Reprogramming Audi A4 ECU

The check engine light has been on in my 99 Audi A4 ever since I put a new (used) ECU in it. The code it is throwing is a check transmission. However, my car is a manual. Is it possible to reprogram the ECU to a manual so the engine light will turn off and I can pass emissions? Please help

If it is still possible for anyone to reprogram the ECU on a 16 year old car, I suspect that the dealership would be the only place where it could be done. However, phone calls to all of the indy foreign car specialist mechanics in your area would probably be a good idea.

Did the used ECU you installed come out of a vehicle with a manual transmission?


I am not sure what type of car it came from

I’d look for a VW/Audi specialist, they have their own very unusual quirks as far as the electronics are concerned.

It’s possible you might be able to add some phony compenents hooked up to certain connectors to fool the ECU into thinking you have an automatic. Not the best option, but that’s another possibility anyway. You’d need someone with some electronics expertise and a wiring schematic.

Edit: Also check w/the emissions folks. They might not automatically fail your car in this situation. But you might need to take it to a special testing station.

It seems pretty simple to me . . .

Check engine light is permanently lit . . . automatic failure

Either reprogram, so that it isn’t looking for all those sensors in the auto trans . . . or get a correct module

I would not go to the trouble of adding those phony components to fool the ECU . . . that is tampering, and constitutes automatic failure

Simpler to just get your hands on the correct module, in my opinion

I second db4690 in regards to getting the right part. You may find that with many cars there may be half a dozen or more ECMs used on the same model year car and those different code numbers on the ECM tag are there for a reason.