ABS/Traction Off Lights issues
 

I have a 1998 Aurora with 160K+ miles, which I have taken very good care of. About four weeks ago, the ABS Light and the Traction Off lights came on and were staying on. Other than the lights being on, everything worked fine. I sometimes noticed that when I drove for a 15 or 20 minute distance, stopped my car, ran into a store, came back out and started the car, the lights would be off. And as before, everything worked fine.

Until about two weeks ago. Same scenario, I had driven about an hour and stopped to get some lunch, and when I returned to my car and started it, the lights were off, but as I pulled out of the parking spot, when I applied pressure to my brakes, they acted as they do when I have applied pressure on the brakes on icy roads - in other words, the ABS was kicking in. This was very distressing because it meant that when I tried to stop, my car kept moving forward as the ABS pumped for my car to stop. I proceeded very carefully, applying my brakes from a distance back so I knew I would stop well behind the car in front of me. I noticed then that I heard some noise which seemed to come from directly in front of me in the engine, the lights came back on and my brakes were now working fine.

This has happened two or three more times since then. In addition, the last time it happened, after I had come to a stop where the ABS was pumping, I heard a noise from directly in front of me in the engine that sounded like the traction control went on, the Traction Active light came on, (I was at a stand still) and then all of a sudden, my brakes were working fine - and the ABS and Traction off lights were back on.

This does not happen all the time, which makes it hard for my mechanic to diagnose.

My mechanic hooked the car up to the computer system to check the codes, and he found that it was not connecting to the computer in the engine, so he has no idea what is causing the problem. He suggested replacing the ABS module to see if that will fix it, and then perhaps looking at the ABS pump, but he has been very honest in telling me that he has no idea if either of these will work.

Any suggestions from anyone?

It's not the pump because it's functioning properly.

My gut tells me you have a bad ABS sensor. That's where I would start.

I second svnt442s opinion. The ABS pump seems to be working. Wheel speed sensors or the wiring to them would be the best place to start. The fronts are the most vulnerable to wires breaking. Also look at the connectors, make sure they are not corroded.