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Diagnostic Dilemmas: Parallel Universes






Old School Misfire, New School Engine Not all problems can be solved by reading codes and sensor outputs. Gary Goms looks at how a once common problem can baffle the best box diagnostics.

High-Pressure Diagnostics Wrapping your mind around the fundamentals of common rail injection is tough. Robert McDonald helps you to grasp pressures, droplet size and diagnostics.

Diagnostic Dilemmas


Diesel Dialog

Networked Starters No BUS, No Crank Diagnostics Brian Wing comes across a dead BMW that can’t crank or communicate.

AUGMENTED REALITY CONTENT IN THIS ISSUE: SmartChoice™ Mobile App, powered by Federal-Mogul….page 4-5 (Open AVI Play and hold your smart device over the SmartChoice™ logo) ASE Test Prep 11 Power Stroke Diesel 38 Key Diagnostics 58 AVI Test Prep 65 P0430 Sensitive Vehicles 76 Publisher Jim Merle email: 330-670-1234, ext. 280

Graphic Designer Dan Brennan email: 330-670-1234, ext. 283

Editor Andrew Markel email: 330-670-1234, ext. 296

Contributing Writers Gary Goms, Scott “Gonzo” Weaver, Bob Dowie and Randy Rundle

Managing Editor Jennifer Clements email: 330-670-1234, ext. 265

Ad Services (Materials) Cindy Ott email: 330-670-1234, ext. 209

Technical Editor Larry Carley Circulation Manager Pat Robinson email: 330-670-1234, ext. 276 Subscription Services Maryellen Smith email: 330-670-1234, ext. 288

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HOME OFFICE 3550 Embassy Parkway Akron, Ohio 44333-8318 330-670-1234 FAX 330-670-0874

8 Quick Tip 11 ASE Quick Tip 14 Publisher’s Perspective 16 Directions 18 Gonzo’s Toolbox 20 Aftermarket Update 24 Customer States... 26 Rotating Electrical 46 Gaskets 64 Training Update 66 Wiring Harness 70 Water Pumps 74 Converters 80 Tech Tips 87 Shop (New Products) 91 Rapid Response 92 Classifieds 96 Ultimate Underhood


PRESIDENT Bill Babcox 330-670-1234, ext. 217 VICE PRESIDENT Jeff Stankard 330-670-1234, ext. 282


Sales Representatives: Bobbie Adams 330-670-1234, ext. 238 Doug Basford 330-670-1234, ext. 255


Sean Donohue 330-670-1234, ext. 206 Jamie Lewis 330-670-1234, ext. 266 Dean Martin 330-670-1234, ext. 225


Editorial advisory Board Brent Crago, owner Top Tech Automotive Cleveland, Tennessee

Marvin Greenlee, owner Meade & Greenlee Inc. Salem, Oregon

Rick O’Brien, technician Coachworks Portland, Maine

Paul Stock, owner Stock’s Underhood Specialists Belleville, Illinois

Marc Duebber, owner Duebber’s Auto Service Cincinnati, Ohio

Anthony Hurst, owner Auto Diagnostics Ephrata, Pennsylvania

Tom Palermo, general manager Preferred Automotive Specialists Jenkintown, Pennsylvania

Michael Warner, owner Suburban Wrench Pennington, New Jersey

Audra Fordin, owner Great Bear Auto Repair Flushing, NY

Roger Kwapich, owner Smitty’s Automotive Toledo, Ohio

Van Pedigo, owner Richfield Automotive Center Richfield, Ohio

Glenn Warner 330-670-1234, ext. 212 John Zick 949-756-8835 List Sales Manager Don Hemming 330-670-1234, ext. 286 Classified Sales Tom Staab 330-670-1234, ext. 224

Underhood Service is a member of and supports the following organizations:

UNDERHOOD SERVICE (ISSN 1079-6177) (October 2013, Volume XVIII, Number 10): 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. 288, 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.

6 October 2013 |

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Adjustable Clutch Master Cylinders

Figure 1

Following a new clutch installation, there is nothing worse than experiencing slipping or release problems. Many times technicians even begin to believe that the new clutch kit is defective. This is not correct, in most cases. The majority of the time a simple, quick adjustment will alleviate any problems. Most Japanese/Korean imports utilize an adjustable clutch master cylinder (Figure 1). When a new clutch kit is installed, the master cylinder needs to be re-adjusted to work properly with this new kit and avoid release and slipping problems. The steps listed below demonstrate the proper way to adjust the master cylinder and avoid potential release problems with the new clutch.


Figure 2

1. Verify that hydraulic fluid is clean and that correct fluid was used. 2. Locate the master cylinder push rod that attaches to the clutch pedal. 3. Using Figure 2 as reference, extend the push rod to allow for more throw. After the rod has been extended, tighten the locking nut. Caution: DO NOT extend the rod out too far. Extending too far out can block the compensating port in the master cylinder.

PREVENTING SLIPPING: Figure 3 1. Verify that hydraulic fluid is clean and that correct fluid was used. 2. Locate the master cylinder push rod that attaches to the clutch pedal. 3. Using Figure 3 as reference, shorten the push rod to allow for less throw. After the rod has been shortened, tighten the locking nut. Note: In a slipping situation, the rod is too long causing the compensating port to be blocked off not allowing fluid to return to the fluid reservoir. Courtesy of Schaeffler Aftermarket, â–


October 2013 |

» ASE Test Prep L1



he Advanced Engine Performance Specialist (L1) test contains 50 scored questions focused on the diagnosis of general powertrain, computerized powertrain controls (including OBD II), ignition systems, fuel and air induction systems, emission control systems and I/M test failures. Section B of the Task List on computerized powertrain controls states that you should be able to perform the following items on circuits: • Voltage Drop • Current Flow • Continuity/Resistance • Waveform Analysis Many of the circuit testing questions relate to a sample vehicle using a composite powertrain control system fea-

turing computerized engine control technology used by most manufacturers. This vehicle is described in the Composite Vehicle Type 3 Reference Booklet that is provided both before and at the time of testing. The Type 3 vehicle was introduced in 2006. This vehicle has several serial data buses and multiple modules. There will be question on the test concerning how different conditions like shorts, opens and changes in resistance can alter serial data bus traffic. You also have to be able to understand the test results from voltage drop, resistance and scope analysis. Most of all you need to understand how a serial data bus network shares information by just changing voltages over two wires. Good luck! ■


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» Publisher’s Perspective




echs can make virtually any repair “look easy” to their customers. The typical scenario consists of the customer dropping off his/her vehicle in the morning and by Ed 5 o’clock the same evening it’s in top-running condition with a happy customer behind the wheel. However, behind the bay door those of us in the business know the trick of making it look easy is having the proper training, tools and personal drive to complete each job, exceeding both the shop’s and their customers’ expectations. For 15 years Ed Sunkin, the editor of Underhood Service, has made it “look easy” by producing 177 consecutive monthly issues. Ed’s commitment to providing relevant “under-the-hood” technical content and industry news for shop owners, shop managers and technicians was led by his personal drive to exceed his own expectations with each issue while simultaneously expanding the digital presence of the Underhood Service website and social media channels. Recently, Ed decided to take advantage of a new opportunity and the good news is he’s not going far. Ed has been named editor of Engine Builder, our sister publication serving the engine rebuilding industry. I’m also pleased to announce and introduce Andrew Markel who has been named editor of Underhood Service. Some of you may already recognize Andrew, who currently serves and will continue to serve as the editor of Brake & Front End and has contributed numerous technical features within past issues of Underhood Service and ImportCar. Combined, these three monthly magazines serve more than 100,000 individual repair shops. Andrew’s extensive publishing experience, coupled with being an ASE-Certified automotive technician, will ensure a smooth transition beginning with this issue! Andrew’s adjacent note provides a snapshot of his background and impressive automotive aftermarket heritage. I’m glad to have Andrew on board to direct the editorial content of Underhood Service and its continued success. Jim 330.670.1234, ext. 280


October 2013 |




ecoming the editor of Underhood Service is a dream come true. I grew up in the industry and remember the first issue of Underhood Service. Why do I remember that issue? The IM240 cover story helped the shop I was working at make the correct decision in purchasing a new OBD II scan tool. Like a lot of you, I am the third-generation of my family to work in the automotive service industry. My grandfather owned several repair businesses, gas stations and even a few new car dealerships in Denver, CO. My father began his career at his father’s Hudson and American Motors dealership before being drafted into the Army. After being honorably discharged, he became a resident instructor at a GM Training Center. In 1981, he made the move to Detroit to become ACDelco’s supervisor of service training. My career started at the age of three when I managed to crush my fingers under an engine block of a Chevy Vega (I still have the scars). My first paying job was at a new car dealer as a porter while attending college. Later, I went on to work as a service advisor and technician for several independent shops. It has been 18 years since reading that first issue of Underhood Service, it is a true honor to be steering the editorial direction. If you would like to introduce yourself, give me a call. ■ Andrew 330.670.1234, ext. 296

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By Andrew Markel | EDITOR


Once just for looks they are now functional


lastic engine covers are becoming a plague for technicians and it is only getting worse. Every year they get bigger and more difficult to remove.

Once, they only cleaned up the engine bay, hiding unsightly wire harnesses, piping and intake manifolds. Now they have become barriers to technicians like the tamper-resistant screws on an iPhone.

My first experience with these covers was on a Buick 3800. The cover could be removed by twisting the oil cap and strategically pulling on the corners. Anybody could remove it in under 5 seconds. Soon I started to notice more of these covers. Like the 3800, to remove many of the early covers, it did not take any tools or maybe just the turn of a few screws like on the Cadillac Northstar. About a decade ago, I started to notice more insulation and fasteners. Some automakers like Hyundai saw the cosmetic and comedic value of


October 2013 |

these covers by making a transversely mounted V6 look like a longitudinally mounted V6. During the past five years, more of these covers are turning into sound-dampening devices so the driver is not exposed to the clatter of injectors, whir of a camshaft or the buzz of an idle air control valve. In order to accomplish this, the covers are becoming stiffer with fastener systems that could make a door panel jealous. On one 2013 engine, the cover took me more than five minutes to figure out how to remove it. Worst of all, it made the engine bay look like an appliance that could wash clothes or bake a cake. Unfortunately, these covers add one more step to a diagnosis or repair process that in my opinion is not making it into the labor guides. What is your worst engine cover? Email me at â–

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» Gonzo’s Toolbox By Scott “Gonzo” Weaver

Sometimes a Short is a Few Thousand Volts More than Expected


ne day, one of my customers called and said he just purchased a car from the police auction, but it had some sort of strange noise coming from the driver’s-side electric seat. It seems that every time he moved it, there was a strange electrical sound. He thought there was something wrong with the seat motor, and asked if I could take a look at it. “Sure,” I said. “What kind of car is it?” “It’s a Peugeot,” he answered. Within a few days, the car arrived at the shop, and after pulling it into a bay, I tried the driver’s seat. Sure enough, as you moved the seat forward an inch or two, a horrible, loud buzzing sound emanated from under the seat. Rolling the seat back would stop the noise. In disbelief, I rolled the seat forward to the spot that made the noise, but it seemed to be pretty consistent — same place, same noise. The second time I moved the seat to the spot that made the noise, I got out of the car and looked underneath. The noise immediately stopped…there was nothing, not a whisper of any strange noise or buzzing. I rolled the seat forward and back several times to produce the noise, but to no avail. What in the world was going on? I called over my helper and asked him, “Listen to this and see what you think.” The noise was gone. I explained to my assistant what had happened and he was also at a loss. I climbed back in the car and, sure enough, as long as I was sitting in the seat, it would make the noise. But, when I got back out of the car and tried it again, there was nothing. This is ridiculous. I heard the sound myself but thought, “I’m not going crazy, am I?” I got out again, and this time I had my helper get in the car and move the seat. He moved the seat forward and it starting making the noise. I told him to lift his butt out of the seat…and the noise stopped immediately. He tried several times, and then I tried a couple of times.


