Hi everyone, I need a answer, I have a 1996 Audi a4 automatic, my question is that I need a new tcu because mine crapped out, now I've been looking at ones and realized that I'm finding the same tcu ad the part number is the same except for the last letter, all the numbers are the same but not the letter, there are tons of different letter combos but the same numbers , does the letter matter or can I buy a new tcu with same part number but different end letter and if so what does that letter mean thanks!

 

Chances are if there are different letters at the end of the part number that you need one with the letter yours has. You could take a risk and try one with a different last letter but there's no guarantee that everything will work as it should. What are your symptoms that you need a new TCM?