRAINT indicator light should go off. For more information, see AIR BAG RESTRAINT SYSTEM article in ACCESSORIES/SAFETY EQUIP section.

ADJUSTMENTS PARK LOCK CABLE Ensure gear shift lever is in Park. turn lock cylinder to PARK-LOCK position and remove key. Using Park Lock Cable Pliers (J-41396), unlock adjuster ring on cable assembly. Pull on cable until park lock latch contacts gear shift lever. Release cable. Using park lock cable pliers, lock adjuster ring securely in place.

Use only specified screws. Using screws that are too long may prevent column from compressing upon impact.

STEERING WHEEL & HORN PAD WARNING: Wait 10 minutes after disabling air bag system before servicing system. Microsoft Saturday, August 29, 2009 11:51:18 11:51:14 AM

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Servicing air bag system before 10 minutes may cause accidental air bag deployment and possible personal injury. Removal (With Air Bag)

1. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Inflator module is located on steering wheel hub. Turn steering wheel 90 degrees to access rear shroud hole. Insert screwdriver and push leaf spring to release pin. Turn steering wheel 180 degrees to access remaining shroud holes. Repeat release procedure with screwdriver. 2. Partially remove inflator module from top. Disconnect steering wheel inflator module connector, CPA clip and horn contact from inflator. Remove inflator module. 3. Position steering wheel straight ahead. Remove snap ring and steering wheel retaining nut. Mark steering wheel and shaft for reassembly reference. Using Steering Wheel Puller (J-1859-03), remove steering wheel. CAUTION: To prevent damage to canceling cam and switch assembly, turn signal switch must be in neutral position before steering wheel is installed. Installation

1. Ensure turn signal switch is in neutral position. Install and align steering wheel. DO NOT misalign steering wheel. Install and tighten steering wheel retaining nut to 30 ft. lbs. (41 N.m). Install snap ring. 2. Install horn contact, steering wheel inflator module connector and CPA clip. Install inflator module to steering wheel. Press inflator module firmly until all latch pins are engaged. 3. To complete installation, reverse removal procedure. Check INFLATABLE RESTRAINT indicator light to ensure system is functioning properly. For more information, see AIR BAG RESTRAINT SYSTEM article in ACCESSORIES/SAFETY EQUIP section. Removal (Without Air Bag)

Disconnect negative battery cable. Remove horn pad. Remove snap ring and steering wheel retaining nut. Disconnect horn lead assembly (if equipped). Mark steering wheel and shaft for reassembly reference. Using Steering Wheel Puller (J-1859-03), remove steering wheel. CAUTION: To prevent damage to canceling cam and switch assembly, turn signal switch must be in neutral position before steering wheel is installed. Installation

Before installing steering wheel, ensure turn signal switch is in neutral position. Install steering wheel onto steering shaft aligning marks made during removal. DO NOT misalign steering wheel rim more than .79" (20 mm) from centerline. Connect horn lead assembly (if equipped). Install and tighten steering wheel retaining nut to 30 ft. lbs. (41 N.m). Install snap ring and horn pad. Connect negative battery cable. STEERING COLUMN Microsoft Saturday, August 29, 2009 11:51:14 AM

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

NOTE:

Although columns are similar, some procedures do not apply to all steering columns.

Removal

1. Disconnect negative battery cable. Disconnect transmission shift linkage from column shift tube levers. Mark position of joint to steering shaft. Remove upper intermediate shaft bolt and nut from steering shaft. 2. Remove steering column support bracket bolts and nuts. Remove support bracket. Remove steering column seal bolts and seal. Remove steering wheel. See STEERING WHEEL & HORN PAD . Disconnect electrical connectors at column harness. 3. Disconnect start/neutral switch and back-up light switch electrical connectors (if equipped). Disconnect transmission indicator cable (if equipped). On column shift models, rotate column so shift lever can clear dash opening. On all models, remove steering column assembly. Installation

To install, reverse removal procedure. Tighten bolts and screws to specification. See TORQUE SPECIFICATIONS . INTERMEDIATE SHAFT Removal

Set front wheels in straight-ahead position. Mark joint-to-steering shaft position. Mark joint-to-steering gear worm shaft position. Remove intermediate shaft shield screw (if equipped). Remove shield (if equipped). Remove upper and lower intermediate shaft bolts and nut. Remove intermediate shaft. Installation

To install, reverse removal procedure. Tighten bolts, nut and screw to specification. See TORQUE SPECIFICATIONS . LOCK CYLINDER (FUNCTIONAL) Removal & Installation

1. Remove steering column. See STEERING COLUMN . Using Modular Column Holding Fixture (J41352), secure steering column. Remove tilt lever (if equipped). Remove 2 lower shroud screws. Tilt lower shroud down and slide back to disengage locking tabs, then remove lower shroud. Remove upper shroud. 2. Hold key in START position. Using 1/16" Allen wrench, push on lock cylinder retaining pin. Release key to RUN position, and pull lock cylinder set from lock module assembly. 3. To install, insert key into lock cylinder and turn to RUN position. Ensure sector in lock module is in RUN position. Insert lock cylinder into upper cover. Align locking and positioning tabs with slots in lock module assembly, and press lock cylinder into position. To complete installation, reverse removal procedure. Microsoft Saturday, August 29, 2009 11:51:14 AM

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

LOCK CYLINDER (NON-FUNCTIONAL) Removal

1. Remove steering Column. See STEERING COLUMN . Using Modular Column Holding Fixture (J41352), secure steering column. Remove tilt lever, if equipped. Remove 2 lower shroud screws. Tilt lower shroud down and slide back to disengage locking tabs, then remove lower shroud. Remove upper shroud. 2. Remove retaining ring. Remove SIR clockspring assembly. See AIR BAG RESTRAINT SYSTEM article in ACCESSORIES/SAFETY EQUIP section. Remove wave washer. Using Lock Plate Compressor (J23563-SIR), remove and discard retaining ring. Remove shaft lock shield assembly. Remove turn signal cancelling cam. 3. On models with park lock cable, ensure lock cylinder is in OFF-LOCK position and gearshift is in Park. Insert small screwdriver into slot in lock module assembly, push against locking tab on end of cable and remove park lock cable. 4. On all models, remove 3 screws, and remove lock module assembly with upper shroud. Remove backing plate from lock module assembly. Mark 2 sector gears at PARK-LOCK position for installation reference. See Fig. 1 . Remove both sector gears. 5. Using 1/8" burring tool, remove positioning tab on end of lock cylinder. See Fig. 2 . Remove all burrs in and around lock module assembly and lock cylinder. From inside lock module assembly, push on locking tab and pull out lock cylinder. Clean debris from lock module assembly. NOTE:

Ensure 2 sector gears are properly aligned at OFF-LOCK position, or lock cylinder will be improperly timed.

Installation

1. Install sector gears and backing plate to lock module assembly, ensuring reference marks are aligned. Ensure sector gear in lock module is in OFF-LOCK position. Insert key in lock cylinder, and turn key to OFF-LOCK position. Align position and locking tabs with slots in lock module assembly and press lock cylinder into position. Turn lock cylinder to ACC position, and check alignment of arrows on sector gears (arrows should point toward each other). Turn lock cylinder back to OFF-LOCK position. 2. To complete installation, reverse removal procedure. When installing turn signal cancelling cam, lubricate lower brass surface with synthetic grease. Use NEW shaft lock retaining ring. Tighten all screws to specification. See TORQUE SPECIFICATIONS . Adjust park lock cable, if necessary. See PARK LOCK CABLE in ADJUSTMENTS.

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Fig. 1: Aligning Sector Gears Courtesy of GENERAL MOTORS

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Fig. 2: Removing Lock Cylinder Positioning Tab Courtesy of GENERAL MOTORS TURN SIGNAL & MULTIFUNCTION SWITCH Removal

1. Ensure lever is in center of OFF position. Disconnect negative battery cable. Disable air bag system (if equipped). See DISABLING & ACTIVATING AIR BAG SYSTEM . Remove steering wheel. See STEERING WHEEL & HORN PAD . Remove knee bolster, if necessary. 2. Remove bolts/screws and lower column cover. Remove bolts/screws and upper column cover. Remove lock cylinder, if necessary. See LOCK CYLINDER (FUNCTIONAL) . Remove harness strap. Disconnect steering column electrical connector. Disconnect turn signal and multifunction switch Gray and Black connectors. Remove turn signal and multifunction switch. Installation Microsoft Saturday, August 29, 2009 11:51:14 AM

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Install turn signal and multifunction switch. Using small flat-blade screwdriver, compress electrical contact and move switch into position. Ensure electrical contact rests on cancelling cam. See Fig. 3 -4. Tighten turn signal and multifunction switch screws to specification. See TORQUE SPECIFICATIONS . To complete installation, reverse removal procedure.

OVERHAUL NOTE:

Use illustrations for exploded view of steering columns. See Fig. 3 -4.

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Fig. 3: Exploded View Of Non-Tilt Steering Column (Typical) Courtesy of GENERAL MOTORS

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Fig. 4: Exploded View Of Tilt Steering Column (Typical) Courtesy of GENERAL MOTORS

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Lower Intermediate Shaft Bolt Steering Column Support Bracket Bolts

Ft. Lbs. (N.m) 25 (34) 22 (30)

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1997 Chevrolet S10 Pickup STEERING COLUMN 1997 STEERING Steering Columns - General Motors Corp.

Steering Wheel Retaining Nut Upper Intermediate Shaft Bolt/Nut INCH Lbs. (N.m) Column Shroud Screws Dimmer Switch Screw Ignition Switch Screw Intermediate Shaft Shield Screw Turn Signal Switch Screws

30 (41) 45 (61) 80 (9.0) 35 (4.0) 35 (3.8) 53 (6.0) 35 (3.8)

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1997 Chevrolet S10 Pickup STEERING KNUCKLES - 4WD 1996-97 Drive Axles - 4WD Steering Knuckles

STEERING KNUCKLES - 4WD 1996-97 Drive Axles - 4WD Steering Knuckles

ADJUSTMENTS BALL JOINT TURNING EFFORT NOTE:

Front axle ball joint adjustment is only necessary when there is excessive play in steering, irregular wear on tire or persistent loosening of tie rod.

REMOVAL & INSTALLATION STEERING KNUCKLE Removal

1. Raise and support vehicle. Remove wheel and tire assembly. Install Axle Shaft Boot Seal Protector (J28712) on axle shaft boot to protect boot during repair. Depress brake caliper piston, detach brake caliper and wire aside. Remove brake rotor. 2. Remove cotter pin and retainer (if equipped) from axle shaft nut. Remove nut and washer from axle shaft. Remove cotter pin and tie rod end nut. Separate tie rod end from steering knuckle. See Fig. 1 . 3. Attach puller to hub. Tighten pressure screw, and force axle shaft from hub and bearing assembly. Remove hub and bearing assembly from steering knuckle. Remove splash shield. Support lower control arm using floor jack or jackstand. CAUTION: Support lower control arm with floor jack or jackstand to maintain tension on torsion bar.

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1997 Chevrolet S10 Pickup STEERING KNUCKLES - 4WD 1996-97 Drive Axles - 4WD Steering Knuckles

Fig. 1: Exploded View Of Hub & Steering Knuckle Assembly Courtesy of GENERAL MOTORS CORP. NOTE:

"T" Series shown; "K" & "L" Series Are Similar.

4. Remove cotter pins from ball joint studs. On "T" Series, place Ball Joint Separator (J-34026) over upper or lower ball joint. See Fig. 2 . Loosen ball joint nut. Back off until nut contacts ball joint separator. Continue backing off nut until nut forces ball stud out of steering knuckle. 5. On all other models, separate ball joint from steering knuckle using Ball Joint Separator (J-36607). On all models, remove steering knuckle from vehicle without damaging or moving axle shaft. Remove seal from steering knuckle.

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1997 Chevrolet S10 Pickup STEERING KNUCKLES - 4WD 1996-97 Drive Axles - 4WD Steering Knuckles

Fig. 2: Separating Ball Joint From Steering Knuckle ("T" Series) Courtesy of GENERAL MOTORS CORP. Installation

1. To install, reverse removal procedure. Install NEW seal into steering knuckle using Seal Installer (J36605 for Astro and Safari; J-36606 for "K" Series; J-28574 for "T" Series). 2. On "T" Series, ensure spacer is installed on steering knuckle at upper ball joint stud hole. On all models, tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS . If necessary, tighten tie rod and ball joint nuts to align cotter key hole. DO NOT loosen nuts for alignment. Remove boot protector from axle shaft.

