rAudiA8

Is it really the end of the transmission road when you get the "Incorrect Gear Ratio" code as well as "Transmission Range Sensor"? Anyone else been here and got through it okay?

I did end up in limp mode a couple of times; reverse was still strong as well... any input? or is it time to say "bye bye"?

silverd2

I'm not the expert, but from those codes, I would not give up hope.
As I understand it, that "could" be a problem with the F125 switch...replaceable on outside of trans...may have failed or lost good contact at plug...or some other electrical problem.
Going into limp mode is not always an internal mechanical problem...can be triggered by outside control or monitoring problems.
Hopefully Tozo will see this and chime in with an expert opinion.

rAudiA8

Thanks for the feedback, a bit promising so I'll wait to see if Tozo has any additional input.

rAudiA8

Instead of putting too much money into the A8 at this point I bought an 04 A6q. I may just hold on to it and see what happens in the future. The A8 treated me well for the past five or so years.

Prospeeder

I would definatly suspect a trans speed sensor or low fluid. I have gotten codes like that for a few 96-97 A6 cars that i had to add 3-4 quarts of fluid to, im surprised they moved!

rohit13

USUALLY when this error occurs in the 5hp-24 trannys it means its toast. the v8 engines had this tranny and they usually trip this code around 100k

there may be a small possibility a fluid change might help but ive never read any threads of this actually happening.

Carpoof

It very well could be the F125 connector or a simple sensor if its giving that code. My tranny was slipping badly, going into limp mode, and making buzzing noises once. It was so bad I parked it for a year thinking it was toast, but then I decided to try to change the fluid. I flushed the fluid out using factory fluid and it drives like new now. (Shouldn't have said that). Anyway, it's been 20K miles since I did that and I just changed the fluid again, it was very dirty, but it's still chugging along so it may not be the end of the road.

silverd2

Agreed...the code(s) point right to an electrical fault, according to the manual. I'd definitely eliminate that as a cause before giving up or assuming a $4-5K rebuild.

Assume the worst...but, hope the best