Hey guys

I recently had to have a replacement TCM as my A/C drain was blocked and the passenger side footwell got flooded, frying the TCM.

The used dealer we bought the car from replaced it for us, as it was their oversight, with a recon item, but this unit doesn't seem to change gear as smoothly as the original one.

It holds 2nd gear too long, and when in third and you slow down its doesn't drop to 2nd readily enough, it makes you pull away in third with too few revs. It's all fairly subtly but noticeable.

I was wondering if the TCM is supposed to programmed to match the car in some way, but we couldn't get a definitive answer from Audi or some Independents.

Some say it does other say its doesn't as long as its from the same year/model. (1999 2.8 Avant)

Anyone had any experience changing a TCM?

My serial no. was almost the same 4BO 927 156 G (original ended CE) but i think these are interchangeable.

VagCom also gives- 00668 'Supply Voltage Terminal 30' 'Open or Shorted' for the new TCM not sure if that's related?

Cheers

 

Are you sure that the different TCMs are interchangeable? How did you come to that conclusion?

http://wiki.ross-tech.com/index.php/00668

Sounds to me like the 00668 could be causing some issues. Is the wiring corroded?

 

I remember reading it on VWVortex i believe although they were talking about Passat's which use a similar TCM and the supplier said it should be OK.

Its possible the wire has corroded, but when i put my old TCM i don't get that Terminal 30 error, i just get a bunch of Valve errors i'm assuming the valve controllers on the TCM are the bits that got fried.

So i don't think its the wiring otherwise surely that would show up on the new one too?

Maybe i should just look for a new (to me) TCM as i think they are about $1700 new.

 

all TCM are interchargeable and can fit in any car

 

If you need another used one try www.shokan.com and I think Chefro knows of a few others. Try to PM him.
Shkan sell used parts unfortunatley I have been able to find new parts cheaper than their used parts, but worth a try.

 

Sounds like a bad replacement TCM. Have the dealer obtain and install another one. See if he has another Audi on the lot you could swap TCMs with to see if the error code goes away.

Bob

 

Thanks guys, yeah i'm going to get the dealer to sort out another one. This one has a warranty for 90 days so should be OK.

We just weren't sure about having to program it to the car, but it seems from the replies we should be good to go with a straight swap.

cheers

 

When I had the same problem the dealer said as long as the part numbers matched on the tcm's you could just swap them with no issues I did that and have had no problems. They told me to be sure not to use any tcm other than the exact part number to match my old tcm.