Just got my A4 2.8 Quattro back from service, they could not find out why my ABS warning light is coming on as typically it did not do it why they had the car. The computer did not show any faults with the system. As I was leaving it came on so I showed the guy and he plugged the computer back in. This time it would not access the brake system. He said the most likely cause was a faulty ABS control unit. Apperantly these are £400! Anyone had the same problem, I am hoping there is a cheaper / different solution! Thanks in advance!