Accelerator Position Sensor

[sutherland]

This thread started with what seems to be a fairly common fault with my S8:

EPC, ABS, Traction control lights came on, couldn't rev much past 2000rpm and I got the following fault codes:

18047 - Accelerator Postion Sensor 1/2 (G79/G185): Implausible Signal.

18624 - Throttle Potentiometer (G69): Error message from ECU.

I checked the ECU box and made sure it was water-free, checked measuring block 062 for linear progress when I depress the accelerator. This looks correct with S2 generally about half of S1, although they never went over 82% and 41% (nothing to do with kickdown switch).

I also tried the adaptation in block 60, but it never goes to RUN, always just stays at OK. After doing this I had turned off the igntion, then restarted and all my gearbox lights came on (PRNDS). I then checked for faults in there and it reported two pressure solenoid faults.

After this cleared the codes, have driven the car about 100 miles and the faults have not returned. I've ordered a secondhand TPS from A8 Parts in case I need it, but I'm suspicious that this actually may have nothing to do with the TPS and seeing the gearbox faults appearing at the same time made me wonder if it is an air flow meter issue. I remember reading of some unfortunate fellow who had Audi change his A8 gearbox three times before it dawned on them that the problem was caused by the MAF sensor. I'd like to avoid going down that route.

Any advice would be much appreciated.

Thanks.