2001 GMC Sierra 1500 SLT 4WD Extended Cab SB

Question type: Maintenance & Repair

Today I turned my truck on and the ABS light came in. Driving home ABS kept engaging. Replaced one of the ABS sensors and the light will now come on at start up, go away once I start moving then come back when I get up around 25-35MPH. But brakes seem to be working fine. Any ideas on what's causing my ABS light to come on? I disconnected my battery after changing the sensor as well. I'm lost in the sauce on this one!!

Answer: Did you just guess at which sensor to replace or did you scan the system for trouble codes?

Front wheel speed sensors are the most common cause of ABS brakes engaging and the ABS light on the dash, but without a scan of the codes, how do you know which one to replace?

Another common cause is a bad front hub bearing. There is a gear in the hub that the sensor looks at. If there is a problem in there the hub would need to be replaced.

There are also wiring problems on the GMC Sierra, ground problems or even the module can go bad. Again, a scan of the ABS codes is needed.

Silverado ABS And Brake Light On

My ABS light and brake light come on after starting sometimes. I can turn it off while driving and restart, problem goes away. It doesn't happen every time i start my truck. any ideas? 2000 Chevy 4x4 Silverado

Answer: This can be a lot of things. First, check the brake fluid level in the reservoir. Low brake fluid will turn on the regular brake light as well as the ABS light. But an ABS problem will also cause the regular brake light to come on. Many things can cause an ABS light. Most common on your truck is a front wheel speed sensor. But this usually happens while the truck is moving. A scan of the ABS computer will reveal a code to show where the problem is.