Not always on when vehicle started, but usually does come on somewhere along the trip. Have noticed that it sometimes comes on if hit pothole or railroad track, like maybe a vibration can trigger it. Is this just a light problem? Or is it a brake issue?
ABS & brake lights come on simulateously, but is intermitant problem. on 2001 Chevrolet Blazer
Most likely a wheel speed sensor problem, scan test will confirm but scanner really needs to be connected at the time of the falt! May have to let a mechanic drive it with the scanner hooked up until this happens, that is IF no memory codes can be found.
1 more answer
yes wheel speed sensor is erratic