■ Feature: Dissecting PCMs ■ Tech Talk: Biodiesel or Bio Mess? ■ Gonzo’s Toolbox: Handling 'Helpers'
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CONTENTS 22
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2.13 Volume XVIII, No. 2
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Diagnostic Dilemmas
Tech Feature
Tech Talk
Approaching No-Code Diagnostics
Dissecting PCMs
Biomass or Bio Mess?
In this installment of Diagnostic Dilemmas, technical contributor Gary Goms discusses in detail how he approached the no-code, intermittent driveability complaints of three different vehicles — a Jeep Cherokee, a Toyota Camry and a Ford Mustang.
Contributor Omar Trinidad provides an in-depth analysis of how sensor circuits are designed, how the powertrain control module (PCM) interprets the signal voltage and the criteria that trigger the module to set diagnostic trouble codes (DTC).
Diesel specialist Bob McDonald takes a look into the misconceptions surrounding diesel bio-fuel. His results may surprise you, no matter which side of the fence you sit on regarding the use of bio-fuels in your customer’s vehicle.
Editor Edward Sunkin, ext. 258 email: esunkin@babcox.com Managing Editor Jennifer Clements, ext. 265 email: jclements@babcox.com
Technical Editor Larry Carley Contributing Writers Gary Goms, Scott “Gonzo” Weaver, Bob Dowie and Randy Rundle
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Graphic Designer Dan Brennan, ext. 283 email: dbrennan@babcox.com
Ad Service Director Cindy Ott, ext. 209 email: cott@babcox.com
Publisher Jim Merle, ext. 280 email: jmerle@babcox.com
Circulation Manager Pat Robinson, ext. 276 email: probinson@babcox.com
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EDITORIAL ADVISORY BOARD Brent Crago, owner Top Tech Automotive Cleveland, Tennessee
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Marc Duebber, owner Duebber’s Auto Service Cincinnati, Ohio
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Paul Stock, owner Stock’s Underhood Specialists Belleville, Illinois Michael Warner, owner Suburban Wrench Pennington, New Jersey
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UNDERHOOD SERVICE (ISSN 1079-6177) (February 2013, Volume XVIII, Number 2): Published monthly by Babcox, 3550 Embassy Parkway, Akron, OH 44333 U.S.A. Phone (330) 670-1234, FAX (330) 670-0874. Periodical postage paid at Akron, OH 44333 and additional mailing offices. POSTMASTER: Please send address changes to UNDERHOOD SERVICE, 3550 Embassy Parkway Akron, OH 44333. UNDERHOOD SERVICE is a trademark of Babcox Media, Inc. registered with the U.S. Patent and Trademark Office. All rights reserved. A limited number of complimentary subscriptions are available to individuals who meet the qualification requirements. Call (330) 670-1234, Ext. 260, to speak to a subscription services representative or FAX us at (330) 670-5335. Paid Subscriptions are available for non-qualified subscribers at the following rates: U.S.: $69 for one year. Canada: $89 for one year. Canadian rates include GST. Ohio residents add current county sales tax. Other foreign rates/via air mail: $129 for one year. Payable in advance in U.S. funds. Mail payment to UNDERHOOD SERVICE, P.O. Box 75692, Cleveland, OH 44101-4755. VISA, MasterCard or American Express accepted.
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» Directions
BY Edward Sunkin | EDITOR
Selling the Fuel-Cell Concept ver the past few years, the automotive industry has focused on plug-in electric vehicles and various gasoline- and diesel-electric hybrid designs; but now, electric fuel-cell vehicles are returning to the spotlight. Recently, a collaborative partnership approach between Daimler, Ford and Renault-Nissan was announced in an effort to begin mass producing hydrogen-fueled fuel-cell electric vehicles (FCEVs) in the next four years.
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emission transportation options available to consumers. While each vehicle is expected to use the same electric core design and components, models will still be unique to each automaker. This allows manufacturers to offer different body styles, cabin designs and branding to buyers. But the concept of sharing fuelcell core platforms and components would also be helpful for
The benefit of these zeroemissions vehicles is their potential to reduce pollution and cut down on the world’s reliance on oil for transportation. However, the drawback over the years has been cost. The automakers believe that combining resources could help alleviate the largest challenge for such vehicles — a fueling infrastructure. Powered by electricity generated from hydrogen and oxygen, FCEVs emit only water while driving. FCEVs are considered complementary to today’s battery-electric vehicles and will help expand the range of zero-
repair shops in the future, as diagnostic tools used to service these vehicles could also be shared, instead of shops purchasing tooling for individual manufacturers. It also would be helpful for the Society of Automotive Engineers (SAE) to become involved with the alliance as well as other OEMs to create conformity in fuel-cell components and connectors. “Working together will significantly help speed this technology to market at a more affordable cost to our customers,” said Raj Nair, group vice president, Global Product Development, Ford
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Motor Company. “We will all benefit from this relationship as the resulting solution will be better than any one company working alone.” Daimler’s research division had reported in the past that it planned to commercialize fuelcell vehicles by 2015. However, it did not appear that this goal would have been met, and partnering in this alliance will help the automaker provide such cars just a few years later than expected. While FCEV technology has been in the development stage for a number of automakers including General Motors and Toyota since the late 1990s, the implementation of a consumer vehicle hasn’t taken off due to the high costs of development, design and patents. Hydrogen fueling stations have been introduced in the U.S., but are mainly concentrated around FCEV testing areas out West. Under the alliance agreement from Daimler, Ford and Nissan, each company will invest equally in the technology. The cars could be available as early as 2017. According to a release from the alliance, “The collaboration sends a clear signal to suppliers, policymakers and the industry to encourage further development of hydrogen refueling stations and other infrastructure necessary to allow the vehicles to be massmarketed.” ■
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Damage Control: Plug Removal Techniques on Ford Modular Engines
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ord’s Modular engine, used in various Ford, Lincoln and Mercury products during the mid- to late-2000s, has been known to give techs a hard time during a spark plug replacement. The problem lies with excessive carbon buildup on the plugs, especially on engines that have gone beyond an OEM-recommended replacement interval. This can cause a plug to break in the chamber during its removal, creating stress on the tech and additional labor time to remove the damaged component. Techs we talked to advised addressing the issue before it can become a problem — meaning replace the plugs prior to their recommended replacement interval. That, obviously, can be a hard sell to your Ford driving customers. Some techs who have come across the broken plug problem recommend performing an engine flush the day prior to changing out the spark plugs and letting the vehicle sit overnight as a way to loosen up the carbon deposits, allowing for less of a chance for a plug to break. This too, might not be an option, since there are many customers that expect a spark plug replacement job to be completed the same day.
