I've found a few schematics on other sites as well and they are all fuzzy. I pulled the BCM and reinstalled it just in case hoping for a bad contact. No luck. Was kind of a biotch to get out. At this point I think the BCM failed.

 

When I post a pdf it is printing a picture to Microsoft print to pdf. The pictures are way too big to post and the printer does not get all of the pdf/svg info. I'm sure somebody else has more time and resources than me

 

Ah! That explains it. Before “printing” may be able to tweak the virtual “printer” settings in the dialog box for higher DPI or page size or scale or something.

 

Less than 130K on the car and the BCM has several problems. No third brake light, thus disabling cruise control and no remote start. Also started having intermittent blower motor. BCM's are obsolete from Chevy. No reman's in stock anywhere. I contacted both companies that rebuild them. One said 10 days min turnaround time to send it in and see if they could fix it. Ended up buying a used one for $50 off ebay. Still need to get it to the dealer for reprogramming but everything is working again. For now locked out of the radio, which is stupid, and every warning light on the dash lit up. LOL Forced obsolescence in play.

 

So?
What does the BCM have to do with the third stop light or the blower?

 

No third brake light causes no remote start! Try reinstalling the original BCM and tighten up the four bolts in the under hood fuse box and do some investigating, corrosion at any ground point! I don’t see to many BCM ‘s failing.

 

Over 90% of BCM's replaced are perfectly fine. Yours is perfectly fine.

 

My BCM will not power the relay to turn on the third brake light along with the blower motor power going intermittent. It works with the used one I installed, but not with the OEM. I swapped it back and forth to verify. OEM module shows signs of moisture inside. Likely from drains getting plugged on sunroof. With the used one I just installed the rear gate will not open any more and the rear wiper also will not work???? Dealer is telling me $150 flat fee to try and reprogram the new BCM but likely locked out of it because its from a different Vin that I do not have along with a 2 week wait to get in.

 

The programming involved is inserting the VIN, if guys on the internet can do it the guy in a GM shop can. Find a dealer that knows something, any GM dealer does not need to be Chevy. $150 sounds right, if the technician has a clue. The computers in the HHR have been obsolete for several years.

 

Do you know if there more programming to be done other than inserting the Vin? I found out just swapping out the prom chips did not work. Maybe because I'm going from the old 25945048 module to the newer superseded 25928052? The microprocessor on the board does have an on board eprom.