Jim Grant's Tech Tips

'99 Pontiac Grand AM, ABS Light After Brake Work

Q: The ABS light and Traction light in my '99 Pontiac Grand AM with a 2.4 L engine, will not extinguish even after I have changed my pads and rotors. Any suggestions on how to get it to turn off or what to check as to what might be the problem?

- Pablo S.

A: There is a funny thing about Anti-lock Braking Systems that many people do not realize. The system doesn't know any thing about brakes. That's right the ABS system doesn't know anything about brake pads, shoes, calipers, rotors, brake drums, etc. In fact, I could remove your brake pads, brake caliper, even brake rotors and drums on some vehicles block the brake line so the fluid doesn't spill all out and your vehicle's ABS system wouldn't even know they were missing. Computers assume, yes they take for granted that the core components of the braking system are in good working order. If you have an ABS light on the first item that should be checked is the brake fluid level. Many ABS systems do tie a fluid level sensor warning light in the ABS warning light. But let's not assume and be sure the brake fluid is at the correct level. You now know that you have good brakes and that the ABS system doesn't know the difference. The next step would be to have a code check performed on the ABS computer. With the warning light being on there will be a code. That code will direct you in which part of the ABS system needs diagnosis. It is also likely that your traction control warning light will go out once the ABS problem is corrected. The 2 systems rely on some of the same sensors to operate correctly.