My daughter has a 2002 Grand Prix. Last week the ABS & Trac light came on for a short time. It ran a self-test & the light went off & didn’t come back on. A few days ago, it came on again, but went back off. A few times while braking, it feels like brakes a grabbing a bit. Took it to repair shop & they said no codes show up. They drove it around quite a while & couldn’t get it to do anything. They said something triggered the ABS to engage. Any ideas? Thanks
How old is the battery in the car?
I had a similar vintage Buick Park Avenue, and when the battery was on its last couple weeks of reliability, the same thing happened with my brake/abs lights.
Also, when was the last time the brakes had a full fluid flush?
There might be debris in the lines that is affecting the ABS modulator assembly, and causing a valve to stick open on occasion.
Thanks, that will be something we will check.
Have a good day.
I would also just pull and clean all of the electrical connectors for the wheel sensors. I had a similar intermittent problem on a GM and I seem to have cleared it up by doing this. One of the sensors had gotten caked with grease from a torn CV boot, but in general I’ve found my own GM electrical connectors to be easily disturbed (very much unlike the ford & dodge that I also own).
Have your repair person check out your speed sensor wiring harness. Should be able to replace part and labor for about $260.