VEHICLES WITH THE PLUG REMOVAL ISSUE: • Ford: 2005-’08 Mustang; 2004-’08 F-150; 2005-’08 Expedition and F-Super Duty; 2006-’08 Explorer and 2007-’08 Explorer Sport Trac • Lincoln: 2005-’08 Navigator and 2006-’08 Mark LT • Mercury: 2006-’08 Mountaineer
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» Aftermarket Update Ford recognized the plug the left-hand cam cover informaplug service. Removing the spark removal problem and issued a tion sticker. plugs from a warm/hot engine tech bulletin — TSB 08-7-6 — to increases the chance the threads To remove the spark plugs on address the problems associated could be damaged. these engines without damage, it with plug removal on various is necessary to adhere exactly to Spark Plug Removal Ford vehicles. This article superthis procedure before removal is Procedure sedes TSB 08-1-9. attempted. 1. Remove the coil-on-plug According to Ford, some F-150s, Caution: Do not remove plugs assemblies and thoroughly blow Mark LTs, F-Super Dutys, when the engine is warm or hot. out the spark plug wells and surExpeditions and Navigators with The engine must be at room temrounding valve cover area with the 5.4L 3V engine; Mustangs, perature when performing spark compressed air. Explorers, Mountaineers 2. Back out the spark and Explorer Sport Tracs plugs no more than 1/8 with the 4.6L 3V engine to 1/4 of a turn. Using and F-Super Dutys with Motorcraft Carburetor the 6.8L 3V engine may Tune-Up Cleaner, fill the experience difficulty with spark plug well just spark plug removal. This above where the jamb may cause damage to the nut hex sits (1/2 - 3/4 spark plug and leave part teaspoon). A minimum of the spark plug in the period of 15 minutes of cylinder head. soak time is required. Affected engine build The cleaner will wick dates are as follows: 5.4L Figure 1: New plugs should be installed using a down to the ground 3V and 6.8L 3V before Oct. film coating of Motorcraft high-temperature electrode shield and 9, 2007, 4.6L 3V before nickel anti-seize lubricant on the ground elecsoften the carbon Nov. 30, 2007. The engine trode shield. Do not coat the electrode strap. deposits in this time. Do build date can be read on not work the spark plug back and forth at this point. Caution: Excessive Motorcraft carburetor tune-up cleaner, or repeating the process several times with too much cleaner fluid, could introduce enough liquid volume to hydro-lock the engine. 3. Tighten, and then loosen the spark plug, working the plug back and forth. Some screeching and high effort may be noticed. The expected removal torque is about 33 lb.-ft. (45 Nm). Repeat the back and forth turning as needed until turning effort is reduced, and remove the spark plugs. Ford says do not use power tools for the plug removal — spark plugs must be only be removed with hand tools. Reader Service: Go to www.uhsRAPIDRESPONSE.com
10 February 2013 | UnderhoodService.com
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» Aftermarket Update Separated/Broken Spark Plug Removal If the spark plug separates after following the Spark Plug Removal Procedure, it will fail in one of three modes. Refer to the appropriate removal procedure as required. • Mode 1: The ground electrode shield is left behind as an empty shell. (See Figure 2.) • Mode 2: The entire porcelain insulator and ground electrode shield remains in the Figure 2 cylinder head. • Mode 3: The upper section of four turns into the ground elecporcelain broke off with remaintrode shield. Back the tap up freing porcelain left inside the quently to break chips and avoid ground shield. cut material from coiling-up in the spark plug well. A tap socket Mode 1 Procedure: adaptor is provided with service Use Rotunda special service tool tool 303-1203 update to connect 303-1203 to remove an empty the tap to a 3/8′′ socket drive. ground electrode shield from the Caution: Do not attempt to cylinder head. remove the ground electrode Note: This tool is only designed shield with the tap and wrench. to work with an empty ground The tap may break if this is electrode shield. If porcelain attempted. remains, proceed to Mode 2 or 3 4. Thread Rotunda special servremoval. ice tool 303-1203 into the ground 1. Modify vacuum cap to a 3/8′′ electrode shield. See Figure 3 on (10 mm) length for each ground page 14. electrode shield that needs to be a. Install the stepped end of the removed. tool pilot bushing into the spark 2. Use the installation rod proplug well ensuring it bottoms out. vided with service tool 303-1203 b. Screw the center shank into update to install the modified vac- the ground electrode shield. Do uum cap. Push the cap into the not over tighten the shank, to ground shield down to the elecprevent thread stripping. trode strap. This will plug and c. Install the nylon washer and protect the combustion chamber jack nut until finger tight. from contamination. d. Turn the jack nut until the 3. Thread-tap the ground elecground electrode is freed from the trode shield using a 9.0 x 1.0 mm cavity and withdraw the tool plug tap (tap profile is about 3-4 assembly. reduced diameter threads on the Mode 2 Procedure: tip end). 1. Add an additional 1/2 teaa. Coat the end of the tap with spoon Motorcraft Carburetor general-purpose grease. Tune-Up Cleaner fluid into spark b. Turn the tap about three to Go to www.uhsRAPIDRESPONSE.com
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» Aftermarket Update plug well and allow 15 minutes of soak time. 2. Using long-nose pliers, grasp and remove the porcelain with an up and down motion taking care not to fracture the porcelain. 3. Refer to Mode 1 Procedure to remove the remaining ground electrode shield from the cylinder head.
Mode 3 Procedure: Caution: Do not drive porcelain down into the ground shield with a punch as fragments may enter the combustion chamber. Note: Use Rotunda special service tool kit 303-1398 to remove porcelain broken inside the ground electrode shield. Caution: The engine and the bonding adhesive must be room temperature of 70° F (21° C) or higher for proper cure and bond strength. Verify the expiration date of the adhesive. Caution: Do not reuse pins from the tool kit. This ensures the correct surface characteristics for bonding. 1. Remove any remaining electrode material from broken porcelain with long-nose pliers. 2. Spray Motorcraft Metal Brake Parts Cleaner into the porcelain
hole for two to four seconds using the straw nozzle supplied with the brake cleaner can. 3. Using the tool kit, insert a pin into the collet. Screw the collet onto the threaded rod. Install the assembled collet, pin and threaded rod into the steel tool pilot. 4. Retract the collet and pin into the steel tool pilot, protecting the pin. Note: Pin tip damage or bent pins will prevent insertion into the Figure porcelain. 5. Insert the completed assembly into the spark plug well and fully engage the pin into the porcelain. See Figure 4. 6. Spray Motorcraft Metal Brake Parts Cleaner two to four seconds between the spark plug well and steel tool pilot. The steel tool pilot must be lifted up approximately 1/2” to allow brake cleaner to flood the porcelain and pin. 7. Scrub the porcelain inside diameter by moving the threaded rod up and down vigorously.
Figure 4
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Take care making sure the pin does not disengage the porcelain. 8. Repeat steps 6 and 7. 9. Remove the tool assembly. Again flood the porcelain with Motorcraft Metal Brake Parts Cleaner for two to four seconds, then blow out the entire spark plug well and porcelain with dry compressed air. Note: Clean and dry components are key to bonding the pin to the porcelain. 10. Repeat steps 1-9 to prepare remaining porcelain fragments as needed. 11. Disassemble the collet and pin from the threaded rod. Dry the tools thoroughly with dry compressed air. ■
For additional information and steps for using the bonding agent, e-mail us at esunkin@babcox.com for a copy of TSB 08-7-6.
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» Gonzo’s Toolbox By Scott “Gonzo” Weaver
Handling Temporary Helpers Dealing With Customers Who Find Their Way Into Your Bay
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here are times when I find I have more helpers in the shop than I have on the payroll. I didn’t ask for this extra help, but there they are, right in the middle of the shop. Who are they, and where did they come from? Ah, yes, it’s those customers who want to keep an extra eye on their ride. It’s pretty sneaky how they manage to get past the front desk, the waiting area, through the service door and then squeeze by the tire racks. For safety reasons, it’s best that customers stay in the waiting room. But some of these adventurous individuals are compelled to help me out, no matter what.
It’s pretty sneaky how customers manage to get past the front desk, the waiting area, through the service door and then squeeze by the tire racks. For safety reasons, it’s best that they stay in the waiting room. But some of these adventurous individuals are compelled to help me out, no matter what.
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There are too many hoses, cords and dangerous types of equipment to be spending the afternoon in a place with which you are not familiar. A lot of times, an unsuspecting
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“What do you think it is?”