October 2013 |

Actually, we were having fun with it. One of us would sit in the seat and make a fake pistol with our fingers as if we were shooting each other. We would raise and lower our butts in and out the seat and pretend we were Buck Rogers or something. “OK, enough fun, sit back down,” I said, “I’ll look underneath this time.” I got down to where I could look under the seat, and at about the same time he was putting his weight back into the cushion. Then, I spotted the problem. Oh my! I had to look again and again just to confirm what I was seeing. My helper asked: “What is it?” with great surprise and anticipation. As I looked underneath the seat, I could see a perfect bluish-white lightning bolt glow about an inch or so long. It was pointed right at the bottom of the cushion, but only a fraction of an inch from the seat’s metal bracing. In a very calm voice I told him, “Now listen carefully, I want you to raise your butt out of the seat, and I’ll move the seat toward the rear. There is a police taser pointing at your keister right now. Move very carefully, and I don’t think you’ll get shocked.” I think it shook him up a bit. But he carefully lifted his weight out of the seat. The Taser was the exact same color as the carpet and underside of the seat. It was so well camouflaged that it appeared to be a part of the seat mechanism. If it weren’t for the lightning bolt, I don’t think anyone could have spotted it. It really looked like a part of the seat brackets. After moving the seat back, the Taser eased off of the button and came back to rest with the business end pointing harmlessly away from his “derriere.” I then reached under the seat and carefully pulled the Taser out. I called the customer and told him what I found, and to say the least, he was shocked. So were we for that matter…well, almost. ■

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New Federal-Mogul ‘SmartChoice Mobile’ App Speeds Repair Process Through Real-Time Connection to Parts and Customers Federal-Mogul has introduced a powerful, free mobile app designed to help automotive service providers dramatically increase operational efficiency, sales and customer satisfaction. The innovative new “SmartChoice Mobile” app enables shop owners, service writers and professional technicians to use their iPhone or Android devices to instantly access the latest parts information for virtually any passenger car or light truck and communicate detailed inspection findings — including photos of worn or broken parts and a repair estimate — directly to the vehicle owner. The SmartChoice Mobile app is available immediately through the Apple App Store and Google Play as well as Federal-Mogul’s new website. “SmartChoice Mobile is much more than a parts lookup tool – it helps speed the entire repair process by providing extensive parts and repair information and establishing a real-time connection with the vehicle owner,” said Brian Tarnacki, director, global market strategy, Federal-Mogul. “This free solution sets the bar for all automotive service apps and positions the shop as a technology leader committed to customer service excellence.” The app includes VIN scanning technology that allows the user to instantly capture critical vehicle information and access all corresponding part and repair information via Federal-Mogul’s applications database. The app also provides comprehensive lookup options such as specific part number/interchange search or traditional year, make and model. The service professional can use the app’s “Send Inspection Results” feature to compose and send a shop-branded email — featuring inspection results, repair estimate and images of worn parts — to the vehicle owner. This customizable email summary also includes instant-reply and callback buttons to encourage the vehicle owner to ask questions and/or authorize the repair. A “Chat with a Pro” feature automatically connects the shop professional with an ASE-certified technical specialist at the Federal-Mogul Technical EducationCenter (F-M TEC). The app also includes a link to Federal-Mogul’s growing library of technical information and latest news. To learn more and to download this free business-building tool, simply search for “SmartChoice Mobile” in the Apple App Store or Android Market or visit Go to

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» Aftermarket Update Wagner ThermoQuiet First Ceramic Full Line Brand of Brake Pads to Achieve Low-Copper Certification Wagner ThermoQuiet Ceramic brake pads featuring Wagner OE21 formulations are the first full line of replacement ceramic pads to achieve lowcopper certification. Approval was provided by NSF International, the independent registrar overseeing manufacturer compliance with copper legislation. The official industry “LeafMark,” indicating compliance with 2021 legislative requirements, will now appear on Wagner ThermoQuiet Ceramic boxes. Federal-Mogul has developed OE21 low-copper formulations specifically for the Wagner ThermoQuiet aftermarket product line. These new ThermoQuiet low-copper ceramic pads are 35% quieter while providing 15% more stopping power and 40% greater fade resistance than previous formulations. “These low-copper certifications demonstrate that Wagner Brake is leading the way in address-

ing the latest environmental regulations. In addition, our engineers have redefined the science of ceramic friction technology by developing ecofriendly formulations that provide across-theboard improvements in overall braking performance,” said Martin Hendricks, vice president and general manager, braking, Federal-Mogul. Reduction of copper content in vehicle friction materials is required with the recent passage of environmental legislation in California and Washington. This legislation mandates that the use of copper in new OE and replacement brake pads be reduced to less than 5% (“Low-Copper”) of material content by weight by Jan. 1, 2021. To learn more about the proprietary OE21 lowcopper friction formulations and Wagner ThermoQuiet Ceramic brake pads, visit

October is Car Care Month October is Fall Car Care Month and the Car Care Council urges shops, stores and other industry organizations planning community car care events to register their events at www.carcare. org/industry-participants/ host-an-event. Events registered on the Car Care Council’s website will be promoted by the council through its various social media platforms, including Facebook, Twitter and Pinterest. In addition, the council has a map feature at to make it easier for motorists to locate a vehicle check-up event in their area. Each year during Fall Car Care Month, hundreds of community car care events are conducted nationwide by

independent repair shops and auto parts stores as well as vocational schools and other aftermarket organizations. The free inspections held during these events have revealed that a vast majority of vehicles require some type of service or new part and provide an opportunity for technicians to talk one-on-one with motorists in a fun, nonthreatening environment. The Car Care Council is the source of information for the “Be Car Care Aware” consumer education campaign promoting the benefits of regular vehicle care, maintenance and repair to consumers. For a free copy of the council’s Car Care Guide or for more information, visit

22 October 2013 |

Federated Free Fuel Fridays Back On Facebook Federated Facebook fans have spoken. Federated Free Fuel Fridays has returned to the Federated Auto Parts and Federated Car Care Facebook pages. Federated will give away two $50 gas cards on each of its Facebook pages every Friday through Oct. 25, 2013. Fans of Federated can enter for a chance to win and will receive extra entries when sharing the contest with their Facebook friends. “Federated Free Fuel Fridays was a big hit with our Facebook fans earlier this year, so we decided to bring it back as a ‘thank you’ to our loyal followers,” said Phil Moore, senior vice president for Federated Auto Parts. “We received so many wonderful posts and emails about this contest, so there was no question that we should run it again.” For more information, visit ■

» CustomerStates...

“The car will not start and please ignore the soda can tab holding the crankshaft position sensor.” “Customer came in with a 2007 Honda Civic with an intermittent no-start condition and leaking water pump. As I removed the timing belt and balance shaft belt, I noticed this soda can tab holding one of the crank sensors in place. Apparently, the customer knew of this from a year ago when the balance shaft belt broke but couldn’t afford the sensor or a new water pump. While the customer waited to have the recommended repairs, the leaking water pump washed the bearings of both the tensioner pulleys. After replacing the water pump, both belts, both tensioner pulleys and the broken crank sensor, the customer was happy to have his little Civic back on the road. He promised to not go the cheap route again.” ■

Marty Tate Tuffy Auto Service Tallahassee, FL


October 2013 |

If you have your own “customer states...” story and picture of a problem that was ignored for too long, please send it and you could win $50 if your entry is selected to appear in the magazine. Send your entry to Thanks!

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Diagnosing Blown Fuses By Omar Trinidad, contributing editor


esides the multimeter, test light and a terminal jumper lead kit, diagnosing blown fuses requires a device that can be utilized as a resettable fuse (Figure 1). A circuit breaker, similar to those found on early model vehicles, or a positive temperature coefficient thermistor (PTC), found in any electronics store, can replace the fuse during blown fuse diagnosis. It is important to choose the proper amperage rating for these devices to protect the circuit from further damage.

Figure 1

Similar to diagnosing other electronic problems, diagnosing blown fuses can be categorized into four main stages: verify the complaint, understand the circuit, isolate and test, fix and verify the fix. However, before jumping into diagnosis, it’s important to ask the customer about any changes made to the vehicle prior to the issue. Adding loads to an existing circuit can cause fuses or other components to fail. Another important question to bring up to the customer relates to the type of condition in which the issue occurs. One last important question to ask is if the vehicle has already been seen by another technician. The next step is to verify the complaint. This stage requires utilizing the circuit breaker or PTC to verify the conditions that cause the fuse to fail. Additionally, a thorough visual inspection should be performed to look for exposed wiring, melted components or anything that will slow down the rotation of a motor.


October 2013 |

Problems that occur based on temperature can be triggered with a test drive or a heat gun. A spray bottle can be utilized to simulate moisture. If the failure of the fuse is related to movement, a shake down test can be performed by slightly tugging on the wiring harnesses until the circuit breaker or PTC opens. Although these steps seem like simple diagnostic procedures, it might take a long time to find the problem without any knowledge of which circuit the fuse powers. Understanding the circuit is very beneficial to diagnosing the problem. This second stage includes fully assessing the power distribution and wiring schematics. The power distribution schematics provide information on which system or systems the fuse is designed to protect. Once the problem is verified and the circuit is understood, the third stage is to isolate and test the circuit based on the information gained from the prior stages. Based on the perceived location of the problem, sections of the circuit can be isolated by disconnecting connectors, loads, switches or modules. Testing the circuit for shorts requires the use of an ohmmeter to test for continuity to ground or another wire. A quick way to test for a short to ground is to test continuity from the suspected wire to ground while the section of the circuit is disconnected from the rest of the system. If the wire is shorted to ground, the meter will indicate a resistance lower than 1â„Ś (Figure 2). A similar test can Figure 2

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be done if a wire is suspected of being shorted to another wire. It’s very important to verify that the section of the circuit being tested is isolated from the whole system. False readings may be found if not isolated. Fixing shorts usually requires replacing a section of a wire or taping the exposed section of the wiring harness. Depending on the nature and severity of the problem, components, wiring harnesses or loads might need to be replaced. Below are two case studies to better illustrate the diagnostic procedure for issues that cause fuses to fail.

