7 9 3 C O F F - H I G H WAY T R U C K
Š 1997 Caterpillar Inc.
793C MAINTENANCE ice 793C Serv Procedure
WALK AROUND INSPECTION
GAUGE CLUSTER MODULE
SERVICE LAMP
SERVICE KEYSWITCH
VIMS RS-232 PORT
SPEEDOMETER/ TACHOMETER MODULE
12
MAIN MODULE
KEYPAD MODULE
3F
VIMS SERVICE TOOL AND SOFTWARE
ELECTRONIC TECHNICIAN/ECAP DISPLAY DATA LINK
VIMS
MPH km/h
MESSAGE CENTER MODULE
VIMS INTERFACE MODULE
VIMS INTERFACE MODULE
KEYPAD DATA LINK CAT DATA LINK
ADEM II CONTROL ACTION ALARM
ACTION LAMP CAT DATA LINK SENSORS
SENSORS SENSORS
VITAL INFORMATION MANAGEMENT SYSTEM (VIMS)
AUTO RETARDER CONTROL
TRANSMISSION CONTROL
ADEM II CONTROL MODULE ELECTRONIC UNIT INJECTORS
3516B ELECTRONIC CONTROL SYSTEM COMPONENT DIAGRAM GROUND BOLT 15 AMP BREAKER
THROTTLE
ENGINE COOLANT TEMPERATURE REAR AFTERCOOLER TEMPERATURE
ENGINE OIL PRESSURE (FILTERED)
DISCONNECT SWITCH
MAIN KEY START POWER RELAY SWITCH
24 V
TIMING PROBE CONNECTOR OIL LEVEL SWITCH (ADD) SPEED/TIMING SENSOR ENGINE OIL PRESSURE (UNFILTERED)
OIL LEVEL SWITCH (LOW)
ETHER SOLENOID ATMOSPHERIC PRESSURE
TURBO OUTLET PRESSURE (BOOST)
THROTTLE OVERRIDE SWITCH
MANUAL ETHER SWITCH
GROUND LEVEL SHUTDOWN SWITCH
RIGHT TURBO INLET PRESSURE FUEL FILTER SWITCH CAT DATA LINK
LEFT TURBO INLET PRESSURE CRANKCASE PRESSURE
RIGHT TURBO EXHAUST
A/C PRESSURE SWITCH
LEFT TURBO EXHAUST FAN CLUTCH SOLENOID FAN
FAN SPEED SENSOR
EXHAUST WASTEGATE SOLENOID
SERVICE TOOL EPTC II ARC VIMS
ENGINE OIL RENEWAL SOLENOID
SHUTTER SOLENOID PRE-LUBRICATION RELAY COOLANT FLOW SWITCH
3516B IMPROVEMENTS INPUT SWITCHES AND SENSORS • COOLANT FLOW • REAR AFTERCOOLER TEMPERATURE • ENGINE OIL LEVEL • TURBOCHARGER TEMPERATURE • ENGINE OIL FILTER PRESSURE/RESTRICTION • ENGINE FAN SPEED • FUEL FILTER RESTRICTION • AIR CONDITIONER COMPRESSOR PRESSURE • CRANKCASE PRESSURE
3516B IMPROVEMENTS PREVIOUS LOGGED EVENTS • AIR FILTER RESTRICTION • LOW OIL PRESSURE • HIGH COOLANT TEMPERATURE • ENGINE OVERSPEED
3516B IMPROVEMENTS ADDITIONAL LOGGED EVENTS
• OIL FILTER RESTRICTION
• HIGH CRANKCASE PRESSURE
• FUEL FILTER RESTRICTION
• LOW COOLANT FLOW
• HIGH EXHAUST TEMPERATURE
• USER DEFINED SHUTDOWN
• HIGH AFTERCOOLER TEMPERATURE
• LOW BOOST PRESSURE
• ENGINE OIL LEVEL LOW
• HIGH BOOST PRESSURE
3516B IMPROVEMENTS SYSTEMS CONTROLLED BY ECM