“helper” won’t notice that floor jack, or those sharp tools at the edge of the workbench. The possibility of encountering danger just doesn’t matter to some of these new helpers. They’ll still want to wander into the bay and “help” me out. I can usually spot who’s going to be the next shop helper. All I have to do is pull
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their car into the shop. If there’s a fresh, icy drink in the cup holder, an open pack of cigarettes and lighter lying on the passenger seat, and a book or a laptop, there’s a good chance they’ll be popping their head around the corner. “Do you mind if I get my drink out of the car?” my new shop helper will ask. Well, I just can’t say no. Now, sometimes they’ll grab their drink and head right back to the waiting room. Other times, I’m not that lucky. It’s their perfect excuse to hang around the car. Soon, the new shop helper is leaning over the fender with their ice-cold drink, watching the process of me figuring out what’s up with
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» Gonzo’s Toolbox their ride. At times, it’s rather interesting; at other times, it’s simply annoying. I can never tell until the conversation starts. If the first question is, “What do you think it is?” I know it’s going to be one of those days. Like most new helpers, they’re unaware of the dangers of posing such an inappropriate and pointless question at this point in time. I’d rather not guess at this stuff. If I’m wrong, the next thing you know is that I’m trying to explain why whatever I thought it was is “not the problem.” Thinking just gets me into trouble. It’s always best to verify, diagnose and then repair the problem. “Let’s run some tests, and then we’ll know for sure,” I tell them. Some realize that they’re out of place and should probably stick to watching the ice in their drink melt. But, for others, it wouldn’t take much to have them reach over and pick up a wrench or two. They’ll lean on the A/C recovery machine while it’s running as if it’s an old-fashioned hitching post, or stick their head through the passenger window while I’m
A lot of times, an unsuspecting “helper” won’t notice that floor jack, or those sharp tools at the edge of the workbench. The possibility of encountering danger just doesn’t matter to some of these new helpers. They’ll still want to wander into the bay and “help” me out.
under a dash. I have to keep from laughing as I watch their jumpy reactions to the recovery machines’ unexpected clicks and groans, while they stand there trying to act casual. And, no matter how clumsy they may look with all of their uncoordinated antics, they’re still going to keep a firm grip on that drink. This little trip into the back of the shop isn’t so much to check up on their car, but a way to observe the process of diagnosing the problem. It’s as if it were some sort of exhibition. They’ll look high and low throughout the shop, take a few sips from their drink and then pay attention to what I’m doing
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to see how I determine what’s wrong. The new help will concentrate on what I’m doing, so they can go home and tell their friends about some sort of crazy-looking machine, or detail a technique they watched me perform on their car. I guess in another decade or two, I’ll be the old guy hanging around the next generation’s repair tech. There’s no doubt I’ll be that unwanted temporary helper telling stories about how I used to fix cars, too. Yep, that day is coming. I don’t know when, but it’s coming. Guess I better prepare. Now where did I put that ice-cold drink? ■
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» DiagnosticDilemmas
By Gary Goms, technical contributor
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hanks to the increasing reliability of modern vehicles, most diagnostic technicians are seeing fewer pattern-failure driveability complaints. For that reason, many techs won’t gamble expensive shop time chasing an illusive no-code driveability complaint. Instead, many will write “no problem found” on the repair order and move on to the next vehicle. Unfortunately, at some point in time, the intermittent, no-code driveability will either be solved or the vehicle will be traded or sold for scrap. This month’s Diagnostic Dilemma will discuss in detail how I approached the no-code, intermittent driveability complaint on three different vehicles.
The Stalling Camry Last summer, I encountered a customer with a no-code, intermittent stalling complaint on a 1997 Toyota Camry. According to the customer, the stall most often occurred during engine warm-up or would manifest itself as an occasional hesitation at road speeds. Although wellmaintained, this vehicle had rolled up in excess of 200,000 miles. At this point, the crankshaft position (CKP) sensor had been replaced with no result. While I don’t believe in searching for silver bullets, I do believe in doing preliminary research by consulting a professional database for technical
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1 997 Toyota Camry and anecdotal case-study information. It didn’t take but a few minutes online to determine that a faulty engine coolant temperature sensor (ECT) was causing many Camry stalling complaints. The simplest procedure might have been to replace the relatively inexpensive ECT and let the customer drive the vehicle to verify the repair. But, because just about any other component in the engine management system could also cause a similar stalling complaint, I decided to pursue a more complete diagnosis. As part of my Standard Operating Procedure, I cleaned the throttle plate assembly with throttle plate cleaner with a toothbrush and followed up with solvent-penetrating oil that lubricates the throttle plate and bore. Next, I tested the battery for state of charge (SOC) and state of health (SOH), and checked the voltage drop at both battery terminals.
» DiagnosticDilemmas
Photo 1: The ECT (green connector) appeared to be a frequent culprit in many stalling complaints.
Although the battery terminals passed both tests with less than a 0.5-volt drop, it’s important to remember that the terminal-tocable connection on Toyota battery cables can conceal severe corrosion, so I physically took these connections apart and cleaned those surfaces. I also physically inspected the ECT sensor, throttle position (TP) sensor and idle air control (IAC) connections and used the graphing feature on my scan tool to wiggle-test each circuit to verify that these sensors didn’t have any broken wires. Before starting the engine, I connected my scan tool to the Toyota so I could record coolant
temperature on the data graph. Luckily, I felt the engine “hiccup” as it warmed up and pushed the “save” button on my scan tool to store the image. After recovering from that minor stall, the engine ran without fail for another 30 minutes. As Photo 2 indicates, the indicated ECT plunged from +14° F to -4° F for just a few milliseconds, with the engine rpm dropping a few rpm as well. For me, this was the smoking gun that proved the ECT sensor was at fault. At that point, I replaced the ECT sensor and asked the owner to report back if he had another stalling problem. So why wasn’t an ECT-related
Photo 2: Notice that, as the indicated coolant temperature plunges to -4° F, the data graph indicates a small but sharp dip in engine speed.
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UnderhoodService.com 23
» DiagnosticDilemmas diagnostic trouble code (DTC) stored in the PCM’s diagnostic memory? Let’s keep in mind that any failure must meet the enabling criteria required to store an applicable DTC. Because seven different generic ECT-related codes are listed for this application, I can’t list their enabling criteria in this space. But, while this glitch didn’t last long enough to store a code, it did last long enough to richen the air/fuel mixture ratio and stall the engine at idle speed.
1 996 Jeep Cherokee
The Stalling Cherokee While the engine management technology on a 1996 Jeep Cherokee might be obsolete, the diagnostic methods used to find the cause of an intermittent, no-code stalling complaint are not. What makes this case unusual is that the Jeep is a right-hand-drive model driven by an independent contractor on a daily rural free delivery mail route. Given the replacement cost for a right-hand-drive vehicle, the owner elected to spend whatever it might cost to keep this Jeep running. Off the top, the Jeep had a new TP sensor, IAC valve, new ignition coil and remanufactured distributor installed, presumably to remedy the stalling complaint. All of the above indicated that the problem might turn out to be a real headscratcher, which it proved to be. Once the vehicle was warmed up, it might be driven for hours without stalling. Other times, the stalling complaint occurred so frequently that the vehicle was impossible to drive. After I began testing, the engine idled from a cold-soak for 30 minutes and then stalled. Thanks to my long experience with Jeep systems, I had a two-channel lab scope connected and ready to record the CKP and camshaft position (CMP) sensor waveforms. Photo 3 illustrates the correct relationship between the CKP and CMP sensors. Notice that the green trace at the top is the CMP sensor, which indicates whether the No. 1 cylinder is on a compression TDC or exhaust TDC stroke. Notice also that the CMP “on” signal below covers four Hall sensor signals indicating the positions of three cylinders while the remaining three cylinders are covered by the “off” CMP signal. Needless to say, the CMP signal went straight-line when the engine stalled. Since remanufactured distributors can have their 24 February 2013 | UnderhoodService.com
problems, I elected to replace the Hall sensor with a premium-brand CMP sensor. In doing that, I also recognized that the failed CMP sensor was a secondary, rather than primary, cause of the stalling complaint. I might add that, because it takes about 20-30 minutes for the distributor to reach engine temperature, this time period alone was enough to make me suspect that the CMP sensor was failing.
