thenickbutler

So, I tried posting this on Audi Forum, but to no avail.

I have a 1998 A8 Quattro with (of course) the ZF5HP24A transmission in it.

What is happening is whenever I place the vehicle in drive and do not move, just sit there with my foot on the break, it goes into limp home mode. If I put it in reverse, neutral or even if I put it in drive and start moving it will not go Into limp home mode until I come to a complete stop. If I don't ever stop completely I'm fine. I just have to shift into neutral whenever I come to a stoplight.

I have replaced the following:

- Torque Converter
- Valve body wiring harness (was leaking fluid out of the pins and corroded the connections)
- Rebuilt the valve body myself with ZF rebuild kit (made a large improvement in shift quality)
-Filter and Fluid (Pentosin ATF1)

While I had the car taken apart, I looked at the internals of the transmission and all was well. None of the common signs of failure. Clutches were all good and the clutch "a" housing had no cracks that I could see.

There's probably some more that I'm not thinking of. I also have the VAG-COM scanner that is giving me code 17114? Gear ratio incorrect.

Now, I checked out with the VAG-COM and graphed my vehicle speed sensors to see how they were acting when I was in park, neutral, and drive. The engine RPM is consistent at around 730, while the input is usually bouncing around from 730 - 1500 while in park and neutral. If I shift it into drive, the input goes up to around 2000 rpm and it goes into limp home mode. If I rev up the car while its in drive and limp home, the input and engine rpm readings match exactly. A perfect matched curve is present on the graph.

So not in limp home - rpms random on input speed sensor

In limp home and 5th gear- rev it up and the two readings match. Come back to an idle and the reading is sporadic again.

I'm guessing this is my issue, but what does this mean? Is the "a" clutch bad? Is the valve body not pressurizing the "a" clutch enough? Is there a wiring fault? I never tested the male connector going to the transmission, but it did have corrosion in there like the valve body harness connector did.

If anyone has any ideas, please help. I'm about at my wits end with this. I also have a video of me graphing the input/output sensors.