TORQUE SPECIFICATIONS Microsoft Saturday, August 29, 2009 11:50:35 AM

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1997 Chevrolet S10 Pickup STEERING KNUCKLES - 4WD 1996-97 Drive Axles - 4WD Steering Knuckles

TORQUE SPECIFICATIONS Application Astro & Safari Axle Shaft Nut Ball Joint Nut (Lower) Ball Joint Nut (Upper) Brake Caliper Bolt Hub & Bearing Assembly Bolt Splash Shield Bolt Tie Rod Nut Wheel Lug Nut "K" Series Axle Shaft Nut Ball Joint Nut (Lower) Ball Joint Nut (Upper) Brake Caliper Bolt Hub & Bearing Assembly Bolt Splash Shield Bolt Tie Rod Nut Wheel Lug Nut Dual Wheel (Heavy-Duty) Dual Wheel Single Wheel "T" Series Axle Shaft Nut Ball Joint Nut Brake Caliper Bolt Hub & Bearing Assembly Bolt Tie Rod Nut Wheel Lug Nut

Ft. Lbs. (N.m) 173 (235) 94 (128) 66 (90) 37 (50) 66 (90) 12 (16) 37 (50) 103 (140) 173 (235) 94 (128) 74 (100) 37 (50) 133 (180) 19 (26) 35 (48) 177 (240) 140 (190) 118 (160) 181 (245) 70 (95) 37 (50) 77 (105) 35 (47) 96 (130)

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

INTRODUCTION Before testing separate components or systems, perform procedures in the BASIC TESTING - 2.2L article. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in the TESTS W/CODES - 2.2L article. NOTE:

Testing individual components does not isolate shorts or opens. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter and refer to the WIRING DIAGRAMS article to isolate wiring harness shorts or opens.

The following table provides the location of commonly used diagnostic information. GENERAL MOTORS REFERENCE System Or Component Malfunction Indicator Light (MIL) DLC & MIL On Steady No Scan Tool Data No-Start Diagnosis Injector Circuit Diagnosis Fuel Pump Relay Fuel System Diagnosis Injector Balance Test MAP Sensor Transmission Range Switch IAC Valve Fuel Evaporation Control Ignition Control Circuit Knock Sensor Check EGR System

Diagnostic Information Location See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in BASIC TESTING - 2.2L article See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in BASIC TESTING - 2.2L article See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in BASIC TESTING - 2.2L article See appropriate NO-START - ENGINE CRANKS OKAY in BASIC TESTING - 2.2L article See BASIC FUEL SYSTEM CHECKS in BASIC TESTING - 2.2L article See MODULES, MOTORS, RELAYS & SOLENOIDS See appropriate BASIC FUEL SYSTEM CHECKS in BASIC TESTING - 2.2L article See FUEL SYSTEM See ENGINE SENSORS & SWITCHES See ENGINE SENSORS & SWITCHES See IDLE CONTROL SYSTEM under FUEL SYSTEM See EMISSION SYSTEMS & SUB-SYSTEMS See IGNITION SYSTEM See IGNITION SYSTEM See EMISSION SYSTEMS & SUB-SYSTEMS

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

Torque Converter Clutch

See MISCELLANEOUS PCM/VCM CONTROLS See MISCELLANEOUS PCM/VCM CONTROLS

Manual Transmission Shift Lights A/C Clutch Control

(1) See MISCELLANEOUS PCM/VCM

Electric Cooling Fan Control

(1) See MISCELLANEOUS PCM/VCM

CONTROLS CONTROLS (1) Complete coverage in the A/C-HEATER SYSTEM article in the AIR CONDITIONING & HEAT section.

COMPUTERIZED ENGINE CONTROLS CONTROL UNIT NOTE:

To perform the following ground and power tests, use appropriate wiring diagram in the WIRING DIAGRAMS article.

Ground Circuits

1. Using an ohmmeter, check for continuity to ground on PCM/VCM ground terminals. Resistance should be zero ohms. If not, repair open to ground. 2. Using a voltmeter, touch negative lead of voltmeter to a good ground. Touch positive lead of voltmeter to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If voltmeter reading is more than one volt, check for open, corrosion or loose connection on ground circuit. Power Circuits

1. Using a voltmeter, check for battery voltage between PCM/VCM continuous power terminal(s) and ground. If battery voltage is not present, check for blown fuse or open fusible link. If okay, check for open in wire between PCM/VCM terminal and power source. 2. Turn ignition on. Using a voltmeter, check for battery voltage between PCM/VCM ignition power terminals and ground. If battery voltage is not present, check IGN fuse. If fuse is okay, check for an open in wire between battery and ignition switch, and between ignition switch and PCM/VCM terminal. If okay, check for a defective ignition switch. 3. Connect voltmeter between ground and PCM/VCM starter (crank) signal terminal. On vehicles with manual transmission/transaxle, depress clutch pedal. Turn ignition switch to START position. Battery voltage should be present ONLY when ignition switch is in START position. 4. If voltage is not present, check CRANK fuse or fusible link between ignition switch and PCM/VCM terminal. If fuse or fusible link is okay, check for an open in wire between ignition switch and PCM/VCM terminal, or check for a defective ignition switch.

ENGINE SENSORS & SWITCHES Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

A/C ON SWITCH/SYSTEM TEST 1. Turn ignition switch to RUN position. Move mode selector switch to any position other than OFF position. With A/C control assembly connected, measure voltage between mode selector switch Light Green wire and ground. For wiring schematics, see the WIRING DIAGRAMS article. 2. Battery voltage should be present. If battery voltage is present, mode selector switch is operating normally. If battery voltage is not present, check wire from mode selector switch to fuse for an open circuit. Also check A/C high and low pressure switches for open. 3. Check voltage between mode selector switch Dark Green/White wire or Light Green wire and ground. Voltage should not be present. If voltage is present, replace mode selector switch. BRAKE SWITCH Disconnect brake switch harness connector. Using an ohmmeter, check continuity between brake switch terminals. Continuity should be present. Depress brake pedal or activate brake switch, continuity should not be present. ENGINE COOLANT TEMPERATURE (ECT) SENSOR If a coolant sensor-related code is present, see the TESTS W/CODES - 2.2L article. An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. Disconnect ECT sensor connector. Measure resistance between sensor terminals. Resistance should be high when engine is cold and drop as engine warms. See ECT SENSOR RESISTANCE VALUES table. ECT SENSOR RESISTANCE VALUES Temperature °F (°C) 212 (100) 158 (70) 100 (38) 68 (20) 23 (-5) 0 (-18) -40 (-40) NOTE:

Resistance (Ohms) 177 467 1800 3520 12,300 25,000 100,700

Intake Air Temperature (IAT) sensor is also referred to as Manifold Air Temperature (MAT) sensor.

INTAKE AIR TEMPERATURE (IAT) SENSOR If an IAT sensor-related code is present, see the TESTS W/CODES - 2.2L article. An out-of-calibration sensor may not set a trouble code. Use following procedure to test calibration. Disconnect IAT sensor harness connector. Connect ohmmeter between sensor terminals. Sensor resistance should be as specified. See IAT SENSOR RESISTANCE table. With vehicle sitting overnight, IAT sensor and coolant sensor should have close to the same resistance reading. Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

IAT SENSOR RESISTANCE Temperature °F (°C) 212 (100) 158 (70) 100 (38) 68 (20) 40 (4) 20 (-7) 0 (-18) -40 (-40)

Resistance (Ohms) 185 450 1800 3400 7500 13,500 25,000 100,700

KNOCK SENSOR 1. Disconnect knock sensor harness connector. Using an ohmmeter, measure knock sensor resistance between sensor terminal and engine block. Resistance should be 3300-4500 ohms. Connect voltmeter between sensor terminal and ground. Set voltmeter to 2-volt AC scale. 2. Start and idle engine. Tap on engine block near sensor. A signal should be indicated on voltmeter. If no signal is indicated, replace knock sensor. Also see TIMING CONTROL SYSTEMS under IGNITION SYSTEM and the TESTS W/CODES - 2.2L article. MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1. MAP sensor circuit malfunction should set a related code in PCM/VCM memory. If a code is present, see the TESTS W/CODES - 2.2L article. An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. If driveability problems exist, MAP sensor failure is suspected and no MAP code is present, disconnect MAP sensor connector. If driveability condition improves, check MAP vacuum hose for splits, kinks, proper routing and blockage. If no problems are found, replace MAP sensor. 2. With ignition on and engine off, check MAP sensor parameter using a scan tool connected to Data Link Connector (DLC). Voltage should be as specified in MAP SENSOR VOLTAGE RANGE table. 3. If MAP sensor voltage is as specified, go to next step. If voltage is not as specified, check 5-volt reference supply to sensor. Check harness integrity. If no problems are evident, replace MAP sensor. 4. Using a hand-held vacuum pump, apply 10 in. Hg to MAP sensor and note voltage change. Voltage should drop to about 1.0-2.5 volts less than specified in table. If voltage is not as specified or voltage reading does not immediately follow vacuum change, MAP sensor is faulty. MAP SENSOR VOLTAGE RANGE Altitude (Ft.) Below 1000 1000-2000 2000-3000 3000-4000 4000-5000

Range (Volts) 3.8-5.5 3.6-5.3 3.5-5.1 3.3-5.0 3.2-4.8

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5000-6000 6000-7000 7000-8000 8000-9000 9000-10,000

3.0-4.6 2.9-4.5 2.8-4.3 2.6-4.2 2.5-4.0

OXYGEN SENSOR (O2S) 1. Start engine and warm to operating temperature. Disconnect oxygen sensor. Connect DVOM between Purple wire of oxygen sensor and ground. Place DVOM on 2-volt scale. 2. Using another DVOM on 20-volt scale, connect DVOM in series between Purple wire from PCM/VCM and positive post of battery. This will simulate a rich condition, causing PCM/VCM to respond by leaning mixture. Reading on DVOM connected to oxygen sensor should decrease to less than .3 volt. 3. Move DVOM lead from positive battery post to negative battery post. This will simulate a lean condition, causing PCM/VCM to respond by richening mixture. Reading on DVOM connected to oxygen sensor should increase to greater than .8 volt. If reading does not change as specified, replace oxygen sensor. 4. If a second DVOM is not available, connect a jumper in Purple wire from PCM/VCM. Hold jumper in one hand and touch positive post of battery with other hand to simulate a rich condition. Touch negative post of battery to simulate a lean condition. For additional testing procedures, see the TESTS W/CODES - 2.2L article. OXYGEN SENSOR HEATING ELEMENT On models with oxygen sensor heating elements, disconnect 3-wire connector at oxygen sensor. Measure resistance between White wire terminals on sensor side of connector. Resistance should be 3.5-14 ohms at 68°F (20°C). If resistance is not 3.5-14 ohms, replace oxygen sensor. THROTTLE POSITION (TP) SENSOR 1. Install jumper wires to enable connection of a DVOM in parallel between TP sensor harness connectors. Connect DVOM positive lead to Dark Blue wire terminal. Connect negative lead to Black wire terminal. See Fig. 1 . 2. Turn ignition on, engine off. Slowly depress accelerator pedal. Signal voltage should gradually change from less than one volt at closed throttle to about 5.0 volts at wide open throttle position. If reading is not as specified, replace TP sensor. 3. TP sensor circuit malfunction should set a related trouble code. For further information, see the TESTS W/CODES - 2.2L article. Also see TP SENSOR ADJUSTMENT in the ADJUSTMENTS - 2.2L article.

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

Fig. 1: Typical Throttle Position (TP) Sensor Circuit Courtesy of GENERAL MOTORS CORP. TRANSMISSION RANGE SWITCH A problem in transmission range switch circuit will set related diagnostic trouble code. See the TESTS W/CODES - 2.2L article. VEHICLE SPEED SENSOR (PM GENERATOR) Disconnect vehicle speed sensor harness connector (located in transmission/transaxle). Place gear selector in Neutral. Raise vehicle drive wheels off the ground. Turn drive wheels by hand (more than 3 MPH). Measure AC signal voltage between sensor terminals. Voltage reading should vary from 0.1 to 0.5 volt AC as wheel is turned. If reading is not as specified, replace vehicle speed sensor. If a code is set, refer to the TESTS W/CODES - 2.2L article.