Photo 3: This waveform illustrates a perfect cam/crank synchronization on a Jeep 4.0L engine.
After I replaced the faulty CMP sensor, the engine again stalled after about an hour of running time. Here again, I’m guessing that the stall might be caused by a temperature-related failure in one or more components. Since I couldn’t establish a relationship between the PCM’s temperature and the stalling complaint, I began to suspect the CKP sensor. Since a visual inspection revealed that the CKP sensor had recently been replaced, I began to look a little deeper for the cause of the stalling complaint. For example, the PCM had reached about 130° F hot-soak temperature. At this point, I removed the PCM connector to check for possible
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» DiagnosticDilemmas corrosion. Before reassembling, I coated the connector pins with some Stabilant-22 connectivityenhancing agent and cleaned all chassis grounds and both battery terminals. I also verified the battery’s SOC and SOH. I was certain that the stalling problem wasn’t being caused by the IAC valve because I could hear a noisy sucking sound as the IAC began to open up as the engine stalled. I also believed that the throttle sensor wasn’t at fault because, in most cases, an erratic TP sensor voltage at idle will cause the PCM to increase, rather than decrease, engine idle speed. Nevertheless, since the IAC and TP circuits share a ground circuit on this application, I connected a DVOM set at the min/max function to record any discrepancies in the TP ground. As with the previously mentioned Toyota Camry, the most valuable tool in locating potential wiring faults and sensor failures is the data graphing
feature included in most scan tools. In this case, I monitored the synchronization between the CMP and CKP sensors. As shown in the data capture in Photo 4, a loss of cam/crank sensor synchronization is extremely important because it indicates that the CKP sensor might be momentarily failing to synchronize with the CMP sensor. Although a two-channel lab scope and scan tool was connected to the engine to record cam/crank sensor data, it was extremely difficult to capture the failure as it occurred. In any case, the suspected CKP failure happened so quickly that I couldn’t capture it on either tool. I experimented with setting my lab scope on normal trigger and still had a normal cam/crank synch pattern at the time of failure. But there were clues. First, the stalling condition required about an hour of warm-up time from an overnight cold-soak. Second, each stalling incident included a loss of cam/crank synch. So I speculated
Photo 4: Although the baro pressure is irrelevant to the diagnosis, the loss of the cam/crank sensor synchronization is extremely important.
Photo 5: Notice the disappearance of rpm and the declining CMP count as the engine begins to stall.
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» DiagnosticDilemmas that it might take about an hour for the CKP sensor located on the bell housing to warm up from cold-soak to engine temperature. Keep in mind that, because the failure occurred only after an hour running time from cold-soak, this testing procedure was becoming very timeconsuming. I will say that I am equipped to deal with this type of diagnostic scenario more so than a technician working in a production situation. Once I understood the time frame, I could warm the engine up and work on other projects. But, at some point, it’s also mathematically cheaper to replace suspect parts than to test to the point of failure. So at this point, I replaced the CKP sensor and ran the Jeep through several more warm-up cycles. Here again, I’m not sure that the PCM was programmed to recognize a CKP glitch that evidently occurred just for a few milliseconds. Fortunately, the engine didn’t stall during several cold-soak warm-ups. Because several road tests also confirmed a no-stall condition, the vehicle was delivered to the customer and, presumably, it’s still running just fine.
No-Code Mustang Misfire Let’s take a brief look at a no-code misfire complaint on a 2002 Mustang equipped with the 3.8L engine and automatic transmission and with about 120,000 miles on the odometer. Because this car belonged to a young, do-it-yourselfer friend of mine, I recommended that he bring
Photo 6: This Mustang had an obvious part-throttle misfire problem, but no P0300-series code to go with it.
28 February 2013 | UnderhoodService.com
2002 Ford Mustang
his maintenance up to date by installing new spark plugs and wires. None of that, of course, solved the misfiring complaint. Fortunately, my friend claimed that his Mustang misfired most frequently as throttle was applied from a 60 mph cruise condition when climbing a nearby hill. At wide-open throttle (WOT), the misfire would disappear. Long story short, I verified the identical symptoms and recorded exactly 41 misfires during the half-mile climb up the hill. As most of us know, misfires can be caused by fuel, ignition, compression and timing problems. In this case, the seat-of-my-pants indicated a bad secondary misfire. One diagnostic scenario is that the misfire occurs only at part-throttle because the air/fuel (A/F) mixture ratio is transitioning from lean to rich. A contributing reason is that the running compression in the cylinders increases as the throttle is opened. So, during lean cruise, the engine doesn’t build enough cylinder pressure to cause the misfire, but, as the throttle is opened, the lean A/F mixture begins to increase firing voltages. Once the throttle reaches WOT, the fuel mixture richens enough to reduce firing voltages and eliminate the misfire. The reason no misfire codes were stored is that 41 misfires during a half-mile interval isn’t enough to store a P0300-series DTC. So after returning to the shop, current-ramping the ignition coils indicated no failures in the primary ignition circuits or drivers. At this point, I’m speculating that the waste-spark ignition coil has a potting failure in the epoxy compound used to insulate the coil windings and form the coil body. So the coil developed an internal short that was sensitive to spark demand created by both running compression and air/fuel mixture ratio. A new coil fixed this intermittent, no-code misfire complaint. ■
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» TechFeature Dissecting the Control Module CONTROL MODULES
UNDERSTANDING CIRCUIT DESIGNS TO IMPROVE DIAGNOSTIC SKILLS By Omar Trinidad, assistant professor, Southern Illinois University
...Turn the ignition switch to the ON position. Test voltage at terminal 2 of connector C302. Is the voltage 4.92V or higher? If yes, go to step 4. If no, check for bad connections... With the complexity of automotive electrical systems increasing steadily, manufacturers have developed troubleshooting trees and strategies (see example above) to make it easier for technicians to diagnose problems. These steps and strategies are very helpful for technicians when followed, but they can also prevent them from using their cognitive skills.
Therefore, it’s very important for technicians to understand how sensor circuits are designed, how the module interprets the signal voltage, and the criteria that trigger the module to set diagnostic trouble codes (DTC). This article will help explain how switch inputs and variable resistive-type sensor circuits are designed, and provide simple electrical diagnostic tips.
What Lies Beneath
Figure 1
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February 2013 | UnderhoodService.com
When looking at a wiring schematic, it’s tempting to wonder what lies within the box representing a control module. The fact is, these thoughts usually arise when the technician is already frustrated at a vehicle in his bay. Although it’s interesting to know what lies within the depths of a module, the most important parts to understand are the pull-up (PU) and pull-down (PD) resistors (see Figure 1). Understanding these two components and applying basic electrical principles will explain how most sensor circuits are designed. The most important point to remember is that switch inputs or variable resistive-type sensors do not produce their own voltage, they merely control or change the voltage measured by the module. All modules — including the power control module (PCM), transmission control module (TCM) and body control module (BCM) — utilize the same input circuit design. These resistors are also used for monitoring outputs and other sensors, but this article will focus on switch inputs and variable resistive-type sensors.
» TechFeature ***Not Actual Values***
Figure 2
Basic Principles Pull-up and pull-down resistors are utilized for many electronic purposes, but they’re mainly used to allow signal voltage to change based on resistance changes in the sensor or switch, and enable the module to recognize circuit faults based on that signal voltage. These resistors are inside the module and are in series with each switch input or variable resistive sensor. The module measures the voltage between the two resistors, or between the resistor and the switch, to infer the status (resistance) of the sensor or switch. Without these resistors the voltage before and after the sensor would never change regardless of any resistance changes in the sensor. In order to understand how these sensor circuits function, it’s important to understand two basic electrical principles. First, positive and negative
voltage/electrical pressure will build up at the highest resistance. Last, if two resistors are wired in series, the resistor with the highest resistance will drop or build up the most voltage/electrical pressure.
