12.6 volts, almost a dead battery. We’ll be waiting for the load test results.

 

Why are you worrying the wheel speed sensors? C0550 means internal fault in EBCM.
It will cause the ABS light, the TCS light, and the BRAKE light.
The "book" says replace the EBCM.

 

I replaced the battery today with a new one. Still have the C0550 DTC and all three lights are illuminated. Also rechecked the ohm readings for the wheel speed sensors again at the EBCM connector. They are reading correctly..... operator error.

Do you think it would be worthwhile to pull out the board on the EBCM and reflow some of the joints? I have seen where ppl on other forums do this to correct some other DTC. What do I have to loose at this point?

Thanks

 

I would price a junkyard part.

 

Do I need to find an EBCM/ESC module that has the same part number as mine? The number on mine is 20777328. The module that shows up when I look it up is 20827127.

scratch the idea about opening this up and resoldering. Can't open this one. Appears the cover is glued on and the unit would probably be damaged if opened.

 

The module superseded, many times over.

Have a look in here


https://www.chevyhhr.net/forums/prob...on-ebcm-64754/

 

Both Rock Auto and GMPartsdirect show 20827127 as the correct brake controller for 2009-2011 HHR.

GMPartsDirect doesn't even list any part with the number 20777328. Often GM will change the part number to a new number after the original parts were produced. Sometimes this is done because GM redesigned a part so it can fit several vehicles so they don't have to stock as many different parts for repair.

Steve

 

The RockAuto listing

https://www.rockauto.com/en/parts/ac...ol+module,1844


the module will require programming to your HHR. It could be corrosion at the ground wire

 

I'm pretty sure the circuit board is "potted" in epoxe.

 

I had already checked the ground by ohming from the ABS connector back to the ground. I also pulled off the ground (G201 I think) just forward of the LH strut and cleaned it. No corrosion was there to begin with but I cleaned it anyways. Made no diff. Still have the C0550 code.
Is there another ground that I need to look at?
If I buy a used "junkyard" part, you saying I will have to get it "programmed"? Who can do this?