A8(D3) Vehicle Authorisation ECU
 

Does anyone know the location of the keyless ECU. My keyless entry is not working (both locking and unlocking ) but starting the vehicle is ok.
Thanks in advance

Do you have two keys ? Neither one works, including panic button? Door locks work with driver door switch and trunk opens with remote button in car?

Location of receiver probably doesn't matter. If not the key battery or fuse blown (or relay problem...don't have wiring diagram for your car), could be a coding problem (vag.com repair)? Changed a key battery recently?

More than likely needs new batteries in the key fobs and a coding procedure from a vag com.

Both keys fail to work on keyless but the other functions ok. Battery is newish (the green light on the key fob comes on when buttons are pressed). All interior switches are working. This issue happen before, the last episode lasted for over a year and AUDI dealer said a new ECU is required but due to the cost i didn't get it done. This keyless start working again all of a sudden(the car been to the dealer to change the thermostat due to overheating and replace the rear windows moulding due to rust , they never fix the keyless at that visit ) this time it works for over a year, that is why i want to look at the ECU and if needed i'll replace it myself. Do i need to reset the keys or ECU using vag com after installation
Thanks

Looking at wiring for 2003 D2, the antenna for the central locking and alarm is built into the rear window, with wire coming down into left side of trunk. Does your panic button on the key set the alarm off ? I wasn't clear on your answer. The wires would pass through (or by) the molding around the rear window...coincidence (?).

The control unit for the central locking and alarm is in the trunk behind left panel somewhere. Were they talking about replacing your MAIN ECU (ECM) or just the "central locking/alarm/interior light delay module" in the trunk?

The above is assuming that your D3 has similar wiring and locking system to a 2003 D2 (?)

Don't know if this helps much.

P.S. Wait,wait, WAIT...."RUST" around the rear window??? What's to rust? ...Aluminum body, aluminum trim and rubber molding! What am I missing?

The D3 has its own unit for the locking mechanism, and its own unit for immobilizer. The unit isn't in the trunk. Its not something you can do by yourself as 90% of the modules in the D3 need to be coded, and its beyond most peoples abilities with different access codes etc. Its going to be a dealer ONLY job.

P.S. to the OP, don't say ECU/ECM, that means the engine control module/unit which has nothing to do with what you're doing.

P.S.S Don't let the dealer change just the thermostat on you, thats an old school trick to get the most out of your wallet. Every 80k it needs to be replaced along with the timing belt and water pump, and the labor to reach this is HIGH! So you probably should have had the T belt and water pump done with the thermostat is what im saying. Now you'll have to pay an additional $2,000 just to get the belt done somewhere down the road.

I mean rust around the rear doors window. It is the little black triangular shape moulding . It took a long time for the factory to approve the warranty. I did ask the dealer to change the T belt and water pump when they fix the thermostat but they said the car has only cover 35000 miles and should be 75000 miles for the belt and pump . Anyway the quote to repair the keyless last time by the dealer was almost 1000 euros and it 's too much