• ETHER INJECTION • RADIATOR SHUTTER CONTROL • COLD CYLINDER CUTOUT • ENGINE START FUNCTION • ENGINE OIL PRE-LUBRICATION • VARIABLE SPEED FAN CONTROL • ENGINE OIL RENEWAL SYSTEM • EXHAUST BYPASS AT HIGH BOOST
JACKET WATER COOLANT FLOW
THERMOSTAT HOUSING
SHUNT TANK
ENGINE BLOCK
RADIATOR
ENGINE OIL COOLER
TORQUE CONVERTER/ TRANSMISSION OIL COOLER REAR BRAKE OIL COOLERS
JACKET WATER PUMP
AFTERCOOLER COOLANT FLOW SHUNT TANK AFTERCOOLER
FRONT BRAKE OIL COOLER
RADIATOR
AFTERCOOLER WATER PUMP
ENGINE OIL SYSTEM ENGINE BLOCK ENGINE OIL RENEWAL SYSTEM SOLENOID
TO FUEL SYSTEM
SCAVENGE PUMP
BYPASS VALVE ENGINE OIL FILTERS
ENGINE OIL COOLER ENGINE OIL PUMP
FUEL SYSTEM FUEL PRESSURE REGULATOR ENGINE OIL RENEWAL SYSTEM SOLENOID
CYLINDER HEAD
ENGINE BLOCK
SECONDARY FUEL FILTERS
FUEL TANK
PRIMARY FUEL FILTER
FUEL HEATER
FUEL TRANSFER PUMP
ADEM II CONTROL
EXHAUST SYSTEM WASTEGATE SOLENOID VALVE
EXHAUST BYPASS VALVE MUFFLER
FROM BRAKE AIR SYSTEM
PRESSURE REDUCING VALVE
HIGH PRESSURE TURBOCHARGER
AFTERCOOLER
FROM AIR FILTER LOW PRESSURE TURBOCHARGER
POWER TRAIN 793C
LOCKUP PISTON
TURBINE
IMPELLER
TORQUE CONVERTER STATOR
CONVERTER DRIVE
TORQUE CONVERTER INLET OIL
FREEWHEEL ASSEMBLY
TORQUE CONVERTER LOCKUP OIL PASSAGE
LOCKUP PISTON
TURBINE
IMPELLER
TORQUE CONVERTER DIRECT DRIVE STATOR TORQUE CONVERTER INLET OIL
STATOR
FREEWHEEL ASSEMBLY
TORQUE CONVERTER LOCKUP OIL PASSAGE
POWER SHIFT PLANETARY TRANSMISSION
1
2
3 4 5
6
REAR AXLE OIL COOLING AND FILTER SYSTEM OIL COOLER
OIL FILTER
FLOW CONTROL VALVE TEMPERATURE/ PRESSURE CONTROL VALVE
DIFFERENTIAL OIL PUMP
REAR AXLE
SUCTION SCREEN
FIRST REDUCTION RING GEAR
SECOND REDUCTION RING GEAR
SECOND REDUCTION CARRIER SECOND REDUCTION PLANETARY GEAR
FINAL DRIVE SECOND REDUCTION SUN GEAR
FIRST REDUCTION SUN GEAR
FIRST REDUCTION CARRIER
FIRST REDUCTION PLANETARY GEAR
TORQUE CONVERTER LOCKUP CLUTCH CONTROL DIRECT DRIVE LOCKUP CLUTCH PILOT OIL PRESSURE LOCKUP MODULATION VALVE
SELECTOR PISTON
LOCKUP SOLENOID
TO LOCKUP CLUTCH
TO TRANSMISSION LUBE PUMP
LOCKUP REDUCING VALVE
ON
FROM TRANSMISSION CHARGE PUMP
TO STATION "D"
SHUTTLE VALVE RELAY VALVE
FROM TRANSMISSION CHARGE PUMP
TRANSMISSION ICM HYDRAULIC SYSTEM LOCKUP SOLENOID
UPSHIFT PRESSURE
DOWNSHIFT UPSHIFT SOLENOID SOLENOID
DOWNSHIFT PRESSURE
ROTARY ACTUATOR
A
ON 3
E N1
TO TORQUE CONVERTER RELAY VALVE
NEUTRALIZER VALVE PRIORITY REDUCTION VALVE
PILOT OIL PRESSURE
CHARGING PUMP
TRANSMISSION CHARGING FILTER
LUBE PUMP
B
ROTARY SELECTOR SPOOL
