Ok so heres what happened, I have an 4.2L A8 Q. The Tranny feels fine and drove great until I was driving home one night and at a stop light I hit the gas and I went no-where. It then made a clunk and went into limp mode. I continued driving and at about 40 mph I put the car into (N) and turned the car off and back on put it into triptronic and I shifted all the way down to 2 and then hit the gas and the car shifted itself all the way into 5th gear and went into limp mode again. Reverse works fine for the record.

I plugged into the car and got a P0730 code and a friend told me to put some ATF fluid in it because sometimes low levels cause this. So I crawled down under the car and I am pretty sure I heard what I think was the tranny pump cavitating, so I added about 2.5 quarts before it started pouring over the fill area, this was done while the car was running in (P); I tested it again and now I get 3 codes the same P0730 and these 2 P0751, P0753.
P0730: Incorrect Gear Ratio
P0753: Shift Solenoid "A" Electrical
P0751: Shift Solenoid "A" Performance or Stuck Off

I was reading about the shift solenoid and that it may need to be replaced, I have also heard of flushing the fluids and putting in a new filter and new fluid, but I am not sure what to do, Anyone who has had similar or the same problems please help?

 

Hi i am having the exact same problems with my 99 A8. I also got the same codes. Not sure where to go from here. Have you had any luck as of yet?

 

That is a question for TozoM8, the resident expert on transmissions.

Not sure if he is on this board but is on every other one I've seen.

 

No I have not had any luck with it at all ... I will look for this todo character... thanks!!!

 

I think you need a rebuild. This is a common problem in the zf 5hp 24 fla. even in the 4.2 a6. Changing fluid is probably waste of money.