A4QuattroV6

Hey so if Im correct, this car applies brakes to wheels with no traction so that wheels with traction get power. I recently bottomed out in a rut of mud, but my left two wheels were on smooth, dry concrete. My friend was driving and I got out to look/push and I see the right two wheels just spinning in the mud and I was thinking shouldn't the power be going to the left two to pull the car out? Help appreciated, thanks.

mmasire88

Is your brake/ABS light illuminated/flashing? ABS module failure rate is quite common in audi's. It uses your ABS by pulsing the brakes on the free-spinning wheels to transfer power to the other wheel. If your ABS module is bad, that's why it's not working.

A4QuattroV6

My abs light is not on

mmasire88

The only thing I can think of is perhaps your car did not come equipped with EDL(Electronic Differential Lock). My 2001 a4 says it is equipped with it on the original window sticker. I'm a bit curious if my 2000 a4 has it. I always assumed it was a standard feature. Have you vag-com'd the ABS system? See if there's any codes in there for perhaps an ABS wheel sensor?

twentysevenlitres

I would suggest your car is not equipped with EDL or traction control.
Your front and rear diffs are standard open diffs. The centre torsen diff is basically limited slip (it's more than that, but for the sake of arguement we'll call it a limited slip diff).
So to have two wheels spinning on the one side is consistent with that set up.

David.Norton

The A4 has EDL from 1998. There is a limit to the torque that can be transferred by the EDL, when you bottomed out you were done, the system is really not intended for off roading. There is a nice write up here: Quattro Evolutions | awd cars, 4x4 vehicles, 4wd trucks, 4motion, quattro, xDrive, SH-AWD, Haldex, Torsen, wiki - How it works

A4QuattroV6

So how do I make it work? Swap abs modules?