PUMP PRESSURE
F C
SCAVENGE PUMP
OIL COOLER
G D
COOLER BYPASS VALVE
H
LUBE PRESSURE
RELIEF VALVE
TORQUE CONVERTER HOUSING
TRANSMISSION CASE
LUBRICATION RELIEF VALVE
SELECTOR VALVE GROUP
LOCKUP DUAL STAGE RELIEF VALVE
PRESSURE CONTROL GROUP
TC LOCKUP VALVE
TORQUE CONVERTER AND TRANSMISSION HYDRAULIC SYSTEM TORQUE CONVERTER/ TRANSMISSION COOLER
TC CHARGING FILTER TRANSMISSION CHARGING FILTER
TC OUTLET RELIEF VALVE
TC/TRANS PUMPS
TC LOCKUP VALVE
TC INLET RELIEF VALVE TC OUTLET SCREEN
TRANSMISSION MAGNETIC SCREENS
RETURN SCREEN
RETURN SCREEN SUCTION SCREEN
712 - WH
A12 A13
713 - OR 714 - YL 715 - GN
A14 A15
716 - BU
A16
706 - BR
A6 D1
D2
KEY START SWITCH
307 - OR
B5
ENGINE SPEED
450 - YL
A29
CONVERTER SPEED
452- PU
A30
D996 - PU
B6
D997 - YL
B7
SERVICE "SET" AND "CLEAR" SWITCHES
3
A - 37 PIN CONNECTOR B - 10 PIN SURE-SEAL CONNECTOR
710 - GN
709 - OR
A9 A10
TOS
4
5
6
7
8
219 - BK
A36
280 - BK
A37
227 - BK
MACHINE ID CODE
A31
G714 - PU
RAISE SOLENOID
A32
G711 - BR
FLOAT SOLENOID
A33
G712- GN
LOWER SOLENOID
B1
306 - GN
STARTER SOLENOID
B2
321- BR
B9 B10
893 - GN 892 - BR
A21 A22 A23 A24 A25 A26
TRANSMISSION GEAR SWITCH TRANSMISSION
9
A3 A4 A5 703 - BU
A27
726 - BU
E750 - PU
725 - GN
BODY UP
13
724 - YL
A28
12
723 - OR
707 - PU
2
722 - WH
HOIST LEVER
A19
D3
11
721 - BR
720 - PU
A20
217 - BK 218- BK
EPTC II 10
SECONDARY BRAKE
A17 A18
705 - PK
SERVICE/ RETARDER BRAKE
A11
704 - GY
SHIFT LEVER SWITCH
711 - BR
UP, DOWN, LOCKUP SOLENOIDS
BACK-UP ALARM RELAY DATA LINK
EPTC II DIAGNOSTIC WINDOW D1
D2
D3
10 11
2
12
13
3
4
5
6
7
8
9
STEERING 793C
STEERING PUMP DURING CHARGING (CUT-IN) CUT-OUT VALVE
FROM ACCUMULATORS
CUT-IN VALVE ACCUMULATOR CHARGING VALVE
TO ACCUMULATORS PUMP OUTPUT
HIGH PRESSURE CUTOFF VALVE ACTUATOR PISTON LOAD SENSING PRESSURE
FLOW COMPENSATOR LOAD SENSING CONTROLLER SWASHPLATE PISTON
STEERING PUMP LOW PRESSURE STANDBY (CUT-OUT) CUT-OUT VALVE
FROM ACCUMULATORS
CUT-IN VALVE ACCUMULATOR CHARGING VALVE
HIGH PRESSURE CUTOFF VALVE
TO ACCUMULATORS PUMP OUTPUT ACTUATOR PISTON
LOAD SENSING PRESSURE
FLOW COMPENSATOR LOAD SENSING CONTROLLER SWASHPLATE PISTON
ACCUMULATOR CHARGE VALVE DURING CHARGING (CUT-IN) FROM PUMP
TO PUMP CONTROL SIGNAL PORT
TO TANK FEEDBACK ORIFICE
CUT-OUT VALVE
FROM ACCUMULATOR
CUT-IN VALVE
ACCUMULATOR CHARGE VALVE LOW PRESSURE STANDBY (CUT-OUT) FROM PUMP TO TANK
TO PUMP CONTROL SIGNAL PORT FEEDBACK ORIFICE
