Abs Ebcm Ground Wire Location

[jenandjimj]

I have a 2000 Chevy Astro AWD throwing a Po265 Abs code. Which is the ebcm relay. Both the abs and brake lights go on and off while driving. When the lights are off Abs works great and the AWD works. When the lights are on no abs and the AWD does not function. I have done a ton of research and have found out it is one of 2 things....a bad ebcm or bad ebcm ground. Before I send the ebcm in to be rebuilt I would like to clean the ground. But I do not know where the ground for the ebcm is connected to the frame. I just need to know exactly where the ground is located on the frame. I was told by someone possibly the radiator support? But I looked and there are at least 3 different ground wires on the radiator support. Anybody have an idea exactly where it is at?? Thank you.

[Phantom]

Try looking at the left rear of engine , there is a mounting point that a black ground wire from ECBM , a blk/wht wire for signal ground from ECBM and the black ground wire for the brake pressure warning switch and another black ground wire that all ground at the same location , this is on a 99 , not able to get to the diagrams at this time , but this should be similar
The ECMB should be mounted on the left front side of frame to the left of the transmission

[Corsemoto]

Phantom is right if I remember correctly (can't access my service manual anymore from this computer), left rear of the engine. Certainly a good idea to check but it is most likely still a faulty ebcm which you're aware of. I had the same intermittent symptoms as you with my '04.

If you do pull the ebcm for repair, there is some info I posted in this thread https://www.astrosafari.com/viewtopic.php?f=45&t=13496 and it doesn't hurt to test the speed sensors and abs pump at the same time to make sure they are all functioning properly as well.

The shop that repaired my ebcm gave me a list of codes stored in the ebcm and one of them was a faulty wheel speed sensor but told me it isn't uncommon to show a code for that when the ebcm goes bad and that the sensor was probably fine it was all ebcm related. Sensors turned out to be fine, it was ebcm related and has been great having full braking potential since having repaired a few months ago.