So I am helping out a friend with a 1999 a4 1.8t avant quattro. The car recently took on water and the transmission started acting funny. I located the TCU (completely under water when i located it) removed it, dried it out and plugged it back in. The best i can get out of it is limp home mode... So i have found on ebay another TCM out of another 1999 a4 1.8t quattro, but the last 2 digits of the part number are different. Does anyone know if the units are interchangeable? Would the difference be a subtle change in shift characteristics... or more serious stuff?? Any input would be appreciated, the item ends pretty soon. Thanks guys!

 

I wonder if my 2000 TCU in the classifieds will work... whats the part#?

 

its 8d0927156bn

 

I would not use a TCU with a diff part#.

Mine is 8d0927156 AT so most likely not interchangeable.