Random Anti-lock & Brake Warning Lights Come On

bandera · January 9, 2009

I have a 2000 Siverado Z-71 (Auto/93000 mi). About 6 months ago my anti-locks warning lamp AND the regular brake came on simultaniuosly after driving over some railroad tracks. The warning lamps clear EVERYTIME I turn off the key. It may go a couple of days without them coming on and sometimes they might come on 10 times in a day. Pretty much every time it happens when on rough road bumps. But everytime I can clear it by turning it off and then turning the engine back on. The brakes work fine, even the anti-lock portion which I found out by experience about 2 weeks ago! Finally I took it to a repair shop. They said they could not fix it. To go to a dealer. They told me the codes shown are: CO 245 EBCM Internal Solenoid or Control Valve circuit AND in the history it has a CO 265 Relay Circuit when they hooked it up to the scanner. They said it is probably in the EBCM and that is BIG $ to fix. Any ideas ?

jbordi · January 13, 2009

It is pretty common for the brake control module to go out, or some times a bad ground. I had my module rebuilt at module master for $150, check out their web-site. The rebuilt ones are better than a new one. Wheel speed sensors can also be a problem. They can be cleaned with electronic spray cleaner.

bandera · January 22, 2009

It is pretty common for the brake control module to go out, or some times a bad ground. I had my module rebuilt at module master for $150, check out their web-site. The rebuilt ones are better than a new one. Wheel speed sensors can also be a problem. They can be cleaned with electronic spray cleaner.

Does any one know what these codes mean ? Can the dealer "re-program" the BCM to fix the problem ?

jbordi · January 23, 2009

My Blazer started doing the same thing randomly. It eventually stayed on all the time. When the lights are on you do not have anti-lock brakes. It happened to me this winter in the snow. The Kesley Hayes 325 Module is the most common module for GM. Once these internal components go out, they must be replaced. GM is aware of the issue. They have service bulletins out for checking the ground connection. That does not always work. You can call the dealer to get the code definition. My bet is that there is a communication problem with the EBCM. However, if you remove the module (4 screws) and have it rebuilt it will most likely solve your problem. If you buy a new one from the dealer it will only have a one year warranty. The rebuilt ones come with a 5 year warranty. If the abs pump starts to run all time it will burn up. Then you have a bigger cost. I hope this helps. Another good web-site is absfixer.com. It talks about trouble codes.

bandera · January 26, 2009

Thanks for that info. I checked their website and it seems that is my problem. They had a series of questions to diagnose the problem and one of them was exactly like mine. Sure appreciate the 'go to' information. Now all I have to do is pull the EBCM and send it in. Thanks again !