no when u replace a bcm, u have to reprogram it using either a tech 2 or a mdi and gm’s Service information. maybe there are ways around it but i probably wouldn’t recommend it.
I hope you guys are giving GTO specific information about BCM’s. I didn’t have to do any reprogramming on the tib BCM I replaced.
Yeah, swapping the BCM isn’t really an option. Not only is it programmed to the radio but it’s also programmed to the fancy little chipped keys. Not to mention I wouldn’t want to just borrow someone’s $1500+ BCM when a short in my car might be frying it. There are all kinds of nightmare stories on LS1gto.com about Pontiac dealers not even being able to figure out how to link a new BCM to the old keys.
However, a little update. Last night I swapped in the new ignition cylinder since GM finally got some of the redesigned parts in stock. While I was at it I crawled under the passengers side dash and checked out the BCM and it’s wiring harness. The connections were tight, no sign of water leaking anywhere, and doing a “push/pull/squeeze” test on the harness I was unable to recreate any of the glitches I saw when I was having problems. That leads me to believe the problem isn’t in that area of the car at least.
What I did find was the voltage at warm idle with the lights off and minimal draw was only 13.66 volts. That seems a little low since it should be 14.2-14.5 so now I’m going to be hunting grounds. Someone on LS1gto.com suggesting a ground near the passengers fender that serves at the main ground for the BCM so that sounds like a real good place to start. That plus the two major engine block grounds.
After a 50+ mile joyride last night I wasn’t able to recreate a single glitch. Autozone couldn’t read the codes either so before I blow money at the dealer getting a tech II reading I’ll be chasing these grounds.
I would get the wiring diagram for the ECM. I couldn’t believe where gm put some grounds in the s10
I’ve got the full GM service database for Pontiac’s through 2005 installed on my server at home so getting the wiring diagram shouldn’t be a problem. I love ebay and dealers willing to make a quick buck by selling the GM DVD’s and the login. 
Believe it or not, I did not see a BCM on car-part.com
Thats a 1st for me.
On the topic of BCM’s, My moms old camaro had issues with it.
Her car was DOA whenever the temp dropped below 32 deg.
5 or 6 “Try’s” at the dealer to “reproduce” the problem failed.
until, they parked it out side that is… Then they were clueless, but did get to
replace the battery that was perfectly fine in the process. She ended up trading it in because they refused to do anything other than reprogram it.
When the car was flaky, what was the air temp?
Both times it had been sitting in my attached garage. It wasn’t even one of the colder nights we’ve had.
I had an electrical gremlin that would leave the car dead occasionally, happened 5 times over an 8 month period. Then one time driving it died and restarted itself immediately. Electrical stuff blows brother.
I’d say just keep driving it as usual until the problem starts surfacing more often. At some point it will either get worse or better and produce more symptoms. It doesn’t sound like there’s much you can specifically do to figure it out at the moment. It’s at the point where it’s WTF, i’ll try to fix this and maybe that.
Bump
Off to Don Davis on a flatbad this morning. Same problems as I was originally having. Good news is they found a short in the ignition and should have the part tomorrow.
Great way to start the week (I was off yesterday).
Electrical problems are always the worst to try and diagnose, I’d always rather pay someone experenced to fix it than spend hours on it troubleshooting
good luck dude
Really have my fingers crossed that the short they found was it. If it is this was money well spent (1 hour diag, $80 part + install + tow). I spent hours checking grounds, harnesses etc etc and there are just far too many miles of wire in a modern car to want to mess with this anymore.
I was honestly hoping it wouldn’t fix itself this time so that the dealer could actually troubleshoot it. When the tow truck showed up he wanted to try a few things to get it started and was like, fuck no, drag it up on the trailer and drop it off with the dealer.
Don’t you know all tow truck drivers are master techs.
Most of the time I’d let them take a shot. Maybe I’ve been lucky buy my experience so far with tow truck drivers has always been positive. The guy who came to tow my Expedition when it died spent about 15 minutes and got it started. Turned out the main lead on the starter was just corroded. Saved me pulling the starter off and lots of troubleshooting.
This though, I knew it wasn’t something simple and I wanted it delivered to the dealer still acting up so they could actually troubleshoot it beyond what I had done. The reason I didn’t take it in last time this happened was I knew once it magically started working again the dealer would never be able to find it.
Wow - those wheels look awful familiar…
Hope it works out for you.
Thanks, and thanks for buying those wheels, selling them for a pretty good deal to the guy who then sold them for half what he paid to you making them a super deal for me. 
they usually carry a fuel pump wrench and know a couple quick fixes for the typical user error problem.
The miles of wires are easy. It’s all the magical black boxes they end at that you can’t trouble shoot with a multimeter that makes it impossible. :jays:
$270 later the car is home with a new ignition switch and airbag fuse. The switch was shorting causing all the problems. Once the switch was replaced it fired right up other the the airbag light being on. Since it wasn’t on when this started I was worried something else had shorted but the fuse did it’s job.
:tup: to Don Davis.
Didn’t you say that you fixed the ignition and it was not the problem?
I fixed the ignition cylinder. The metal part the key turns inside. This was a short inside the switch which is a separate piece.