I am having a weird problem on my Pontiac Bonneville SLE 2001. Well it started a few months ago when i was driving or when i hit a month my ABS and Traction control kick off and the car beeps when it happens. It use to happen very rarely. But, now it happens everyday. But recently my breaks started grinding. The catch is they only grind before the ABS and traction control kick off. Once they kick off they do not grind. Just yesterday i also got the engine code p0442. I did search it and i guess it means their is a small leak somewhere in the engine. I had my buddy clear it for me with his scanner. But i am concerned about the ABS and Traction control my mechanic said he thinks it could be a sensor in the wheel? But, the grinding think kinda has me stumped how it only does it before the traction control kicks off.

The code is a small leak in the Evaporative Emission Control System.

When was the last time you had the brakes done and are they good?

It sounds to me like a wheel speed sensor is bad. When the system see'* one wheel turning faster than another, the traction control system compensates and tries to slow the wheel down. The only way to repair the speed sensor is to replace the hub and if you are going to replace one, you should replace them both. They are not the expensive and fairly easy to do.

To check your abs T/C light you need another scanner different form the OBDII that will probably be able to tell you

Ok is it something that needs fixed immediately? What about the grinding in the brakes as soon as my abs and traction control kick off, the grinding stops completely. I think when i told a mechanic about it they said it sounded like a bad wheel bearing or something and they cost around 200-250.

Replace both front hubs. They will eventually cause premature brake wear and rotor warping. So..pay a bit now, or pay allot more later.

Agreed. The grinding noise sounds like the traction control system is trying to compensate for a bad VSS reading. Im gonna go ahead and agree with everyone on this one, replace both front hubs and check your brakes while your at it.