This is the problem (a pretty strage one):
Two weeks ago I fitted a xenon kit to my Astra coupe turbo. All was smooth and easy but the TC and ABS light poped up from time to time, especially when the car was cold (if shut down the engine after 10-20 minutes and restart the car, it was ok, no lights).
I thought it had nothing to do with the xenon but to make sure i removed the xenon and put back the halogen buls...still the TC and ABS lights comes up. So I put the car on tester, it says that the ABS sensor from the left front wheel was faulty. It was the weekend so i said i'll go to service on monday. But the lights didn't poped up anymore after a day !
I put the car on tester monday, it showed the error, but after erasing it, all was ok.
So last night I fitted another xenon kit (a different one) and guess what: when the car is cold TC and ABS lights poped up again...
Any advice will do since I'm the dark here