Warped rotors would cause shake at any speed. The reverse problem seems to indicate a transmission problem. Has the control module gotten wet? I would start by pulling up the carpet and looking at it.

One good thing about your mechanic, he is honest enough to not take your money for guessing at the problem. A lot of mechanics aren't that honest.

Good luck!

Bob

 

Hm sorry to barge in on this one guys...but my A6 has been giving me hell as of late

Does anyone know anything baout replacing the TCM? or in other words, my transmission computer got wet due to some truly questionable leakage from my sunroof or some other clogged water duct in my car.

Anyone know the cost to fix something like this? or how much it would cost to refurbish or re-build my TCM?

Any info would be verrrrrrrrrrrrrrrrrrrrry helpful. I am located in Boston, MA and would appreciate any tips or advice.

Thanks
TwinturboJD

 

Oh yes the splendid TCM problem... Just went through this myself... DONT DRIVE IT!!! You will destroy the 4th gear clutches!

Lemmie guess. The cars display either has PRND321 all backlit (If so the TCM mightr be salvagable)

Or the car's display is telling you "Press clutch to start engine) at this point the TCM is toasted.

Both instances will leave your car with a brash hard shift from park to reverse or drive and most likely stuck in fourth gear.

Here's what to do...

1st. Pull carpet up in the front passenger floorboard.

2nd. Find the black box that the harness is going into and pop it up from the floorboard. This ir right in front of the passenger seat. Pop the black box open and disconnect the TCM harness from thje TCM.

3rd. Pop the metal casing open and douche the circuit board with electronics cleaner. Dry itr out! Leave it in front of a heater for 4 days!

If this does not solve the problem, Call Shokan and give them your part number.. 4B0 927 156 CE (or something like this, "the last letter digits will be different from car to car) and replace with the EXACT PART NUMBER. It has to be the exact matching number due to changes in gear ratios, engine types, and other stuff even though yes they all control the same tip transmission.

For me Shokan charged 400 for the TCM.

Check your contacts on the wire harness for corrosion. If there is clean them with a brush and some electronics contact cleaner.. Then possibly dialectric grease to stop further corrosion.
Good luck.