CUT-OUT VALVE
FROM ACCUMULATOR
CUT-IN VALVE
ACCUMULATOR CHARGE VALVE LOW PRESSURE STANDBY (CUT-OUT) FROM PUMP TO TANK
TO PUMP CONTROL SIGNAL PORT FEEDBACK ORIFICE
CUT-OUT VALVE
FROM ACCUMULATOR
CUT-IN VALVE
ACCUMULATOR CHARGE VALVE BEGINNING STAGE OF CUT-IN FROM PUMP
TO PUMP CONTROL SIGNAL PORT
TO TANK FEEDBACK ORIFICE
CUT-OUT VALVE
FROM ACCUMULATOR
CUT-IN VALVE
SOLENOID AND RELIEF VALVE MANIFOLD SUPPLY FROM PUMP AND ACCUMULATORS
TO TANK
BLEED DOWN SOLENOID BACK-UP RELIEF VALVE
STEERING DIRECTIONAL VALVE NO TURN RELIEF/MAKEUP VALVE
LEFT TURN CYLINDER
TO TANK
RIGHT TURN CYLINDER
BACK PRESSURE VALVE RELIEF/MAKEUP VALVE
RIGHT TURN PILOT OIL
LEFT TURN PILOT OIL
COMBINER/CHECK SPOOL AMPLIFIER SPOOL
PRIORITY SPOOL LOAD SENSING PORT FROM ACCUMULATOR
HAND METERING UNIT SUPPLY AND THERMAL BLEED
STEERING DIRECTIONAL VALVE RIGHT TURN LEFT TURN CYLINDER
TO TANK
RIGHT TURN CYLINDER
BACK PRESSURE VALVE
RELIEF/MAKEUP VALVE RELIEF/MAKEUP VALVE
RIGHT TURN PILOT OIL
LEFT TURN PILOT OIL
COMBINER/CHECK SPOOL
AMPLIFIER SPOOL
PRIORITY SPOOL LOAD SENSING PORT FROM ACCUMULATOR
HAND METERING UNIT SUPPLY AND THERMAL BLEED
HAND METERING UNIT NEUTRAL POSITION
T
L
R
P STATOR
METERING SECTION
CONTROL SECTION CENTERING SPRINGS
ROTOR SPOOL
PIN
DRIVE
SLEEVE
THERMAL BLEED PASSAGES
HAND METERING UNIT RIGHT TURN
T
L
R
P STATOR
METERING SECTION
CONTROL SECTION CENTERING SPRINGS
ROTOR SPOOL
PIN
DRIVE
SLEEVE
HOIST SYSTEM 793C
PARKING BRAKE RELEASE PRESSURE RAISE SOLENOID
793C HOIST CONTROL VALVE HOLD TO TANK
FRONT BRAKE OIL COOLER RELIEF VALVE TO HOIST CYLINDER HEAD END
LOAD CHECK VALVE
TO HOIST CYLINDER ROD END LOW PRESSURE RELIEF VALVE
COUNTERBALANCE VALVE
HIGH PRESSURE RELIEF VALVE DUAL STAGE RELIEF VALVE SIGNAL STEM
ROD END VENT SLOT TO FRONT BRAKE OIL COOLERS PUMP SUPPLY PORT LOWER SOLENOID
PARKING BRAKE RELEASE PRESSURE FLOAT SOLENOID
PARKING BRAKE RELEASE PRESSURE RAISE SOLENOID
ON
793C HOIST CONTROL VALVE RAISE TO TANK
FRONT BRAKE OIL COOLER RELIEF VALVE TO HOIST CYLINDER HEAD END
LOAD CHECK VALVE
FROM HOIST CYLINDER ROD END LOW PRESSURE RELIEF VALVE
COUNTERBALANCE VALVE
HIGH PRESSURE RELIEF VALVE DUAL STAGE RELIEF VALVE SIGNAL STEM
ROD END VENT SLOT TO FRONT BRAKE OIL COOLERS PUMP SUPPLY PORT LOWER SOLENOID
PARKING BRAKE RELEASE PRESSURE FLOAT SOLENOID
HOIST COUNTERBALANCE VALVE
HEAD END SIGNAL PRESSURE
TO FRONT BRAKE OIL COOLER
