Thread: Troubleshooting ABS/Trac Control off

I've got one of those ELM327 OBD2 readers, and a laptop. Recently I've been having my ABS kick when braking between 10 and 30km/h, usually while turning. This doesn't always result in ABS/Trac control being turned off, so I don't think I can read a trouble code. What I'd really like to do is log the wheel speed sensor data, but I'm not sure if this can be done with OBD2. Does anyone more learned in this field know whether it's possible or not? Are the PIDs available through OBD2, or do I need a special ABS reader?

Originally Posted by stealthee

Just because a trac off light comes on does NOT mean its a bad wheel bearing. I know for a fact my wheel bearing is fine, but I still get an occasional trac off/ABS light. My issue has to do with the wiring. I can make the light come on just by messing with the connector and wiring.

This is true. I've had wheel bearings replaced in the past. I've also had the lights come on almost three years ago that was diagnosed as a "CODE C0050 RT REAR CIRCUIT ERROR, CONNECTOR ICED UP & NOT MAKING CONTACT. CORRECTION: CLEAN TERMINALS IN CONNECTOR & FILL WITH DIELECTRIC GREASE". Unfortunately it's not winter yet so it's unlikely to be iced up. I just figured that using a scan tool I already have with software might help me dig in a bit deeper, so that if I do need to replace a wheel hub, I can do it when I put on my winter tires.

I was able to hook some software into my car this evening and take it for a spin with a friend. Looks like the right front wheel speed sensor is giving random blips of approximately +- 6km/h. Even experienced the ABS kicking back, unfortunately tonights driving didn't end up disabling ABS/traction control.

Are there any other things I can try to help narrow down whether it's wiring/the hub/etc?

Ended up unplugging the abs connector and cleaning out both heads. Haven't had a problem since

Originally Posted by apok

Ended up unplugging the abs connector and cleaning out both heads. Haven't had a problem since

I think I am having the same issue. Only my ABS/Trac Off light comes on if I make a sharp right turn. So I am thinking it is a connection/wiring issue. If I drive start or make no sharp turns the light does not come on.

How do you get to these sensors to clean them?

Also, took it to OReilly auto parts to borrow their scanner to see if it threw a code and no codes come up. Maybe their scanner can't read ABS codes?

This is on a 2002 Grand Prix SE - 3.1 liter FWD.

Originally Posted by duketter

How do you get to these sensors to clean them?

I just unplugged the connector from the wheel hub, and wiped it down with a clean microfiber cloth. Compressed air may help as well.

I found a TSB described here that might help you as well. Good luck!

Originally Posted by duketter

Also, took it to OReilly auto parts to borrow their scanner to see if it threw a code and no codes come up. Maybe their scanner can't read ABS codes?

I had issues reading the codes once the vehicle is restarted.. they seem to clear quickly.