Figure 3

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28 October 2013 |

Case Study 1 The customer complains that the fuse fails when the system is turned on. After verifying the complaint, the next step is to understand the circuit (Figure 3). Due to the fact that the issue occurs only when the switch is turned on, the problem must be after the switch. On the contrary, if the fuse failed regardless of switch position, the problem would be a short to ground on the wire between the fuse and switch. In the current situation, the fault in this circuit will be found in one of the three following areas: the wire before connector C201, the wire after C201 or at the loads. A short to ground at either wire before or after C201 will cause the fuse to fail once the switch is turned on. An internally shorted light bulb or if both wires going to a load are shorted together will also cause the same issue. It would be best to test the resistance of the loads first. They should both be within specifications. Due to the nature of the issue at hand, a load with very low resistance will cause the fuse to fail. Once the

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» TechTalk


load is verified, the problem can only be on the wires before and after C201. One way to isolate the two sections is by replacing the fuse with a test light and unplugging C201. If the test light stays illuminated when the connector is disconnected, the wire between the switch and C201 is shorted to ground. However, if the test light turns off with C201 disconnected, the problem is the wire between the connector and loads. A continuity test from the faulty wire to ground can be performed to fully show and verify the short circuit. With the loads taken out of the circuit and C201 disconnected, there should not be any continuity to ground on the wire between C201 and the load. The last step would be to replace or repair the wire, and verify the fix. Case Study 2 The customer complains that the vehicle intermittently dies while accelerating, going over bumps and turning left. A blown 30-amp fuse, which powers multiple circuits including the fuel pump circuit, is found to be the cause. One of the hardest faults to diagnose are the those that seem intermittent. It’s best to first study the situation or environment that causes the fuse to fail and try to simulate the exact cause. As listed above, time, temperature, moisture and movement are some of the variables that can cause intermittent problems. Though it’s easy to see that the problem on the second case study seems to be caused by the jouncing movement of the vehicle, which would be easy to simulate, there are two other variables that need to happen. The vehicle must also be in motion while turning left. After verifying the fault in a safe area away from other drivers, it was found that the fault would occur even while moving straight forward. This takes away the variable of turning left. This case study also illustrates the need to filter information from customers. Some will be helpful, but some can be misleading. Once the correct variables have been verified, the next step would be to understand the circuit. However, due to the intermittent characteristic of the issue at hand, it would be difficult to understand where the problem lies. The only step left would be to isolate and test, but it would be very difficult and dangerous to diagnose a moving vehicle. The movement causing the fault in the circuit needs to be simulated while the vehicle is in the bay. Due to the nature of the prob30 October 2013 |

Figure 4

lem, performing a simple shakedown test, with the engine running, was the best way to solve the problem. A PTC or circuit breaker should be utilized in place of the fuse to indicate the high current flow. In addition, a test light can be wired after the PTC or circuit breaker to provide a visual clue of when the fuse would fail. With everything connected as shown in Figure 4, the technicians tugged lightly on the wires around the suspected area. It is best to start from the wiring harness connected to the fuse box and out to the rest of the circuits. The fault in Case Study 2 was found on a wiring harness that had rubbed against a bracket in the engine compartment. After seeing the problem, it was very apparent that the exposed wire in the wiring harness would rub against the bracket when the engine moved during hard acceleration. Furthermore, the fault occurred over bumps when the wiring harness hit the exposed portion of the painted bracket. The problem was fixed by wrapping electrical tape around the exposed wire, replacing the damaged corrugated plastic tube, and finally by rewrapping a portion of the harness with electrical tape. Diagnosing blown fuses can at times be frustrating, but the diagnostic steps listed above should help pinpoint the issue causing the problem. The importance of verifying the variables causing the fault and understanding the circuit can help highlight the fault. Furthermore, the two case studies detailed several issues that followed the diagnostic procedures and highlighted the steps to isolate and test the circuit. Lastly, it’s important to understand that high current is the main cause for blown fuses. Thus, the main question that should be asked is, “What is causing the increase of current flow?” ■

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» DiagnosticDilemmas


What You Can’t See Can Cause a Misfire By Gary Goms, contributing writer


oing mobile part-time diagnostics, I get more than my share of no-code driveability complaints from local shops. In most cases, solving the no-code driveability complaint calls for “thinking out of the box.” The “box” in this case is the enabling criteria required for setting an OBD II diagnostic trouble code (DTC). To give the no-code issue some perspective, early OBD I engine control modules (ECMs) could detect a circuit fault like an open or shorted-to-ground circuit in a sensor and could, in many instances, rationalize inputs from two or more sensors to diagnose a third sensor. But most wouldn’t run diagnostics until the engine reached a closed-loop status with the coolant temperature exceeding 160° F and the oxygen sensors switching voltage from about 200 to about 800 millivolts (mV). Because these on-board diagnostic systems often didn’t detect some of the most obvious failures, many experienced techs left their scan tools on the shelf and began rounding up the usual “no-code” suspects through the expert use of a digital voltmeter and lab scope. On-board diagnostics were vastly improved when OBD II appeared on all 1996 passenger and light truck vehicles. For the first time, technicians were treated to a standardized, well-defined, on-board diagnostic system that began running test monitors, often as soon as the ignition switch was turned on. Most OBD II systems could recognize circuit faults, low and high voltages in specific circuits, intermittent circuits, and out-of-range or rationality faults. It’s also important to remember that OBD II popularly introduced the misfire monitor, which detects cylinder misfires. In addition, many vehicles begin entering fuel control and closed-loop mode as soon as the oxygen sensors begin generating voltage signals. Thanks to the use of heated oxygen and air/fuel ratio (AFR) sensors, fuel control and closed-loop status are now being achieved within seconds after the engine starts. Last, all of the hundreds, if not thousands of “glob-


October 2013 |

al” DTCs list enabling criteria that provide exact conditions under which the test monitor runs and how that test monitor generates and stores a diagnostic trouble code. Last, most OBD II global DTCs include “freeze frame” data that describes the driving conditions under which the DTC was recorded.

The No-Code Dilemma With that said, what happens when we experience an intermittent, no-code driveability complaint? Obviously the engine isn’t running well, so why isn’t a DTC being stored in the vehicle’s OBD II PCM? At this point, we can only speculate because the factual answer to this problem is likely hidden deep in the vehicle manufacturer’s research and engineering data. Maybe the engineers didn’t visualize a problem like the one we’re experiencing, or

» DiagnosticDilemmas the latest PCM calibrations is an essential part of the diagnostic process.

The Mysterious Dodge Ram Now that we’ve briefly discussed enabling criteria and how the PCM might detect circuit failures and store diagnostic trouble codes, this month’s Diagnostic Dilemma involves a 2005 Dodge Ram 1500 series truck equipped with automatic transmission and 5.7L Hemi V8 engine with 250,000 miles on the odometer. Before I get too deeply into the no-code problem affecting this vehicle, let me note that this particular vehicle has been experiencing a number of electrical/

maybe they did, but couldn’t devise a diagnostic monitor that would accurately measure and record that specific condition. Or maybe the condition lies outside the parameters originally written into the DTC’s enabling criteria, which might require a reflash or reprogramming to correct. And some monitors like the OBD II misfire monitor are occasionally re-engineered several different times to eliminate false DTCs by raising the threshold of the enabling criteria. This is why checking the current calibrations in a PCM and checking TSBs for

electronic problems, including repeated fuel pump failures for several years. The repeated fuel pump failure was dealt with by thoroughly inspecting the fuel tank for abrasive debris, installing a quality fuel pump and relay, meticulously inspecting the wiring harness and cleaning the fuel pump ground located in the engine compartment. But this Ram 1500 also began experiencing a jerking or “trailerhitching” sensation when the driver applied light throttle to pass another vehicle. My initial clue to the exact complaint occurred during my first test drive when I accelerated from a stop sign to about 30 mph at light

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» DiagnosticDilemmas throttle. I could briefly and faintly feel the trailerhitching sensation, but could not put a finger on it or duplicate it. After letting the owner drive the vehicle, I noticed she was accelerating as if she were passing on the highway. After noticing this tendency, I asked if she noticed the “jerking” or trailer-hitching problem while passing. The answer was “yes.” Unfortunately, further test-driving failed to duplicate the complaint, much less produce significant data including engine performance trouble codes on my scan tool. The PCM’s diagnostic memory did contain some rather odd transmission DTCs, including a fluid level code and a few other codes that simply weren’t rational and therefore irrelevant to this text. In short, it’s not likely that the transmission could simultaneously fail in so many different ways. We did encounter a later failure in the total integrated power module (TIPM) that included a cranking, no-start problem and many other DTCs, but that’s a separate failure and another story altogether. But, given those automatic transmission failure codes, I began to wonder if the problem was an unlikely case of a drive clutch chattering or slipping. Upon inspection, the fluid looked perfectly clear, as did the transmission oil pan when it was removed for service. I might add that replacing a worn transmission control module (TCM) relay seemed to rem-


At 250,000 miles, this Dodge 5.7L Hemi engine began developing a number of electrical and performance complaints.

edy most of the irrational transmission failure codes, which is to be expected on a vehicle with more than 250,000 miles on the odometer. Nevertheless, the trailer-hitching problem continued to worsen as time went on.

Over-The-Shoulder Diagnostics Mobile diagnostics has very unusual limitations. For example, unless a mobile tech owns a very wellequipped van full of the latest diagnostic equipment, he might not have exactly the right equipment or tooling to diagnose the vehicle. Since he’s rarely familiar with the customer or the vehicle, he’s reliant on information provided by his client shop. Unfortunately, many client shops don’t properly interview the customer or record that information in a logical way. To illustrate, writing “vehicle jerks while driving” on the repair order is a very generalized way of describing the problem. When the mobile diagnostic tech discovers that the complaint is actually a nocode, intermittent or random performance issue, he must radically adjust his diagnostic strategy and, in most cases, get even more information from the customer regarding the specifics of how, when and where the problem occurs.

A Clue from the Distant Past A technician’s past experience is always an important part of the diagnostic equation. During the early 34 October 2013 |

» DiagnosticDilemmas 1960s, I owned a 1953 Ford car equipped with Ford’s famous “flat-head” V8 engine. Being the young gear-head that I was, I installed twin carburetors, dualpoint ignition, free-flow cast-iron exhaust manifolds, and milled the cylinder heads 0.030” to boost compression. When I started college in 1961, I moved to a college town in a much lower altitude. About one month into my first college year, I noticed that my old flat-head engine would start jerking as I approached a steadythrottle cruise at about 35 mph on College Avenue. Water and sediment from the fuel tank was always a problem in those days, so I cleaned the fuel pump sediment bowl and removed the float bowl covers on the Holley 94 carbs to check for clogged carburetor jets. Everything checked perfectly, including the distributor point gaps and timing. I even took the car to a professional tune-up shop for a scope test with no result. One night, my diagnostic “light bulb” came on, so to speak. While reviewing the characteristics of basic electricity in my college physics class, it occurred to me that I had loomed the bright-red, solid steel-cored spark plug wires parallel to each other through a pair of fancy chromed steel wire looms. Each wire popped out of the loom at precisely the correct point to attach to the spark plug. It also dawned on me that my problem occurred at cruise when my two finely tuned Model 94 Holley carbs were leaning out their air/fuel mixture. Because it requires more firing voltage to ignite a lean fuel mixture, this increased firing voltage increases the strength of the magnetic field surrounding each spark plug

wire. Since each wire ran parallel from the distributor through a steel loom, each wire was likely inducing a spark in its companion wire. When that happened, the jerking sensation was probably caused by the cylinder firing as much as 45° or more before topdead center (BTDC) at relatively low engine speeds. Many years later when I was teaching auto mechanics, we

often invited a major spark plug manufacturer to demonstrate ignition diagnostics at our community college. The manufacturer equipped a commercial van to hold all of the instructional media, including a chrome-plated, single-cylinder air-cooled engine. The most attention-getting part of each class was when the instructor ran the engine by holding two spark plug wires

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» DiagnosticDilemmas

Unlike a conventional coil-on-plug assembly, the ignition coils on this Dodge are mounted on one engine bank and connect to the spark plugs on the opposite bank through conventional spark plug wires.

parallel to each other to demonstrate the principle of how one spark plug wire can induce a spark in another wire.

Back to the Dodge As a diagnostic tech, I don’t do a tremendous amount of hands-on service work so I don’t have a working knowledge of each engine configuration on the current service market. In this case, I didn’t understand that on the Dodge Hemi V8, each of its eight ignition coils fires a respective cylinder on the


This OEM wire loom routes each spark plug wire in parallel order to its appropriate cylinder.

opposite bank through a conventional spark plug wire. So the effect is that all eight cylinders are fired by spark plug wires running in parallel to each other and held in place by a plastic guide that routes them under the air intake across the engine’s intake manifold. Sure, I’m applying an experience learned 50 years ago on a flat-head engine to a modern state-of-the art hemispherical combustion chamber V8. So, if I’m so smart, why weren’t any misfire DTCs present in the PCM? And how could Chrysler Corporation design such an obvious fault into their famous Hemi V8? And, given modern technology, how could such a problem appear on a modern vehicle?