MODULES, MOTORS, RELAYS & SOLENOIDS RELAYS NOTE:

To perform the following tests, use the WIRING DIAGRAMS article.

A/C Clutch Relay

See MISCELLANEOUS PCM/VCM CONTROLS . Fuel Pump Relay

1. If a prolonged crank is required to start vehicle, fuel pump relay may be faulty. To verify, start engine. With engine running, disconnect oil pressure switch (fuel pump back-up circuit). If engine stalls, fuel pump relay is faulty. If vehicle continues to run, relay is okay. Check for other causes of prolonged crank. 2. To test fuel pump relay, disconnect fuel pump relay. Refer to COMPONENT LOCATIONS . Apply battery voltage and ground to fuel pump relay winding terminals (control and ground). 3. Using an ohmmeter, check continuity between fuel pump relay control and ground terminals. Continuity should exist. If continuity does not exist, fuel pump relay is defective. 4. To by-pass fuel pump relay on vehicle (fuel pump not operating), turn ignition off. Disconnect fuel pump relay connector. Using a fused jumper wire, connect fuel pump test connector to positive side of battery. Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

Fuel pump should run. 5. If fuel pump runs, check for faulty connections to relay or replace defective relay. To locate fuel pump test connector, refer to COMPONENT LOCATIONS . SOLENOIDS NOTE:

All PCM/VCM-controlled solenoids should have at least 20 ohms of resistance (except fuel injectors).

Canister Purge Solenoid

See EMISSION SYSTEMS & SUB-SYSTEMS . Idle Air Control (IAC) Valve

See IDLE CONTROL SYSTEM under FUEL SYSTEM. Torque Converter Clutch (TCC) Solenoid

See MISCELLANEOUS PCM/VCM CONTROLS .

FUEL SYSTEM FUEL DELIVERY NOTE:

For fuel system pressure testing, see the BASIC TESTING - 2.2L article.

Fuel Pressure Regulator (SFI)

Fuel pressure regulator is a vacuum-controlled diaphragm type, which uses manifold vacuum to modify fuel pressure to compensate for engine load fuel requirements. Connect fuel pressure gauge to fuel pressure service port. Start engine and note fuel pressure. Disconnect vacuum hose from fuel pressure regulator. Fuel pressure should increase 4-10 psi (.28-.70 kg/cm2 ). If pressure does not increase 4-10 psi (.28-.70 kg/cm2 ), check for presence of manifold vacuum at signal line. If vacuum is not present, check for kinked, cut or split vacuum hose or plugged throttle body vacuum port. If vacuum is present and no pressure change occurs, replace fuel pressure regulator. Fuel Pump Oil Pressure Switch (Back-Up Circuit)

To test fuel pump oil pressure switch (fuel pump back-up circuit), start engine. With engine running, disconnect fuel pump relay. If engine stalls, fuel pump oil pressure switch is faulty. If vehicle continues to run, switch is okay. Fuel Pump Relay

See FUEL PUMP RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS . Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

Fuel Pump Relay By-Pass Procedure

If fuel pump will not energize, relay may be by-passed to test fuel pump. Turn ignition off. Using a fused jumper wire, apply battery voltage to fuel pump test connector. Fuel pump should turn on. For fuel pump test connector location, refer to COMPONENT LOCATIONS . FUEL CONTROL SFI Fuel Injector(s)

Disconnect fuel injector harness connector. Measure resistance across injector terminals. Resistance should be as specified. See SFI FUEL INJECTOR RESISTANCE table. SFI FUEL INJECTOR RESISTANCE Application 2.2L (1) Injector resistance specification is at 140°F (60°C).

(1) Resistance (Ohms)

11.6-12.4

Oxygen Sensor (O2S)

See ENGINE SENSORS & SWITCHES . NOTE:

If injectors are dirty, they should be cleaned using approved injector cleaning procedure before performing fuel INJECTOR BALANCE TEST.

Port Fuel Injector Balance Test (SFI)

The injector balance test is used to pulse the injector for a precise amount of time, spraying a measured amount of fuel in the intake manifold. As each injector is pulsed, a drop in fuel rail pressure occurs. This pressure drop can be recorded and compared to other injectors. All injectors should have a pressure drop of 1.5 psi (.11 kg/cm2 ) or less. If pressure drop is more or less than other injectors, replace appropriate injector. NOTE:

Allow engine to cool to avoid irregular readings due to "hot soak" fuel boiling. To prevent flooding, INJECTOR BALANCE TEST should not be repeated more than once without starting and running engine.

1. Turn ignition off. Connect Fuel Pressure Gauge (J-39021-301) to pressure tap. Unplug harness connector at all injectors. Connect Injector Switch Box (J-39021-210) to one of the injectors. 2. Follow manufacturer's instructions when installing adapter harness. Ignition should be turned off at least 10 seconds to complete PCM/VCM shutdown cycle. 3. Turn ignition on. Fuel pump should run at least 2 seconds after ignition is turned on. Bleed air from gauge and hose to ensure accurate gauge reading. Repeat this procedure until all air is bled from system. Turn ignition off for at least 10 seconds. 4. Turn ignition on again to bring fuel pressure to maximum. Record initial pressure reading. Energize Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

switch box one time and note pressure drop at lowest point. 5. Disregard any slight pressure drop after low point is reached. Subtracting second pressure reading from initial reading indicates amount of injector pressure drop. 6. Repeat step 4) on each injector and compare pressure drop. Recheck injectors not within pressure drop range. Replace injector(s) failing second check. If injectors are all okay, plug in harness connectors and review SYMPTOMS in the TESTS W/O CODES - 2.2L article. IDLE CONTROL SYSTEM Idle Air Control (IAC) Valve

1. Disconnect harness connector to motor. Check resistance across IAC coil terminals "A" to "B" and "C" to "D". See Fig. 2 . Resistance should be 40-80 ohms. If okay, go to next step. If resistance is not as specified, replace IAC valve. 2. Check resistance between IAC terminals "B" to "C" and "A" to "D". Resistance should be infinite. If resistance is not as specified, replace IAC valve. NOTE:

Functional testing of Idle Air Control (IAC) valve requires a bidirectional scan tool capable of cycling PCM/VCM output devices or a special IAC Driver and Noid Light Set (222L or J-37027). Text in TESTS W/CODES - 2.2L article may refer to Tech 1 tester, General Motor's bidirectional scan tool.

Fig. 2: Identifying IAC Valve Circuits (Typical) Courtesy of GENERAL MOTORS CORP.

IGNITION SYSTEM NOTE:

For basic ignition system checks, see the BASIC TESTING - 2.2L article.

TIMING CONTROL SYSTEMS Ignition Control Circuit

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

An open or short to ground in Ignition Control (IC) or by-pass circuit will cause PCM/VCM to turn on Malfunction Indicator Light (MIL) and confirm fault by setting a related trouble code. Refer to the TESTS W/CODES - 2.2L article. Knock Sensor Circuit (Models Using External Spark Controller Module)

1. An open or short circuit on IC module control wire to PCM/VCM will cause a loss of 12-volt IC module signal. This will cause PCM/VCM to fully retard ignition timing. 2. If a scan tool is available, connect tester to Data Link Connector (DLC). Using a metal object, tap on engine next to knock sensor and note knock parameter. Knock should be indicated on scan tool. 3. If a scan tool is not available, backprobe PCM/VCM knock sensor signal terminal with a DVOM. With engine idling, 8-12 volts should be present at this terminal. Using a metal object, tap on engine close to knock sensor. Voltage signal at PCM/VCM terminal should drop to zero volts, and return to original voltage when knock signal ceases. 4. If voltage signal does not respond as described, check knock sensor-to-module-signal. On vehicles equipped with automatic transmission, it may be necessary to place transmission in Drive for timing change to occur. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES . Knock Sensor Circuit (Models Using Knock Sensor With Internal Spark Controller Module)

1. An open or short circuit on knock sensor wire to PCM/VCM will set a related trouble code. A false detonation signal will not cause PCM/VCM to set a code. 2. If a scan tool is available, connect it to Data Link Connector (DLC). Tap on engine next to knock sensor and note "knock" parameter. Knock should be indicated on scan tool. 3. If a scan tool is not available, connect tachometer to engine. Start engine and hold RPM above idle. Using a metal object, tap on engine close to knock sensor. A noticeable decrease in engine RPM should occur. If no RPM decrease occurred, check knock sensor to PCM/VCM circuit. 4. On vehicles equipped with automatic transmission, it may be necessary to place transmission in Drive for timing change to occur. See KNOCK SENSOR under ENGINE SENSORS & SWITCHES .

EMISSION SYSTEMS & SUB-SYSTEMS EXHAUST GAS RECIRCULATION Linear EGR Valve (Digital Valve)

1. Install scan tool. Ensure transmission range switch is operating properly. See ENGINE SENSORS & SWITCHES . With engine at normal operating temperature, command EGR pintle position to zero percent. Increase engine speed to 2000 RPM. If scan tool reads actual EGR pintle position at greater than 3 percent, EGR valve is stuck open. Replace EGR valve. 2. If scan tool reads actual EGR pintle position at 3 percent or less, command a 25 percent position step increase (i.e. 0-25 percent, 25-50 percent, 50-75 percent, etc.). Observe MAP reading and actual EGR pintle position for 3 seconds. EGR should increase by about 25 percent position and MAP reading should also increase. 3. If actual EGR pintle position is stable and within 10 percent of desired EGR pintle position command Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

after 2 seconds, go to next step. If actual EGR pintle position is not as specified, go to step 5). 4. MAP reading should have increased when EGR pintle responded. If MAP did not respond, check EGR passages and EGR valve for blockage. If MAP responded, set desired EGR pintle position to 100 percent. If EGR pintle position sets to 100 percent, EGR is okay. If not, replace EGR valve. 5. Turn engine off. Check EGR electrical circuit and connecting components. Turn ignition on, check for 5volt reference voltage on harness connector terminal "D" (Gray wire). If 5-volt reference voltage is not present, check PCM/VCM. See CONTROL UNIT under COMPUTERIZED ENGINE CONTROLS. If circuits are okay, replace EGR valve. FUEL EVAPORATION CONTROL EVAP Control System

A problem in the EVAP control system will set a Diagnostic Trouble Code (DTC). See the TESTS W/CODES - 2.2L article. POSITIVE CRANKCASE VENTILATION Required Service

The PCV system may require service for obstructions if any of the following conditions exist:     

Rough Idle Stalling or Low Idle Speed Oil Leaks Oil in Air Cleaner Sludge in Engine

A leaking PCV valve or hose could cause:   

Rough Idle Stalling High Idle Speed

If engine idles roughly, check for clogged PCV valve and for plugged or broken PCV hoses BEFORE adjusting idle. Check for correct PCV valve application to ensure the correct valve is fitted. Replace PCV valve if required. Checking PCV Valve Function

1. Remove PCV valve from rocker cover. Run engine at idle. Place thumb over open end of valve to check for vacuum. If there is no vacuum at valve, check for obstruction in manifold port, hoses or PCV valve. Repair or replace as necessary. 2. Turn engine off. Remove PCV valve. Shake valve and listen for rattle of check valve inside PCV valve. If a clear rattle is not heard, replace PCV valve. Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

3. Visually inspect valve for varnish or deposits that may make PCV valve sticky, restricted or incompletely seated. Replace if necessary. 4. Engine must be sealed for PCV system to function as designed. If leakage, sludging or dilution of oil is noted and PCV system is functioning properly, check engine for cause and repair as required to ensure PCV system will continue to function properly. 5. Since an engine operating without any crankcase ventilation can be damaged, it is important to replace PCV valve and air cleaner breather at regular intervals (at least every 30,000 miles). Check all hoses and clamps for failure or deterioration.

MISCELLANEOUS PCM/VCM CONTROLS NOTE:

Although not considered true engine performance-related systems, some controlled devices may affect driveability if they malfunction.

TRANSMISSION NOTE:

To perform the following tests, use appropriate wiring diagram in the WIRING DIAGRAMS article.

Torque Converter Clutch (TCC) Solenoid

Disconnect harness connector to TCC solenoid. Measure resistance between TCC solenoid terminals. Solenoid resistance should be 10-15 ohms at 68°F (20°C). NOTE:

Some solenoids have an internal pressure switch in series with solenoid winding and will not show continuity until transmission hydraulic pressure is applied.

