This is usually caused by a faulty abs sensors.
What you can do as a preliminary check if you are good with a spanner is:
Jack up each corner of the car, the front wheel sensors are held with an allen key bolt on the back of the wheel hub (side closest to the doors).
Remove the sensor (very easy), check that they are clean, make sure that the gap in hub where the sensor sits is not being at all obstructed by the large circlip which is used to secure the wheel bearing in the hub (i.e the circlip can some times turn a couple of degrees - the sensor must sit fully flush to the back of the hub and not at an angle). If the circlip is stopping the sensor from sitting flush, just turn the circlip a couple of degrees by tapping with with a small punch and light hammer.
Follow the wire from each sensor - you'll see it goes into a plug tucked behind the plastic fender liner - unplug it and check for any dirt or corrosion.
Then drive the vehicle for a while and see if the fault resets.
If you have cured the fault it will not immediately reset as it will change status in the ECU from a permanent fault to an intermittent fault and then after a few km and a few times of driving the car it will then clear completely as long as the fault does not re-appear during that time.
Failing that you'll have to have a diagnostic run on the vehicle.
Sean, October 2009
