i have a 2004 audi a4 that i just bought and its the first audi i have ever owned. it has a problem with the tranny though. for some reason i cant drive the car in its regular drive mode, i must use the tiptronic and shift myself, but it will downshift by its self, the car drives great and shifts fines. if anyone knows anything about this problem please let me know.

 

I have the opposite problem. Auto transmission works fine but the tiptronic options don't do anything.

 

Probably the magnetic switch under the shifter plate. Sometimes it stops functioning and the car cannot tell when the shifter is moved from D to tip mode and vice versa.

Here ya go:
tip Issues