Most of those mechanics were in grade school back in 2008, tell them to google it! Or ask them to PM Donbrew, he knows they have to reflash the RCDLR with the Tech 2 scanner. If they still have one.
My dealership does not even use theirs anymore.

 

The new computer system works on the older cars.
I don't think this is the problem in this case but tell them to look up TSB 08-03-16-001B.

 

They say they are still going back and forth with GM and trying to find the current drain. I'd bet the battery drain and the door lock issue are related as both started the same time. I measured a 900ma constant drain before we drove it to the dealer. TPS was working and keyfob was also communicating as it was sounding the horn when lock was pushed and turning on the lights when unlock was pushed.

 

One of the locks is stuck, Should not be difficult to diagnose; unplug one at a time while reading draw. OR, just pull fuse #26 on the BCM.
Maybe one of the master lock buttons is stuck.
Longshot possibility (the one the dealer will suggest) the BCM is bad because the relays are part of the PrintedCircuitBoard. Dealer mechanics always blame "the computer" first. That could be tested easily also.

I guess a test lamp and VOM are beyond some peoples skill set.

If they want to replace the BCM get it in writing that they guarantee the fix. Don't pay if it doesn't.

 

They say they eliminated the current draw down to the radio. ?? Looks like I can pickup good used radio's for cheap. Any surprises I need to know when installing a different one? Hopefully just plug in play if I get one out of another 2008? I would assume I have to redo my XM account?

 

Needs to be matched by dealership or get after market with bypass module. See our AV section https://www.chevyhhr.net/forums/audio-video-17/

I don't know how that is possible with a stock radio. "Prove it!!!!"

 

X2 ask them to prove their hypothesis, how is the radio draining the battery. Where is the short?

 

I not at all confident they found the real problem. Radio was working fine and to be causing the current drain I measured it would have to be fried.

 

Does the car have OnStar, even if you don't use it? Sharkfin antenna? That might be the radio they mean. OnStar has known issues.
Pulling fuses is a pretty simple thing!

 

Just a quick follow up. It appears most of the problem ended up being a bad battery that made my electronics go retarded until after a 10 mile drive. ???? Next I have to find out what's up with the 3rd brake light. Not getting power to the bulbs but the rest of the brake lights work. I guess I either find a broken wire or bad contacts somewhere.