Converter Lock-Up Signal At Transmission

1. Warm engine to operating temperature. Raise vehicle and support drive wheels. Support suspension where necessary to prevent damage to drive axles. 2. Disconnect converter clutch connector at transmission. Connect a test light across converter clutch harness terminals. Start engine and place transmission in Drive. Accelerate vehicle to 45 MPH and note test light. 3. If test light is not on, check solenoid power supply wire of harness for open or short to ground. Check ground circuit for open between harness connector and PCM/VCM. If harness is okay, see CONVERTER LOCK-UP SIGNAL FROM PCM/VCM. Converter Lock-Up Signal From PCM/VCM

1. Warm engine to operating temperature. Raise vehicle and support drive wheels. Support suspension where necessary to prevent damage to drive axles. 2. Connect a test light to battery voltage. Touch TCC control driver terminal with test light. Accelerate Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

vehicle to 45 MPH and note test light. If test light does not illuminate, problem is a faulty PCM/VCM connector or PCM/VCM. Shift Light (Manual Transmission)

1. These tests assume a shift light problem exists. Use this procedure only if the light will not illuminate, or illuminates all the time. 2. Turn ignition on, with engine off. Note shift light. Shift light should not be on. If shift light is on, check for a short to ground between bulb and PCM/VCM or for bad PCM/VCM. 3. Turn ignition on, with engine off, ground test terminal No. 2 (Purple wire) of Data Link Connector (DLC). Malfunction Indicator Light (MIL) should flash and shift light should come on. If MIL illuminates, go to next step. If MIL does not flash, perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in the BASIC TESTING - 2.2L article. 4. If shift light does not come on, ground Tan/Black light driver wire at PCM/VCM terminal using a jumper wire. For circuit identification, see SHIFT LIGHT CIRCUIT IDENTIFICATION table. See Fig. 3 . 5. If shift light still does not come on, check for blown GAGES fuse, blown bulb or open circuit between fuse and PCM/VCM. If shift light illuminates when grounding PCM/VCM terminal with a jumper wire, problem is a bad PCM/VCM connection or bad PCM/VCM. SHIFT LIGHT CIRCUIT IDENTIFICATION Application 2.2L

VCM Connector (Terminal No.) C2 (50)

Fig. 3: Typical Shift Light Circuit Courtesy of GENERAL MOTORS CORP. PCM CONTROLLED WARNING LIGHTS & GAUGES Warning Light Diagnosis

1. Perform On-Board Diagnostics (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in the BASIC TESTING - 2.2L article. After performing OBD system check, go to next step. 2. Check instrument cluster. See the INSTRUMENT PANEL article in the ACCESSORIES/SAFETY EQUIPMENT section. If instrument panel is okay, go to next step. 3. Turn ignition off. Disconnect PCM connector. Turn ignition on. Using a DVOM, check voltage between Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

6. 7. 8. 9.

10. 11.

12.

13. 14. 15. 16. 17.

affected PCM output circuit at PCM harness connector terminal and ground. See the WIRING DIAGRAMS article. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage was not present, go to step 7). Set DVOM to 10-amp scale. Check current between affected PCM output circuit and ground. Monitor reading for about 2 minutes. DVOM should read .05-1.50 amps. If reading is as specified, go to step 12). If reading is not as specified, go to next step. Disconnect instrument cluster, leaving PCM connector disconnected. Using DVOM, check voltage between affected PCM output circuit and ground. DVOM should read zero volts. If voltage reading is as specified, go to step 15). If voltage reading is not as specified, go to next step. Locate and repair short to voltage in affected PCM output circuit. After repairs, go to step 17). Check ignition feed fuse for instrument cluster indicator lights. If fuse is blown, go to next step. If fuse is okay, go to step 9). Locate and repair short to ground in ignition feed circuit for instrument cluster indicator lights. Replace fuse and go to step 17). Disconnect instrument cluster connector. Turn ignition on. Check voltage between ignition feed circuit for instrument cluster indicator lights and ground. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage was not present, go to step 14). Check affected PCM output circuit for an open or shorted circuit to ground. If circuit is open or shorted, go to step 17). If circuit was okay, go to next step. Check affected PCM output circuit and ignition feed circuit for poor connection at instrument cluster and at PCM. If problem is present, repair as necessary and then go to step 17). If problem was not found, go to step 15). Turn ignition off. Reconnect PCM harness connector. Disconnect instrument cluster connector. Turn ignition on. Connect a test light between affected PCM output circuit and ignition feed circuit at instrument panel harness connector. Using a scan tool, perform OUTPUTS TEST function to cycle affected warning light on and off. If test light flashes on and off, check for shorted component or circuit in the output driver circuit. Check for faulty instrument cluster. If test light does not flash on and off, go to next step. Check affected PCM output circuit for poor connection to PCM. Replace defective terminal and then go to step 17). If terminal is okay, go to step 16). Repair open in ignition feed circuit to instrument cluster indicator lights. After repairs, go to step 17). Replace instrument cluster and then go to step 17). Replace PCM and then go to next step. Using scan tool, operate affected warning light. If warning light does not operate properly, go to step 3).

Tachometer Control Circuit Diagnosis

1. Diagnose instrument cluster. See the INSTRUMENT PANEL article in the ACCESSORIES/SAFETY EQUIPMENT section. After diagnosis, go to next step. 2. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in the BASIC TESTING - 2.2L article. After performing OBD system check, go to next step. 3. Turn ignition off. Disconnect PCM connector. Turn ignition on. Using a DVOM, check voltage between tachometer control circuit at PCM harness connector terminal and ground. See the WIRING DIAGRAMS Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

6. 7. 8. 9.

10. 11.

12.

13. 14. 15. 16. 17.

article. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage was not present, go to step 7). Set DVOM to 10-amp scale. Check current between tachometer control circuit and ground. Monitor reading for about 2 minutes. DVOM should read .05-1.50 amps. If reading is not as specified, go to next step. If reading is as specified, go to step 12). Disconnect instrument cluster, leaving PCM connector disconnected. Using DVOM, check voltage between tachometer control circuit and ground. DVOM should read zero volts. If voltage reading is as specified, go to step 15). If voltage reading is not as specified, go to next step. Locate and repair short to voltage in tachometer control circuit. After repairs, go to step 17). Check ignition feed fuse for instrument cluster. If fuse is blown, go to next step. If fuse is okay, go to step 9). Locate and repair short to ground in ignition feed circuit to instrument cluster. Replace fuse and go to step 17). Disconnect instrument cluster connector. Turn ignition on. Check voltage between ignition feed circuit for instrument cluster and ground. Battery voltage should be present. If battery voltage was not present, go to step 14). If battery voltage is present, go to next step. Check tachometer control circuit for an open or shorted circuit to ground. If circuit is open or shorted, go to step 17). If circuit was okay, go to next step. Check tachometer control circuit and ignition feed circuit for poor connection at instrument cluster and at PCM. If problem is present, repair as necessary and then go to step 17). If problem was not found, go to step 15). Turn ignition off. Reconnect PCM harness connector. Disconnect instrument cluster connector. Turn ignition on. Connect a test light between tachometer control circuit and ignition feed circuit at instrument panel harness connector. Using a scan tool, perform OUTPUTS TEST function to cycle tachometer control output light on and off. If test light flashes on and off, check for shorted component or circuit in the output driver circuit. Check for faulty instrument cluster. If test light does flash on and off, go to next step. Check tachometer control circuit for poor connection to PCM. Replace defective terminal and then go to step 17). If terminal is okay, go to step 16). Repair open in ignition feed circuit to instrument cluster. After repairs, go to step 17). Replace instrument cluster and then go to step 17). Replace PCM and then go to next step. Start engine and observe tachometer. If tachometer does not operate properly, diagnose instrument cluster. See the INSTRUMENT PANEL article in the ACCESSORIES/SAFETY EQUIPMENT section.

A/C COMPRESSOR CLUTCH CONTROLS The A/C compressor clutch relay is controlled by the PCM. The PCM improves idle quality by delaying A/C compressor clutch engagement until idle speed is increased, or disengages A/C compressor clutch when idle speed is too low. A/C compressor clutch is cycled by PCM. PCM smooths cycling of A/C compressor clutch by adding fuel the instant A/C compressor clutch is applied. NOTE:

See the WIRING DIAGRAMS article for component location, terminal and wire

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

color identification. RELAY LOCATION A/C COMPRESSOR CLUTCH RELAY LOCATION Application Location S/T Series In Engine Compartment, On Bracket At Center Of Firewall WARNING: Vehicles may be equipped with a PCM using an Electronically Erasable Programmable Read Only Memory (EEPROM). When replacing PCM, the new PCM must be programmed. NOTE:

A/C CLUTCH CIRCUIT DIAGNOSIS Description

PCM receives an A/C request signal from Instrument Panel Cluster (IPC) over serial data line. When A/C is requested, PCM provides a ground path to A/C clutch relay control circuit. When relay circuit is grounded, A/C compressor clutch relay is energized. After A/C request has been selected, PCM will delay grounding A/C compressor relay control circuit for .3 second. This allows PCM to adjust engine idle RPM for additional load. PCM will temporarily de-energize A/C compressor clutch relay for a hot engine restart, wide open throttle, engine speed greater than 6000 RPM, or Idle Air Control (IAC) valve reset. A/C compressor clutch relay will remain de-energized when a Diagnostic Trouble Code (DTC) P0530 is set, or there is no A/C request signal due to an open A/C select switch circuit. Compressor Clutch Control Circuit Diagnosis

1. If On-Board Diagnostic (OBD) System Check has not been performed, see the BASIC TESTING - 2.2L article and go to OBD SYSTEM CHECK. If OBD SYSTEM CHECK has been performed, go to next step. 2. Install scan tool. Check if DTC P0530 is set. If DTC P0530 is set, see the TESTS W/CODES - 2.2L article. If DTC P0530 is not set, go to next step. 3. Turn ignition on, engine off. Check if A/C compressor clutch is engaged. If A/C compressor clutch is engaged, go to next step. If A/C compressor clutch is not engaged, go to step 5). 4. Disconnect A/C relay. If A/C compressor clutch disengages, go to step 6). If A/C compressor clutch does not disengage, go to step 7). 5. Start engine and allow it to reach normal operating temperature. Cycle A/C selector switch on, then off. If A/C compressor clutch cycles on, then off, go to step 8). If A/C compressor clutch does not cycle on, then off, go to step 9). Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

6. Using a test light connected to battery voltage, probe A/C relay control circuit terminal (Dark Green/White wire). If test light illuminates, go to step 10). If test light does not come on, go to step 11). 7. Disconnect A/C compressor clutch harness connector. If A/C compressor clutch disengages, go to step 12). If A/C compressor clutch does not disengage, go to step 13). 8. Turn ignition on, engine off. Install A/C manifold gauge set. Observe A/C high-side pressure readings on gauge set and scan tool. If high-side pressure readings are within 20 psi (1.4 kg/cm2 ) of each other, go to step 36). If pressures are not as specified, go to step 14). 9. Turn A/C on, then off. If scan tool indicates that A/C was requested, then not requested, go to step 15). If operation is not as specified, go to step 16). 10. Check A/C compressor clutch relay control circuit (Dark Green/White wire) for a short to ground. Repair as necessary. Go to step 36). If no problem is found, go to step 22). 11. Replace A/C compressor clutch relay. Go to step 36). 12. Repair short to power in A/C compressor clutch ignition feed circuit (Dark Green wire). Go to step 36). 13. Replace faulty A/C compressor clutch assembly. Go to step 36). 14. Turn ignition on, engine off. Disconnect A/C refrigerant pressure sensor harness connector. Using a voltmeter, measure voltage between battery positive and Black wire at A/C refrigerant pressure sensor harness connector. If reading is battery voltage, go to step 18). If reading is not as specified, go to step 19). 15. With ignition on, engine off, observe A/C HIGH-SIDE pressure reading on scan tool. If reading is 40-430 psi (2.8-30.2 kg/cm2 ), go to step 20). If reading is not as specified, go to step 21). 16. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Using a test light connected to ground, probe A/C selector switch input circuit (Light Green wire) at PCM harness connector. Cycle A/C selector switch on, then off. If test light toggles on, then off, go to next step. If operation is not as specified, go to step 23). 17. Check Light Green wire for a poor connection at PCM. Repair as necessary. Go to step 36). If no problem is found, go to step 22). 18. Replace A/C refrigerant pressure sensor. Go to step 36). 19. Repair open or poor connection in A/C refrigerant pressure sensor ground circuit (Black wire). Go to step 36). 20. Disconnect A/C relay. Using a test light connected to ground, probe A/C relay ignition feed circuits (Orange and Pink wires). If test light comes on for both circuits, go to step 24). If test light does not come on for both circuits, go to step 25). 21. Install A/C manifold gauge set. With ignition on, engine off, observe A/C high-side pressure readings on gauge set and scan tool. If high-side pressures are within 20 psi (1.4 kg/cm2 ) of each other, diagnose A/C-heater system. If high-side pressures are not as specified, go to step 18). 22. Replace PCM. Go to step 36). 23. Repair A/C request signal circuit (Light Green wire) from A/C selector switch. Go to step 36). 24. Connect a fused jumper wire between A/C relay harness connector cavities No. 87 (Orange wire) and No. 30 (Dark Green wire). If A/C compressor clutch engages, go to step 26). If A/C compressor clutch does not engage, leave jumper wire installed and go to step 27). 25. If test light did not come on at Orange wire, check for a short to ground in A/C compressor clutch ignition Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

26.

