A4 ESP Light on

[fitzyr]

Hi all
I have 2002 A4 1.9TDI 130BHP with 136k on clock. Just had tracking/wheel alignment done this morning and after I left ESP/Traction control light came on and is staying on.
Any ideas on what the reason or fault could be.
Any help or suggestions would be grateful.

Cheers.

[Dr G]

Brake pedal switch is a common (cheap) failure on those, nasty little plastic thing.

However lots of things could cause that (even a low battery) - get teh fault codes read to be sure.

[jimmyb]

Yup brake light switch. Mines been doing it for the last 140k miles or so. May get it looked at in two weeks at mot time.

[Tame Technician]

Brake pedal switch in indeed common, but brings on Engine light and abs. If its only the ESP circle light thats on, and If its only since they did the wheel alignment, they did it wrong. That OR someone has had the steering wheel off at some point before and not put it on properly. The steering angle sensors gets confused as the other ESP sensors tell the ECU its going striaght, but the steering angle sensors shows the wheel isnt straight ahead

You need to have the steering wheel central, not just as you see it, but as the steering angle sensor sees it too. If they took the wheel off, and moved it round a few splines, or its not actually straight when you drive straight it causes this problem, I seen it loads of times, always after wheel alignments been done, and especially when customers have refused our very expensive wheel alignment and had some tyre fitter do it instead.

You will have to have the code read to be sure, but I'd bet alot of money that thats what it is.

[fitzyr]

Thanks All
It isn't brake pedal switch. I had that changed a few months ago.
The steering wheel has never been off in my time which is over 3yrs now and I have had tracking done every time I change tyres and never had this problem before.
Anyway I brought car back to garage this morning and I told them what the problem might be. Tracking was out again and they corrected it. I brought car for a test drive and ESP light stayed off this time. I returned and they checked tracking again and it was out again. They corrected again.
I have recently changed all track control arms, top and bottom and track rod ends both sides. The only thing I haven't changed is the drop links and bushes on the anti-roll bar. Would these cause the tracking to keep going out.

Alloys aren't buckled. I will be returning in a months time to change front tyres as they are nearly gone and owner said he will check them for sure then and do alignment again.

Cheers.