I have a 1998 v6 quattro w/Tiptronics. The TCM was flooded and a replacement was found on ebay. However, I lost Tiptronic function.

The car works fine in Drive mode and I can select gears by moving the shift lever along PRND432. But can't shift gears in Tiptronic mode and also the gear display in the instrument cluster doesn't change to 54321 from PRND432.

I've checked the magnets in the shift lever assembly. I've also tried replacing the circuit board and magnets from a donor car without any success.

VAG does not show any error codes.

Any suggestions how to diagnose? Thanks.

 

Did the TCM come from a Tiptronic car? Probably just need to recode the TCM to recognize the tiptronic inputs.

 

I'm quite sure the TCM came from a Tiptronic car as the code on the replacement is exactly the same as the original: 8D0 927 156 BQ.

Thanks.

 

Turns out the TCM I got on eBay is bad.

I found another one at the local junkyard and now my Tiptronics work.