Hi, i am currently working on a 97 a4 quattro turbo 5speed. I was taking the rear seats out of my 97qtm when I noticed a ecu/ecm bolted to the body with harnes and all. I did the same thing right after to my 98 QTM but noticed there wasnt one there!?!? Its obviously a yr model difference but wut is it/or does it control?? If you have any accurate answers please share, i would like to learn more about me audis!!??

 

if i recall its the abs computer

 

inn that case wouldnt the 98 have it aswell? both being Quattro abs?

 

im pretty sure they probably changed the location of many items as it went from the b5 to b5.5 gen. for example were the obd2 port on my car is next to the rear ashtray the newer ones have the obd2 port under the dash

 

The earlier version of ABS on the A4 had a separate ABS ECU under the rear seat, whereas the new one has an integrated unit under the hood (left front).

 

Alright. im going to accept these answers.. Thanks for the replys. I appreciated it as it will better help me understand my car..

 

When did they move the OBD2 port? My '97 2.8q has it under the dash, but there's still aspot for itnext to the rear ashtray The cover has an icon of an engine with a lightning bolt but there's nothing underneath but a port-shaped hole. I've been wondering about that for a while.

 

That port is there because on the 96 model thats where they located the OBD 2 connector because it wasn't federal law yet to locate it under the dash. Some cars still have the OBD port located there.
As for the module question its only the ABS module if the connector end of the module is colored yellow.
As far as i know the ABS module was always located under the center console on the A4 model.