so I tested again and theres voltage at wht/blk and ground when trunk release is pressed and trunk opens


when fuse #11 is pulled the trunk release button still works as it should but nothing happens
the motor doesn't unlock.


I'm guessing the light blue wire from bcm is the issue?
is there a way to reset bcm?


The owner replaced the airbags after an accident he said. and the airbag warning is on


I have a feeling they did some stupid stuff to this car or maybe burned the BCM
can a dealer diagnose this with their plug in tool?

 

A dealer can hook up a Tech II Scan Tool to the HHR and "query" the BCM as to its status, now I'm assuming that you've probably had the battery disconnected at some point, but if you haven't here's a trick to try.

We call it a "Lobotomy", disconnect the NEGATIVE battery cable at the battery, then grab a cup of coffee, cruise the 'net, or however you'd like to kill 30 minutes.

Then reconnect the battery and check the functions again, a "Lobotomy" resets all of the vehicle's modules to the factory OEM defaults and it's been known to cure a bunch of electronic gremlins on HHR's for zero Dollars.

 

I like to live dangerously :)
never disconnect battery during my installs...
but no I just tested the wires in the hatch with the fuse #11 in and with fuse out to see what it does.


theres 3 light blue wires around bcm I tested 2 and the second one was alive with fuse in and dead with fuse out.
light blue goes from bcm to the underhood relay trigger according to that diagram

 

Did you read the TSB I posted ? Especially the blue highlighted part ? There is not supposed to be a fuse in #11.
The TSB pretty well explains why there should be no fuse there.

 

yea but did you read my replies?


the hatch doesn't work at all without fuse in..


he needs to open the hatch to get in it..

 

All signs point to wiring that's definitely "Boogered Up" George, TSB or not, this poor HHR seems to want a fuse in the #11 slot.

I'd give the "Lobotomy" a try fuzzysig, if nothing else happens, at least the BCM will be baselined back to its OEM flash which could help...maybe.

If nothing else, you get a 30 minute break for a cup of coffee or a smoke.

 

Yes. Read them all. Point being, if it doesn't work correctly with the #11 fuse removed, that is the key. If you're trying to do any diagnostics with the fuse in place, that will be misleading.
I've done a lot of automotive electrical trouble shooting over the years on many types of vehicles. Newer cars can be a real pain. Wish I could pull up my HHR wiring schematic for you but it's stuck in my old PC that died a few weeks back.

Good Luck

 

oh I also found a 2 wire yellow plug in the driver side pillar but couldn't find where its from.
its on the bottom of the pillar right behind driver side seat. yellow and white/??? wire in it.


yea its been raped by "mechanics" seems like but I work on imports mostly. and can only do so much since I don't have a general idea how americans design the electrical systems...


I sent him a txt to do the battery reset. will see what it does. hopefully does something good lol




the diagram seems pretty simple that's why I'm thinking its bcm faulty. since it works with the fuse in with no problems
and when fuse is out the button also works like it should but the motor gets nothing so I'm guessing the relay doesn't get the signal through the light blue wire from bcm

 

Yellow colored plug connectors are usually the SRS. (airbags)

 

Ok I'm going to throw this question out.

The #11 fuse that you are removing is in the under hood fuse box. (Correct?).

There is a #11 fuse in the fuse box under the dash. That's not the one that should be removed.