Operating Strategy

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36 October 2013 |

Any PCM has various diagnostic strategies programmed into its memory. I don’t want to get deeply involved in misfire monitors in this space, because experienced diagnostic technicians know that most misfire monitor strategies vary too widely to describe in a few sentences or paragraphs. Suffice it to say that some nameplates don’t record misfires in an identical way to other nameplate manufacturers. And, keep in mind that many descriptions of misfire monitors are generic, rather than applicationspecific, examples.

» DiagnosticDilemmas So I speculated that the misfire monitor on this 2005 Dodge Hemi V8 is programmed to detect acceleration in the crankshaft after the crank pin passes top-dead center (TDC) on a compression stroke. If the PCM doesn’t sense that acceleration, it will store a P03XX-series misfire trouble code in its diagnostic memory. What the misfire monitor might not do is detect a sudden crankshaft deceleration when the cylinder is fired, let’s say, 45° BTDC. But it might, nevertheless, detect enough acceleration after TDC to prevent a misfire code from being stored. So the engine is running very rough, but according to the programming in the PCM, it’s not detecting a “real” cylinder misfire. With that said, why would Dodge deliberately route the spark plug wires parallel to each other through a plastic loom? The answer might lie in the construction of the wires themselves. For younger techs, the old steel-cored spark plug wires used in the 1950s and early ’60s would put on quite a light show at night, thanks to the corona produced by the electromagnetic field surrounding each wire as it fired each cylinder. While carbon-cored spark plug wires rarely produce this type of corona, they nevertheless generate an electromagnetic field that can be detected and accurately measured by the inductive pickups we use to display secondary waveforms on a lab scope.

plug wire manufacturers use a spiral-wound core that will conduct very high voltages without generating as much spark induction as conventional carbon-core wires. In this case, the OE spark plugs and wires had recently been replaced by the client shop. The technician had individually routed the premium-grade aftermarket wires through its respective groove the OE wire loom. So what could go wrong? Here again I’m speculating because I don’t have the old wires in front of me. But I’m guessing that the OE wires might have been spiral-wound or otherwise specially constructed to reduce spark induction, whereas the aftermarket replacement wires

might not. The simplest way to confirm my diagnosis was to temporarily remove the wires from the loom and allow them to cross each other at random angles to eliminate the parallel routing that is the source of spark induction. This random distribution of spark plug wires positively ended the trailer-hitching complaint. My recommendation was to install the OE wires according to their OE routing. Sometimes “thinking out of the box” to solve a no-code driveability complaint requires the experiences we gained as beginning mechanics in an age when enabling criteria and diagnostic trouble codes were terms that lay somewhere in our distant future. ■

The Rest of the Story As the late Paul Harvey might say, it’s time for the Rest of the Story. If you’re into high-performance engines, you’re probably aware that many high-end spark

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» DieselDialogue


Diesel Injection Components Coming to terms with the common rail diesel injection system is not an easy task Robert McDonald, contributing editor


or some time now, most of the development in diesel technology has been aimed toward making the engines environmentally friendly. But as diesel engines have become cleaner, the power levels have also increased. This is somewhat backward to what the country went through in the 1970s with gasoline engines. The problem back in the ’70s was we were trying to clean the engine’s emissions by adding more devices, but there were no design improvements to make any efficiency improvements. Back then, the OEs were just coming to terms with new devices to control emissions; however, technological advances and different ways of thinking have now enabled manufacturers to have the best of both worlds — more power and a greener environment. Common rail injection has been in existence for


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In order to inject diesel fuel at high pressures, you need a very unique pump known as a high-pressure fuel pump. The pump is usually engine-mounted and driven by the engine gear train.

a long time but has become more popular in diesel engines over the past decade. In order to have a cleaner running engine, you have to make it more efficient. One thing that has been discovered with diesel fuel injection is the higher the pressure at which it is injected, more efficiency is created. The purpose of common rail injection is to deliver highpressure fuel to the injector. Fuel in a common rail system will be injected into the combustion chamber through the injector nozzle at pressures as high as 28,000 psi. This is far from the mechanical systems of the past that would inject fuel into the combustion chamber at 2,000 to 3,000 psi. When diesel fuel is injected at high pressure, you can only imagine the difference in the fuel atomization. Fuel atomization, along with port swirl is the biggest contributing factor to the efficiency of today’s diesel engines. The increased atomization of fuel from common rail injection also created design changes to the pis-

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Âť DieselDialogue


ton and combustion chambers along with the design of the intake ports and valve train. In order to inject diesel fuel at high pressures, you need a very unique pump known as a highpressure fuel pump. The pump is usually engine-mounted and driven by the engine gear train. A regulator controls the amount of pressure that the pump makes. The regulator, also known as the fuel-metering valve, regulates the amount of fuel that the high-pressure fuel pump will intake. Even though the engine drives the high-pressure pump, the pump will produce the necessary high pressures regardless of the engine speed. After the pump has been pressurized, the fuel is stored in the fuel rails. The fuel rails are accumulators for the high-pressure fuel to be delivered to the injectors through lines that branch off of them. The fuel rails also dampen vibrations from the high-pressure fuel pump and

After the pump has been pressurized, the fuel is stored in the fuel rails, which are accumulators for the high-pressure fuel to be delivered to the injectors through lines that branch off of them.

injection cycles from the injectors. Inside the fuel rails is a fuel rail pressure sensor that reads the pressure in the fuel rail for the PCM (powertrain control module). The PCM uses the

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» DieselDialogue input from the fuel rail pressure sensor to determine how much to open the fuel regulator. If more pressure is needed, the PCM will command the regulator to open for more fuel to be taken in by the high-pressure pump. A fuel rail pressure control valve also controls highpressure fuel in the fuel rails. The pressure control valve is usually placed in the end of the fuel rail where it will be opened or closed by the PCM for precise pressure control inside the fuel rails. This helps to keep the optimum fuel pressure in the fuel rails to be delivered to the injectors for various demands placed on the engine. Just in case the fuel pressure was to spike abnormally, the fuel rails have a fuel rail pressure limiter inside of them also. If fuel pressure were to get out of hand for some strange reason, the limiter would open, allowing the excess pressure to return to the fuel tank. As high-pressure fuel travels through the rails and lines, it arrives at the injector, which is controlled by the PCM. When the PCM commands the injector to open, fuel enters the injector and is sent through some intricate passages in the injector that leads to the injector’s tip. The tip of the injector has microscopic holes through which the fuel will be delivered that create a very fine mist. The droplet size of the fuel as it is sent through the tip is about seven times smaller than a human hair. Injectors can be actuated by a solenoid type of driver or a Piezo electric device. Solenoid-actuated injectors have Go to


been around for some time, but have been replaced with Piezo actuation. Piezo is a type of crystal that is wafer-thin and generally stacked on top of each other. These stacks of Piezo crystals, when energized by the PCM, will expand and open the injector’s valve, and its actuation is four times faster than a solenoid. The PCM uses inputs from sensors on the engine to control actuators, which control fuel delivery. Fuel delivery is based upon demands on the engine, such as the amount of boost, the throttle position, engine temperature, etc. With the use of common rail, there can be multiple injections per combustion cycle. This can also be beneficial during cold weather start-ups. The use of common rail has brought about many advantages to the diesel engine. These advantages are higher injection pressures for increased atomization of fuel, multiple injections per combustion cycle, and more reliable pressure regardless of engine speed. The benefits include the reduction of emissions, reduction in diesel particulate matter, reduction in noise, increased fuel efficiency and increased performance. Even though diesel engines are becoming cleaner and more emission-friendly, the use of electronics along with better engineering keeps propelling power levels and durability. I think that as diesel engines continue to evolve and get even more efficient, they will become more of a competitor for the car buying public’s transportation needs in the near future. ■

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» GasketFacts


Head Gasket FAQs Can an overheating motor cause a head gasket failure? One reason head gaskets fail is because of engine overheating. If the engine gets too hot, the cylinder head can swell to the point where it crushes the head gasket (usually

bolt breaking. Some replacement head gaskets come with new TTY head bolts, but

to lubricate the bolts before they are installed, can cause false torque readings when the bolts are tightened, which may allow the head gasket to leak. between the cylinders because this is the thinnest point). The extruded material and/or cracked combustion armor then provides a leak path for coolant and/or combustion gases.

Can head bolts be reused? Bolt breakage and uneven gasket loading or loss of torque can cause a newly installed head gasket to leak. TTY head bolts are designed for one-time use because they stretch permanently once they are torqued down. This helps even out the clamping force of the cylinder head on the head gasket. But if the bolts are reused, stretching them even farther greatly increases the risk of the


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Can engine knock cause a head gasket to fail? others do not. If the bolts are not included, they should be included as an addon sale. Many customers may not realize they should not reuse TTY head bolts. If an engine has conventional head bolts, it’s okay to reuse them — provided the bolts are in good condition and the bolts are not stretched. Bolts can be cleaned, then lightly oiled and reused. Dirty or damaged threads, or failing

Another reason head gaskets fail is because of damage caused by detonation (spark knock). Detonation causes a sharp spike in combustion chamber pressure, which, over time, can overload and crack the gasket armor that surrounds the cylinder. This leads to burn through and loss of compression. Detonation can be caused by a variety of problems. One is an accumulation of carbon in the combustion chamber that increases compression. Many late-model

» GasketFacts

engines run fairly high compression ratios, and some require premium octane fuel. If compression reaches a point where the fuel ignites spontaneously before the spark can set it off, the engine will knock and ping under load.

What is the best way to pinpoint a head gasket leak? Doing a cylinder leak-down test rarely misses a problem and provides the added advantage of knowing which cylinder is leaking. This looks more closely at that cylinder for cracks or problems that will affect the success of the repair. The leak-down test also gives the best look at how well the cylinder is sealed from a mechanical perspective. A leakdown test is more labor intensive than other methods and the customer has to understand the costs involved, but it beats pulling a head off without being sure there’s a problem. This test

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involves removing the spark plugs and filling the cylinder with compressed air, while monitoring how well the cylinder holds pressure.

Why are some vehicles more prone to head gasket failures? Sealing problems are inherent in bi-metallic engines because aluminum cylinder heads expand faster than cast-iron cylinder blocks during the warm-up cycle. The difference in expansion rates is further aggravated because the cylinder head tends to heat up much faster than the cylinder block. The difference in expansion rates between aluminum and cast iron creates a “scrubbing” effect that eventually wears out the stainless steel “fire ring” that keeps combustion gases from entering the cooling system. Because the cumulative effect of these repeated thermal events results in failed cylinder head gaskets,

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» GasketFacts most aftermarket gasket manufacturers have designed head gaskets using space-age materials that resist scuffing wear in bimetallic applications.

How can you test for exhaust gas in the coolant? One way to test for exhaust gases is a dye that will change color if exhaust gasses are present. This test works well as long as you follow some precautions. The first is to be sure the dye is good; it doesn’t have a long shelf life. The other is to be careful that none of the coolant finds its way into the tester and gives you a false reading. Some techs have had good success using their gas analyzer to look for hydrocarbons coming out of the radiator, but be very careful about the coolant being ingested here.

Can a leak only occur during warm-up? Yes. Temperature-related fail-

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ure patterns are the most common. As always, the primary symptom of a leaking head gasket is increased consumption of coolant with no apparently visible external coolant leakage. If cylinder leakage occurs during coldengine operation, combustion gases accumulate under the engine’s thermostat during cold engine operation, forcing the coolant back through the radiator and resulting in an overflow condition at the coolant reservoir. If, on the other hand, leakage occurs only under full throttle, hot engine operation, the coolant may become aerated with combustion gases, which reduces cooling system efficiency and increases operating temperatures.