27.

28. 29. 30.

31. 32. 33. 34. 35. 36.

feed circuit (Dark Green wire), or for a faulty A/C compressor clutch diode. Repair as necessary. Go to step 36). If no problem is found, go to step 28). Remove jumper wire. Start engine and let idle. Using a test light connected to battery positive, probe A/C relay harness connector cavity No. 85 (Dark Green/White wire). Using scan tool, command A/C relay on. If test light comes on, go to step 11). If test light does not come on, go to step 29). Disconnect A/C compressor clutch harness connector. Using a test light connected to ground, probe Dark Green wire at A/C compressor clutch harness connector. If test light comes on, go to step 30). If test light does not come on, go to step 31). Repair open in Orange wire or Pink wire to A/C relay. After repairs, go to step 36). Using a test light connected to ground, probe A/C relay harness connector cavity No. 85 (Dark Green/White wire). If test light comes on, go to step 32). If test light does not come on, go to step 33). Using a test light connected to battery positive, probe A/C compressor clutch ground circuit (Black wire) at A/C compressor clutch harness connector. If test light comes on, go to step 34). If test light does not come on, go to step 35). Repair open in A/C compressor clutch ignition feed circuit (Dark Green wire). Go to step 36). Check A/C compressor clutch relay control circuit (Dark Green/White wire) for a short to power. Repair as necessary. Go to step 36). If no problem is found, go to step 17). Check A/C compressor clutch relay control circuit (Dark Green/White wire) for an open or poor connection. Repair as necessary. Go to step 36). If no problem is found, go to step 17). Replace A/C compressor clutch coil. Go to step 36). Repair open or poor connection in A/C compressor clutch ground circuit (Black wire). Go to next step. Start engine and let idle. Cycle A/C selector switch on, then off. If A/C compressor clutch cycles on, then off, system is okay at this time. See DIAGNOSTIC AIDS. If operation is not as specified, go to step 2).

Diagnostic Aids

If DTC P0530 is set, do not perform this diagnostic procedure. Diagnose appropriate DTC before proceeding. See the TESTS W/CODES - 2.2L article. A/C refrigerant pressure less than 43 psi (3.0 kg/cm2 ), or greater than 428 psi (30.1 kg/cm2 ) will cause PCM to disable A/C compressor clutch. With engine running and A/C on, use scan tool to monitor A/C high-side system pressure for 2 minutes. If pressure goes out of range, diagnose A/C-heater system.

COMPONENT LOCATIONS COMPONENT LOCATIONS Component A/C Compressor Relay

Location Center Rear Of Engine Compartment At A/C Evaporator Right Side Of Engine Forward Of Coil Packs Right Side Of Engine Below Coil

A/C Pressure Sensor Camshaft Position (CMP) Sensor Crankshaft Position (CKP) Sensor Microsoft Saturday, August 29, 2009 11:38:27 AM

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1997 Chevrolet S10 Pickup I - SYSTEM/COMPONENT TESTS - 2.2L 1997 ENGINE PERFORMANCE General Motors Corp. - System & Component Testing - 2.2L 2WD

Packs Lower Left Side Of Instrument Panel Top Rear Of Engine Right Side Of Engine Near Camshaft Position Sensor Front Of Engine Near Thermostat Housing Right Side Of Engine Near Camshaft Position Sensor Right Rear Side Of Engine Above Coil Packs Crossmember Area Of Fuel Tank Right Rear Side Of Engine On Fuel Rail Top Of Fuel Tank Left Rear Side Of Engine Compartment In Relay Center Behind Glove Compartment Top Of Fuel Tank Top Right Side Of Engine Left Front Of Engine Compartment On Air Intake Duct Lower Right Side Of Engine Below Coil Packs Top Right Side Of Engine On Intake Manifold

Data Link Connector (DLC) EGR Valve Electronic Ignition Control Module Engine Coolant Temperature (ECT) Sensor Engine Oil Pressure Gauge/Fuel Pump Switch EVAP Canister Purge Solenoid EVAP Canister Vent Solenoid Fuel Injectors Fuel Level Sensor Fuel Pump Prime Connector Fuel Pump Relay Fuel Tank Pressure Sensor Idle Air Control (IAC) Valve Intake Air Temperature (IAT) Sensor Knock Sensor Manifold Absolute Pressure (MAP) Sensor Oxygen Sensor (O2S) Pre-Converter Post-Converter (Heated) Powertrain Control Module (PCM)

In Left Exhaust Manifold Rear Of Catalytic Converter Right Side Of Engine Compartment Behind Glove Compartment Top Right Side Of Engine Right Rear Of Transmission

Relay Center Throttle Position (TP) Sensor Vehicle Speed Sensor

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

IDENTIFICATION Transfer case can be identified by an I.D. tag, located on rear case. I.D. tag provides model number, serial number and low range ratio. Date of manufacture is the serial number (I.D. number). This information is necessary when ordering parts.

DESCRIPTION Model 231 transfer case is a part time, chain-driven, 4-position unit with 2-piece aluminum case. Torque input in 4WD high and low range is undifferentiated. 2WD operation is achieved by a vacuum shift motor. Shift motor disconnects right front axle when 2WD is selected. Vacuum shift motor is controlled by a vacuum switch located on front of transfer case and actuated by shift sector.

ON-VEHICLE SERVICE FRONT OIL SEAL Removal & Installation

1. Mark front drive shaft and flange for installation alignment reference. Remove front drive shaft. Remove flange. Discard washer and nut. Using a screwdriver, carefully remove oil seal. Ensure seal contact surface is clean. 2. Apply ATF to seal lip and flange seal surface. Install NEW oil seal. Install flange and NEW washer and nut. Tighten nut to specifications. See TORQUE SPECIFICATIONS . Install front drive shaft using alignment marks. Check transfer case fluid. EXTENSION HOUSING OIL SEAL & BUSHING Removal & Installation

1. Mark rear drive shaft and flange for installation alignment reference. Remove rear drive shaft. Tap extension housing in a clockwise direction and remove extension housing. DO NOT pry on extension housing. Using a screwdriver, remove oil seal from extension housing. 2. Using bushing driver, replace bushing in extension housing. Install NEW extension housing oil seal. Apply silicone sealant to extension housing mating surface. Install extension housing. To complete installation, reverse removal procedure.

ADJUSTMENTS GEARSHIFT LINKAGE Remove transfer case shift lever knob retainer. Remove shift lever knob. Remove floor console. Place shift Microsoft Saturday, August 29, 2009 11:57:43 11:57:39 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

lever in Neutral. Pry control cable end from shift lever. Loosen control cable lock nut. Check transfer case to ensure it is in Neutral. Ensure shift lever is in Neutral. Turn shift lever end of cable in or out as needed until it is aligned with shift lever. Install control cable on shift lever. Tighten control cable lock nut.

TROUBLE SHOOTING SYMPTOM DIAGNOSIS Will Not Shift Or Difficult To Shift Into Gear

Vehicle speed too high; slow vehicle to 2-3 MPH to shift. Vehicle operated too long on dry paved surface; stop vehicle and place in Reverse or Neutral to relieve driveline torque. Ensure transfer case external linkage is not binding. Ensure correct fluid is used. Internal parts may be worn or damaged. Noisy In All Gears

Check fluid level. Ensure correct fluid is used. If fluid is okay, locate possible internal mechanical problem. Jumps Out Of Gear Or Noisy In 4WD

Transfer case not completely in gear; check shift linkage. Range fork damaged. Shift fork pads are worn or shift fork binding. Low range gear worn. Fluid Leaking From Vent Or Seals

Transfer case overfilled. Vent plugged. Output shaft seals are damaged or not installed properly.

TESTING VACUUM SWITCH Shift to 2WD position. Locate vacuum switch on front of transfer case. Apply 15 in. Hg vacuum to "L". See Fig. 1 . Vacuum should be present at "M". Connect a vacuum gauge to "N". Shift to 4WD position. Apply vacuum to "L". Vacuum should be present at "N". If switch fails any test, replace switch.

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

Fig. 1: Testing Vacuum Switch Courtesy of CHRYSLER CORP.

REMOVAL & INSTALLATION TRANSFER CASE Removal

1. Shift transfer case into 4H position. Disconnect negative battery cable. Raise and support vehicle. Drain fluid. 2. Mark front and rear output shaft yokes and drive shafts for reassembly reference. Support transfer case with hydraulic jack and remove rear crossmember and skid plate, if equipped. Remove front and rear drive shafts. 3. Disconnect transfer case gearshift linkage, vent hose and all electrical and vacuum connections. Remove transfer case-to-transmission bolts. Remove transfer case from vehicle. Installation Microsoft Saturday, August 29, 2009 11:57:39 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

1. Clean all old gasket material from transmission and transfer case mating surfaces. Position NEW gasket on transfer case with orientation tab at upper left bolt hole. 2. Install transfer case, aligning splines of input shaft with transmission. Slide transfer case forward until seated against transmission. Install transfer case-to-transmission bolts and tighten to specification. See TORQUE SPECIFICATIONS . Install rear crossmember and skid plate. 3. Reconnect gearshift linkage, vent hose and all electrical and vacuum connections. Using reference marks made during removal, reinstall front and rear drive shafts. Refill transfer case. Adjust gearshift linkage. See ADJUSTMENTS . To complete installation, reverse removal procedure.

TRANSFER CASE DISASSEMBLY 1. Remove front companion yoke. See Fig. 2 . Discard washer and nut. Shift transfer case to 4L and remove extension housing. Remove rear bearing snap ring. Using 2 screwdrivers under each tab, remove retainer housing. Remove rear case and oil pump as an assembly. 2. Remove oil pump pick-up screen and tube from rear case. Remove oil pump. Remove "O" ring from oil pump and discard. Do not separate oil pump halves. Pump must be replaced as an assembly if necessary. 3. Remove mode spring. Using a soft hammer, tap front output shaft upward and remove with drive chain as an assembly. Remove mainshaft, mode fork and shift rail as an assembly. Remove mode fork and shift rail from synchronizer sleeve. 4. Mark synchronizer sleeve position for reassembly reference. Remove synchronizer sleeve from mainshaft. Remove synchronizer hub snap ring. Remove synchronizer hub, stop ring and drive sprocket. Slide range fork pin out of sector. 5. Remove range fork and shift hub as an assembly. Remove range lever from sector shaft. Remove shift sector, bushing and "O" ring. Remove shift detent pin, spring and plug. Remove front bearing retainer. Remove input gear snap ring. 6. Press input and low range gear assembly from input gear bearing. Remove low range gear snap ring. Remove input gear retainer, thrust washers and input gear from low range gear. 7. Remove all oil seals. Remove magnet from front case. Remove front bearing snap ring. Using a plastic hammer, remove front bearing. Press input gear bearing from front case. 8. Using slide hammer and internal puller, remove input gear pilot bearing. Press bearings from drive sprocket. Using internal puller and slide hammer, remove output shaft rear bearing.

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

Fig. 2: Exploded View Of Model 231 Transfer Case Courtesy of CHRYSLER CORP.

