Hello everyone!

I've run into some issues with a customers car that I just can't seem to understand why the EBCM unit won't communicate..
Its a '01 SS with LS1 and traction control.

It started with one single fault code EBCM C0550 - internal malfunction. So I ordered a used EBCM of a scrapyard with the same P/N and installed it, now it's the first time it throws SRS U1040 - No communication with EBCM.
So I started to check all the wiring to see if i've been wrong with just replacing the EBCM.. BUT:

- Ground OK
- Power Supply OK
- Class 2 wire measured 0.3 ohms between splicepack and EBCM connector
- Removed the comb in the splicepack and did a wire bypass to see if any other module brought the EBCM down, but all the other modules EXCEPT the EBCM communicates..

So I ordered 2 used units and sent them to UpFix to have them serviced / repaired just to be 100% sure it would fix the problem.

Units arrived, installed them, fault still pressent ..


What am I missing / doing wrong ?