2011 Tahoe LTZ battery goes dead because of intermittent draw on battery

[Geotrash]

My 2013 Tahoe LTZ is doing the same. More frequently the last few days. Before Christmas we changed the battery fusr and it seemed to solve all the issues. That was a $6 fix. Now it's doing it again. System reboots while driving, sometimes it cuts completely out, engine and all the starts right back up, while rolling. If the entire system reboots. The door locks, lock and unlock rapidly amoung more crazy stuff. Sometimes it will reboot 3-4 times within seconds. Idk what to do from here.

Sounds like it's time for a thorough cleaning of all grounds and battery cable replacement. The battery cables corrode from the inside out. Search "Big 3 upgrade" here for the deets.

 

[LiteUrEyes]

Sounds like it's time for a thorough cleaning of all grounds and battery cable replacement. The battery cables corrode from the inside out. Search "Big 3 upgrade" here for the deets.

If you're talking to me, new battery and cables. That's not the problem. It's electrical for sure. I cut the Tahoe off today and both doors started clicked, the Hvav clicks randomly, too.

 

[Geotrash]

If you're talking to me, new battery and cables. That's not the problem. It's electrical for sure. I cut the Tahoe off today and both doors started clicked, the Hvav clicks randomly, too.

Yep, I'm talking to you. So about 1000 times a year we have people who come here to report strange electrical gremlins exactly like you describe and 95% of the time it's a problem with: 1/ A bad ground 2/ An internally corroded battery cable or 3/A bad cell in the battery. The remaining 5% of the time it's either the BCM itself, corrosion damage to the bottom of the fuse block in the engine compartment, or a broken wire in one of the looms. A broken wire is rare but it happens. Finally, the factory charging system on these trucks is not optimized for the unique charging needs of AGM batteries and we see a lot of people here with AGM batteries gone bad in as little as a few months. Happened to me twice as well, so I upgraded my alternator on both trucks to a newer design.

Sensitivity to weak electrical grounds is a well-known vulnerability of the GMT900 platform.

 

[LiteUrEyes]

If you're talking to me, new battery and cables. That's not the problem. It's electrical for sure. I cut the Tahoe off today and both doors started clicked, the Hvav clicks randomly, too.

My son just pulled the fuse box from under the hood and reset it. This fuse box comes completely out. Tahoe was dead, it started right up after he reset it. There could be a bad pin or corrosion there. Hopefully we found my issue.

 

[Gearz]

So I did 2 new things that may solve your issue even though it didn’t solve mine. I replaced the negative battery cable and the engine ground strap to the back of the left cylinder head to the stud on the fire wall. I relocated the ground strap to the threads on the cylinder head near the spark plugs because I couldn’t remove the old bolt in back of the head. I am leaning toward either the VCIM (ONSTAR) or BCM but the truck has no symptoms at all.

 

[Geotrash]

My son just pulled the fuse box from under the hood and reset it. This fuse box comes completely out. Tahoe was dead, it started right up after he reset it. There could be a bad pin or corrosion there. Hopefully we found my issue.

Thanks so much for following up. Fingers crossed for you!

 

[LiteUrEyes]

Sounds like it's time for a thorough cleaning of all grounds and battery cable replacement. The battery cables corrode from the inside out. Search "Big 3 upgrade" here for the deets.

Update, my husband found the battery on the negative side was super hot after about 5 seconds of the truck being started. He traced the wires and found one that was shorting out. He fixed that and so far so good. Hopefully, it didn't cause more damage and that was the problem.

 

[Gearz]

Awesome

 

[j91z28d1]

Awesome

so you traced it to the tcm?


I was going to say I noticed a weird thing in my 2011 that I've not seen anywhere else talked about. I had the after blow turned on, to dry the evap to keep from smelling moist all the time. you've probably heard of it working at a dealer, but it's supposed to turn the blower motor on for a few mins after you turn the truck off, well I was on a long road trip, and was going to catch a nap in the back seat. after a bit the blower came on, ran for what seemed like a normal amount of time and went off. it should only do this once, but funny thing after a while it did it again. and then a 3rd time. by then I was like man I don't wanna get stuck at a random rest stop by myself with a dead battery over this. so I reached up and cycled the key and it shut off.

have always wondered how many times it would have done that if left alone.

I've since turned off the afterblow setting and just try to turn the ac off before parking it. I have a steep driveway and the water doesn't drain out till I back out the next day. leaving a long water line and smelly air lol.

4amps seems low for a blower motor running. but just something it made me think of.


also there's youtube video somewhere that shows how to measure current drain across the fuses using voltage drop instead of trying to read inline current. I wasn't sure that would work till I had a Ford truck that was killing me and I went ahead and tired it. it lead to me to water getting in a bed light housing. craziness.

 

[Coolman1987us]

I don’t have any access to TSB’S anymore..

CHEVROLET Technical Service Bulletins (TSBs) - Chevrolet Forum - Chevy Enthusiasts Forums

CHEVROLET Technical Service Bulletins (TSBs). Check for technical service bulletins (TSBs) on your vehicle by make, model, and year.

chevroletforum.com