Trac Off and Check Engine Lights

[bballwnder02]

Hi everyone,

I have a 2004 Pontiac Grand Am SE1 4dr sedan. It is a v6. Recently the Trac off and check engine lights have been coming on at the same time. If I turn the car off and back on again it goes away. This has happened 3-4 times over the last 2 months. About a week ago I had to push the breaks down to the floor in order to stop, and the car began to drive funny. I pulled over and let the car sit for about 10 minutes, and then turned it back on, it was fine. I took it to my mechanic, and he ran some diagnostic tests and said that the car lost communications with the break system, but he could not get it to repeat the problem and after driving it around for two days could not figure out what caused it. I picked the car up this pass Wednesday, and yesterday when I was pulling out of the gas station the Trac Off and Check Engine lights both came on again. I pulled over turned the car off and back on again, and it went away. I drove the car for the rest of the day without incident. Also, it does not seem like I'm getting as good gas mileage as I was before, and when the problem occurs there is a faint burning smell coming from the front passenger side of the car. I have a lengthy road trip coming up in 3 weeks, and would love to get this fixed before then. Can someone please help me? I would greatly appreciate it!

[xeroinfinity]

Welcome to AF! And sorry for the delayed reply !

You could have burnt your brakes up if you were braking super hard! I would think the mechanic would have checked be you never know.

As far as the lights coming on, that sounds like one of your wheel speed sensors are going bad. If you get it checked for trouble codes with an ABS capable scan tool they should see which one is faulting causing the light to come on.

These are pricey, anywhere from $120-220 each depending on who does the work. That doesnt include labor, and that's outragous any where unfortunately.

[evo-00]

I would guess it's the Service Vehicle Soon light and not the Check Engine Light. 2 diff. animals. Speed sensors are in wheel bearings and need to be replaced to fix this problem. A garage can pinpoint which wheel is bad.

[procaddytech]

Whatever is causing the check engine light to come on is also causing the Trac off indicator to come on. The only way for these 2 warning lamps to come and go off together is when the PCM diagnoses a condition preventing the engine control portion of the traction control function and sends a serial data message to the EBCM indicating that torque reduction is not allowed. The EBCM will set a C1275 and the ECM will also set a code. It is the code in the ECM you need to focus on. It is also likely to be what is causing your car to drive funny. See if you can get the trouble codes retrieved when the lights are on and write them down. A wheel bearing will not cause a check engine light but will cause and ABS light along with a Trac off indicator. You did not mention an ABS light being on.