HVAC ECM
 

Anybody have any experience with the HVAC ECM?
None of the main head functions are working.
A/C, blower fan, front defog, rear defog, seat heaters, etc.
I’ve checked all the fuses and they’re good.
Is it possible the whole HVAC ECM could have failed?
If so, what’s the best way to diagnose/replace?
2015 SS 1LE

I'm guessing you mean the head unit, as what you are referencing does not exist. "Air Conditioning Engine Control Unit" (that's what ECM stands for)

And the head units do fail

I know this thread as aged, but if you haven't fixed the issue try removing and replacing the fuse for it. I don't recall the exact fuse, but it's located in the panel under driver side A/C vent. Mine has done this twice and removing/replacing the fuse fixed it both times.

The heater control is under the glove box. I have read where unplugging and plugging the wiring harness at the unit fixes alot of issues.