Switch Input Circuits Figure 2 illustrates one switch in the ON/closed position and the other in the OFF/open position. This particular circuit is designed to allow the module and the technician to measure 0 volts when the switch is closed and 5 volts when the switch is open. Switch inputs such as a brake, door or window switch utilize the first electrical principle. Due to the fact that the switch would be the highest resistance when the switch is open, the positive voltage and negative voltage will meet at the switch. This explains why a technician and the module would measure 5 volts at the sensing side of the switch. On the contrary, a technician’s meter would read 0
volts when the switch is closed because the positive and negative potentials would meet at the 4Ω resistor, which is the highest and only resistor in the circuit. The meter won’t see a difference in potential between the two leads and will indicate 0 volts if the switch is closed with one DVOM lead on a chassis or battery ground and the other lead on the switch sensing side. Notice that this example uses a ground-controlled circuit with a 5-volt reference. Some circuits, similar to one that will be discussed later, use a powercontrolled 12-volt circuit.
Variable Resistive Input Circuits Using the second electrical principle listed above, Figure 3 on page 32 illustrates the fact that the resistance of the second resistor affects the voltage reading before it. A higher resistance would build up more voltage/electrical pressure before it, and the opposite result would occur if the resistance decreased. This type of circuit is utilized in variable resistive-type sensors such as the engine coolant temperature sensor (ECT), throttle position sensor (TPS) and ambient light sensor (ALS). Differing from a conventional conductor, the ECT is constructed of a
UnderhoodService.com 31
» TechFeature
CONTROL MODULES
semi-conductive material that decreases in resistance as temperature increases. This explains why the signal voltage to the PCM decreases as temperature increases. An increase in temperature will cause the ECT to decrease in resistance, thus building up less voltage/electrical pressure between the PU resistor and ECT. The PCM is programmed to interpret the signal voltage as an indication of engine coolant temperature. From this information, the PCM can initiate closed loop, enable monitors and perform other emissions-related functions. Conventionally, a contact-type ignition switch directs high current to most of the electrical system. But with the implementation of push-start, advanced anti-theft and other body control functions, the ignition switch is now merely an input to a module rather than a high current switch. Even non-push-start systems with conventional lockcylinders and keys can utilize this design. These systems have a specific fixed resistor for each key
***Not Actual Values***
Figure 3
position. Figure 4 illustrates a 1.3K Ω inside the ignition switch in series with a PD resistor inside the BCM. The BCM will reference the ignition switch position based on the voltage between the two resistors. Once the BCM informs the ECM that the key is in the start position and the shifter is in park or neutral, the ECM will send positive voltage to the control side of the starter relay.
Diagnostic Trouble Codes
Figure 4
32 February 2013 | UnderhoodService.com
Understanding basic electrical principles and sensor circuits will allow any technician to efficiently diagnose any complex computer-controlled system. However, due to the current compact design of connectors and wires, it’s now very difficult to acquire any voltage measurements at a connector through probe-type tools such as a t-pin. Fortunately, using a scan tool, DVOM and a jumper wire kit can alleviate this problem. It’s always wise to start the diagnostic procedure by verifying the customer complaint and checking for DTCs. However, technicians must first understand how DTCs are set and interpret what voltages the module should and is currently seeing. Furthermore, the technician must analyze the circuit to verify if it utilizes a PU or PD resistor. The resistors will always be on the signal side of the module, not the 5-volt reference or low-reference side of the sensor. Variable resistivetype sensors with a low-reference wire will utilize a PU resistor on the sensing
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Âť TechFeature side. On the other hand, sensors with a 5-volt reference wire, will utilize a PD resistor on the sensing side.
Diagnosing Switch Inputs All DTCs are set by certain malfunction conditions. Input switches, such as a brake pedal switch, normally experience the lowest and highest voltage parameters (0 or source voltage). Most input switches can set two DTCs: switch circuit low input (voltage) or switch circuit high input (voltage). In addition, the module utilizes a systematic logic to set a DTC when certain conditions are met. For example, the brake pedal should never be engaged for a long period of time while the vehicle is accelerating. A P0719 brake switch circuit low input would be set if the PCM sees 0 volts at the brake switch input for a certain period of time while accelerating. This logic is programmed into the module. The schematic on Figure 5 illustrates a basic brake switch ***Not Actual Resistance Values***
CONTROL MODULES
circuit that can be categorized into three sections: the components before the switch, after the switch and the switch itself. Normally, 12 volts should be found at the PCM when the brake pedal is disengaged. If 0 volts is found at the brake switch, there might be an open before it, or a blown fuse caused by a short to ground in between the PCM and the fuse. If the fuse is good, the next step would be to diagnose where the open is located. A technician can test the resistance of each component or wire to find the open, but that would take some time to find every component or connector. It would be more efficient to test at the switch. After testing the resistance of the switch, a voltmeter can be used to verify the section containing the open. Depending on the source of voltage, the voltage before the switch should be high. If so, then the open is between the switch and the module. The PCM should only be suspected once all three sections are verified.
Diagnosing Variable Resistive-Type Sensors
Figure 5
As stated above, it is normal for a module to measure or sense the highest and lowest voltage threshold for switch inputs. However, unlike switch inputs, variable resistive-type sensors will set a DTC if the module senses the highest or lowest voltage threshold within a certain period of time (see Figure 6). Sensor circuit high-voltage codes, such as a P0118 on an ECT sensor, will set if the PCM senses an output voltage of 4.92 volts or more for at least 2 seconds. This fault will
34 February 2013 | UnderhoodService.com
Figure 6
also cause the scan tool to indicate an extremely cold temperature. In contrast, sensor circuit low-voltage codes, such as a P0117 on an ECT sensor, will set if the PCM senses an output voltage of 0.08 volts or less for at least 2 seconds. With a sensor circuit low-voltage code, the scan tool will indicate an extremely hot temperature. There are also conditional-type codes that can be set, such as a P0128 cooling system malfunction. These conditional-type codes are set when the computer senses something illogical happening. The PCM is programmed to infer that the coolant temperature should increase after a certain amount of engine running time. Utilizing the IAT sensor and other driving conditions, the PCM obtains an estimated engine coolant temperature. The cooling system
» TechFeature malfunction code is set if the actual and estimated coolant temperatures are too far apart or if the actual temperature is lower than the estimated temperature reading. This problem can be caused by a stuck-open thermostat, sensor circuit fault or a defective ECT. As designed, the ECT will increase in resistance as coolant temperature decreases. The increase of resistance will increase the voltage/electrical pressure built up before it. With this stated, only an open or an extremely high resistance can cause the PCM to sense 4.92 volts or more and cause the scan tool to indicate an extremely low coolant temperature reading (see Figure 7). Although a DVOM can be used to diagnose opens and high resistances in the circuit, it’s more efficient to utilize the scan tool and jumper terminals. Similar to the switch circuit
CONTROL MODULES ***Not Actual Resistance Values***
Figure 7
diagnostic procedures, it’s important to categorize the sensor circuit into three sections: the wire before and after the sensor, and the sensor itself. There are four steps to isolate an open or high resistance on sensor circuits similar to the ECT: 1. Unplug the sensor connector and test the resistance of the
