ok first of all this is my friends 2001 A4 1.8T QM that she just bought on tuesday.
and I already searched around and didnt really find anything! so if you guys could help me out it'd be greatly apreciated.

so we were driving around and came to a right hand turn, and as we entered the turn (she was on the brake) it seemed like the front left wheel locked or something because the ABS kicked in, but only on that wheel. this turned on the ABS and traction control lights.
She shut off the car and restarted it and the lights went away, so we kept driving to see if it would do it again, and it did. (its now done it maybe 3 or 4 times)
It doesnt do it everytime, it seems like its only happening sometimes when she's breaking relatively hard and they always go away when you turn off the car. another thing we saw was that ABS wasnt working when the lights come on.

we're gonna borrow my friends vag-com (today maybe) and see wht the codes are. But I wanted to see what you guys taught it might be.
I guess it could be the 'wheel speed sensor' or ABS module right?
im thinkin its the wheel-speed sensor since it seems like its only done it on that one wheel.
THANKS in advance guys!

 

Is it the TC or the Brake light coming on? I don't have TC, so I have no idea about that. But I do have the infamous Brake and ABS light on everytime I start the car. My understanding is that it is the electronic control unit for the ABS. Search 'ABS Brake Light' and you should get a few hits... Good luck!

 

THANKS for ur input!
Its the TC (the exclamation point in the triangle with the circle around it) and the ABS. but not the Brake light, which is another reason why i think it might be the wheel speed sensor...

 

BUMP!
anyone??

 

My guess is wheelspeed sensor... if it was the ABS control module your brake like and ABS lights would be on. Also, if the vagcom wont communicate with the car, unplug the abs control module and it should work.

 

^Yeah, that's what I was thinking. But since I don't have ESP, I have no way to prove that theory... I read where some guy cleaned his wheel speed sensor and it worked fine, others have replaced it and had it work. Good luck either way...

 

most likely the speed sensor like people have said. post up the codes first b4 you take things apart

 

THANKS A LOT GUYS!!!
I checked the codes real fast so i didnt have time to save them, i just wrote them down!
(I'll probably check them again...)
here they are:
16684 P030035-10
16685 P0301-35-10
00526 27-10
01542 37-10
It was something about the yaw rate sensor, cylinder 1 misfire, and EVAP... lol thats what i remember...
edit: oh and the break switch...