v8phil

My car has too many communication errors to access the codes, in other words $$$$$$ to find and fix this problem.

TIA

Phil

spdfrk135

v8phil...no,but been thinking about since last thread...as I can best remember,it was an electronic device called a "regulator".This takes the sys. +12volts & "regulates" (modifys the v.) to a STEADY +9v & this is what is sent to the "multi-function switch" on top of the tranny.I'm guessing this is important v. because this is what the TCU must monitor.Tommorrow,a part I have on order from the stealer is due in from Chicago audi warehouse.I'm 23 mi. from stealer & fortunately (for you) this is the dealership that finally fixed my weird tranny prob. that no one else could.Bad news is ser. mgr is not easy to deal with,but will try to speak with ser. tech. who actually works on V8's.Also,don't remember where the device is located,but think it was also on top of tranny like the MF-switch (no that's not short for mother-f*****)but some would refer to it that way because it is problematic.I'll keep looking for slip,think part # of device was on there.Again,your prob. is similar to mine,but not exactly (I had all "lights" on PRND321) + limp mode simultaneously).Maybe "audiqv8" could add to this if he reads thread.Sorry to ramble on so,but I remember how I got so frustrated because so many garages (even audi) had no clue.-Bill

spdfrk135

Oh yeah,almost forgot to mention...with my tranny prob. there was NEVER a fault-code stored when I went to 3 different Audi stealers to put VAG1551 to pull codes.Perhaps that's why most of them had no idea where to look.-Bill

audiqv8

The first question to ask is What gear is the car starting in when it goes to Limp mode?

Is the car starting in 3rd gear? If so, you are probably looking for an electrical problem. If you have gears other than 3rd, you probably have a valve body or solenoid problem.

v8phil

I have spent hours searching Audifans Archives/Audiworld these last few weeks...common problem but no frickin solutions! Even drove to 2 shops today, one trip in limp mode >
Car wont let VAG-COM read codes either..."Communication Error".
Frustration: High
Patience: Thin

Thanks for your troubles Bill.

v8phil

After starting, it drives ok at first...then driving a few miles, it starts to "feel" different. Then their is the banging (U joint?) as the car drives only in 3rd. It stays in 3rd even from a stop.
I agree it is probably an electrical problem...something is "heat soaked"???

Appreciate your help.

Phil

spdfrk135

Yeah...that was my prob.ONLY had 3rd gear & Reverse!