CLEANING & INSPECTION Clean all parts with solvent. Dry with compressed air. Replace all oil seals, "O" rings and snap rings. Check all parts for wear or damage. Replace all worn or damaged parts. If low range annulus gear inside front case is damaged or worn, front case and gear must be replaced as an assembly. Replace oil pump as an assembly if any part is damaged or worn.

TRANSFER CASE REASSEMBLY NOTE:

When installing bearings, ensure bearing bores are aligned with oil feed holes.

1. Lubricate all parts with Dexron III before installing. Install output shaft front bearing with NEW snap ring. Install output shaft oil seal in front case. Install snap ring on NEW input gear bearing. See Fig. 2 . 2. Press input gear bearing so snap ring is seated against case. Using press, install NEW input gear pilot bearing. Assemble low range gear, input gear, thrust washers and retainer. Microsoft Saturday, August 29, 2009 11:57:39 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

3. Install snap ring. Ensure snap ring is seated in low range gear groove. Start input gear shaft into bearing in front case. Press input shaft gear into bearing. CAUTION: DO NOT press against end surfaces of gear. Failure to use proper size tool could lead to gear case or thrust washer damage. 4. Install input gear snap ring. Install oil seal in front bearing retainer. Apply a 1/8" bead of silicone sealant to retainer mating surface. Align oil channel in retainer with oil feed hole in case. Install retainer on case. Tighten bolts to specification. 5. Install sector shaft "O" ring and bushing. Install range sector in case. Install range lever and nut. Install detent, detent spring and plug. Tighten to specification. See TORQUE SPECIFICATIONS . Install NEW pads and fork rail bushings on range fork. Install range fork and shift hub. 6. Ensure range fork pin is engaged with range sector slot. Press front bearing in drive sprocket until bearing is flush with bore edge. Install rear bearing until bearing is flush with lower edge of chamfer in bearing bore. 7. Install inserts and spring in synchronizer hub. Install sprocket on mainshaft. Install synchronizer stop ring on mainshaft. Ensure stop ring is seated. Install synchronizer hub on mainshaft. Align and seat hub inserts on stop ring lugs. Install synchronizer hub snap ring. 8. Install synchronizer sleeve on hub. Ensure sleeve is positioned so beveled spline ends are facing stop ring. Ensure sleeve tooth is aligned (centered) over each synchronizer strut. Gear clash will occur if strut and sleeve teeth are misaligned. Install NEW pads on mode fork. Engage mode fork in synchronizer sleeve. Install mainshaft and fork assembly in case. Ensure mode fork shift rail is seated in both range fork bushings. 9. Install output shaft and drive chain assembly. Install mode spring on shift rail. Using bearing driver, install output shaft rear bearing. Lubricate bearing after installation. Install seal in oil pump feed housing. Install oil pump in housing. Tighten to specification. 10. Install oil pick-up tube "O" ring in oil pump. Prime oil pump by pouring ATF into pump through pick-up tube opening. Install oil pump and pick-up tube in case. Ensure oil screen is properly positioned. See Fig. 3 . Install magnet in front case. Apply 1/8" bead of silicone sealer to front case. Install rear case. Tighten to specification. See TORQUE SPECIFICATIONS . Ensure mainshaft splines are engaged with oil pump inner gear and a washer is used on bolts at dowel locations. 11. Install rear bearings in retainer. Apply 1/8" bead of silicone sealer and install retainer to case. Install rear retainer snap ring. Install extension housing. Install front companion yoke. Install NEW gasket on vacuum switch. Install vacuum switch in case. Fill transfer case with Dexron III.

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

Fig. 3: Identifying Oil Pump Screen Position Courtesy of CHRYSLER CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Companion Flange Nut Detent Plug Drain & Fill Plug Extension Housing Bolt Front Bearing Retainer Bolt Front Case-to-Rear Case Bolt Range Lever Nut Rear Bearing Retainer Bolt Rear Crossmember Shift Lever Lock Bolt Shift Selector Lever Nut Speed Sensor Bolt Transfer Case-to-Transmission Nut Vacuum Switch

Ft. Lbs. (N.m) 80 (108) 11 (15) 30-40 (41-54) 26-34 (35-46) 14 (19) 23 (31) 20-25 (27-34) 20-25 (27-34) 30 (41) 10 (14) 20 (27) 23 (31) 26 (35) 17 (23)

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 231 Overhaul

INCH Lbs. (N.m) 18 (2)

Control Cable Lock Nut

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

IDENTIFICATION Transfer case can be identified by an I.D. tag, located on rear case. See Fig. 1 . I.D. tag provides model number, assembly number and low range ratio. This information is necessary when ordering parts.

Fig. 1: Locating Identification Tag Courtesy of GENERAL MOTORS CORP.

DESCRIPTION Model 233 transfer case is a chain drive, 2-piece aluminum case, 3-position unit. Transfer case uses an electronic control system and a shift motor to shift the transfer case.

ADJUSTMENTS GEARSHIFT LINKAGE Model 233 uses a electronic control system and shift motor for transfer case shifting and is not equipped with transfer case gearshift linkage.

ON-VEHICLE SERVICE Microsoft Saturday, August 29, 2009 11:58:17 11:58:11 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

FRONT OIL SEAL Removal

Mark front drive shaft and flange for alignment purposes. Remove front drive shaft. Remove flange. Discard washer and nut. Using a screwdriver, carefully remove oil seal. Ensure seal contact surface is clean. Installation

Apply ATF to seal lip and yoke seal surface. Install oil seal and yoke with NEW washer and nut. Install front drive shaft using alignment marks. Check transfer case fluid. EXTENSION HOUSING OIL SEAL & BUSHING Removal

Mark rear drive shaft and flange for installation purposes. Remove rear drive shaft. Tap extension housing clockwise and remove extension housing. DO NOT pry on extension housing. Using a screwdriver, remove oil seal from extension housing. Installation

Using bushing driver, replace bushing in extension housing. Install NEW extension housing oil seal. Apply silicone sealant to extension housing mating surface. Install extension housing. To complete installation, reverse removal procedure.

TESTING ELECTRONIC SYSTEM For testing of electronic system and components, see NV 233 DIAGNOSIS article.

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

Fig. 2: Exploded View Of Model 233 Transfer Case Courtesy of GENERAL MOTORS CORP.

TROUBLE SHOOTING SYMPTOM DIAGNOSIS Will Not Shift Or Difficult To Shift Microsoft Saturday, August 29, 2009 11:58:12 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

Vehicle operated too long on dry paved surface. Stop vehicle. Place transmission in Reverse or Neutral to relieve drive line torque. Ensure correct fluid is used. Internal parts may be worn or damaged. Noisy In All Gears

Check fluid level. Ensure correct fluid is used. If fluid is okay, locate possible internal mechanical problem. Jumps Out Of Gear Or Noisy In 4WD

Transfer case internal shift mechanism faulty. Range fork damaged. Fork pads are worn. Shift fork binding. Low range gear worn. Fluid Leaking From Vent Or Seals

Transfer case overfilled. Vent plugged. Output shaft seals are damaged or not installed properly.

REMOVAL & INSTALLATION TRANSFER CASE WARNING: When battery is disconnected, vehicles equipped with computers may lose memory data. When battery power is restored, driveability problems may exist on some vehicles. These vehicles may require a relearn procedure. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. Removal

1. Shift transfer case into 4H and disconnect battery negative cable. Raise vehicle, remove skid plate and drain fluid. 2. Mark front and rear output shaft yokes to drive shafts for reassembly reference. Support transfer case and remove rear crossmember. Remove drive shafts. 3. Disconnect speedometer cable, electrical connections and vacuum (hoses) harness at transfer case. Remove transfer case attaching bolts. Remove transfer case from vehicle. Installation

1. Clean all old gasket material from transmission and transfer case mating surfaces. Position NEW gasket on transfer case with orientation tab at upper left bolt hole. 2. Install transfer case, aligning splines of input shaft with transmission. Slide transfer case forward until seated against transmission. Install transfer case attaching bolts and tighten to specification. See TORQUE SPECIFICATIONS . Install rear crossmember. 3. Attach speedometer cable, electrical connections and vacuum harness at transfer case. Using reference marks made during removal, reinstall front and rear drive shafts. Refill transfer case. Install skid plate and lower vehicle. Connect negative battery cable. Road test vehicle. Microsoft Saturday, August 29, 2009 11:58:12 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

TRANSFER CASE DISASSEMBLY NOTE:

See Fig. 2 for exploded view of transfer case.

1. Remove front output yoke. Discard lock nut. Remove shift motor, vacuum switch and speed sensor. Remove detent plug, spring and plunger from underside of case. Remove extension housing and rear output bearing retainer snap ring. Remove rear retainer housing bolts. Using 2 screwdrivers under each tab, remove pump retainer housing. Remove VSS rotor and snap ring from mainshaft. Remove case bolts (2 longer bolts go in doweled holes; mark all bolts for reinstallation position). Separate case halves by carefully prying only in molded slots. Remove oil pump assembly. 2. Remove pump pick-up tube, "O" ring and filter. See Fig. 3 . Remove mode shift fork spring (positioned in middle of drive chain). Remove front output shaft seal and snap ring. 3. Remove mainshaft, drive chain, and driven sprocket as an assembly (mode fork and shift rail will be removed with this assembly). 4. Remove synchronizer-to-mainshaft snap ring. Remove drive sprocket. Remove range shift fork and range shift hub as an assembly. Rotate sector shaft to obtain clearance for range fork. Remove shift sector shaft snap ring and sector shaft assembly. 5. Remove input bearing retainer bolts, then remove retainer. Remove input gear snap ring. Use soft-face hammer to remove input and low range gear assembly. Remove input gear to low range gear assembly snap ring. Separate input gear from low range gear assembly. Remove input bearing. Remove needle bearings from input gear. 6. Remove front output bearing snap ring. Remove front output bearing. Remove oil seal from mainshaft extension housing, then remove input bearing retainer seal. Remove front output rear bearing. Remove mainshaft bearing from oil pump retainer. Remove magnet from front case. 7. Mark and disassemble main drive synchronizer stop rings from sleeve. Remove spring retainers from synchronizer hub. Separate synchronizer hub from synchronizer. Remove oil pump screws from oil pump.

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

Fig. 3: Removing & Installing Oil Pump Oil Screen Courtesy of GENERAL MOTORS CORP.

CLEANING & INSPECTION Clean all parts with solvent. Dry all parts with compressed air, except bearings. Bearings must be wiped dry or allowed to air dry. Replace all oil seals, "O" rings and snap rings. Check all parts for wear or damage. Replace all worn or damaged parts. If annulus gear, inside front case, is damaged or worn, front case and gear must be replaced as an assembly. Replace oil pump as an assembly if any part is damaged or worn.

TRANSFER CASE REASSEMBLY NOTE:

See Fig. 2 for exploded view of transfer case. When installing bearings, ensure bearing bores are aligned with oil feed holes.

1. Lubricate all parts with Dexron-II ATF before installation. Install needle bearing into rear case half. Be sure bearing is flush with boss on case housing. Install front output shaft bearing with NEW snap ring. Install bearing into rear retainer housing. 2. Install input gear bearing. Install input gear assembly into planetary gear. Install input gear snap ring. Install input bearing. Install mainshaft extension housing seal. Lubricate seal lip with ATF fluid. Install input bearing seal into bearing retainer. Lubricate seal lip with ATF fluid. 3. Install magnet into front case half. Ensure synchronizer hub and sleeve mating marks are aligned, then install synchronizer hub to sleeve. Install hub spring retainers and stop rings. Install synchronizer drive Microsoft Saturday, August 29, 2009 11:58:12 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

5. 6.

sprocket. Install synchronizer assembly and snap ring. Use soft-face hammer to install input and low range gear assembly. Install input gear snap ring. Install input bearing retainer. Apply RTV sealant to bearing retainer mating surfaces. Apply thread-lock to bolts, then install retainer bolts and tighten evenly. Install shift sector assembly and snap ring. Install range shift hub and fork (rotate sector to align range shift fork). Install drive chain, mainshaft and driven sprocket assembly. Install fork shift spring. Install oil pump pickup tube and screen into rear case (use care not to damage "O" ring). Install oil pump onto pickup tube. Apply RTV sealant to case mating surface. Install rear case to front case (use care to avoid damage to oil pump. Apply thread-lock to case bolts. Install case bolts and tighten evenly. Install mainshaft snap ring. Install VSS rotor and snap ring. Install rear retainer housing. Apply RTV sealant to rear retainer housing-to-rear case joint. Install pump retainer housing bolts. Install output bearing snap ring. Apply RTV sealant to extension housing mating surface and install housing. Apply thread-lock to extension housing bolts and install bolts. Install detent plug, spring and plunger to bottom of case. Install vehicle speed sensor with new "O" ring. Install vacuum switch with new "O" ring. Install electronic shift motor and bolts. Install front output shaft seal. Lubricate seal lip with ATF fluid. Install front output shaft snap ring. Fill transfer case with Dexron-II ATF.

