I haven't seen anything like this in the forum so forgive me if this has already been answered. I finally broke down and took my '01 Crew Cab 4.3L to the shop today because the ABS and Brake lights on the dash have been coming on. Between customers, the mechanic ,"Jim", was nice enough to help and he pulled Code C0265...EBCM Relay - Open. We have not yet located the EBCM relay...neither the Owner's Manual nor Haynes seems to identify it. (Jim was busy and I was in a hurry) The lights have been coming on intermittently for about three months. They don't blink, just stay lit. I haven't noticed what causes them to come on yet but I have noticed a few things. At first, I was able to restart the truck and reset the lights which of course doesn't work any longer. At lunch or on the drive home, the lights usually come on when I start the truck and will then stay on. Usually in the morning drive, the lights don't come on at all...occasionally they will when I hit a bump in the road though. I have not felt any change in brake "feel" or effectiveness during normal city driving/stopping. Haven;t done it in a while but I had noticed that during a stop on sand/gravel and the ABs kicked in, the lights came on.
A little history on this... Last year I noticed that if the ABS engaged or if I pushed firmly, the brake pedal would go all the way in so bled the brakes myself last year. Didn't solve the problem and the mechanic suspected a bad master cylinder which I swapped (rebuilt) but had no affect. I always suspected that there may still be air trapped in the lines so a couple months ago after the dash lights started their thing, I took the truck in to have the brakes 'pressure-bled'. That mechanic, "Gary", noticed that the rear discs showed over-heat marks (discolored and spider-web marks). I thought that was odd since all the pads and discs were changed in '05. So, I changed the rear brakes. Today Jim thought he noticed that the brakes seem to drag...I thought I had noticed that also 'cause the engine seemed to lack power in the 95°-plus heat but had chalked it up parasitic loss from the cooling fan. Also, Jim noticed that his code scanner showed the truck moving at 3MPH while parked in the shop.
There has been no identifiable pattern to the lights coming on except that they usually come on in the heat of day. Has anyone experinced anything similar? I would like to change the EBCM Relay, does anyone know were it's located? Any other ideas how to further diagnose my brake issues? I'll be lifting the truck as soon as I can to spin the wheels and see if they drag or free-wheel.