Trac off and ABS light goes off

[PontiacMatt]

Hello everybody, i'm new so first off i just want to say hello and im glad i am a member at this forum...anyways, my 1999 grand am, sometimes when i'm driving my ABS light goes off and then my Trac Off light lights up, and its usually when i go over bumps or something like that....and its nearly everytime i drive my car now...any ideas what it could be? any help would be great, thanks

[xeroinfinity]

Hello pontiacmatt. When you hit bumps the car thinks it spinin a wheel so the traction control system kickes in showing/flashing the low trac light.

The 99-04 have problems with the ABS HUB/bearing units going bad. My 99 has had the hubs replaced 4 times(thats 8 bearings both sides).

You dint say how many miles but if I had to guess, one or both of the hub/bearings need replaced. It is expensive if you cant do the work your self, but if you hav a warranty, they might be coverd under it, mine were the first time I replaced them.

[Ridenour]

Like Xero said, bearings are deffinately a big issue with our cars. In matt's case though, it sounds like it might actually just be a bad hub assembly sensor. If you're lucky, it's just the sensor thinking you have a bad hub. I had to replace all 4 of my hubs after rolling my car, and a few months later, in the winter, I would keep getting the light combination on the instrument cluster. It would only go off in really slushy / shitty weather. It turns out my front driver side hub assembly connector just had a ton of dirt that had packed itself into it, which was keeping it loose, which allowed the slush / water to spray in. So I cleaned the hell out of the connector, put it back together, and no problems since. If you do actually have a bad hub assembly, you should be able to hear it. It will start off as a droning / pulsating dull roar, that progesses and amplifies as speed increases. My guess is that since it only goes off when you hit bumps / since then, the sensor is getting knocked loose, and it's getting freaked out because sometimes it doesn't get a reading. I would check / clean / tape all your connectors, and see if that solves the problem.

[xeroinfinity]

yes i guess intermitant signaling of the trac/abs lights, could be a plug at the wheel sending false signals. When I drive over RR tracks or speed bumps my lights will flash also.

Thats weird, winter is when mine does things like this too. Maybe cold temps affect the circuits inside the HUB, I may hav to look into this sometime.

[HART209]

Same problem with ABS light and Trac light. Mine is a 1999 SE with 4 cyl and 65,000 miles. Rear brakes original and front brakes 10,000 old. I can take off in any weather condition and at any speed and both lights can come on. ABS really starting to be a problem cause it doesn't go out unless you shut off car and restart. Trac only stays on a short while. Weather is not a factor here in South Carolina. HELP!!!