Thread: Replacing the BCM on a 08?

I think I have the lock issue and battery drain figured out on my wife's 08. All signs looking to be pointing at the BCM is starting to go bad. From reading it looks like the Lock Relay is built into the BCM unlike past years. I have a relay going bad that is not allowing us to lock the car. Searching this seems to be a issue with 08+ GM cars. I have found this same issue in most of the Chevy line.

What i can not find is a DIY on how to replace it. I know I have to get it reprogrammed when I get a new BCM.

I would like to first locate it and check over the pins and make sure everything is OK.

If I have to replace it can I start the car with the new BCM or does it have to be reprogrammed first? I all ready called the dealer and the cost to reprogram it is $125.

Thank you for any help on trying to get done on replacing it.

Yea the bcm will need setup by tech 2 then the theft will need programmed by service programming system best bet would b buy it and take it to them with the car and have them do it.. If you were in kc I could do it for ya

Just after posting this I found the same issue on a LS1 forum. Found out some of the cold solder joints like to fail. That explains why this is happens on and off.

Now I need to figure out how to remove the BCM. Then check the joints and maybe resolder the lock relays that are on it.

Sent from my Nexus 7 using Tapatalk HD

I wanted to send an update. I got home today and the locks still where not locking. So I got to the BCM played with the wires and no luck. So then I removed the BCM. I looked over the board it is different then the older ones on the LS1 forum pics. The 08 board is a lot tighter. So I did not feel comfortable doing any soldering. I put the BCM back together and plugged it back in. After getting the battery connected again the locks are back to working.

Just a FYI the night before I did disconnect the battery for a long time and that did not do anything. So I know that did not help in the fix today.

Not sure it could be the board or maybe it is was a bad connection on the plug or terminal. When I unplugged it and plugged it back in it cleaned the connection.

If the locks go back not work working again then I know it is the board. I will post up.