Battery? BCM?
Thread Starter
Intermediate
Joined: Aug 2007
Posts: 46
Likes: 1
Battery? BCM?
Looking for diagnosis/thoughts.... Had to replace head gasket. Since that time, the pull key wait code pops up once, then works fine. My mechanic had a long talk with somebody about the pull key code and BCM, and that is supposed to be replaced this week. Yesterday one of my running lamps was blinking but not staying on, and car started having weird little electrical problems, key fob not working, seats and mirrors moving when I put the key in, etc, all intermittent. Changed the lamp out, it worked fine, put it back in the car and it stopped working. While I was running codes, (only two, something to do with the radio, which I missed, and the dRL B0502) the bass went out on the stereo, then everything died and now car won't start (clicking noise). The battery was checked and slow charged while in the shop. Does this all sound BCM related? A short somewhere? A bad battery? My poor car has been in and out of the shop for three weeks now. Thanks for any help/advice.
Drifting
Joined: May 2007
Posts: 1,547
Likes: 210
From: Huntersville, NC
Since the mechanic had to talk to someone else, Would cause me to pause deciding to replace the bcm. If you decide to let him replace the bcm, then have an agreement in place about who eats the cost if that is not the problem.Bcm’s tend to be one of those parts hard to find, hard to return.
Troubles with bad grounds is a good possibility. Heads off and back on get mighty close to important grounds and splice packs. This can probably be mostly cured learning to find and clean splice packs, and ground points. Also the connectors in the door accordions. Both these problems are well covered in the electrical section stickies. Then, the ignition switch.
Troubles with bad grounds is a good possibility. Heads off and back on get mighty close to important grounds and splice packs. This can probably be mostly cured learning to find and clean splice packs, and ground points. Also the connectors in the door accordions. Both these problems are well covered in the electrical section stickies. Then, the ignition switch.
Drifting
Joined: Mar 2015
Posts: 1,421
Likes: 302
From: CSRA, SC
Yeah I wouldn't let the mechanic change the BCM without irrefutable proof that it's bad. From reading what you said, I can almost assure you he is just guessing at this point. There really isn't anything you can do during a head gasket replacement that can kill your BCM but these cars are most definitely well known for having spooky behavior like you're describing JUST by having a bad battery. And if your battery sat there in the car for a while while getting worked on without ever being driven, especially if it is already a bit older, then there is a very high chance that it is just really weak. If everything I said turns out to be the case, then I would strongly suggest you find another more competent mechanic, someone who is familiar with C5 platform.
Drifting
Joined: Nov 2003
Posts: 1,645
Likes: 65
Looking for diagnosis/thoughts.... Had to replace head gasket. Since that time, the pull key wait code pops up once, then works fine. My mechanic had a long talk with somebody about the pull key code and BCM, and that is supposed to be replaced this week. Yesterday one of my running lamps was blinking but not staying on, and car started having weird little electrical problems, key fob not working, seats and mirrors moving when I put the key in, etc, all intermittent. Changed the lamp out, it worked fine, put it back in the car and it stopped working. While I was running codes, (only two, something to do with the radio, which I missed, and the dRL B0502) the bass went out on the stereo, then everything died and now car won't start (clicking noise). The battery was checked and slow charged while in the shop. Does this all sound BCM related? A short somewhere? A bad battery? My poor car has been in and out of the shop for three weeks now. Thanks for any help/advice.
Intermittent Pull Key is typically voltage
Weird intermittent electrical problems, typically voltage
What I would do:
Load check battery
Clean battery connections including the one at the starter solenoid
Re-check all grounds were properly re-installed after head gasket repair
Clean all grounds especially in the engine compartment
Don't change the BCM, the mechanic is shotgunning the problem without proper diagnostic troubleshooting
Drifting
Joined: May 2007
Posts: 1,547
Likes: 210
From: Huntersville, NC
If you got the pull key notification, then you need to status whether you have a column lock bypass. This problem is most often battery condition related first, and later ignition switch, dropping enough volts. If your car has a LMC5 column lock bypass, then you need to check if the brown wire mod was done.
You are in the best Corvette library on the planet. However, trouble shooting is a linear process; one problem at a time. You have gotten some really great suggestions from those “been there done that”.
You are in the best Corvette library on the planet. However, trouble shooting is a linear process; one problem at a time. You have gotten some really great suggestions from those “been there done that”.
Thread Starter
Intermediate
Joined: Aug 2007
Posts: 46
Likes: 1
If you got the pull key notification, then you need to status whether you have a column lock bypass. This problem is most often battery condition related first, and later ignition switch, dropping enough volts. If your car has a LMC5 column lock bypass, then you need to check if the brown wire mod was done. You are in the best Corvette library on the planet. However, trouble shooting is a linear process; one problem at a time. You have gotten some really great suggestions from those “been there done that”.
- The battery was tested and passed, but it is 3 years old.
- The bypass was done years ago, but when he looked at it, some wire wasn't there, so they supposedly fixed that.
- They checked all the grounds.
- He talked to someone at GM maybe? about the BCM and that's why they decided to replace it.
- I've known him for years and he's done stuff for me for nothing so I don't think it's a parts chasing thing.
- Having the battery retested today but when pulling it out, found the red cable has a melt mark that was not there when the battery was tested last week. This seems to be getting worse.
Really appreciate all the comments.
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