What determines the gasket surface of the head and block? The level of surface finish is determined not only by the engine materials, but the gasket type. The aluminum

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» GasketFacts


cylinder head surface should be resurfaced to the cylinder head gasket manufacturer’s specifications. In short, the head gasket surface should appear polished rather than rough, with composite gaskets requiring a finish of no more than 45 roughness average (RA) and MLS gaskets a finish of 20-30 RA. The rougher the surface on an aluminum cylinder head, the shorter the cylinder head gasket life.

When can you start a head gasket job? Always allow the engine to cool to room temperature before removing the cylinder head. ■

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» Diagnostics


Bringing Down the Bus: Battling a BMW No-Crank By Brian Wing, contributing writer


s a mobile diagnostic tech, I spend my days with a song in my head. I love going to a different shop every day, interacting with the techs and shop owners, and solving issues that have everybody running in circles. It feels good to help a crew get past their “problem cars” so they can get on to the profitable work. Occasionally a diagnostic challenge comes along that forces me to consider how intricately modern vehicles have evolved. The other day a client shop called to tell me they had a “BMW paperweight” on their lot that would not crank. “It’s a 2003 745i; we’ve checked everything we can think of,” the shop owner cringed. “We’re about to replace the DME (engine control unit), but wanted to get a second opinion before we go there. We’ve already replaced the battery, the starter, main relay and ignition switch assembly. This beast is going kill us.” I arrived at the shop and verified the no-crank condition. The dash lit up brightly, but no starter action was forthcoming. Beginning with the basics, I tested power supply at the ignition switch, behind the Car Access System (CAS). This is the module in which the key is inserted. Power and ground was intact; I tested at the starter and found actuation voltage unavailable for starting. Next I connected a scan tool and interrogated the DME for faults. No faults were stored, and none were pending. My heart sank as I realized this would be no easy diagnosis. It was right about this time that the day’s song jolted into my head: “Don’t Bring Me Down” by Electric Light Orchestra. The problem was definitely bringing me down. I asked the shop owner to get on the horn with the customer and ask if they had all the keys for the vehicle in their possession. The customer supplied the other key, but it lacked the magic to breathe life into the creature. This confirmed it was not a key failure. It also proved the owner had not been kidnapped (seriously; BMW’s engineers programmed this model to arrest start if a key is


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» Diagnostics


detected in the luggage compartment, figuring if a key is in there, the owner must be too!). Those Germans think of everything. Since the DME gets its wake-up signal from the CAS, I monitored the DME PID for the signal from the CAS. As I suspected, there was no signal. This more than likely ruled out a failed DME, but it didn’t get me a whole lot closer to finding the actual culprit. We had to find out why the CAS was not sending the signal, but without a factory scan tool, we had no way of communicating with it. Fortunately, there is an alternative to buying the expensive BMW hardware. With an approved J-2534 pass-through device and a subscription to BMW’s website (coupled with steady patience), we have the same diagnostic and reprogramming capabilities as a dealer. I fired up the laptop and connected to BMW’s site, attempting to interrogate the CAS. And wouldn’t you know it, there was no communication possible.

This car just about had me on the floor. A communication issue? This didn’t seem to be getting any easier. Whatever was causing the communication problem was most likely our nocrank prankster. Thinking I may have a software problem with the pass-through device, I attempted to communicate with modules on the PTCAN (engine controller, transmission controller, etc.). I found they all interacted normally. But when I tried to communicate with various body control modules, they, like the CAS, wouldn’t sing. It seemed there was an issue with the dual-body busses (K-CAN-S and K-CANP). That makes sense; the CAS is the “gateway” for the two Kbusses and, if inoperable, both busses would fail to communicate. I was beginning to suspect a shorted CAS; the light at the end of the tunnel had me singing again. I accessed the CAS and disconnected it, expecting to see revived bus signals. My hopes were soon dashed; the CAS was

» Diagnostics


not guilty of shorting the busses to ground; it was a victim. Now I would have to unplug all the K-CAN-S modules one by one until the busses came back to life (K-CAN-P modules were designed so any short circuit in one module would not pull down the entire bus). I began with some of the modules that are more easily accessible; the center console control module (BZM), the sunroof module (SHD), the driver’s seat module (SMFA), etc. When I arrived at the integrated heating and air conditioning (IHKA) control unit, disconnecting it brought back communica-

tion on both K-busses; the car started immediately and ran like…the ultimate driving

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62 October 2013 |

machine. I reported to the shop owner that the IHKA module had short-circuited internally and was pulling the K-CAN networks to ground, requiring replacement. He sourced and installed an IHKA module; programming and coding of the new unit was carried out to complete the repair. This case illustrates how complex and interdependent vehicle control systems have become. Utilizing the proper resources and factory repair information to determine how a given system functions is imperative if we want to stay ahead of the curve and keep these customers loyal. We should not be surprised anymore when the failure of a seemingly unrelated item, like an air conditioning controller, causes a no-start condition. Sometimes the song in your head is just a meaningless ditty to pass time. In this case, I can’t help but think what the K-CAN might be singing to the IHKA module. ■

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Dill Air Controls TPMS Educational Videos To view the videos, go to

Elite Shop Management Training Seminars/Webinars For more information, visit

Federal-Mogul Technical Education Center To register for a Federal-Mogul TEC training workshop and to access any archived webinar, follow the “Aftermarket” and “Technical” links at or call 888-771-6005. To register for any Federal-Mogul TEC live webinar, go to

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SKF: Book an SKF Technical Training Truck Nothing beats a face-to-face training session with a technical expert. SKF technical training trucks can deliver hands-on technical training right to your location. Contact your SKF representative or call 800-882-0008 for details!


October 2013 |

Standard Motor Products TechSmart Tech Session Training Videos Available for viewing at TechSmartParts and TechSmartParts by clicking on the video channel button.

VDO REDI-Sensor TPMS Training Video Shows technicians the proper procedure for maintaining and replacing damaged VDO clamp-in TPMS sensor valve stems. Watch the video along with other REDI videos here:

WORLDPAC Advanced Technical Training Program Dates The WORLDPAC technical training program provides advanced level diagnostic training for independent repair technicians. The complexities of properly diagnosing and repairing late model vehicles requires training, that until now, has not been readily available to the Independent Repair Professional. • October 12: Volvo VIDA, Portland, OR • October 12: VW and Audi Engine Management and Scan Data Diagnostics, Fort Lauderdale, FL • October 12-13: Porsche M96, Atlanta, GA • October 19-20: BMW Chassis Dynamics III, Houston, TX • October 19-20: Modern Diagnosis and Service Techniques, Milpitas, CA • October 26-27: Mini R56, Milpitas, CA • October 26: Volvo Engine Management, Raleigh, NC • November 2: Volvo VIDA Diagnostics and Networking Systems, San Francisco, CA • November 9: VW and Audi Engine Management and Scan Data Diagnostics, Portland, OR • November 9: BMW Motorsport II, Milpitas, CA • Novemebr 9: MINI R56 Complete Vehicle, Cambridge, MA Register at under Technical Training Seminar or call your WORLDPAC associate at 800-888-9982 ext. 5470. ■

» WireSplicing





long time ago, I learned a method of splicing wire that has stuck with me since those early days. I actually picked this method up while I was in the military (USMC), so I can’t take credit for inventing it or perfecting it. The resistance from a weak connection or poor connection can produce a tremendous amount of centralized heat. This heat can build the longer the current is flowing, which increases the resistance even more. Electricity does not flow “in” the wire, but actually travels “on” the surface of the wire. This is one of the many reasons why there are so many small strands in a given wire. A butt connector is a very small connected surface, the surface area of the strands in a wire are not entirely used. The strands in the middle of the wire are trapped between the other strands and have no chance to pass their electrical effort. This forces the current to travel only through those strands that are actually touching the surface of the butt connector. More heat buildup will be the result of fewer wire strands being used. Using this hand-splice method will allow a great deal more strands from each wire section to be touching the spliced area as possible. First, strip back about 3/4 of an inch of insulation from both of the wires that you’re going to be splicing. Add a section of shrink tubing onto the wire. (Don’t forget this step… or you’ll regret it after you’ve finished the


October 2013 |

splice.) Divide the bare strands into two equal sections and form them into a “Y.” Hold a wire in each hand, and then take the “Y” and interlock the two wires together. But, (very important) leave room between the two “Y”s that’s large enough for the outer insulation from the “none” strip section of wire to easily pass through. Lay the “Y” sections down along the wire without bending them backward, straight and even with the wire. Find the edge of the gap you left in the “Y”s (That thickness measurement of the outside insulation, just about halfway between the two wires). Using one hand, pinch down on that spot while taking the legs of the “Y” from the same side and stand them straight up 90 degrees from the splice. Now, using your other hand, with firm finger pressure, rotate the two legs of the “Y” around the splice toward the opposite wire. If done correctly, the spacing you left between the two “Y”s will actually lie down and end up right where the insulation begins. Also, as you pinch and roll the bare wire, keep it as snug as possible. You want to end up with it no larger than the outside diameter of the insulated sections. Now switch procedures from the right hand to the left hand and stand the other set of “Y”

» WireSplicing legs 90 degrees, do the same crimp and turn all the way to the other insulated section of wire. Once you’ve got the hang of it, you’ll find that the splice is extremely strong, even without solder or shrink tubing. When soldering, be sure not to soak the splice with solder. The solder should only aide in holding the splice in place so it won’t unravel. Obviously, the shrink tubing is for overall weather protection, and to shield the bare wire.

Done right, the splice should have plenty of mechanical hold without soldering. I don’t recommend this for battery cable (4 gauge and larger). Crimped or soldered connectors are still the best method for them. But for the average gauge wire, this method works extremely well. Give it a try, and when you've mastered the technique, try it on your friends and see how much effort it takes them to pull it apart, even without soldering it. ■

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» Electrical

ALTERNATORS By Andrew Markel, editor

Alternator Pulley Diagnostics



hen faced with an illuminated charge light diagnosis on most late-model vehicles, do not automatically assume the problem is inside the alternator and potentially unserviceable. The problem could be the pulley and belt drive system. Neglecting to test and diagnose the pulley can lead to unnecessary replacement. Almost every late model car or truck is equipped with an overrunning alternator pulley (OAP) or an overrunning alternator decoupler (OAD). An OAP is a one-way clutch like a socket wrench that turns in one direction and locks when turned the other direction. An OAD operates in the same manner, but has a special clutch and spring that absorbs vibration to smooth out vibrations in the drive belt system. Regardless of the type, the pulley should be checked before condemning and removing the alternator. These new pulleys allow the alternator to “free-wheel” or “overrun” when the belt suddenly slows down. This prevents the belt from slipping and reduces vibration. Best of all, the system need less tension and even a narrower belt can be used. This can result in a 1.5% to 2% fuel economy improvement. However, these pulleys have a limited lifespan due to how they operate internally. OADs and OAPs behave the same, except the OAD will have a “spring feel” because of the internal spring. Testing can be performed on the vehicle with the belt attached.


