ABS Fault

[foggy50361]

Hi Guys,

My ABS light comes on after driving for a meter or a mile if it doesn't come on the braking force is greatly reduced and will then come on violently on one side (drivers) pulling the car in the same direction, if the light is on braking force is normal but with no anti-lock. My assumption is the sensor (drivers front) is the problem but I've changed that one and the problem is still present. Any suggestions greatly received. Sorry if this is a repeat but I have searched the forum and been unable to find the same fault.

Cheers

Foggy

[e301988325i]

The sensors can be checked for resistance, do a search on here for the values, they are £100+ each new so s/hand is worthwhile. It's worth removing them all (one 5mm alen key bolt each) and cleaning the crap stuck to the magnetic end, and wirebrushing the ABS toothed rings. After that all checks out ok, next cheapest would be to replace the ABS ECU in the glovebox with a known working s/hand one normally available for about £15.

[foggy50361]

Cheers will try that

Foggy

[Brianmoooore]

'Normal' ABS faults shouldn't affect the braking performance of the car in any way, other than the loss of ABS when there's a fault. It should either be a car with fully working ABS, or behave exactly as an E30 that doesn't have ABS.
In this case, I think the ABS pump assembly is suspect, although it would probably be a good idea to try a different ECU first, just in case, as that's a lot easier to change.