When driving at times, I know when the Trac control light will come on.
As I am driving, the Trac Control will pull the gas pedal away from my foot as to act if loosing traction. When I apply brakes to come to a stop, pdeal goes down an d pump runs momentarily, and Both Trac & ABS lights come on. I turn ignition on and off and it doesn't occure the rest of the trip.
Last fall I replaced righ front sensor and problem ceased for 6 months. Do the hall effect sensors deteriorate?

Tony Mamut
Highland, Michigan
313.718.0116
tmamutatswcontrols.net

Submitted by nicholasclare@… on Tue, 06/20/2006 - 07:14

Id agree with Bevan that you need to check the wheel sensors or more precisely thier connectors.

Sensors themselves dont breakdown but sometimes the waterproof connectors do and you get a short. If you get a short the abs warning light will come on. Bevan i dont remeber the

You also need to check that the abs sensor rotor is not glogged with debris. It doesnt have to be spotless as the sensor measures magnetically and therefore the steel sensor should always be clear to it but sometimes you can get something that represents a false reading and hence the warning light.

If as you say you stop and the wait something like 30 sec before recranking and the light goes out and stays when you restart the engine but still at rest then it is definitely a wheel sensor. I had this on my 1996 XJ6. If you then move off and the light comes on again this would point to a wheel sensor.

If the warning light comes on during startup and stays on you need to get to a jag dealer and use the diagnostics to check the system and it will be able to pin point the problem. Also sometimes fault codes are logged and this latches the light to the on position until you have visited a dealer who will clear the fault codes and reset the lamp to off.

This is done to ensure that these faults are fixed properly and clearly indicated to the driver and can only be cleared by a qualified technician when he has checked and repaired the system.

Nick Clare
Ex Jaguar Product Development Manager
Coventry
England

Submitted by bevanadams@hot… on Tue, 05/16/2006 - 11:12

ABS wheel sensors sound like a good place to start. The traction control works by comparing front and individual wheel speed; this is dose through the ABS sensors. If I where in your position I would check the Abs sensors with a multi-meter before buying new replacement parts.
Make sure to use a digital multi-meter to check resistance (why they say use a digital instead of an analogue I donÔÇÖt know, it was in one of the magazines once).
You donÔÇÖt say what car it is? If the lights go out when you turn the car off, IÔÇÖd guess itÔÇÖs a pre1990 xj40.
If this is the car you drive: the next time the lights come on, get the code of the trip computer. On later cars it will stay on until the problem is fixed or the battery is disconnected. Older cars will reset just by turning the ignition all the way off.
I hope this helps.