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Inspection Procedure 1. Raise engine speed to 2,000-2,500 rpm in Park (auto trans) or Neutral (manual trans) and then shut off the engine. Listen for any noises from the OAD after the engine is shut off. A worn-out bearing will generate a “buzz” noise during this test. If the OAD is noisy during this test, replace it. 2. Remove the cap, and with the proper tool inserted into the front of the OAP, rotate the alternator’s shaft in both directions. In the overrun direction it should feel smooth and in the drive direction it should have a spring feel. • If the pulley is locked up, replace it. • If the OAD has no spring feel in the drive direction, replace it. • If the OAD requires more than 9-13 in./lbs. (1-1.5 Nm) of torque to turn in the overrun direction, replace the OAD. • If the OAD is not smooth in the overrun direction, replace it. Courtesy of Litens Automotive Group ■

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Failure Profiles WHEN AND WHY PUMPS FAIL By Gary Goms, contributing writer


lthough the modern water pump may appear simple in design, the actual coolant circulating capacity of the pump is based on mathematical models that take into account the amount of heat generated by the engine under various driving conditions. Severe operating conditions, for example, may range from stop-andgo driving on a hot day to pulling a camping trailer over a high mountain pass on summer vacation. The impeller is designed to circulate coolant by using centrifugal force to impart motion to the coolant. Impellers are designed for either clockwise or counter-clockwise rotation so, for all practical purposes, an impeller driven in opposite rotation becomes a very inefficient coolant pump. In addition, an impeller must fit the water pump housing and engine block cavity perfectly to achieve optimum efficiency. In the modern vehicle, water pumps are designed to consume as little engine torque as possible while achieving the greatest possible coolant circulation. Consequently, the water pump is a compromise between circulating too little coolant at engine idle and too much coolant at maximum engine speed. Too little coolant circulation obviously causes overheating, while too much circulation wastes gasoline and aggravates water jacket erosion. Most passenger car water pumps may be designed to deliver approximately 10-gallons-perminute flow at normal engine speeds. Here again, the flow depends largely upon the engine’s size and average load. Many manufacturers also boost water pump performance by installing molded plastic impellers, which may operate more efficiently than stamped alloy steel versions.


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Failure Profiles Leaking shaft seals, which are the most common water pump failure, usually reveal themselves by leaving a coolant stain around the vent area. Shaft seal leaks can be difficult to diagnose because they can be intermittently temperature and pressure sensitive, and can be aggravated by rust and other particulate contamination in the system. Shaft seal leaks can often be diagnosed by using a cooling system pressure tester to pressurize the cooling system. In most cases, however, a visual inspection is the most reliable method simply because most intermittent shaft seal leaks are detectable only by the traces of coolant around the vent area and surrounding parts. Noisy shaft bearings are usually the second-most common water pump failure. Most shaft bearings fail due to normal wear in the bearing or due to the normal oxidation of lubricant on the bearing surfaces. In rare cases, bearing failure can be hastened by over-tightening conventional accessory drive belts. In many cases, a water pump bearing also fails because it supports an unbalanced fan assembly that also may have bent or misaligned blades. Water pump bearings also can fail because an amateur mechanic diluted the lubricant by washing the pump in a solvent tank! The third and most rare water pump failure is the impeller slipping on the water pump shaft. Since the impeller and shaft is a press-fit assembly, slippage occurs most frequently on remanufactured water pumps. In other cases where a plastic impeller is used, the plastic material can degrade through sustained heat and age. In any case, slippage can be intermittent in nature and can depend greatly upon the temperature and

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» WaterPump


speed of the engine. Last, some replacement impellers can be manufactured from inferior metals that are susceptible to rust corrosion. In most of these cases, impeller blades begin to break away from the impeller due to a rust-through condition, which results in decreasing pumping capacity and an increasing presence of

rust contamination in the cooling system.

Installation Precautions Since most water pump failures are caused by leaking seals, it’s important to inspect the cooling system for the presence of abrasive rust or sand particles. Rust, in particular, will cause early seal failure because of its abrasive qualities. Although rust is difficult to remove, it should be flushed from the system as thoroughly as possible before the old water pump is removed. Adequate flushing is aided by removal of the thermostat, which allows for a maximum water pump circulation rate. Before installing a new water pump, always compare the fan or belt pulley flange height with that of the old pump. If the height isn’t to specification, belt alignment may be adversely affected. To ensure the pump has the correct rotation, compare the impeller for similarity of configuration and size. Also, make sure that the old gasket has been completely removed from the engine block in order to maintain correct tolerances between the pump impeller and engine block mount and, of course, to prevent leaks. Before bolting the pump to the block, test for insufficient block clearance by holding the pump against the block and turning the impeller. When all dimensions and clearances have been checked, the water pump is ready for installation. To prevent damaging the new water pump seal, make sure that the engine is completely filled with new coolant before starting the engine. With that done, always warm the engine until coolant circulates freely through the radiator and all air is bled from the system. Last, inspect for leaks and check the coolant level before releasing the vehicle to your customer. ■

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» Emissions By Andrew Markel, editor


atalytic converter efficiency codes can be a long diagnostic road that can either lead to a happy customer or an expensive comeback. Chances are the original converter didn’t fail on its own, but conditions upstream hastened its demise. Catalytic converter failures on today’s vehicles are rarely caused by defects in catalytic converters. Most catalytic converter failures can be traced back to problems caused by what happens in the combustion chamber. Almost every part on the engine determines how long it will last. It could be a faulty line of computer code that pulses an injector too long, or it could be a stuck piston ring that allows oil to be sucked into the combustion chamber. These little details can limit the life of a catalytic converter.

dize hydrocarbon or fuel by turning it into inert carbon products and water (H2O). This is called reduction in chemistry and breaks down molecules into smaller parts. The precious metals act as catalysts in the process and are not changed, they just store and use oxygen to break down combustion products.

BASIC CHEMISTRY Platinum, palladium, rhodium and cerium store oxygen in the converter during periods of lean operation or by an external air source. The oxygen is used to oxidize hydrocarbons and toxic gases during periods of “rich” operation. This oxidation changes harmful carbon monoxide (CO) into carbon dioxide (CO2). It will also oxi-


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However, they can’t break down or oxidize some chemicals in the exhaust stream. If the catalyst is blocked by carbon, silica or phosphorus, the converter will fail to work.

THE CODE For a catalyst efficiency code to be set, a number of criteria

must be met. The specific enabling criteria is different for almost every vehicle. For a code to be set, the oxygen or air/fuel sensor and the rear oxygen sensor must see a reduction in the efficiency of the converter. In other words, if the oxygen levels before and after the converter do not change, the converter is not working. But, this is not an automatic pass or fail. The oxygen sensors need to see this loss in efficiency over a number of drive cycle conditions. This is why it might take a few hours or a few days for the light to come back on after an efficiency code is erased and no other service is performed. On most vehicles, an efficiency code will not be set if an oxygen sensor heater code or any oxygen sensor-related code is set. The same is true for coolant and air temperature sensors. You could repair these items only to have the customer come back with the check engine light on and an efficiency code set. Even if the converter is operating below 95% efficiency or the oxygen sensor is bad, the chances of the light coming right back on are slim. If you clear the code, the light might stay off for a while until the

» Emissions system goes through two readiness cycles. This might take a couple of days or a couple of weeks. But, no good deed goes unpunished. The customer will be back and your quick fix will be forgotten. One thing to keep in mind about non-continuous OBD II monitors is that they may not catch a problem until the vehicle has been driven several times and conditions are right to detect the fault. Consequently, any time you’re troubleshooting an OBD II problem, it’s very important to use a scan tool that can tell you if all the monitor readiness flags have been set. If one or more monitors are not ready, the vehicle will have to be driven under varying speeds and loads until all the monitors are set. Then, and only then, will you get an accurate diagnosis from OBD II.

cleaning up the exhaust. But if efficiency drops much below 92%, it will usually turn on the MIL. With vehicles that meet the tougher LEV (low emission vehicle) requirements, there’s even less room for leeway. A drop in converter efficiency of only 3% can cause emissions to exceed federal limits by 150%. The LEV standard allows only 0.225 grams per mile of hydrocarbons, which is almost nothing.

PROBLEM VEHICLES Some vehicles have difficulties passing the emission warranty or replacement converter warranty before an efficiency code is set. However, there are some solutions to consider if you are stuck with a problem vehicle.

SOFTWARE WHAT IS EFFICIENCY? The converter has an efficiency rating that is computed by the vehicle. This number rates the amount of reduction that is occurring in the converter and its ability to store oxygen. But, efficiency of the converter is tied to the fuel trim of the engine. Most engines minutely alter the fuel trim to replenish the oxygen in the converter and to add fuel for reduction. This helps to keep the converter at the correct temperature for the most efficient operation. If an engine is running too rich, it cannot store oxygen. If it is running too lean, the reduction process might not occur due to an inability to heat up. If the engine is dealing with a leaking vacuum hose or a stuck injector, it can’t switch the fuel mixture properly to replenish oxygen and reduce harmful contaminates. Converter efficiency can be checked with some scan tools along with the switching between rich and lean. Lab scopes can also be used to monitor the switching. The converter efficiency threshold of a vehicle is part of a vehicle’s software. Once the efficiency drops below a specified level and other criteria are met, an efficiency code will be set. The software is designed to filter out data that may be erroneous or random signals that may interfere with the oxygen sensor. Most converters start out at about 99% efficiency when new, and quickly taper off to about 95% efficiency after 4,000 miles or so of driving. As long as efficiency doesn’t drop off more than a few percentage points, the converter will do a good job of

Some vehicles have more sensitive catalyst efficiency monitors. This means that the tests and parameters for testing that were programmed in at the factory for the efficiency of the converter might be a little too sensitive or the drive cycle is too narrow. The programming may not take into account realworld conditions. Many OEMs will release updated engine management calibrations that alter the enabling criteria of the catalyst monitors. The new calibration can then be re-flashed onto the ECM or PCM. For a vehicle with a damaged converter, the re-flash will do nothing. For a converter that is near the threshold, it may extend the life of the converter and prevent the light from coming on for 10,000 or 80,000 miles. It is always a good idea to check if the car has the latest calibration if the converter is being replaced; this can save you a comeback down the road.

OIL CONSUMPTION GM, Toyota, Honda and other manufacturers have issued technical service bulletins (TSBs) concerning excessive oil consumption. Most of these problems relate to cylinder deactivation and variable valve timing. The main culprit in these problems is vacuum generated in the cylinders sucking engine oil past the rings and into the combustion chamber. On vehicles with cylinder deactivation, the deactivated cylinder is a negative pressure and would draw oil droplets in the crankcase past the ring and eventually into the converter. This has happened on some GM and

Âť Emissions Honda engines. On some vehicles with variable valve timing (typically on the exhaust and intake cams), the valve timing could produce higher than normal vacuum pressures that could suck oil past the rings. This was the case for some recent Toyota models. While the oil getting past the rings is bad enough, the oil trapped in the rings can become carbonized and cause damage to the cylinder walls. This can lead to even more damage and more oil consumption. The oil consumption problem must be solved first before the converter is replaced. The most common fix is new engine management software designed to reduce negative cylinder pressures. Some manufacturers have also released special splash shields and oil valves to alleviate the problem. These problems may occur on vehicles with as little as 20,000 miles.

COOLANT LEAKS The chemical components of engine coolant can block and prevent the precious metals of the catalyst from storing oxygen and reducing toxic components of exhaust gases. It is not the coolant that can damage the catalyst, but the silicates, phosphates and other chemicals added to the coolant to prevent corrosion. Engineers have been using alternative chemicals and lower levels to prevent leaking coolant from damaging a converter. This is why it is critical to use the right coolant for a vehicle. Some vehicles are notorious for head and intake gasket leaks. Some of these leaks may weep over time and eventually damage the converter. Most modern cooling systems do not require the coolant to be topped off regularly. Often, closed cooling systems can go 20,000 miles without needing additional coolant. But if a driver has to top off the coolant monthly, they might be damaging the converter. Always pressure-check the coolant system and check for exhaust gases in the coolant before replacing a converter. Even the smallest of leaks can kill a catalytic converter. 76 October 2013 |

MAINTENANCE In the past two decades, the greatest leaps forward in engine technology have been in the combustion chamber. Using high-speed cameras and quartz windows to see inside a combustion chamber, engineers are about to change the shape of the combustion chamber to produce the best possible flame front that produces more power, burns the fuel more completely and at a higher compression ratio. This is called thermal efficiency. But this increase in efficiency makes it more sensitive to changes in the combustion chamber due to lack of maintenance. Carbon deposits on the pistons and valves can cause changes in the fuel spray pattern and the velocity of the air in the combustion chamber. This can cause misfires and unburned fuel to be sent to the catalytic converter. If the spark plugs are worn, a missed combustion event can cause raw fuel to be sent to the converter and burned. This can lead to premature death of the converter. If the driver continues to drive with a misfire, the driver can kill a converter in a few thousand miles. Since 1986 and the introduction of GF1 oil specifications, engine oils have had the levels of zinc, phosphorous and sulfur reduced to extend the life of the catalytic converter so the manufacturer can meet the emissions warranty of at least 80,000 miles. Zinc, phosphorous and sulfur can contaminate the

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Âť Emissions catalyst and reduce the life of the converter even on low-mile engines that consume very little oil. If racing, diesel or agriculture engine oil with high levels of these additives are used, the converter will be permanently damaged. Clogged air filters can shorten the life of the converter. Not being able to draw in enough air, the restricted air filter can cause the fuel mixture to run rich. This can shorten the life of the converter.

