Could a BCM cause this?

turbo_bu

Member
Mar 27, 2007
193
6
18
Central IL
Not quite a Duramax issue, but still GM related. Wife's 2012 Equinox (we are the original owners and it has ~110,000 miles) just left me stranded and had to get it jump started to get home. This is the 2nd time it has done it (last time was in the fall). Battery (Duralast Gold) is 2 years old and I checked all the connections are good and not corroded. Also verified performance with a volt meter. I have not taken the battery out to be load tested, but I did a quick load test last fall when it originally did it and it passed.

A general google search brings up many things, most of them battery related, but a few also point to the BCM. The only reason I ask of the BCM is that it acted different right before it wouldn't start. We had used the Equinox for some quick errands in town earlier today without any issues. I went to pickup my daughter this afternoon, and when I arrived, I was about 5 minutes early. I shut off the engine, turned key all the way off, and left the radio playing on retained accessory power. After about 2 or 3 minutes, the radio shut off. I thought that was odd since it is supposed to time out after 10 minutes, and I knew it had not been 10 minutes yet. I pushed the radio power button. Nope, nothing happened (it will normally power up even if you don't have the key in the ignition). I put the key in the ignition and turned it to on. Nope, no lights, no nothing. Tried to start - nope. I called the wife to bring my Duramax down to jump it. After jumping it, it did crank a little slow, it ran just fine all the way home.

Could a BCM starting to go out cause any of this??? Hate throwing parts at it especially since it's her DD.
 

2004LB7

Well-known member
Dec 15, 2010
6,340
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Norcal
have you had the alternator tested?

A bad BCM could cause all sorts of problems like the ones you mentioned. I would do the easy stuff first. like ground connections, batteries, alternator, harness rub through / chafing, etc before condemning the bcm
 

dndj

Boost!
Apr 13, 2019
302
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Oregon
Check battery voltage at the terminals when the truck fails (no lights, no start) while there's some load on it - while cranking or with headlights on. Since you said it cranked slow after jumping, I'm betting on bad battery. Possible that there's an intermittent problem internal to the battery. Since it's only 2 years old there should be some warranty left.
 

Dozerboy

Well-known member
Jun 23, 2009
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GM has had a lot of issues with bad main ground wires. That is similar to the issues I had with my 2015. Normally if I just disconnected the ground wire from the battery for 5mins or so it would start again. I ended up making up a new ground wire and never had a issue again.
 

turbo_bu

Member
Mar 27, 2007
193
6
18
Central IL
Thanks for all the feed back. Went out yesterday after lunch and started checking things. Low and behold, battery was only showing ~6 volts. Took it out, and it showed ~11 volts. Put load on it, yep toast. Found warranty receipt, it was 38 months old (free replacement warranty was only for 36 months). Took it into back to Autozone, and got some money back (5 yr pro-rated warranty), but talking with the guy behind the counter, he said he has started to see more batteries coming in. Claimed he didn't used to get many returns, but within the last 6-12 months, he has started to see more and more. Sounds like wherever Duralast batteries are coming from is no longer what it used to be. In the past I know I used to get at least 5+ years out of a Duralast without any issues.
 

turbo_bu

Member
Mar 27, 2007
193
6
18
Central IL
One more follow up - when I picked up the replacement battery, the guy behind the counter said that it only comes with a 3 year warranty now. I just checked on their website. The longest warranty that Autozone has for their batteries is 3 years. Mine was a 3 years free replacement, but 5 years pro-rated. Now, they won't even do that. Guess it shows how much faith they have in the batteries they are selling now.
 

Dozerboy

Well-known member
Jun 23, 2009
4,806
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Shit a bunch only due a 2 year now. I buy the cheapest batteries with the best warranty. I haven’t had a battery last me much more than two years since my original AC Delco that made it six.
 

zakkb787

<that’s not me...
Sep 29, 2014
2,340
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48
Granite Falls NC
Deka batteries are the only ones I’ll use now. The ones in my truck are quite old (13 or 14 I think) and are holding up fine tho I know it’s coming soon. I had some Exide batteries in my k10 that took some extreme abuse for 7 years before they finally went bad too