FROM HOIST CYLINDER ROD END
RAISE POSITION
FROM PUMP
TO HOIST CYLINDER ROD END
LOWER AND FLOAT POSITIONS
PARKING BRAKE RELEASE PRESSURE RAISE SOLENOID
793C HOIST CONTROL VALVE
FRONT BRAKE OIL COOLER RELIEF VALVE
LOWER (POWER DOWN) TO TANK
FROM HOIST CYLINDER HEAD END
LOAD CHECK VALVE
TO HOIST CYLINDER ROD END LOW PRESSURE RELIEF VALVE
COUNTERBALANCE VALVE
HIGH PRESSURE RELIEF VALVE DUAL STAGE RELIEF VALVE SIGNAL STEM
ROD END VENT SLOT TO FRONT BRAKE OIL COOLERS PUMP SUPPLY PORT LOWER SOLENOID
ON
PARKING BRAKE RELEASE PRESSURE FLOAT SOLENOID
ON
PARKING BRAKE RELEASE PRESSURE RAISE SOLENOID
793C HOIST CONTROL VALVE FRONT BRAKE OIL COOLER RELIEF VALVE
FLOAT TO TANK
FROM HOIST CYLINDER HEAD END
LOAD CHECK VALVE
TO HOIST CYLINDER ROD END LOW PRESSURE RELIEF VALVE
COUNTERBALANCE VALVE
HIGH PRESSURE RELIEF VALVE DUAL STAGE RELIEF VALVE SIGNAL STEM
ROD END VENT SLOT TO FRONT BRAKE OIL COOLERS PUMP SUPPLY PORT LOWER SOLENOID
PARKING BRAKE RELEASE PRESSURE FLOAT SOLENOID
ON
HOIST SYSTEM
HOIST SCREENS
HOIST PUMP
FROM PARKING BRAKE RELEASE VALVE
HOLD POSITION SUCTION SCREENS
FRONT BRAKES
FRONT BRAKE OIL COOLER
TO HOIST CYLINDER ROD END DIVERTER VALVE
TO HOIST CYLINDER HEAD END
FRONT BRAKE OIL COOLER FILTERS FROM PARKING BRAKE RELEASE VALVE
AIR SYSTEM AND BRAKES 793C
AIR CHARGING SYSTEM AIR COMPRESSOR AND GOVERNOR
AIR DRYER SERVICE/RETARDER BRAKE RESERVOIR REMOTE AIR SUPPLY CONNECTOR
PRESSURE PROTECTION VALVE
PARKING/SECONDARY BRAKE RESERVOIR
LOW AIR SWITCH
RELIEF VALVE
PARKING BRAKE RELEASE PUMP
TOWING SYSTEM PARKING BRAKE RELEASE VALVE
TO HOIST PILOT SYSTEM
CHECK VALVE TOWING PUMP RELIEF VALVE
TOWING PUMP
PARKING/SECONDARY BRAKES SECONDARY BRAKES RELEASED PARKING BRAKES ENGAGED
PARKING BRAKE SWITCH
EPTC II SWITCH
PARKING BRAKE RELEASE PUMP
PARKING BRAKE RELEASE VALVE
SECONDARY BRAKE VALVE PARKING/SECONDARY BRAKE RESERVOIR
TO HOIST PILOT SYSTEM
BRAKE CYLINDER BRAKES ENGAGED AIR PISTON
INDICATOR ROD
FROM MAKEUP TANK OIL PISTON
AIR INLET
TO SLACK ADJUSTER VALVE SPRING
ROD
BRAKE SLACK ADJUSTER
OIL FLOW TO BRAKE CYLINDER
SMALL PISTON LARGE PISTON
OIL FLOW FROM BRAKE CYLINDER
FROM WHEEL BRAKES
FROM WHEEL BRAKES
TO WHEEL BRAKES
TO WHEEL BRAKES
BRAKES RELEASED
BRAKES ENGAGED
SERVICE/RETARDER BRAKE AIR SYSTEM SERVICE BRAKE ENGAGED
FRONT BRAKE OIL COOLER DIVERTER VALVE
ARC RELAY VALVE
SERVICE RELAY VALVE
SERVICE BRAKE VALVE
