Traction Control light on

[cruzanrs6]

So it started with the Trac light coming on and staying on while driving and not being able to turn it off. Turns off with key switch to off. Now getting the ABS and BRAKE light flashing as well as the alert chime, flashes for 5 - 10 secs then they go off and the then the Trac light comes back on and stays on. No evidence of the ABS system engaging. Vag- Com says turn rate sensor (yaw sensor), I replaced it (this is the one under the rear seat). The issue/symptoms are still there. Any advice ?

TIA - Scott

[lswing]

Wheel speed sensor I believe, can be cleaned? Or replace...

[cruzanrs6]

Can Vag- Com isolate which one ?

[lswing]

Can Vag- Com isolate which one ?

Surprised it doesn't, if that's the issue, but I've seen this same thing over the years. You using the full Ross-Tech software right? One per wheel I believe, sometimes you can visually ID the bad one, or bad wiring.

[nubcake]

If the yaw sensor DTC is still there after replacing it - then it's either wiring, or ABS (ESP?) module had crapped the bed, I believe.

[AndrewNC]

Brake light switch (by the pedal)

[cruzanrs6]

Follow-up:

I cleaned all the wheel speed sensors - some really had a lot of build up on the exposed metal piece. The issue is still there, I disconnected the ESP fuse - the ABS and Trac control lights are always on AND I still get a random alarm and flashing of the brake light. I'm going to take in and have it diagnosed.

[AndrewNC]

Do you know if your brake lights work when pressing the pedal? Brake light switch: part# 3B0945511B

[cruzanrs6]

Yes Brake lights work.

[GreggPDX]

If the yaw sensor DTC is still there after replacing it - then it's either wiring, or ABS (ESP?) module had crapped the bed, I believe.

Is the ABS module easy to swap?

Mine is just collecting dust while the engine is out, so if you want, you can try swapping with mine to test.

Gregg

[nubcake]

Just the electrical box can be swapped relatively easily.

[P1054]

^^ What nubcake said. Swapping the "dry side" is pretty simple. The "wet side", not so much.

[cruzanrs6]

So it turns out the ABS module is bad. Audi claims the entire unit has to be replaced. Some research that I'm doing seems the ABS electronic side can be replaced. Any advice ???
TIA

[P1054]

You definitely can just replace the dry side, I did it. It's not hard, you just need to be a little bit creative accessing one of the Torx screws if I recall correctly. Also, you can send the module to a guy that rebuilds them rather than buying a new one. He charges a flat rate of $150 (shipped) for the RS6 ABS module. Check out cheapabs.com. He has a info packet with basic instructions on removing the module, a price sheet, and an order form.

[4.2Crew]

The ABS module is deceivingly more challenging than it looks to remove... Removing the front drivers-side wheel well liner provides access to the lower bolts on the module. You still need to carefully prey enough clearance (brackets, brake lines etc ) to wiggle the module up and out from the topside.

BTW, the car can be driven without an ABS module.

[Aronis]

You definitely can just replace the dry side, I did it. It's not hard, you just need to be a little bit creative accessing one of the Torx screws if I recall correctly. Also, you can send the module to a guy that rebuilds them rather than buying a new one. He charges a flat rate of $150 (shipped) for the RS6 ABS module. Check out cheapabs.com. He has a info packet with basic instructions on removing the module, a price sheet, and an order form.

That is just great! Love to see such industrious people providing such a service! Great to see!

Mike

[cruzanrs6]

Gentleman,

Thanks for all your input. I did reach out to Module Master and they can rebuild the electronic side for $300, I also found a guy in Ks (owns Cheap ABS, INC) - he charges $139 and has been doing these repairs for 9 years. I spoke with him and he would check the unit out first to verify it needs servicing/repair. I think I'm to give him a try. Sunset Audi wants to install an entire "used" unit for $600 plus 3 hrs labor. No warranty on the unit however. If it turns out that the pump/wet side is bad then I'll need to try to track one down. Apparently the RS6 uses a unique # that does not cross over to any other cars.

[cruzanrs6]

So this past weekend, I swapped out the "dry side" with a fellow RS6 owner's module. The swap was not too bad - remove fender liner and loosen up windshield washer fluid tank. I did have to to recode the unit - there is a good detailed Ross Tech You tube video on how this is done. Once recoded- all the lights have gone off (ABS, Brake and Trac Control). Car/ ABS seems to be operating properly. So I will send my unit to Module Masters - for $300 they will rebuild it and also provide 5 yr warranty.