I suspect BCM... thoughts?

[Joseph Garcia]

As a matter of required general maintenance the battery grounds should be replaced. They rot from the inside out effectively acting like a backed up pipe. Essentially it drains slower & slower until it’s time to call a plumber when it doesn’t.

The presumption of the BCM failing goes hand in hand with the grounding issues. The boards get cold joints. The price of replacement is so inexpensive that it doesn’t make sense not to swap out both when the signs are there.

$129 for a coded replacement BCM.

ARES Technologies No1 Reman Pre-Programmed Engine Computer PCM ECM ECU

If you need an engine computer, we are here to help you to identify the right module for your car.

arestechnologies.com

That's not a bad price, since a new, uncoded BCM costs about $75. So a $50 programming fee is quite reasonable.

 

[Rocket Man]

As a matter of required general maintenance the battery grounds should be replaced. They rot from the inside out effectively acting like a backed up pipe. Essentially it drains slower & slower until it’s time to call a plumber when it doesn’t.

The presumption of the BCM failing goes hand in hand with the grounding issues. The boards get cold joints. The price of replacement is so inexpensive that it doesn’t make sense not to swap out both when the signs are there.

$129 for a coded replacement BCM.

ARES Technologies No1 Reman Pre-Programmed Engine Computer PCM ECM ECU

If you need an engine computer, we are here to help you to identify the right module for your car.

arestechnologies.com

I do not see them listing a 2011 Suburban, much less a 2500, and they don’t even do BCM’s if they did, they do engine computers (ECM/ PCM) only from what I can see. Your data is off. I have replaced the BCM in my 08 Silverado and programmed it myself with my Tech2 and a used BCM cost me about that much, without programming.

The correct PN for a 2011 2500 Suburban is 25835966. I have seen them on eBay, reman, programmed, for about $200. I’ve never seen one for $129, that would be a steal. If you have a link, please share it with the OP. Otherwise you’re just blowing smoke.

Link for eBay programmed 25835966. You need to look at the superseded parts list in the listing, you’ll see this one in there.

Gm Body Control Module Programmed To Your Vin Part No 25844480 | eBay

Find many great new & used options and get the best deals for Gm Body Control Module Programmed To Your Vin Part No 25844480 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Rocket Man]

That's not a bad price, since a new, uncoded BCM costs about $75. So a $50 programming fee is quite reasonable.

Actually, Joseph, new BCM’s for the NNBS are closer to $200. Search GM 25835966, the correct one for the OP’s truck. I noticed this because I’ve replaced mine in my 08 Silverado and remember it wasn’t cheap. I ended up buying a used one.

 

[TrybalRage]

The correct PN for a 2011 2500 Suburban is 25835966. I have seen them on eBay, reman, programmed, for about $200. I’ve never seen one for $129, that would be a steal. If you have a link, please share it with the OP. Otherwise you’re just blowing smoke.

Link for eBay programmed 25835966. You need to look at the superseded parts list in the listing, you’ll see this one in there.

Gm Body Control Module Programmed To Your Vin Part No 25844480 | eBay

Find many great new & used options and get the best deals for Gm Body Control Module Programmed To Your Vin Part No 25844480 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Yes, that is the PN for my existing BCM. I've also seen them listed, coded, from Garrett Tuning and Highway 71 Auto Parts (although they actually list a different PN that they say is compatible). I don't know how good of a vendor either of those places are.

 

[petethepug]

$129 for a coded replacement BCM.

ARES Technologies No1 Reman Pre-Programmed Engine Computer PCM ECM ECU

If you need an engine computer, we are here to help you to identify the right module for your car.

arestechnologies.com

I know of them because they 2day shipped a BCM for an 07 Esky last month. They don’t list every vehicle they work on, they specialize in the service not the parts.

Call them after the holiday. I wouldn’t steer you wrong with a solid for a good recommendation or a even a wrong data accusation if the vehicle they supplied it for wasn’t cured with similar symptoms.

 

[Just Fishing]

Go at the grounds first for sure.

I went through some mud and started having issues until I cleaned the undercarriage.
it was really weird.
gauges turned off while driving, lights lit up, stalled, etc.

Hosed down where the bcm stuff grounds out to and all was well.

Later I took the grounds and cleaned them.
Then later still, I did it once more and cut the shrink tubing back on each one and flowed flux and solder into the joint.
One of them was really bad.

I had to break out the "Stay clean" copper pipe flux to fix it.

That stuff works fantastic on really dirty connections, however the instructions on the bottle say to not use it for that...
I flush that crap out with brake clean and electrical contact cleaner after I'm done.

 

[intheburbs]

I find it highly unlikely that any intermittent problem is computer-related. They either work, or they don't.

This is completely and utterly a bad electrical connection issue. I'd even replace both battery cables. Check the primary feeds to the alternator, to the mega fuse holder, and to the load center. You checked grounds? Check them again.

And yes, those wires in the footwell were for a brake controller.

 

[TrybalRage]

I find it highly unlikely that any intermittent problem is computer-related. They either work, or they don't.

This is completely and utterly a bad electrical connection issue. I'd even replace both battery cables. Check the primary feeds to the alternator, to the mega fuse holder, and to the load center. You checked grounds? Check them again.

And yes, those wires in the footwell were for a brake controller.

New ground for battery to passenger head and to frame coming today. Other main ground was braided cable from rear drivers head to firewall, and also checked one under driver's footwell at the frame. My truck is pretty corrosion free and the connections are tight.
While I'm in there I'll take them off and sand/wirebrush the connection points as a double-check.

What I don't understand is that when the problem(s) occur, a quick disconnect and reconnect of the battery and everything is set right again. That's what was making me think computer related - like it was being reset.

 

[intheburbs]

New ground for battery to passenger head and to frame coming today. Other main ground was braided cable from rear drivers head to firewall, and also checked one under driver's footwell at the frame. My truck is pretty corrosion free and the connections are tight.
While I'm in there I'll take them off and sand/wirebrush the connection points as a double-check.

What I don't understand is that when the problem(s) occur, a quick disconnect and reconnect of the battery and everything is set right again. That's what was making me think computer related - like it was being reset.

Low voltage and/or loose connections cause a myriad of issues.

Looking at the problem in a more macro sense, take it to an auto parts store and have them check the battery and charging system.

How old is the battery? If it was me, I might replace just for the peace of mind.

 

[TrybalRage]

Low voltage and/or loose connections cause a myriad of issues.

Looking at the problem in a more macro sense, take it to an auto parts store and have them check the battery and charging system.

How old is the battery? If it was me, I might replace just for the peace of mind.

Battery is about 6 months old. Was the first thing I replaced when all this started.

When charging, the alternator is putting out 14v+.