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September 2010

2002 Chevrolet Malibu Communication Problem
By: Scott Lettow (Field Trainer) Car-X Associates Corp

In This Issue

2002 Chevrolet Malibu Communication Problem Chicago Automotive Networking (C.A. N.) Conference Diagnose Emissions Failures with Simple Tools 2010 Seminar Schedule (NEW) Using Mode $06 Data for OBD Diagnosis and Repair (NEW) Mass Airflow and Fuel Trim Diagnostics (NEW) Advanced Communication Protocol Testing for OBD Failures (NEW) Four Wire Air:Fuel Sensor Diagnostics Dashboard Tip of the Month Keep Your Profile Updated Got a Case Study Share your case study and tips.
Trying to find a solution is not that easy at times. Byron Skinner owns two Car-X stores in the Chicago suburbs. Byron and his team believe in getting to the finish line with every repair they do. Its plain and simple. They fix the problem even though they may have to go out of their way at times. They had a 2002 Chevrolet Malibu with the 3.1L engine come in that failed the emissions test because of no communication. Fred Kline from Byrons Car-X store in Arlington Heights took on this repair. Fred followed the guidelines from the Air Repair article from July of 2004. The article spelled out what to look for in a vehicle that had this condition. The results of his tests at the DLC were as follows: Battery voltage was 12.56 volts with a total voltage drop of.060 volts to Pin #16. Total voltage drop from Pin #4 to the negative battery terminal was.022 volts. Total voltage drop from Pin #5 to the negative battery terminal was.025 volts.
The following snapshot was taken at Pin #2 with the engine running.

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What was unique about this vehicle was that it only failed to communicate at the testing station. Fred was able to communicate utilizing several different scanners and code readers. He went as far as to pull the scanner's batteries out and run the tool directly off of the vehicle's power. The other question was how does he know if he fixed it since there was not a communication error with any other scan tool or code reader? Fred discovered after several attempts with different scan tools and after trying to duplicate the problem, he not only lost communication with the PCM, but he also lost it with the IPC, BCM, EBCM, SDM, and radio. By the time he grabbed his meter, it was back to normal.
This vehicle uses a star bus configuration as seen below. The logic was that if he lost communication with all the modules on the bus, the problem must be between the DLC and the splice on the left side of the instrument panel.
Fred rewired a new bus line from the DLC to the splice and tried to get it to act up. Since he could not duplicate it, he ran it over to the testing station and it passed. It took a lot of time and effort on Freds part to fix this car because of what it took to duplicate the problem. Confirming PIN values at the DLC only led him in the direction that nothing was wrong. It took time and commitment on his part to make sense of what the problem really was. back to top
Chicago Automotive Networking (C.A.N.) Conference
From: Automotive Service Association (ASA) of Illinois
ASA is hosting the Chicago Area Networking (C.A.N.) Conference on September 24th - 26th in Rosemont, Illinois. A variety of topics will be covered for both technicians and shop managers. For details and registration information, www.asacanconference.com. back to top

Diagnose Emissions Failures with Simple Tools
By: Tony Barcham from Car-X Auto Service
A 2001 Isuzu Rodeo came in with a check engine light on that failed an emissions test with a P0440. I didn't have a TECH 2 or any other scanner that would provide detailed data or bidirectional control to activate the solenoids. I started by smoking the system from the engine and by the filler neck, but I didn't see any smoke coming out. I checked all the solenoids manually, and they were working fine.
I decided to check the FTPS (Fuel Tank Pressure Sensor) signal at the PCM, and my voltmeter started to read 4.3 volts. According to FTPS testing procedure KOEO, the sensor should read around 1.5 volts.
Utilizing my flex hands and arms, I reached the sensor on top of the fuel tank. By touching the connector, the voltage jumps from 4.3 to 1.4 volts. After replacing the FTPS and the pigtail, and by driving the car, all monitors set to ready with no problems.

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Thanks for Your Support
From: the Illinois EPA Repair Industry Outreach Team
Jim Butcher, Automotive Technology Instructor (left), Ken Zanders, Outreach Instructor (center), Dominic Pacenti, Program Coordinator- Automotive Technology Technical Center of DuPage (right). Many thanks for your support of the Outreach Training Program and the use of your facility.

2010 Seminar Schedule

All seminars are from 6 pm 10 pm on dates below. They are sponsored by the Illinois EPA for the repair industry, and they are free! 2010 Complete Seminar Schedule Registration

Location

NORTH SOUTH EAST WEST METRO EAST
Using Mode $06 Data for OBD Diagnosis and Repair (NEW)
Monitors are the key to OBD emissions testing success. Mode $06 displays the monitor's results beyond a simple pass or fail. Using Mode $06 data can expedite some emissions repairs and can even make diagnosis of some readiness rejects possible. This class starts with a brief overview of Mode $06 data and how to decipher its meanings. Time will be spent on the dos and donts including the grey areas of invalid data. Many actual vehicle case studies will be used to illustrate the practical applications of using Mode $06 data for successful OBD diagnosis and repair. Different scan tools and information resources will also be discussed. ID S908 back to top Date October 19, Tuesday Presented by: Scott Shotton Location Joliet Junior College
Mass Airflow and Fuel Trim Diagnostics (NEW)
This seminar will help the driveability and emission technician make accurate decisions regarding diagnosing Mass Airflow sensor problems and fuel trim issues. A three-step procedure for testing Mass Airflow sensors will be illustrated. Fuel trim operation and strategies will be discussed as well as using fuel trim values to help diagnose driveability problems. Vehicle repair case studies will be used to enhance understanding. ID M608 M609 M610 back to top Date October 13, Wednesday November 15, Monday December 13, Monday Presented by: Scot Manna Location Lake County High School Tech Campus Technology Center of DuPage Prairie State College

Advanced Communication Protocol Testing for OBD Failures (NEW)
This seminar will take a more in-depth look into communication issues. Case studies will be reviewed with a strong emphasis on labscope and advanced techniques leading to repair. This class was designed for the serious emission and driveability specialists. ID Z105 Z106 Z107 Z108 Z109 Z110 back to top Date October 4, Monday November 8, Monday November 9, Tuesday December 6, Monday December 8, Wednesday December 9, Thursday Presented by: Ken Zanders Location Kennedy-King College Truman College Morton College Moraine Valley Community College Technology Center of DuPage Joliet Junior College
Four Wire Air:Fuel Sensor Diagnostics (NEW)
Over the last ten years, four wire air:fuel sensors have slowly started to replace oxygen sensors. While these sensors look similar to a conventional oxygen sensor, operation and testing techniques are significantly different. This class will discuss operation and testing of air:fuel sensors used by Toyota, Nissan, Honda, and Subaru. The class will discuss in detail air:fuel sensor operation and air:fuel sensor testing. Testing techniques will include the use of a labscope, scan tool (fuel trims and rear oxygen sensor), and a gas analyzer. ID T103 T104 T105 back to top Date October 7, Thursday November 4, Thursday December 2, Thursday Presented by: John Thornton Location Morton College Moraine Valley Community College Oakton Community College
Dashboard Tip of the Month
Keep Your Profile Updated
Everything we do now is by email. Make sure we have your current email address. Simply click on Update Profile at the top of the page to check your profile information. back to top
Articles Needed for eAir Repair

Got a Case Study

We are always looking for short articles of interest for eAir Repair. Many of you have gathered information for successful emissions repairs. It is time to share those tips with your fellow technicians. Please help us out by writing a brief story (a couple of paragraphs) about your success or fix. Those tips can be e-mailed to epa.repair.outreach@illinois.gov. back to top