OTHER THINGS TO CONSIDER PCV VALVES: The spring tension of a PCV check valve is critical to the life of the catalytic converter. If there is too little tension, excessive amounts of oil can enter the combustion camber. If there is too much tension, it could cause oil sludging. Never take this inexpensive emissions device for granted because it could destroy a more expensive emissions device. Some newer vehicles use an electronic PCV valve to control crankcase vapors. Some TSBs have been

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issued and re-flash engine calibrations have been tweaked to help extend the life of the converter. VIBRATION: Broken exhaust hangers and mounts can cause the internal structure of the converter to fail. Signs of this type of damage may be a restricted converter. SEALANTS: Never use silicone-based or nonapproved sealants on systems or components that could enter into the combustion chamber. Most sealants can contaminate the catalyst and oxygen sensor and stop them from working. EGR PROBLEMS: EGR systems are designed to reduce smog-causing nitrous oxides (NOx) by recirculating a portion of the exhaust gases from each cylinder of the engine back into the intake manifold. This process lowers the combustion temperatures. Restricted flow can result in high NOx emissions and detonation (engine knock or ping) under certain driving conditions. This type of misfire can damage a converter. â–

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» TechTips

Audi \ Nissan \ Dodge \ Chrysler \ VW This month is sponsored by:

Audi Has MIL on with P1545, P0121, P0123, P0221 or P0222 stored in ECM

Affected models: 2005-’08 A6 3.2 FSI and A4 2.0 and 3.2 FSI; 2006-’09 A3 2.0; 2007-’08 A4 Cabrio 2.0T; 2007-’09 Q7 3.6; and 2008 TT 2.0

Condition: The MIL is on, with a number of incident memory entries with regard to the throttle valve are stored in the ECM. In most cases, the entries are sporadic.

The most frequent incident memory entries are:

Figure 1: Correctly preassembled wires and seals.

P1545 (throttle control malfunction). P0121 (throttle potentiometer – G69 implausible signal). P0123 (throttle potentiometer – G69 signal too big). P0221 (angle transmitter 2 for throttle actuator G188 implausible signal). P0222 (angle transmitter 2 for throttle actuator G188 signal too small).

used exclusively for wiring harness repairs. • Mark repaired areas using yellow adhesive tape. • Yellow wires and areas in the wiring harness wrapped with yellow adhesive tape mark a previously performed repair. • Perform a function test after each repair. If necessary, check DTC memory, erase and/or bring systems into basic setting.

Procedure: Cause:

1. With the ignition switched off, disconnect the battery ground (GND) cable. Disconnecting the battery ground wire is necessary to work safely on the vehicle’s electrical system. Warning: The above step must be completed to ensure safety during the repair. Also, observe all country-specific regulations. 2. Use the applicable repair manual in Elsa in addition to the following description. Check ETKA to determine if you need set 1 or set 2. 3. Lengthen wires and preassemble seals according to Figure 2: The slot to be used to remove Figure 1. 4. On the new housing, the pink lock.

There is contact resistance in the ECM wiring – throttle valve.

Service Notes: • For repairs on vehicle electrical systems, soldering is not permitted. • Do not repair crimp connectors. If necessary, lay a wire parallel to the inoperative wire. • After crimping, crimp connections must be heatshrunk using a hot air gun to prevent moisture penetration. • Yellow wires are to be


October 2013 |

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Figure 3: The single wire seal, slid as far as the stop.

remove the pink lock with a small flathead screwdriver. Use the slot marked in Figure 2 on page 80. 5. Insert all terminals into the housing until they audibly click. 6. Reinstall the pink lock. 7. Using the appropriate assembly tool, slide the single wire seal up the repair wire until it contacts the housing. Continue to slide the single wire seal into the housing as far as the stop (Figure 3). 8. Strip the wires 6-7 mm using tool VAS 1978/3. Install crimp connectors using crimping pliers (base tool) VAS 1978/1-2 with the head VAS 1978/1-1 (Figure 4). 9. Remove the car harness insulation to the appropriate length (approximately 24 cm). 10. Lay the new harness beside the old harness. Cut the original wires to fit the new harness. 11. Twist wires 3 and Go to

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5 and 1, 2, 4 and 6 as they were originally. 12. Crimp the connections. 13. Use shrink tip (VAS 1978/15) with a hot air gun 220 V/50 Hz (VAS 1978/14) to complete the installation of the shrink tubes. Note: When heatshrinking crimp connections, be careful not to damage any other wiring, plastic parts or insulating material with the hot nozzle of the hot air gun. Always observe operating instructions of heat gun. 14. Re-insulate the harness with yellow tape. 15. Check for proper function. If necessary, check DTC memory, erase and/or bring systems into basic setting. Note: If faults reoccur after repair, replace the main throttle. Courtesy of ÂŽ MotoLOGIC Repair & Diagnostics: www.

Figure 4: Crimp connectors installed on wire ends.

» Spotlight


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• Two 18V 3-in1 combo kits provide a convenient, reliable and compatible solution for technicians’ needs. The ARZ18CSP1 18V combo kit includes the ARI2061 Li-ion ½inch impact wrench, drill/driver (ARD2081) and foldable LED light (ARL2025). The ARZ18CSP4 combo kit includes the ARI2060 Li-ion ½-inch super-torque impact wrench with digital clutch, ½-inch drill/driver and foldable LED light.

• A Li-ion 12V impact driver (ARI1265) makes 105 ft.-lbs. (1,265 in. lbs. / 140 Nm) of torque, 5 percent to 58 percent more maximum torque than its leading competitors. It comes with two battery packs, a quick charger with Air-Forced Cooling System (AFCS) design and a carrying case. ACDelco-licensed power tools and accessories are available from authorized distributors. For more information on the full lineup and purchasing information, please visit

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» TechTips


Heater Core Leak Repair A classic sign of a heater core problem is when the inside of the vehicle’s windshield persistently keeps misting. Warm coolant is leaking out of the core into the vents and then condensing against the cooler surface of the windshield. The automatic response is to turn up the blowers to try and clear the mist, but this only compounds the problem. The solution is usually to remove and either repair or replace the heater core. However, this is a particularly time-consuming task, which on older vehicles is often not cost-effective. An alternative solution is to treat the cooling system with a total coolant leak repair additive. These are designed to flow throughout the cooling system, including through the heater core, to make a quick and low-cost repair. Look for a ceramic-based coolant friendly product, ideally one that conforms to ASTM D-3147. This solution is brought to you by K-Seal

Nissan Hesitates Upon Acceleration Affected vehicle: 2002 Nissan Xterra SE, 3.3L Complaint: The customer states the check engine light is on and the engine hesitates upon acceleration. The technician connected a scan tool and found code P0102 – Mass or Volume Air Flow “A” Circuit Low. He then performed an inspection of the mass airflow (MAF) sensor and related wiring harness, but found no obvious faults. Next, live data was monitored with the scan tool, and the MAF sensor read 2.2 grams per second. The MAF sensor should have read 3.3 grams per second at idle. With a multimeter, a voltage drop test on the MAF sensor ground wire was performed, and the tech found a 0.1-volt drop across the ground wire. Next, he measured the voltage at the MAF sensor connector with the multimeter, and found battery voltage was present at the connector.

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84 October 2013 |

» TechTips

Chrysler \ Dodge \ VW

Also using the multimeter, he checked for continuity between the MAF sensor connector and the powertrain control module (PCM) connector, and found continuity was present between the connectors. With the engine at operating temperature, he

used the multimeter to measure voltage at terminal 54 of the PCM, and found 0.4 volts. The measured voltage should have been 1.0-1.7 volts. It was determined there were no circuit faults and the MAF was defective.

Correction: The MAF sensor was replaced, codes were cleared, he test-drove the vehicle and completed the code set enable criteria. The check engine light did not illuminate and no fault codes returned. Courtesy of Mitchell 1’s SureTrack.

Clogged Oil Line Leads to Chrysler/Dodge Turbocharger Failure Application: 2003-’09 Chrysler PT Cruiser and Dodge Neon with turbochargers; 2T-315. Problem: Premature turbocharger failure. Cause: Extreme temperatures cause the oil circulating through the turbocharger oil feed line to burn. The coked oil buildup restricts oil flow, which leads to turbocharger failure. The oil line may appear fine externally. Solution: The oil feed line must be replaced as well as the turbocharger. Look for a turbocharger that includes a new, upgraded oil feed line with

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86 October 2013 |

heat shield, so you don’t have to source it separately. Installing this new line will restore oil flow and ensure the longest possible service life of the replacement turbocharger. Courtesy of CARDONE Industries Inc.

VW’s Check Engine Light Is On with Trouble Code P2187 Vehicle: 2004 Volkswagen Beetle GLS 2.0L, L4, MFI, SOHC Customer Concern: The check engine light is on, with trouble code P2187, too lean off idle bank 1. Potential Causes: - Defective Mass Air Flow (MAF) Sensor - Leaking Engine Vacuum - N80 Canister Purge Solenoid Tests: 1. Check and verify that there are no vacuum leaks or un-metered air leaks. 2. Check the MAF sensor grams/second readings as follows: a. Idle (about 830 rpm) 3.5 grams/sec. or more (4 to 4.5 grams/sec. preferred). b. 2,500 rpm no load, 9 to 15 grams/sec. (11 to 12 grams/sec. preferred). c. Wide open throttle road (WOT) load (drive vehicle at 45 mph in third gear and perform a WOT acceleration, observe maximum indicated grams/sec. readings on the MAF); 90 or more grams/sec. preferred. d. A MAF that exhibits consistently lower than normal grams/sec. readings can cause a P0102 code to set. 3. Check for a leaking N80 Canister Control Valve. This can cause a vacuum leak and a lean idle condition. Confirmed Fix: Replaced the MAF sensor. Courtesy of Identifix’s “Five Fast Fixes.” ■

» Shop Autolite XP Xtreme Performance Iridium enhanced spark plugs are one of Autolite’s most technologically advanced spark plugs ever. With an iridium-enhanced 0.6 mm finewire design and proprietary V-trimmed platinum sidewire technology, these spark plugs provide better durability* and a more focused ignition for better overall ignitability** and optimal performance. *Compared to 0.8 mm finewire, multi-electrode design and standard plugs. **Compared to average of other premium brands.