Fig. 4: Identifying Synchronizer Assembly Components Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:58:12 AM

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1997 Chevrolet S10 Pickup 1997 TRANSFER CASES General Motors Corp. New Venture 233 Overhaul

Fig. 5: Installing Output Shaft & Drive Chain Assembly Courtesy of GENERAL MOTORS CORP.

TORQUE SPECIFICATIONS TORQUE SPECIFICATIONS Application Detent Plug Drain & Fill Plug Extension Housing Bolt Front & Rear Bearing Retainer Bolt Front Case-To-Rear Case Bolts Oil Pump Housing Screw Output Yoke Nut Range Lever Nut Shift Motor Bolt Transfer Case-To-Transmission Nuts Vehicle Speed Sensor

Ft. Lbs. (N.m) 11 (15) 35 (47) 23 (31) 14 (19) 23 (31) 23 (31) 110 (152) 23 (31) 13 (18) 41 (55) 23 (31)

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1997 Chevrolet S10 Pickup M - VACUUM DIAGRAMS 1997 ENGINE PERFORMANCE General Motors Corp. - Vacuum Diagrams

M - VACUUM DIAGRAMS 1997 ENGINE PERFORMANCE General Motors Corp. - Vacuum Diagrams

INTRODUCTION This article contains underhood views or schematics of vacuum hose routing. Use these vacuum diagrams during the visual inspection of BASIC DIAGNOSTIC PROCEDURES. See the appropriate BASIC TESTING article. This will assist in identifying improperly routed vacuum hoses which may cause driveability and/or computer-indicated malfunctions. F - BASIC TESTING - 2.2L F - BASIC TESTING - 4.3L

EMISSION CONTROL DEVICE ABBREVIATIONS EMISSION CONTROL DEVICE ABBREVIATION Abbreviation ACSRY CNSTR CSI EGR EGR SOL EVAP HVAC MAP PCV REG SFI SOL VAC VLV

Emission Control Device Accessory Canister Central Sequential Port Injection Exhaust Gas Recirculation EGR Solenoid Evaporative Heating, Ventilation & A/C System Manifold Air Pressure Sensor Positive Crankcase Ventilation Regulator Sequential Fuel Injection Solenoid Vacuum Valve

VACUUM DIAGRAMS

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1997 Chevrolet S10 Pickup M - VACUUM DIAGRAMS 1997 ENGINE PERFORMANCE General Motors Corp. - Vacuum Diagrams

Fig. 1: 2.2L 2WD SFI Courtesy of GENERAL MOTORS CORP.

Fig. 2: 4.3L CSI Courtesy of GENERAL MOTORS CORP. Microsoft Saturday, August 29, 2009 11:37:51 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

DESCRIPTION FRONT Wiper/washer system is a pulse delay system. System uses a permanent-magnet, positive-park, 2-speed wiper motor. System includes LOW, HIGH, DELAY and MIST modes. Variable resistor in wiper switch adjusts amount of current to a delay module attached to wiper motor. Delay module controls current to wiper motor. REAR System uses a positive-park, single-speed wiper motor. In addition to ON and OFF positions, switch on instrument panel has momentary WASH and WIPE positions. Washer pump is located in engine compartment, inside washer fluid reservoir.

TROUBLE SHOOTING Ensure WIPER fuse (No. 17), RADIO fuse (No. 11) and PK LPS fuse (No. 3) located in instrument panel fuse block are okay. Visually inspect all system related connectors for being properly seated. Visually inspect wiper arm transmission for damage. FRONT WIPER/WASHER SYSTEM OPERATION CHECK 1. Turn ignition switch to RUN position. Press and hold front washer button to ON position for 1-2 seconds. Washer should spray windshield for as long as button is held. Wipers should run at low speed and continue to run for approximately 6 seconds after washer cycle is complete, then return to Park position. 2. Move front wiper switch to DELAY position. Move wiper switch through delay range. Wipers should make one complete sweep, then pause for 1-25 seconds (depending on delay setting) before making next sweep. 3. Leave front wiper switch in DELAY position. Press and hold front washer button to ON position for 1-2 seconds. Washer should spray windshield for as long as button is held. Wipers should run at low speed and continue to run for approximately 6 seconds after washer cycle is complete, then return to DELAY (pulse) mode. 4. Move front wiper switch to LOW position. Wipers should operate continuously at low speed. 5. Move front wiper switch to HIGH position. Wipers should operate continuously at high speed. 6. Move front wiper switch to OFF position. Wipers should return to Park position at low speed. 7. Move front wiper switch to MIST position, and then release. Wipers should make one complete sweep at low speed, and then Park. 8. If front wiper switch is held in MIST position, wipers should run continuously at LOW speed until switch is released. 9. If front wiper/washer system works intermittently, or is completely inoperative, refer to SPECIAL Microsoft Saturday, August 29, 2009 11:58:53 11:58:50 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

POLICY ADJUSTMENT - WINDSHIELD WIPER MOTOR FAILURES Service Campaign Bulletin 02054A dated May 9, 2003 prior to making repairs. 10. After reviewing Service Campaign Bulletin 02054A noted above, if wiper system does not function properly, perform appropriate test. See SYSTEM TESTS . REAR WIPER/WASHER SYSTEM OPERATION CHECK 1. Push rear window washer switch to WASH position. Washer should spray until switch is released. Wiper should continue to operate for approximately 3 cycles. 2. Turn wiper/washer switch to LO position. Wiper should operate with approximately a 5 second delay between wipe cycles. 3. Turn wiper/washer switch to HI position. Wiper should operate constantly at a faster speed. If wiper system does not function properly, perform appropriate test. See SYSTEM TESTS .

SYSTEM TESTS WARNING: Vehicles are equipped with Supplemental Restraint System (SRS). Air bag system MUST be disabled before servicing ANY steering column component. Disabling system will prevent accidental air bag deployment, resulting in possible serious injury or property damage. See DISABLING & ACTIVATING SIR SYSTEM in AIR BAG RESTRAINT SYSTEMS article. FRONT WIPER/WASHER SYSTEM CAUTION: If front wiper/washer system works intermittently, or is completely inoperative, refer to SPECIAL POLICY ADJUSTMENT - WINDSHIELD WIPER MOTOR FAILURES Service Campaign Bulletin 02054A dated May 9, 2003 prior to making repairs. NOTE:

Ensure WIPER fuse (No. 17) located in instrument panel fuse block is okay before testing system.

Washer Inoperative, Wipers Operate

1. If washer pump motor does not run, go to next step. If washer pump motor runs, check for the following:  Adequate washer solvent in washer reservoir.  Washer hoses for being pinched, kinked or damaged.  Proper washer hose connections at washer nozzles and washer pump motor.  Ensure pick-up screen on end of feed hose in washer reservoir is not plugged.  Ensure washer nozzles are not plugged. 2. Disconnect washer pump connector. Washer pump is located in washer reservoir, in left front corner of engine compartment. Turn ignition ON and wiper switch to LO position. Connect test light between washer pump connector terminals. Observe test light with WASH button pushed. If test light is on, Microsoft Saturday, August 29, 2009 11:58:50 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

replace washer pump. If test light is not on, go to next step. Using test light, backprobe between ground and washer pump connector Pink wire terminal with WASH button pushed. If test light is not on, go to next step. If test light is on, repair open in Black wire between washer pump connector terminal "B" and ground. Using test light, backprobe between ground and wiper motor connector terminal "A" (Pink wire) with WASH button pushed. See Fig. 1 . If test light is not on, go to next step. If test light is on, repair open in Pink wire between wiper motor connector terminal "A" and washer pump. Using test light, backprobe between ground and wiper motor connector terminal "E" (Brown wire) with WASH button pushed. If test light is not on, go to next step. If test light is on, remove wiper motor cover. Ensure spring contacts are making proper contact. If no problem is found with spring contacts, replace wiper motor circuit board. See WIPER MOTOR CIRCUIT BOARD (FRONT) under REMOVAL & INSTALLATION. Check for open in Brown wire between wiper motor connector terminal "E" and washer switch. Repair as necessary. If Brown wire is okay, replace washer switch. See WIPER SWITCH under REMOVAL & INSTALLATION.

Fig. 1: Identifying Wiper Motor Wiring Harness Connector Terminals Courtesy of GENERAL MOTORS CORP. Washer Pumps Continuously

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

1. Turn ignition ON and wiper switch to LO position. Using test light, backprobe between ground and wiper motor connector terminal "A" (Pink wire). See Fig. 1 . 2. Observe test light while momentarily pushing WASH button. If test light stays on after WASH button is released, go to next step. If test light goes out after WASH button is released, replace wiper motor cover. See WIPER MOTOR CIRCUIT BOARD (FRONT) . Check washer switch. Repair/replace as necessary. Wipers Inoperative In All Modes

CAUTION: If front wiper/washer system works intermittently, or is completely inoperative, refer to SPECIAL POLICY ADJUSTMENT - WINDSHIELD WIPER MOTOR FAILURES Service Campaign Bulletin 02054A dated May 9, 2003 prior to making repairs. 1. Turn ignition ON and wiper switch to HIGH position. Using test light, backprobe between ground and wiper motor connector Purple wire terminal. If test light is on, go to next step. If test light is not on, go to step 3 . 2. Turn wiper switch to LO position. Connect jumper wire between wiper motor case and chassis ground. If wiper motor operates, repair ground circuit as necessary. If wiper motor does not operate, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. 3. Using test light, backprobe between ground and wiper motor connector Yellow wire terminal. If test light is on, go to next step. If test light is not on, check WIPER fuse (No. 17). If fuse is okay, repair open circuit in Yellow wire between instrument panel fuse block and wiper motor. If fuse is blown, replace as necessary and check for short to ground in Yellow wire circuit. 4. Check for open in Purple wire between wiper motor connector and wiper switch. Check for faulty wiper switch. Check for open in Yellow wire between WIPER fuse and wiper switch. Repair as necessary. Wipers Run In Low Speed Only

Disconnect wiper motor harness connector. Using jumper wire, connect battery voltage to wiper motor terminal "A". See Fig. 1 . Connect a second jumper wire between ground and wiper motor terminal "B". If wiper motor does not operate, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. If wiper motor operates, check for open in Purple wire between wiper motor connector and wiper switch. Check for faulty wiper switch. Repair as necessary. Wipers Run In High Speed Only

Disconnect wiper motor harness connector. Using jumper wire, connect battery voltage to wiper motor terminal "C". See Fig. 1 . Connect a second jumper wire between ground and wiper motor terminal "B". If wiper motor does not operate, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. If wiper motor operates, check for open in Brown wire between wiper motor connector and wiper switch. Check for faulty wiper switch. Repair as necessary. Wipers Run At One Speed Only

1. Disconnect wiper motor harness connector. Using jumper wire, connect battery voltage to wiper motor Microsoft Saturday, August 29, 2009 11:58:50 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

terminal "C". See Fig. 1 . Connect a second jumper wire between ground and wiper motor terminal "B". Wipers should run at low speed. 2. Disconnect jumper wire from wiper motor terminal "C". Using jumper wire, connect battery voltage to wiper motor terminal "A". Ensure second jumper wire is still connected between ground and wiper motor terminal "B". Wipers should run at high speed. 3. If wipers operate at correct speeds, check wiring between wiper switch and wiper motor. Repair as necessary. If wiring tests okay, replace wiper switch. See WIPER SWITCH under REMOVAL & INSTALLATION. 4. If wipers do not operate at correct speeds, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. Wipers Shut Off, But Will Not Park

