Fixed my CV boots, broke my ABS?

[daveharris]

My '98 A6 2.5TDI was in for its MOT last week, and needed 2 new driveshaft boots, which the garage fitted. In the process they have caused the ABS light to stay on permanently. It has never been a problem before, in the 7 years I have known this car. Does anyone have an idea what the garage might have disturbed to cause the problem? The ABS appears to still work (pulsing pedal under v hard braking), but it will be an MOT fail next year with this light.

Needless to say, the garage will be sorting it, but they plead ignorance at the moment, so I would like to go to them with some possibilities.

Thanks.

[adamss24]

My '98 A6 2.5TDI was in for its MOT last week, and needed 2 new driveshaft boots, which the garage fitted. In the process they have caused the ABS light to stay on permanently. It has never been a problem before, in the 7 years I have known this car. Does anyone have an idea what the garage might have disturbed to cause the problem? The ABS appears to still work (pulsing pedal under v hard braking), but it will be an MOT fail next year with this light.

Needless to say, the garage will be sorting it, but they plead ignorance at the moment, so I would like to go to them with some possibilities.

Thanks.
If they are a respectable garage they should be able to do a diagnostic check and see what fault are stored in the memory. It might be that one off the front ABS sensors is not plugged in all the way or the wiring has become damaged. Either way, the sensors are simple to replace once the front wheels are off and the fault/light will rectify/estinguish itself once the sensor has been properly plugged in/replaced. Give it a try yourself and remember/take a picture/draw how the wire is routed inside the wing. Hope this helps.

[Col]

My guess...

They probably forgot to line up the reluctor ring back in line with the sensor head on one or both of the wheels.