I have a problem with a check engine light staying on. It was diagnosed as a problem in the computer, not a sensor which was replaced twice. I an looking into buying a engine computer from a junker, but could only find the ABS-EDS unit under the back seat. I need to check the part number. Where is it? Thanks!
Where is the engine computer? on 1996 Audi A6 Quattro
by DavidB in San Francisco, CA on February 02, 2009
3 answers 2 comments
ANSWER by patrick mannion on February 02, 2009
Is the repair shop that has told you the computer is bad an Audi dealership or independent Audi specialist? You may want a second opinion before replacing the computer. The engine control module and transmission control module are both in the passenger side foot well area. Its not as simple as just plugging in a new ECU it has to be reprogrammed on most modern cars.
COMMENT by DavidB on February 03, 2009
The analysis was by an independent Audi shop. He also check the wiring to the heat sensor. He came to the conclussion it was the computer since the code showed the sensor as bad, but two new sensors being faulty did not make sense. After installing the new sensors, the fault code would correct, but the computer would relearn the new sensor, and the check engine light would come on after about 20 miles and show a fault. I suggested we jump the sensor to turn off the light, but it did not appear the sensor. The real problem is the California smog laws. I can not get the car registered because they plug into the computer. The tail pipe emissions are fine. Its just the check engine light. I can get a waiver, but only once. In two years I will have the same issue again. A new computer is about $1500. I may be able to get an used for under $200 or get it rebuilt for $450. If I get a unit from the same model, can it be plugged and be ready go? I have already spent about $350 to get where I am.
ANSWER by spyder on February 03, 2009
The computer is plug and play on this model. If the same fault code recurs it is very unlikely it is the computer. Be certain you understand the fault description and the conditions that cause it to be set. Thoughtful diagnosis and testing before replacing parts is the most economical path. Actually if you could tell us the exact code we could offer more help.
COMMENT by Boston-A6q on January 09, 2012
Spyder, I have some what similar problem, fixed head gaskets to timing Belt kit- ran perfect for two weeks. I will not start no spark on plugs. I tried changing the C.U.P. that connects from coil pack three of them it doesn't work ( from junk yard) do you think I need to buy a new one ? Or I need replace the computer itself? And if so wheres it located n which one is it on a 96 a6 Quattro wagon. Thank you hope you get back ASAP ..;). Lol happy new year
ANSWER by Visitor on July 28, 2010
its under the back seat behind driver.
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