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36 February 2013 | UnderhoodService.com
sensor. This also allows the technician to isolate the sensor, wires and the PCM. The sensor should be replaced if the resistance is overload (OL) or out of specification. 2. Use a terminal jumper lead to short the sensing wire to ground (see Figure 8 on page 38). Due to the negative voltage on the sensing wire, the PCM should sense a voltage less than 0.08 volts and the scan tool will indicate an extremely hot temperature reading. If the scan tool does not indicate an extremely hot temperature reading, the fault is between the sensor and the PCM, see Figure 9 on page 38 (circuit 2). 3. If the scan tool indicated an extremely hot temperature reading with the shorted sensing wire, the next step would be to jump the sensing and low-reference wires together (see Figure 10 on page 39). Similar to grounding the sensing wire, the voltage should stay low and the scan tool should indicate an extremely hot temperature reading. But, if the scan tool reading
» TechFeature
CONTROL MODULES
stays extremely cold, the fault is in the low-reference side of the circuit, Figure 9 (circuit 3). 4. Once the sensor and wires are confirmed, the only parts that could cause the fault are the terminal connections to the sensor or the PCM, Figure 9 (circuit 4). One of the most misunderstood and often the
Figure 8
first to be stated fault is a short. A short to power on the sensing wire will cause a sensor circuit voltage high DTC, and a short to power on the low-reference side will melt the wire or destroy the module. On the other hand, only a short to ground on the sensing wire or an internally shorted sensor will trigger a sensor circuit voltage low DTC (see Figure 11). Both of these faults can be tested with an ohmmeter. A technician can measure the resistance of the sensor to verify that the sensor is within specifications. But if a short to ground is suspected, the technician should disconnect the sensor and PCM connectors, insert a jumper terminal in the sensing wire connector terminal and test for resistance/continuity to ground. The ohmmeter should read OL. Again, it’s crucial that the PCM should only be suspected after all of the three sections have been thoroughly tested. A technician doesn’t need to know everything about the internals of a module. However, it’s very important for all technicians 38 February 2013 | UnderhoodService.com
Âť TechFeature ***Not Actual Resistance Values***
Figure 9
Figure 10
***Not Actual Resistance Values***
Figure 11
to understand how the sensor circuit is designed, the normal voltage range of the sensor and the enabling conditions of any DTCs they are diagnosing. â– Reader Service: Go to www.uhsRAPIDRESPONSE.com
» TechTalk
BIODIESEL
Biomass or Bio Mess? Problems Associated with ‘Home Brewed’ Bio-Diesel By Bob McDonald diesel specialist
A
t the shop, I often hear the bad side of everything. One day, a customer started talking about bio-diesel and had nothing good to say about the subject. As time went by (over the course of a period of years), there was still nothing promising to report about bio-fuels. This has been quite disappointing because I hoped that after a lot of time, money and research went into a bio-fuel program, that someone might have finally figured the process out. I decided to look into the bio-fuels program to figure out the real truth. The bio-fuel issue really intrigued me when I was working on two particular Ford vehicles. The engines in question were the 7.3L IDI diesels that
were used in Ford trucks up until 1994 when the Power Stroke was introduced. These trucks were virtually identical, with roughly the same amount of miles and symptoms. The problem plaguing the two trucks was that they both had just shut down and would not run. After some diagnosis, I found that the injection pumps on both trucks were strangely acting the same way, yet they had two different owners. The injection pumps appeared as if they were
This diesel injection pump has been subject to home-brewed bio-diesel. Notice the corrosion along with the nasty deposits and residue.
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February 2013 | UnderhoodService.com
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» TechTalk
BIODIESEL
worn completely out, and simply would not make any pressure to send to the injectors. If you cracked the line at the injectors, the fuel would just barely dribble out. What’s odd is this type of injection pump failure is not at all common on these engines. The injection pumps have a “rotary” design that was manufactured by Stanadyne and when they start to fail, there are generally “tell-tale” signs which alert the owner that something is wrong. You just don’t see these pumps running down the road and suddenly die unless something strange or major happens. It was very odd that both of these pumps had gone bad with the same symptoms at the same time. When an injection pump needs a rebuild, I’ll often send the pump to Carolina Diesel, the Stanadyne remanufacturing facility in Charlotte, NC, located about 70 miles away. When I sent these pumps to Carolina Diesel, they immediately contacted me to ask what kind of fuel these engines had been running. Since I wasn’t sure,
42 February 2013 | UnderhoodService.com
I took a sample out of the vehicles in question and all I could tell for certain was that I wasn’t 100% they were running diesel. I cut the fuel filters open and found that both of the filters from two different trucks were completely stopped up with some sort of brown “ooze.” The guys at Carolina Diesel told me that the pumps were internally damaged and corroded, literally eaten up from the use of biodiesel. I asked how they knew that this was biodiesel and they said that they see this happen quite often when someone tries to make their own fuel. As we talked, I recalled all the bad things that I heard about bio-diesel. Were they universally true? It was sure starting to look that way until I realized what he said: “This type of pump failure tends to happen when people try to make their own fuel.” I wanted to get to the bottom of things and find out more about bio-diesel — this would be a great education for me if I could figure out the situation. In North Carolina, there are only certain counties that offer bio-diesel and none of them are close to me. So,
» TechTalk
Bio-diesel is often used as a fuel for compression ignition engines and can be made from different types of oils: plant oils (soybean, cottonseed or canola), recycled cooking greases, oils or animal fat.
if there have been any ill effects from using bio-diesel, I have not heard about it because no one around me had any access to the product. I recall that several years ago equipment manufacturers, along with several auto makers, had undergone some testing and stated that the use of bio-diesel was approved for use in their vehicles. So why would a manufacturer suggest that it would be fine to use a bio-fuel if it was going to destroy major engine components? Bio-diesel is manufactured as a replacement fuel for compression ignition engines and can be made from three different types of oil: plant oils (such as soybean, cottonseed or canola), recycled cooking greases, oils or animal fat. You can’t typically run a vehicle on this type of oil — to make these oils a bio-fuel, they have to be broken down by a process known as transesterification. This is a process where the oils are reacted with alcohol (usually methanol) with a catalyst (generally sodium hydroxide) to produce bio-diesel. When properly refined, they produce a byproduct — glycerin (sugar) — which then needs to be extracted.
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» TechTalk
BIODIESEL
But these processes have to be handled through super refining and filtering processes. In order for a bio-fuel to be produced legally, it has to conform to a specification known as ASTM D6751. ASTM D6751 gives a specific guideline for proper refining of biodiesel. The EPA will only register bio-diesel as fuel if it is made to this specification. Bio-diesel is generally rated as a percentage, such as B5. This means 5% bio-diesel is mixed with 95% petroleum fuel. There are many different blends ranging from 5% concentrations to 100%. The concentration is generally rated for various applications. Most automotive manufacturers will allow a maximum of a B20 blend for on-the-road vehicles. While conducting research, I located a facility nearby that made bio-diesel. Foothills-Bio Energies makes a bio-diesel that meets ASTM D6751 specifications. Another thing I learned was that it is nearly impossible to make bio-diesel at home, which answers the question of where the negative comments had come from.
