My '03 Astro has an intermittent Brake/ABS warning light. When I first start the van up, the light is off. After driving for a few minutes, the light will come on and stay on until the van is shut down. Time for it to come on varies. However I have noticed that hitting a bump or road irregularities seem to trigger the light on. Had the brakes checked out at a local shop and mechanically everything was in order. Their scanner was not working so they did not check for codes. Any ideas or suggestions are welcome.

Thanks,

JR

Intermittent or failed wheel speed sensors, poor connections, failed control module, and power problems can all cause this. The possibilities are too numerous to speculate, and it's best to scan to help pinpoint the source. Short of that, you can verify all the connections in the systems and even go as far as testing sensor output and circuit continuities. I've even seen that kind of thing after transmission work and having the rear speed sensors connected incorrectly (especially on AWD).

I am having the identical problem with my 03 Astro. The code is CO265 Relay in the ABS unit. My question is, can the relay be replaced by itself, or does the whole module have to be replaced.