1. Disconnect wiper motor harness connector. Using jumper wire, connect battery voltage to wiper motor terminal "E". See Fig. 1 . Connect a second jumper wire between wiper motor terminals "D" and "C". If wipers park, go to next step. If wipers do not park, replace circuit board. See WIPER MOTOR CIRCUIT BOARD (FRONT) under REMOVAL & INSTALLATION. If wipers still will not park, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. 2. Turn wiper switch to OFF position. Check for continuity between wiper motor harness connector terminals "A" (Pink wire) and "E" (Brown wire). See Fig. 1 . If continuity is present, repair open circuit between wiper motor connector terminal "C" and instrument panel fuse block. If continuity is not present, repair open circuit between wiper motor connector terminal "E" and wiper switch. If fault is still present, replace wiper/washer switch. See WIPER SWITCH under REMOVAL & INSTALLATION. Wipers Will Not Shut Off

Disconnect wiper motor harness connector. Using jumper wire, connect battery voltage to wiper motor terminal "E". See Fig. 1 . Connect a second jumper wire between wiper motor terminals "D" and "C". If wipers park, replace wiper/washer switch. See WIPER SWITCH under REMOVAL & INSTALLATION. If wipers still run, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. Wipers Operate Intermittently

CAUTION: If front wiper/washer system works intermittently, or is completely inoperative, refer to SPECIAL POLICY ADJUSTMENT - WINDSHIELD WIPER MOTOR FAILURES Service Campaign Bulletin 02054A dated May 9, 2003 prior to making repairs. 1. Remove WIPER fuse from instrument panel fuse block. Connect a 0-30 amp ammeter across the fuse block terminals where the WIPER fuse was located. Turn ignition ON and wiper switch to HIGH position with windshield dry. Note the lowest current draw reading. 2. If current draw is more than 5 amps, go to next step. If current draw is less than 5 amps, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. Wiper Blades Do Not Move, Wiper Motor Runs Microsoft Saturday, August 29, 2009 11:58:50 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

Check wiper linkage connection to wiper crank arm. Repair/replace linkage as necessary and retest. If linkage is connected, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. Wipers Shut Off, But Park Above Normal Park Position

With wipers parked, disconnect wiper motor harness connector. Check for open between ground and wiper motor terminal "C". See Fig. 1 . If open is found, replace wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. If open is not found, check arm and blade location and/or linkage and correct as necessary. REAR WIPER/WASHER SYSTEM NOTE:

Ensure RR WPR fuse (No. 23) located in instrument panel fuse block, and RR W/W fuse located in underhood fuse block are okay before testing system.

Rear Washer Does Not Operate, Rear Wiper Operates

1. Remove rear wiper/washer switch from instrument panel trim plate. Turn ignition switch to RUN position. Connect test light between ground and rear wiper/washer switch connector Dark Green wire. Push rear wiper/washer switch to WASH position. If test light illuminates, go to next step. If test light does not illuminate, replace rear wiper/washer switch. See WIPER SWITCH under REMOVAL & INSTALLATION. 2. Disconnect rear washer pump connector. Rear washer pump is mounted near center of washer reservoir, in left front corner of engine compartment. Connect test light between ground and rear washer pump connector Dark Green wire. Push rear washer switch to WASH position. If test light illuminates, go to next step. If test light does not illuminate, repair open in Dark Green wire between rear washer switch and rear washer pump. 3. Turn ignition to OFF position. Connect a self-powered test light between ground and rear washer pump connector Black wire. If test light illuminates, replace rear washer pump. If test light does not illuminate, repair open in Black wire between ground and rear washer pump. Rear Wiper Does Not Operate, Rear Washer Operates

1. Remove rear wiper/washer switch from instrument panel trim plate. Disconnect rear wiper/washer switch connector. Turn ignition switch to RUN position. Connect test light between ground and rear wiper/washer switch connector Yellow wire terminal. If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire between rear wiper/washer switch and instrument panel fuse block. 2. Turn ignition switch to OFF position. Connect rear wiper/washer switch connector. Turn ignition switch to RUN position. Turn rear wiper to ON position. Connect test light between ground and Gray wire at rear window wiper cutout switch. If test light illuminates, go to next step. If test light does not illuminate, repair open in Gray wire between rear wiper/washer switch and rear window wiper cutout switch. 3. Connect a test light between ground and rear wiper motor connector White wire terminal. If test light illuminates, go to next step. If test light does not illuminate, check for open in White wire between rear wiper motor and rear window wiper cutout switch. Repair as necessary. If White wire is okay, replace rear window wiper cutout switch. Microsoft Saturday, August 29, 2009 11:58:50 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

4. Turn ignition switch to OFF position. Connect a self-powered test light between ground and rear wiper motor connector Black wire terminal. If test light illuminates, replace rear wiper motor. See WIPER MOTOR under REMOVAL & INSTALLATION. If test light does not illuminate, repair open in Black wire between rear wiper motor and ground.

REMOVAL & INSTALLATION WARNING: Vehicles are equipped with Supplemental Restraint System (SRS). Air bag system MUST be disabled before servicing ANY steering column component. Disabling system will prevent accidental air bag deployment, resulting in possible serious injury or property damage. See DISABLING & ACTIVATING SIR SYSTEM in AIR BAG RESTRAINT SYSTEM article. CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. WIPER MOTOR CAUTION: Before replacing wiper motor and/or wiper motor circuit board, refer to SPECIAL POLICY ADJUSTMENT - WINDSHIELD WIPER MOTOR FAILURES Service Campaign Bulletin 02054A dated May 9, 2003. Removal (Front)

Disconnect negative battery cable. Remove wiper arms. Remove cowl vent grille and screen. Disconnect wiper motor electrical connector. Using Wiper Transmission Separator (J-39232), remove transmission from wiper motor drive link. See Fig. 2 . Remove wiper motor mounting screws. Remove wiper motor. Installation

Install wiper motor. Tighten wiper motor retaining screws to 62 INCH lbs. (7 N.m). Lubricate drive link socket with lithium grease. Install transmission to motor drive link using Wiper Transmission Installer (J-39529). Ensure transmission is assembled to drive link past second detent so that seal is compressed to a maximum height of 1" (25 mm). See Fig. 2 . To complete installation, reverse removal procedure. Tighten wiper arm retaining nuts to 17 ft. lbs. (23 N.m).

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

Fig. 2: Removing & Installing Front Wiper Motor Courtesy of GENERAL MOTORS CORP. Removal & Installation (Rear)

1. Disconnect negative battery cable. Disconnect washer hose elbow. Remove wiper arm cap and nut. Remove wiper arm. Remove nut and spacer from motor shaft. See Fig. 3 . Remove endgate interior panel. Disconnect wiper motor electrical connector. 2. Remove wiper motor mounting screws. Remove wiper motor. To install, reverse removal procedure. Tighten wiper motor mounting screws to 57 INCH lbs. (6.5 N.m). Tighten motor shaft nut to 53 INCH lbs. (6 N.m). Tighten wiper arm retaining nut to 17 ft. lbs. (23 N.m).

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

Fig. 3: Removing & Installing Rear Wiper Arm Courtesy of GENERAL MOTORS CORP. WIPER MOTOR CIRCUIT BOARD (FRONT) CAUTION: Before replacing wiper motor and/or wiper motor circuit board, refer to SPECIAL POLICY ADJUSTMENT - WINDSHIELD WIPER MOTOR FAILURES Service Campaign Bulletin 02054A dated May 9, 2003. Removal & Installation

Disconnect negative battery cable. Remove wiper motor cover screws. Remove wiper motor cover. Pull circuit board from wiper motor. To install, reverse removal procedure. Tighten wiper motor cover screws to 23 INCH lbs. (2.6 N.m). WIPER SWITCH Removal & Installation (Front)

1. Turn steering wheel to straight-ahead position. Disconnect negative battery cable. Remove inflator module. Remove horn contact wire from steering column. Microsoft Saturday, August 29, 2009 11:58:50 AM

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

2. Remove steering wheel nut. Using a puller, remove steering wheel. DO NOT install puller bolts too far as damage to coil assembly can result. 3. Remove lower column cover screws. Pivot lower column cover down, slide back to release. Remove upper column cover. Remove multifunction switch assembly screws. Disconnect switch connector. 4. Remove switch assembly and wiring harness from column. To install, reverse removal procedure. Tighten steering wheel nut to 30 ft. lbs. (41 N.m). Removal & Installation (Rear)

Disconnect negative battery cable. Remove wiper/washer switch from instrument panel trim plate. Disconnect wiper/washer switch harness connector. To install, reverse removal procedure.

WIRING DIAGRAMS

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

Fig. 4: Front Wiper/Washer System Wiring Diagram

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

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1997 Chevrolet S10 Pickup 1997 ACCESSORIES & EQUIPMENT Wiper/Washer Systems - Blazer, Bravada, Jimmy, Sonoma & S10 Pickup

Fig. 5: Rear Wiper/Washer System Wiring Diagram (Blazer, Bravada & Jimmy)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

1997 System Wiring Diagrams Chevrolet - S10

AIR CONDITIONING 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 1: 2.2L (VIN 4), A/C Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 2: Heater Circuit 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 3: 4.3L (VIN W), A/C Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 4: 4.3L (VIN X), A/C Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 5: Heater Circuit

ANTI-LOCK BRAKES 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 6: 2.2L (VIN 4), Anti-lock Brake Circuits 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 7: 4.3L (VIN W), Anti-lock Brake Circuits

COMPUTER DATA LINES 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 8: 2.2L (VIN 4), Computer Data Lines 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 9: 4.3L (VIN W), Computer Data Lines

CRUISE CONTROL 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 10: 2.2L (VIN 4), Cruise Control Circuit 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 11: 4.3L (VIN W), Cruise Control Circuit

ENGINE PERFORMANCE 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 12: 2.2L (VIN 4), Engine Performance Circuits (1 of 3)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 13: 2.2L (VIN 4), Engine Performance Circuits (2 of 3)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 14: 2.2L (VIN 4), Engine Performance Circuits (3 of 3) 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 15: 4.3L (VIN W), Engine Performance Circuits (1 of 4)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 16: 4.3L (VIN W), Engine Performance Circuits (2 of 4)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 17: 4.3L (VIN W), Engine Performance Circuits (3 of 4)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 18: 4.3L (VIN W), Engine Performance Circuits (4 of 4)

EXTERIOR LIGHTS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 19: Back-up Lamps Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 20: Exterior Lamps Circuit

GROUND DISTRIBUTION 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 21: 2.2L (VIN 4), Ground Distribution Circuit (1 of 2)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 22: 2.2L (VIN 4), Ground Distribution Circuit (2 of 2) 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 23: 4.3L (VIN W), Ground Distribution Circuit (1 of 2)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 24: 4.3L (VIN W), Ground Distribution Circuit (2 of 2)

HEADLIGHTS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 25: Headlight Circuit, W/ Composite Headlamps

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 26: Headlight Circuit, W/ Sealed Beam Headlamps

HORN

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 27: Horn Circuit

INSTRUMENT CLUSTER

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 28: Instrument Cluster Circuit (1 of 2)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 29: Instrument Cluster Circuit (2 of 2)

INTERIOR LIGHTS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 30: Courtesy Lamps Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 31: Instrument Illumination Circuit

POWER DISTRIBUTION

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 32: Power Distribution Circuit (1 of 4)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 33: Power Distribution Circuit (2 of 4)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 34: Power Distribution Circuit (3 of 4)

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 35: Power Distribution Circuit (4 of 4)

POWER DOOR LOCKS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 36: Door Lock Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 37: Keyless Entry Circuit

POWER MIRRORS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 38: Power Mirror Circuit

POWER WINDOWS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 39: Power Window Circuit, 2 Door

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 40: Power Window Circuit, 4 Door

RADIO

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 41: Radio Circuits

SHIFT INTERLOCKS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 42: Shift Interlock Circuit

STARTING/CHARGING

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 43: Charging Circuit

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 44: Starting Circuit

SUPPLEMENTAL RESTRAINTS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 45: Supplemental Restraint Circuit

TRANSMISSION 2.2L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 46: 2.2L (VIN 4), Transmission Circuit, 4L60-E

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 47: Electronic Transfer Case Circuit 4.3L

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 48: 4.3L (VIN W), Transmission Circuit, 4L60-E

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 49: 4.3L (VIN X), Transmission Circuit, 4L60-E

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 50: Electronic Transfer Case Circuit

WARNING SYSTEMS

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 51: Warning System Circuits

WIPER/WASHER

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

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1997 Chevrolet S10 Pickup 1997 System Wiring Diagrams Chevrolet - S10

Fig. 52: Front Wiper/Washer Circuit

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