Motor Fuel ‘Moonshiners’ Without the proper refining through the transesterification process, there are a lot of by-products that get left behind that will damage engine components. Even though there are machines that make bio-fuel, this doesn’t mean the result will be suitable for
vehicle use. The biggest problem faced by the ‘home brewer’ is handling the methanol. When the oil undergoes the transesterification process by the use of methanol, the methanol ultimately has to be removed. Unfortunately, this leaves behind methanol, which causes corrosion and does little for the cetane rating of the diesel fuel. This is where the engine damage comes from: improper refining leads to many chemicals left behind. And what about the glycerin? How does the home brewer extract all of that? Who wants sugar in their fuel? After all this, it must be remembered that bio-diesel is a good fuel when properly refined. Studies have shown that bio-diesel produces more energy than petroleum energy. Also, bio-diesel reduces greenhouse gas along with tail pipe emissions. Petroleum diesel fuel combustion has always been toxic and carcinogenic. By using a B20 blend, these toxins can be reduced by 40%. When properly blended, bio-diesel will not cause any serious side effects for a fuel system or components. In fact, because of the way it is made, it is actually going to clean your fuel system. Manufacturers recommend that the filters should be changed quite frequently when first using a biodiesel until all of the fuel system is cleaned out. The sediment you may find in your filters after changing from petroleum diesel to bio-diesel is leftover residue from the petroleum diesel. The B20 blend is most commonly used, although sometimes in cooler climates a blend of B5 is more common. This is due to the fact that at temperatures below 39° F, B20 will start to gel. Just be certain when using bio-fuel to make sure that it is coming from a reliable source; make sure that the processes that were used to make the bio-fuel conformed to the ASTM D6751 specification. As for the Ford trucks I was working on, I found out the fuel from both trucks had been home-brewed. So warn your customers to be careful, the money they save from trying to beat the system will end up costing them in the long run if the fuel is not properly refined. ■
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44 February 2013 | UnderhoodService.com
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» TechTips
HONDA \ SUBARU This month is sponsored by:
Honda Suffers from Hard Start/Long Crank Time Applies To:
2003 Accord V6 — All 2004 Accord V6 2-door — From VIN 1HGCM8... 4A000001 through 1HGCM8... 4A024092 2004 Accord V6 4-door — From VIN 1HGCM6... 4A000001 through 1HGCM6...4A1 00943 If a customer complains one of the above vehicle models is experiencing excessive cranking or hard starting, there are two possible causes: 1. Contamination in the fuel pressure regulator causes the regulator to stick or intermittently stick, causing a delay in fuel pressure at start-up. 2. Exhaust gas backflow into the intake manifold at engine shutdown may cause a poor mixture of intake air and fuel at the next engine start-up. Corrective Action:
Replace the fuel pressure regulator, if needed, and use the HDS to update the PGM-FI software in the ECM/PCM. Note: The 2004 Accords within the following VIN ranges already have an improved fuel pressure regulator. For these vehicles, skip Diagnosis, and go to step 10 of the Repair Procedure to update the PGMFI software in the ECM/PCM: — VIN 1HGCM8...4A018621 through 1HGCM8...4A024092 — VIN 1HGCM6...4A068600 through 1HGCM6...4A100943.
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February 2013 | UnderhoodService.com
Software Information: Year 2003
Program ID CA3150 CA 3160 CAA060 CAL060
Program Part Number 37805-RCA-315 37805-RCA-316 37805-RCA-A06 37805-RCA-L06
2004
CAA250 CAA750 CAL250 CAL750
37805-RCA-A25 37805-RCA-A75 37805-RCA-L25 37805-RCA-L75
HDS Software Version: 2.004.004 or later, PGM-FI Software Versions or later.
Parts/Tool Information:
Fuel Pressure Regulator: P/N 16015-SDB-A00 Fuel Pump Module Gasket Set: P/N 17046-SDA-A30 Fuel Sender Wrench: P/N 07AAA-S0XA100 Diagnosis:
1. Install a fuel pressure gauge. (Refer to steps 1 and 2 on page 11-332 of the 2003-’06 Accord V6 Service Manual Supplement, or online, enter keyword Gauge Test, and select Fuel Gauge Sending Unit Test [V6 Engine] from the list.) 2. Start the engine, and let it
idle for 2 minutes. 3. Turn off the engine. Check the fuel pressure gauge. Pressure should be 380 to 430 kpa (55 to 63 psi). 4. Monitor the fuel pressure reading. If the fuel pressure bleeds down quickly after the engine is turned off, go to the Repair Procedure. If the fuel pressure does not drop quickly, go to step 10 of the Repair Procedure to update the PGMFI software. Note: There is no specification for fuel pressure bleed rate. Many variables can affect fuel line pressure, such as the fuel
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» TechTips
HONDA
pump and fuel injectors. A bad regulator will lose most of the fuel pressure in the first few minutes after shutting off the engine. Repair Procedure:
1. Relieve the fuel pressure. 2. Remove the fuel tank unit. 3. Remove the fuel tank unit from the case. — Disconnect the fuel tank sending unit connector. See Figure 1. — Release the three clips, and then pull out the fuel tank unit from the case. See Figure 2. 4. Release the clips, then remove the fuel pressure regulator mount from the fuel tank unit. 5. Remove the clip, then remove the fuel pressure regulator. Install the new regulator with new Orings. Reassemble the fuel tank unit. 6. Place the new gasket onto the tank body. 7. Align the marks on the fuel tank unit and the fuel tank. (See
Figure 1
page 11-327, step 11 of the 2003-’06 Accord V6 Service Manual Supplement.) Install the fuel tank unit into the tank without dislodging the gasket. Using hand pressure only, slide the fuel tank unit into the tank until it is properly seated. 8. Using the fuel sender wrench, torque the new fuel tank locknut to 93 Nm (69 lb.-ft.). Note: Do not use the locknut to force the pump into the tank. 9. Reinstall all removed parts. 10. Use the HDS to update the PGM-FI software in the ECM/PCM, using HDS version 2.004.004 or later. To update the PGM-FI software, refer to service bulletin 01-023, Updating Control Units/Modules. 11. Do the idle learn procedure: — Make sure all electrical items (A/C, audio unit, defogger, lights, etc.) are off. — Start the engine, and let it warm up to its normal operating temperature (the cooling fans cycle twice). — Let the engine idle (throttle closed and all electrical items off) for 10 minutes. 12. Do the low-rpm CKP pattern learn procedure: — Test-drive the vehicle on a level road. With the A/T in second gear or the M/T in second or third gear, decelerate (with the throttle fully closed) from an engine speed of 2,500 rpm down to 1,000 rpm. — Stop the vehicle, and put the transmission into park or neutral. Set the parking brake. Do not turn off the ignition.
48 February 2013 | UnderhoodService.com
Figure 2
13. Connect the HDS to the DLC, and check the status of PULSER F/B LEARN: — On the Selection Menu, select PGM-FI. — On the Mode Menu, select Data List. — Check the value of PULSER F/B LEARN. — If the value is Completed, go to step 14. — If the value is Not Completed, be sure the engine is at normal operating temperature (the ECT SENSOR [1] value is 176 or higher), and repeat step 12. 14. Do the high-rpm CKP pattern learn: Note: The low-rpm CKP pattern learn must be completed before you do the high-rpm CKP pattern learn. — Test-drive the vehicle on a level road. With the transmission in first gear, decelerate (with the throttle fully closed) from an engine speed of 5,000 rpm down to 3,000 rpm. — Stop the vehicle, and put the transmission into park or neutral. Set the parking brake. Do not turn off the ignition. 15. Connect the HDS to the
HONDA / SUBARU
DLC (if not already connected), and check the status of PULSER F/B LEARN (HIGH RPM): — On the Selection Menu, select PGM-FI. — On the Mode Menu, select Data List. — Check the value of PULSER F/B LEARN (HIGH RPM).
— If the value is Completed, you’ve completed the CKP pattern learn procedure. — If the value is Not Completed, be sure the engine is at normal operating temperature (the ECT SENSOR [1] value is 176 or higher), and repeat step 14.
» TechTips
16. Start the vehicle a couple times to make sure the symptom is repaired. If it is not, continue with normal troubleshooting procedures for hard-starting problems. Courtesy of ALLDATA.