RETARDER VALVE
ARC VALVE
BRAKE ENGAGED SWITCH
BRAKE CYLINDERS
TO FRONT BRAKES
REAR BRAKE COOLING CIRCUIT
TRACTION CONTROL SYSTEM (TCS) VALVE
PARKING BRAKE RELEASE VALVE
PARKING BRAKE RELEASE FILTER
TO REAR BRAKES
HOIST VALVE
REAR BRAKE OIL COOLERS
PARKING BRAKE RELEASE PUMP
BRAKE COOLING PUMPS
REAR BRAKES
PUMP DRIVE SUCTION SCREENS
OIL COOLER RELIEF VALVES
ENGINE SPEED SENSOR ENGINE SPEED
HARNESS CODE INPUTS
SERVICE INPUTS B6
SET
B7
CLEAR
HARNESS CODE PLUG
A17-19 36,37
A10
AUTOMATIC RETARDER CONTROL (ARC)
DATA LINK
A5 A21
ARC ON/OFF SWITCH
BRAKE ENGAGED LAMP
B9 B10
BRAKE ENGAGED LAMP OUTPUT BRAKE ENGAGED PRESSURE INPUT AUTO RETARDER PRESSURE INPUT
A16
ON INPUT A11
OFF INPUT A26
A3
Diagnostic Display
A4
CONTROL OUTPUT SUPPLY OUTPUT
SUPPLY SOLENOID VENT
AIR FROM SERVICE BRAKE RESERVOIR
VENT CONTROL SOLENOID
BRAKE PEDAL AND VALVE
RETARDER LEVER AND VALVE
AUTOMATIC RETARDER VALVE AUTO RETARDER PRESSURE SWITCH BRAKE ENGAGED SWITCH
TO SERVICE BRAKE RELAY VALVE A - 37 PIN CONNECTOR B - 10 PIN SURE-SEAL CONNECTOR
TO FRONT BRAKE OIL COOLER DIVERTER VALVE
TO ARC RELAY VALVE
ARC DIAGNOSTIC WINDOW
1
2
3
4
5
6
7
10
11
8
12 13 D1
D2
D3
BATTERY + BATTERY -
132- PK 255 - BK
A1 A2
TRANSMISSION SPEED
768 - OR
A10
LEFT WHEEL SPEED
769 - BU
A29
RIGHT WHEEL SPEED
770 - GN
A3
774 - YL
SELECTOR SOLENOID - LEFT
A4
775 - BR
SELECTOR SOLENOID - RIGHT
A5
773 - GY
PROPORTIONAL SOLENOID
A9
767 - WH
+V TO BRAKE SWITCH AND WHEEL SENSORS
B9
893 - GN 892 - BR
DATA LINK (NOT USED)
TCS
A30 D1
D2
D3
2
214 - BK
A17
3
13
213- BK 212 - BK
A18 A19
4
12
216 - BK
A36
215 - BK
A37
SERVICE/RETARDER BRAKE SWITCH
772 - BR
B1
TEST SWITCH
700 - PK
MACHINE HARNESS CODES
5
6
7
8
9
10
11
B10
A - 37 PIN CE CONNECTOR B - 10 PIN SURE-SEAL CONNECTOR
B2
TCS DIAGNOSTIC WINDOW D1
D2
D3
2 3
13
4
12
5
6
7
8
9
10
11
TRACTION CONTROL SYSTEM (TCS) ENGINE RUNNING/BRAKES RELEASED
BRAKE SWITCH
TEST SWITCH
SPEED DISTRIBUTOR
LEFT DRIVE AXLE
INPUT SIGNALS
BALL CHECK
TRANSMISSION SPEED SENSOR
ORIFICE
OUTPUT SIGNALS
SCREEN SELECTOR SOLENOID PARKING BRAKE VALVE RIGHT DRIVE AXLE PROPORTIONAL SOLENOID
TRACTION CONTROL SYSTEM (TCS) ENGINE RUNNING/LEFT BRAKE ENGAGED
BRAKE SWITCH
TEST SWITCH
SPEED DISTRIBUTOR
LEFT DRIVE AXLE
INPUT SIGNALS
BALL CHECK
TRANSMISSION SPEED SENSOR
ORIFICE
OUTPUT SIGNALS
SCREEN SELECTOR SOLENOID PARKING BRAKE VALVE RIGHT DRIVE AXLE PROPORTIONAL SOLENOID