All-New ANCO Profile Wipers — The all-new line of ANCO Profile beam blades combines best-in-class performance with an exclusive low-profile connector system that covers more than 98% of vehicles with just 12 SKUs. Each Profile blade also features the ANCO brand’s patented Articulated Contact Technology, which permits unrestricted flexing for more uniform pressure distribution and improved conformance to curved windshields. ANCO is the official wiper blade of the National Hockey League. Visit Reader Service: Go to

BlueDevil Products’ new FUEL MD product line now offers its first installment, BlueDevil Fuel System Cleaner. From cracked heads and radiators to oil pans and transmissions, BlueDevil Products manufactures quality sealants for various repair options in automotive systems. The announcement of FUEL MD marks the debut of BlueDevil Products’ fuel and engine treatment chemicals. BlueDevil Fuel System Cleaner will remove fuel deposits while increasing vehicle performance. FUEL MD improves gas mileage, fuel efficiency, vehicle startup, and will restore a consistent engine idle while lowering fuel octane requirements. Reader Service: Go to

The Innova PRO 31603 expert diagnostic tool allows technicians to quickly retrieve vital information in order to diagnose OBD II, ABS and SRS issues. Extended Asian and European ABS and SRS coverage is available so technicians can complete more repairs more efficiently. Shop management software reports manage vehicle diagnostics. Visit Reader Service: Go to

Four new ACDelco Professional absorbed glass mat (AGM) batteries are designed for demanding vehicles such as police cars, taxis and ambulances, as well as vehicles equipped with start-stop vehicle technology. ACDelco Professional AGM batteries leverage ACDelco’s century of battery expertise and carry a 36-month free replacement warranty. Learn more at 87

» Shop The PlatinumNAPAFilter — NAPA’s Platinum filter offers technology for the latest advancements in synthetic oil and performance oil filters. Featuring a host of oil filter innovations, including wire reenforced fully-synthetic media and ultra-durable Hydrogenerated Nitrile compound anti-drain back valve (where applicable), this oil filter provides the ultimate protection in the NAPA Family of oil filters. Reader Service: Go to

The Gates Corporation recently announced the addition of 394 new parts to its catalog of quality automotive products. The new parts include turbocharger hose for VW and Audi applications, branched radiator hose, timing component kits with water pump, and small I.D. and molded hose. Gates is expanding the largest range of OE exact branch radiator hose coverage with 23 new branched assemblies. This includes 15 new numbers for popular BMW applications with OE exact quickconnect ends. Gates also added 23 new TCKWPs with many containing OE components for the most complete timing system repair solution. The Gates announcement also features two products for cold weather stock-up season: Carbon tensile cord CVT belt for snowmobiles and SCR hose assemblies with carbon fiber heating system. Visit Reader Service: Go to

The Pulstar gg1 Pulse Plug for Jeep vehicles that utilize the Chrysler Pentstar 3.6L engine have shown an increase of 6 hp over stock plugs in dyno testing conducted by Enerpulse Inc. In addition, the testing demonstrated a fuel economy increase of 4.26%. The Pulstar gg1 Pulse Plug fits the V6 engine applications for the 2011 to present Jeep Grand Cherokee in the following models: Laredo "E", Laredo "X", 70th Anniversary Edition, Trailhawk, Altitude Edition, Limited, Overland and Overland Summit Edition. It also has fitment for the 2012 to present in various Jeep Wrangler models. Reader Service: Go to

TechSmart Turbocharger Actuator — TechSmart offers the R75002 Turbocharger Actuator or Variable Geometry Turbocharger (VGT) Control Valve for Ford 6.0L diesel engines. When the VGT actuator fails, the vanes can stick and generate too much or too little boost pressure, damaging the turbocharger. This highquality, direct replacement for failed VGT actuators restores proper turbocharger function. Reader Service: Go to

Jasper Engines & Transmissions now offers the Nissan VQ35DE, a 3.5L DOHC V6 with variable valve timing (VVT), which is available on exchange for the following applications: 2002-’06 Altima, 2002-’08 Maxima, 2002-’07 Murano and 2003-’06 Quest. This remanufactured JASPER engine includes all timing components with a new water pump, timing chain tensioners and new updated cam chains to correct an upper chain noise issue. The pistons have been re-engineered to match OE compression ratios, and include a graphite coating on the skirts to prevent dry startup and piston scuffing. In addition, JASPER installs 100% new intake camshaft actuators to eliminate any VVT issues. Reader Service: Go to

88 October 2013 |

» Shop Permatex offers its specialized Gear Oil RTV Gasket Maker for use as a gasket maker or sealant on transfer cases, differentials and manual transmissions. This gasket maker is specifically formulated to withstand the effects of today’s advanced synthetic and petroleum gear oils, which are known to destroy standard RTV silicones. Permatex Gear Oil RTV Gasket Maker effectively resists the effects of friction modifiers found in newer gear oils and will prevent leaks and ensure proper performance in harsh drivetrain environments. Reader Service: Go to

Spectra Premium Radiators — Know What You Buy — The company prides itself in designing its products to meet or exceed OE specifications. According to the company, Spectra Premium radiator transmission oil coolers incorporate the same plate count as the OE design. OE-grade fittings are also utilized to prevent costly transmission and/or engine repairs. Reader Service: Go to Peerless Electronics offers innovative vehicle circuit breakers from E-T-A. A resettable alternative for standard plug-in type blade fuses for fuse blocks in vehicles with 12V or 24V electrical systems, the 1610 Series circuit breaker reduces downtime caused by blown fuses. A new colorcoding scheme corresponds to the colors of the blade fuses. For 24V systems, the 1620-3 Series resettable thermal automotive style circuit breakers are particularly suitable for installation in inaccessible areas. They fit into fuse blocks designed to ISO 8820-3. Reader Service: Go to

Mighty has introduced full synthetic 5W-30 Engine Guard Motor Oil, which has earned the dexos1 icon of approval for gasoline engines. Mighty dexos-approved Engine Guard oil exceeds the level of many industry standards for: viscometric properties that minimize friction and improve fuel economy; resisting aeration, enabling fuelsaving devices to work optimally; offering improved oxidation, allowing emission systems to operate optimally; and resisting degradation, extending mileage intervals between oil changes. Reader Service: Go to www.

Philips Automotive offers a new range of innovative upgrade headlight bulbs that deliver advanced technology and performance with a focus on safety and style. In this range, Philips offers three lighting options: Philips Vision, which provides 30% more light, Philips VisionPlus offering 60% more light, and Philips X-treme Vision, which can deliver up to 100% more light than a standard halogen headlight bulb. Philips Vision and Philips VisionPlus are offered in 9003, 9004, 9005, 9006, 9007, 9008/H13, H1, H3, H7 and H11 configurations. Philips X-treme Vision comes in 9003, 9004, 9005, 9006, 9007, 9008/H13, H7 and H11. Reader Service: Go to 89

» Shop Mitchell 1 announces the release of its 2014 Emission Control Application Guide (ECAT14) for domestic and import cars, light trucks, vans (diesel engines) and Class A motor homes with gasoline engines, model years 1966-2014. The new guide provides vehicle-specific emission system information for repair shops that perform smog inspections. Content features include: emission application tables; engine displacement conversion charts; emission control visual inspection procedures; approximately 40 years of domestic and imported basic ignition timing specifications; 1980-2013 maintenance reminder light reset procedures; the latest EPA emission recall bulletins; I/M areas that require ignition timing and EGR function testing; and a quick reference listing for major systems, devices and components. Reader Service: Go to DENSO recently released 65 additional First Time Fit Starter and Alternator part numbers, including 44 alternator part numbers and 21 starter part numbers. They accommodate more than 20 million vehicles in operation, including more than 4 million for popular Honda/Acura applications (2003-’09 Honda Civic, 2002-’06 Honda CRV, 2003-’09 Honda Accord and 2003-’09 Acura TSX). The company also has released its 742-page comprehensive new Spark Plug, Ignition Wire and Direct Ignition Coil Catalog (#D1666.330) that includes new part numbers and expanded coverage for more than 75,000 applications. Four new spark plugs add coverage for more than 250,000 late-model Toyota and Honda vehicles.

Pennzoil announces that Pennzoil Ultra and Pennzoil Platinum provide superior cleansing technology to help keep engines as clean as possible. Pennzoil synthetic motor oil technology works to actively seek out contaminants and help prevent them from building up in an engine. Pennzoil synthetics take engine deposit cleanup to a whole new level because they not only help keep the engine clean, but they also clean out engine sludge and contaminants that may have been generated and left behind by inferior oils in the past. Reader Service: Go to

The Ultimate Import Wire — Intermotor Import Ignition Wire Sets are unrivaled for quality, coverage and original match. No one provides more extras like factory-installed separator clips, anchors, protective loom and trays to keep wires sorted properly and safely. Intermotor ignition wire sets install with ease for exceptional power, performance and extra-long service life. Visit Reader Service: Go to

Federal-Mogul has introduced a powerful, free mobile app designed to help automotive service providers dramatically increase operational efficiency, sales and customer satisfaction. The innovative new “SmartChoice Mobile” app enables shop owners, service writers and professional technicians to use their iPhone or Android devices to instantly access the latest parts information for virtually any passenger car or light truck and communicate detailed inspection findings — including photos of worn or broken parts and a repair estimate — directly to the vehicle owner. The SmartChoice Mobile app is available through the Apple App Store and Google Play as well as Federal-Mogul’s new website. Reader Service: Go to

90 October 2013 |

It’s Fast, Easy and Accurate! Get FREE PRODUCT AND SERVICE INFO from the companies featured in this issue of Underhood Service. >> VISIT and click on the company from which you want information. >> OR, go to and click on the Underhood Service Rapid Response Logo.




10, 11, 83


Airtex Corporation

Cover 2, 1

NGK Spark Plugs

Art Blumenthal Auto Value/Bumper to Bumper

Cover Card, 17


O'Reilly Auto Parts


Parts Plus

Cover 4

Perfect Stop


48, 49

Schaeffler Group USA


54, 55


20 44, 45 71 42, 43 8, 9 29

Bar's Leaks


Tendeco Sales Inc

27, 84

BlueDevil Products



12, 13



University Of The Aftermarket


US Motor Works


Champion Spark Plugs/Federal-Mogul

31, 33, 35, 37

CRP Industries

21, 69


DENSO Products and Services America, Inc.

23, 47

Wagner Brakes/Federal-Mogul


Dipaco Inc.



Enerpulse Inc


WIX Filters

Exide Technologies


Federated Auto Parts



52, 53

Innova Electronics Corp.




Jasper Engines & Transmissions


King Electronics




MACS Worldwide Mitchell 1 Motorcraft,Ford Motor Company

Cover 3 15

4, 5 67 50, 51, 63


Reader Service: Go to

19, 59 91


92 October 2013 |


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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Advertising Representatives The Tech Group Bobbie Adams 330-670-1234, ext. 238 Jamie Lewis 330-670-1234, ext. 266 Dean Martin 330-670-1234, ext. 225 Sean Donohue 330-670-1234, ext. 206 Glenn Warner 330-670-1234, ext. 212


Filters Mechatronics Kits Oils Hard Parts Manuals Torque Converters Audi • BMW Jaguar • Porsche Range Rover • VW

Authorized Distributor

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94 October 2013 |

John Zick 949-756-8835 List Sales Manager Don Hemming 330-670-1234, ext. 286 Classified Sales Tom Staab 330-670-1234, ext. 224


» UltimateUnderhood

Jaguar XK Six YEARS PRODUCED: 1949-1992 DISPLACEMENT: 2.5-4.2 LITERS The Jaguar XK inline six-cylinder engine had one of the longest production runs of any engine. Visually, the most recognizable aspects of the XK engine are the dual cam covers atop the engine. The cylinder head’s design was dictated by the desire to make room for two generously sized valves while not excessively restricting the flow of gases into and out of the hemispherical combustion chambers. To do this, a relatively wide angle between the valves was initially chosen, with valve stems that are quite long. ■


October 2013 |


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Underhood Service, October 2013  

Underhood Service identifies and explains the latest ­developments in under-the-hood systems, along with business-critical technical infor...

Underhood Service, October 2013  

Underhood Service identifies and explains the latest ­developments in under-the-hood systems, along with business-critical technical infor...