Hi, I have just brought a 2004, 55k miles 2.0 A6 Avant. Everything seems in order except the transmission! Unlike some previous threads, for the short distance that I have driven it, changes seemed unjerky and without any problem. It was only when I put it in reverse that I noticed that the engine was revving, but the car was only going very slowly in reverse - i.e. felt like clutch slip. Having not dared to drive much distance since, I have noticed that all is well until after about 15 mins of engine running. If I go through the gears and put it in reverse I get the PRNDS flashing at me. When the car has cooled, and restarted in Park etc, the problem goes away until it warms up again. incidentally the gears still seem to work when the flashing warning is on. Also I noticed that the revs drop to almost stalling and then pick up each time it is put in reverse. Any thoughts (other than the possibility of a new gear box at £4.5K!)? Could the oil filter be blocked or the oil not cooling properly? I'll get the car to an audi dealer for a diagnostics and was going to get the box flushed and refilled with oil..... Thanks in advance

 

It might be the trans control module.