Hi, I've been reading the various ABS posts. My ABS light comes on once in a while when I first turn the car on (without moving). If I do nothing else, it just stays on as I drive. But if I just turn the ignition off and re-start the car, the light will come off. None of this is connected to the car moving at all. Does this imply it'* probably not the sensor, and more likely a wiring issue? Can it be an ignition switch issue? I had the codes pulled by GM and they said there was nothing (!).

Thanks.

It might as well be the connector going to your speed sensor.. if it'* loose, dirty it might not get accurate reading when you start it.. then when you turned it off and back on again.. it resets everythin and attempts to (in it'* way) talk to all 4 wheel sensors again. So there has been no signs of it coming on when you're driving? (hit a bit pothole and or badly bumpy road?) I'd personally take all 4 connectors off, clean it.. plug it back in and see if it'll do it again.. I know it'* a bit time consuming.. but I never believed in spending money on things you don't need to.. ( unless you're lookin for a reason to modify and upgrade.. but it'* it'* the speed sensor.. you can't upgrade it really )

If you're not in motion when the light comes on, it'* very likely the PMV assembly self check (originating from the EBCM). PMV is the Pressure Modulator Valve used for ABS and traction. Below your airbox, 6 brake lines attached to it. Very expensive and a bitch to change. Try cleaning the connector to it if you have an intermittent.

The EBCM is attached to the firewall behind the console inside the passenger cabin to the right of the gas pedal. Electronic Brake Control Module. The brain. Rarely fail, thank god, cuz they're expensive as hell.

I'd bet NOT a wheel speed sensor, but it wouldn't hurt to clean all 4 connectors when you clean the PMV connector contacts.

willwren, drifter 420, thanks for the advice, I will try that. Car is otherwise in super condition (& is my 3rd Bonneville, already eyeing the GXP for my 4th, but will let them 'age' for a while - I find if you buy say a 4-5 year old Bonneville, it is unbelievable value for the money).

Thanks.

Aardvark

Found the pc board with cracks (ABS computer) in the solder with intermittent continuity. Replaced computer ok now. You might try that.

Please pay attention to the dates of threads. This one is over 10 years old and the original posters are long gone.