Pontiac Repair: ABS problem I think, volt ohm meter, pontiac grand am

Question
I hear the anti-lock brake engaging when I am driving the car, without engaging the brakes. After this occurs a few times the ABS, low trac, and service engine lights all come on and the problem stops. I am guessing the ABS light coming on disables the anti-lock brake controller.
Have you experience with this problem and can recommend which part is most likely causing the problem?

The car is a 2001 Pontiac Grand Am SE 3.4l

Thanks

Dennis

Answer
Hey Dennis:

Well you more than likely have an ABS whell speed sensor issue with this car and that is what all the lights are comming on for. As for which one is doing it you need a scan tool to read the codes to find out which one it is. My guess is it's one of the front ones reguardless of what one it is they are serviced as an assembly with the wheelbearing/hub. They are expensive. If you handy and have a digital volt ohm meter you can check the resiatance of each speed sensor depending on the temp they should be between 1000 and say 1400 Ohms and they should not be shorted to ground. To check that put one lead on either of the sensors terminals and the other lead on a good body ground. It should read "OL" on the meter if they are not shorted out to ground!  Good luck :)