Mysterious Subaru Leaking Engine Oil Seals? Check the PCV! The Mitchell 1 Techline has heard of a very limited number of cases involving engine oil seals leaking after being displaced from their normal positions. As the engine heats and cools, condensation can accumulate in the PCV system, which, in extreme cold climates, can eventually turn to ice. Upon closer inspection, technicians have reported finding accumulations of ice restricting or blocking airflow through the PCV system. When the engine’s PCV system cannot “breathe” properly, excessive crankcase pressure can build, resulting in oil seal displacement/leak. Once the seal is displaced, the pressure buildup condition is gone. This situation can easily be overlooked if the vehicle is brought into the shop the night before inspection and/or repairs begin and allowed to “thaw out.” Once thawed, the blockage is gone and the PCV system returns to operating normally. This condition has only been found to occur on turbocharged vehicles operating in extreme cold temperatures. Courtesy of Mitchell 1. ■
» Shop Gain Customers and a Great Reputation with OEM Branded Products from NAPA — NAPA Import Auto Parts supplies globally sourced parts for import cars from the most respected original equipment manufacturers and aftermarket suppliers in the industry. With more than 6,000 NAPA Auto Parts stores, the company provides availability in virtually every market nationwide. Original equipment supplier products in the original brand packaging have never been this accessible until now! Visit www.NAPAonline.com. Reader Service: Go to www.uhsRAPIDRESPONSE.com
SMP Releases TechSmart Tech Sessions Video Series — Technicians can learn about the benefits of using TechSmart enhanced engine control parts through a new video series called TechSmart Tech Sessions, which is available for viewing at www.facebook.com/TechSmartParts and www.youtube.com/TechSmartParts. The first three videos discuss the steering column shift tube, air door actuators and variable valve timing (VVT) chain tensioner. Reader Service: Go to www.uhsRAPIDRESPONSE.com
Rislone introduces a full line of super-concentrated fuel additives, packaged in six-ounce bottles featuring Rislone’s new patent-pending EZ Nozzle delivery system that works on any vehicle, including those equipped with capless or obstructed fuel systems. The new line includes: Fuel Injector Cleaner with Upper Cylinder Lubricant, Fuel Injector & Carb Cleaner, Octane Booster, Gas Treatment, Ethanol Fuel Treatment and Water Remover Fuel Dryer. Reader Service: Go to www.uhsRAPIDRESPONSE.com
Bosch’s newly expanded line of mass air flow (MAF) sensors, with nearly 30 new part numbers, now features more than 120 part numbers covering popular vehicles in operation in North America. This new coverage, available through distribution channels immediately, will help assure distributors and retailers that they will not miss sales due to gaps in coverage. And this coverage will help assure repair shop owners and technicians that they can find the OE-quality part they need, quickly and reliably, from their regular supplier of Bosch products. Reader Service: Go to www.uhsRAPIDRESPONSE.com
Several popular Toyota, Honda, Subaru, Hyundai and Kia applications will be among dozens of late-model import vehicles that are being added to Tenneco’s Walker line of catalytic converters in 2013. The company also is significantly increasing its offering of EPA- and CARB-compliant manifold converters to reflect the latest emissions control designs being used by global vehicle manufacturers. Tenneco will introduce more than 40 additional converter part numbers during the first quarter of 2013 and approximately 120 new SKUs over the course of the year. Reader Service: Go to www.uhsRAPIDRESPONSE.com
50 February 2013 | UnderhoodService.com
It’s Fast, Easy and Accurate! Get FREE PRODUCT AND SERVICE INFO from the companies featured in this issue of Underhood Service. >> VISIT www.uhsRapidResponse.com and click on the company from which you want information. >> OR, go to www.UnderhoodService.com and click on the Underhood Service Rapid Response Logo.
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Airtex Corporation ALLDATA APA Management Group Auto Value/Bumper to Bumper BendPak Champion Spark Plugs/Federal-Mogul Delphi Products & Service Solutions DENSO Sales California, Inc. Dipaco Inc. Federated Auto Parts GAAS Hughes Engines, Inc. Jasper Engines & Transmissions King Electronics Mr. Gasket Performance Group NAPA NAPA Belden NGK Spark Plugs Nissan Motor Corp. USA O'Reilly Auto Parts Parts Master Schaeffler Group USA Spectra Premium Industries TechSmart SMP TYC/Genera Corp. WIX Filters
5, 23 39 17 Cover 4 29 12, 13 Cover 2, 1 25 43 20, 21 35 44 47 36 10 3 15 11 Cover 3 27 33 8, 9 41 19 7 45
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Post your job for just $50 a month! Visit AutoProJobs.com to get started today! Contact: Karen Kaim p) 330.670.1234 ext. 295 f ) 330.670.7153 kkaim@babcox.com UnderhoodService.com 51
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Filters Mechatronics Kits Oils Hard Parts Manuals Torque Converters Audi • BMW Jaguar • Porsche Range Rover • VW
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ERIKSSON INDUSTRIES • 800-388-4418 Old Saybrook, CT • FAX 860-395-0047 • www.zftranspart.com
52 February 2013 | UnderhoodService.com
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Why switch to PDQ? PRICES. Low prices. High Quality. Always. 1st time buyer? Order from this ad and receive these special prices.
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54 February 2013 | UnderhoodService.com
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Advertising Representatives The Tech Group Bobbie Adams badams@babcox.com 330-670-1234, ext. 238 Dean Martin dmartin@babcox.com 330-670-1234, ext. 225 Sean Donohue sdonohue@babcox.com 330-670-1234, ext. 206 Glenn Warner gwarner@babcox.com 330-670-1234, ext. 212 John Zick jzick@babcox.com 949-756-8835 List Sales Manager Don Hemming dhemming@babcox.com 330-670-1234, ext. 286 Classified Sales Tom Staab tstaab@babcox.com 330-670-1234, ext. 224
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» Test Drive ‘Holy Car Fan, Batman’ The original 1966 TV Batmobile sold for $4.62 million at BarrettJackson Auction Company’s Scottsdale Auction last month. The original Batmobile started its life as the one and only 1955 Lincoln Futura concept car, which was heavily modified by George Barris to become the Batmobile in the live-action TV series Batman, as well as the movie adaptation, starring Adam West. The auction tent was brimming with excitement as fans watched the price for the Batmobile skyrocket to historic proportions on Photo courtesy Barrett-Jackson/George Barris the Barrett-Jackson auction block. Legendary customizer and creator Barris looked on with pride from the auctioneer’s stand, even adding his signature jacket to the sale, as the crowd cheered the auctioneer on. The original Batmobile is now the highest selling car at the company’s annual Scottsdale Auction. For more information about Barrett-Jackson auctions and classic vehicles, visit www.barrett-jackson.com.
‘Search for a Champion’ Racing Sponsorship Contest Narrows Finalists to 15 More than 160 racing teams have completed their two-minute video entries into the Champion spark plug brand’s $125,000 “Search for a Champion” racing sponsorship contest, and it’s now time for consumers to choose their favorites by logging on, viewing and voting on the website. Voting for the grand-prize winner will take place Feb. 22 through March 24, with the $50,000 Search for a Champion sponsorship being awarded by NASCAR Sprint Cup driver and Champion spokesperson Kevin Harvick on April 2, 2013. For more information about the contest and “Performance Driven” Champion products, visit www.AlwaysaChampion.com.
GUESS THE CAR! WIN $50! #11
What vehicle MAKE does the picture on the left represent? Submit your guess with our online contest form by visiting www.UnderhoodService.com/guessthecar or scan the QR code to the right with your smart phone. The winner will be randomly selected from correct entries and awarded $50. Entries must be received by FEBRUARY 28, 2013.
#10
December Solution: Touareg (Volkswagen) Solved by: Gina Gaddis, office manager, Cecil’s Hi-Tech Auto Care, Vacaville, CA
CONGRATULATIONS Gina! Employees of Babcox Media, industry manufacturers and Underhood Service advertisers are not eligible to enter.
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