Stop running over bumps if you can. I also have a '99 GA GT, the trac off light always comes on, it is one of the most common problems for grand ams. The taction control and ABS are wired to the same harnes behind the brakes in the front. Check to see if they are lose, a wire maybe broken/corroded, it maybe worth replacing them. Unfortunately its costly.
The service engine light will stay on until its fixed.
Thursday, March 12th, 2009 AT 12:17 PM