Trac Off Light

January 30, 2006 5:04 AM

On the way to work today a light on my car said "trac off." Is this a serious issue to the point that I need to take my car to get looked at?
posted by superbird to travel & transportation (11 comments total)

I'm gonna make a guess that its 'traction control' - you may have a button to switch it off and on in the car...otherwise, get it to a mechanic to check it out.
posted by mattr at 5:08 AM on January 30, 2006

mattr is probably right. Also, was the light on the whole time you drove to work or just part of it? And remember to check the manual to see what all the conditions that can cause that light to be off are. And to look for if there's a button.
posted by skynxnex at 5:22 AM on January 30, 2006

Most traction control systems turn off if the ECM goes into open loop control modes. You can tell this, because you'll get the check engine light at the same time.

Otherwise, it's the switch, or one of the sensors. If you're not getting a ABS light, it's the transmission sensor. The simplest problem, as noted, is you hit the switch that turns the traction system off.

Yes, you can drive it, but you won't have traction control. If the check engine or ABS lights are on, getting it looked at now becomes much more important.
posted by eriko at 5:26 AM on January 30, 2006

My Buick has been doing this light and the service engine soon light intermittently; sometimes at the same time but most often not. The dealership has had it twice replacing parts and trying to track the problem down by replacing sensors and modules.

Part of the diagnosing problem is my fault for not taking it in right when it does it. A mechanic needs to see it fairly quickly so they can download the codes it's throwing to the computer. Otherwise, the codes get old and they have to clear them and wait for it to come on again. (or so I'm told)
posted by justlisa at 5:41 AM on January 30, 2006

I have a light that comes on in a 99 Chevy Lumina (yes, feel sorry for me) that says 'Low Trac'. This comes on when I hit a bumpy road here in Detroit, so quite a bit. It goes back off, and just seems to indicate that the car's traction control has hit adverse conditions (probably a huge pot hole that the wheel slides through).

I also had a 93 Town & Country that the ABS light was on constantly. That turned out to be a wheel speed sensor that had gone bad. I let the dealer tell me which one it was (for free) and then I replaced it myself.
posted by Slothrop at 5:42 AM on January 30, 2006

I had a Toyota Corolla which had a push button on the dash to engage the All-Track system. When it was engaged a dash light would come on to remind you. I'm not sure what kind of car you have or if it has an All-Track transmission. Maybe you even have an ex-spy car that has GPS tracking of vehicles that are being pursued and it is just telling you that there are no cars in the vicinity?
posted by JJ86 at 5:54 AM on January 30, 2006

What is the make and model of your car? The manual probably can help, if you haven't lost it.
posted by insomnus at 6:18 AM on January 30, 2006

It's a 1999 Pontiac Sunfire.
posted by superbird at 6:33 AM on January 30, 2006

"Trac Off", not accompanied by an "(ABS)" or "Brake" light as well, signals a problem exclusively with the traction control on late-model GM vehicles (and most other makes). This is no danger to anything other than your ability to keep your front wheels from spinning.

ABS & traction control are very much shared systems. 80% of traction control is the underlying ABS system. The wheels speed sensors at each corner, brake motors & their related hardware - all ABS. Since your ABS isn't throwing a warning light, you can rule out a lot.

Traction control-specific likely points of failure could be: the computer (EBTCM - "Electronic Brake Traction Control Module"), throttle position sensor, or perhaps you pressed the button to turn off your traction control when you got in your car this morning. :)

In any case, most places that offer to scan your car's computer for free and tell you why your "Check Engine" light is on (Autozone, Pep Boys, O'Reilly Auto Parts, etc.) will not be able to do so with an ABS/Trac light. GM's system requires a scan tool that is generally only found in dealerships and shops with enough money to pay for it. A scan at an independent shop should run you around $50.
posted by porntips guzzardo at 7:00 AM on January 30, 2006

My experience with numerous rental cars is similar to Slothrup's. Hit a bump, get stuck in mud or snow, the TRAC OFF light come on. Most times it's a simple matter of turning your engine off and the traction goes back to its default setting on restarting the car. It's not usually a big deal. I've never got a check engine light as the same time as TRAC OFF.
posted by Xurando at 8:05 AM on January 30, 2006

Maybe you just inadvertantly pressed the button turning off the traction control? Check the owner's manual first before assuming anything is broken.
posted by AstroGuy at 8:07 AM on January 30, 2006