ABS PROBLEM

Rover 220 Coupe (sergio snipped-for-privacy@hotmail.com) gurgled happily, sounding much like they were saying :

One of the front wheel sensors - the cable has a slight fracture internally.

OK.Thanks Adrian for the advice.I think i know here the sensor is.I saw some fotos of the abs system for the rover 800 (i think) the system is problably very similer. Its a start. THANKS.

The Problem: At low speed (0-30 k/hm) when i press the breaks the abs starts working.I have no problem at start up if i press the breaks hard the abs will work fine(execept the noise at low speed), but after a few kilometers the ABS light go ON.

IF ANYONE have some good ideas for solving my problem i will apreciate.

It could be one of a few things.

First thing to check is that the ABS sensor rings on the driveshafts are secure. It's not unknown for them to crack and then start spinning on the driveshafts.

Next thing is check all the wheel bearings, and make sure that there's no play in them. If there's play in the wheel bearings, the air gap between the abs sensor, and the ring can cause the sensor not to pick up the correct wheel speed.

After that, you need to check the resistance of all 4 wheel speed sensors. It is best to check this at the ABS control module, but it requires a wiring diagram so you know what pins to probe. All the readings for each sensor should be similar, and also check for any continuity to earth.

If none of those tests show up any faults, you'll need either to use an oscilloscope to compare the readings from each sensor, or have the car plugged into a diagnostic computer to compare the wheel speed readings.

Or breaking into an open ended loop and confusing the whole system.

PDH