I have a 2001 Blazer LT 4wd, both the ABS and Brake lights are on most the time, not always.

Throwing the following codes:

C0222 - Right Front Wheel Speed Sensor Signal Missing
C0241 - Wheel Speed Mismatch
C0242 - Wheel Speed Mismatch
C0245 - Wheel Speed Mismatch
C0246 - Wheel Speed Mismatch
C0251 - Wheel Speed Mismatch
C0252 - Wheel Speed Mismatch
C0265 - EBCM Control Valve Circuit


My question is other then the obvious replace the right front wheel speed sensor since it has been cleaned and still fails, does the last code indicate more might be wrong or just reassuring that the sensor is bad? Where exactly is the EBCM (I am assuming the controller box next to the ABS unit)?

 

look at the reluctor wheel and check for chipped or missing teeth.

 

Might be difficult to tell if you are looking through the WSS hole. I say replace the sensor, clear the codes and see what pops up.

 

EBCM failed, Does yours have the small unit or the larger abs unit. Regardless of what unit you have the ebcm is the control module fastened to the abs unit. The small unit will have a shiny aluminum top that the wiring goes into that is the ebcm it is removable from the ABS modulator assembly. The large unit will have a black top and say kelsey hayes on it. It's also fastened to the abs modulator assemble. You best bet is to look on ebay for a seller called s-10 warehouse. I have bought several units from him and used them on customers vehicles and had great luck. They also average about 20-30 dollars for the complete abs unit.

 

Update:

I bought and replaced the wheel sensor indicated in the code. I then found the ground under the air box behind the passenger light and did some cleaning/grinding on it and put some dielectric grease on it to keep it clean. I also took the ECBM off and unhooked it while I was doing some other maint. upgrades. Put everything back together and the light is now off. Went for a test run and it stayed off. Still have some driving before I feel it's fixed, but a quick test of the ABS and it kicked in like normal (wet parking lot was convenient).

As a side affect I think I may have fixed an issue that I have been having since I got this truck. When in reverse in 4wd it would do a sorta light pop surging . I backed up twice while turning in 4wd and I did not feel that at all. Don't know if it had anything to do with it, but strange it has always done it and for once it didn't.