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

[Gearz]

Hi everyone I'm new to the forum but am a retired GM tech. I have a strange problem with my 2011 Tahoe LTZ. The battery gets weak at times but the other day the battery was dead after sitting for 2 days. The AGM battery is 13 month's old and does recharge to full state. I preformed a parasitic draw test with my Fluke 87 multi meter on the amp setting and after the truck sat for 2 hours it read 20 milliamps with the meter in series but after another hour and the meter on min max it showed 200 milliamps on the high reading and went right back to 20MA. What the be causing this strange problem. It doesn't happen long enough to catch doing a voltage drop across the fuses. All doors are latched including the hood. I have been out of the dealer for 14 years so I have done what I can at this point other than buying a clamp meter but again I can't sit there for a hour just to see 200 milliamps come and go because the average is 30MA. Are there any bulletins out there that could explain this issue like a radio or radio amp or other module come on intermittently.

 

[Fless]

I'm not sure it does you any good right now but if you got hold of one of the devices Ivan tested in this video...

 

[Doubeleive]

that's a odd one, anything aftermarket plugged in or installed?

 

[Gearz]

Yes there is I bought a Phoenix Android 10 13" radio 4 month's ago and it works perfectly but I suppose I can pull it out and put the old stuff back in and retest. I just pulled the 30 amp fuse for the radio amp and waited 2 hours and the draw was gone so it might be the radio causing this weird problem and waking up the amp which would be a expensive mistake. UGH

 

[Fless]

Unfortunately if it continues you may have to invest some time monitoring it to see if it's a regular thing that happens, how much draw, how often, etc.

For the time being I'd leave the radio amp fuse out and see how that goes. If nothing shows up, plug the fuse back in and see if it comes back. You could insert the ammeter inline (using min/max function) with the radio amp fuse by rigging up something to see if only that circuit is acting up, as long as your ammeter will take the expected current.

 

[Geotrash]

Hi everyone I'm new to the forum but am a retired GM tech. I have a strange problem with my 2011 Tahoe LTZ. The battery gets weak at times but the other day the battery was dead after sitting for 2 days. The AGM battery is 13 month's old and does recharge to full state. I preformed a parasitic draw test with my Fluke 87 multi meter on the amp setting and after the truck sat for 2 hours it read 20 milliamps with the meter in series but after another hour and the meter on min max it showed 200 milliamps on the high reading and went right back to 20MA. What the be causing this strange problem. It doesn't happen long enough to catch doing a voltage drop across the fuses. All doors are latched including the hood. I have been out of the dealer for 14 years so I have done what I can at this point other than buying a clamp meter but again I can't sit there for a hour just to see 200 milliamps come and go because the average is 30MA. Are there any bulletins out there that could explain this issue like a radio or radio amp or other module come on intermittently.

Side note: I did not have good luck with AGM batteries in my Yukons until I replaced the alternators in both with brand new aftermarket designs. I had 2 AGMs fail within a year, with similar symptoms to what you’re describing except I didn’t check for a drain. They just wouldn’t start the truck anymore after sitting a few days. My theory is that the factory alternator design and components weren’t designed with the unique charging requirements of AGM batteries in mind.

 

[Doubeleive]

Yes there is I bought a Phoenix Android 10 13" radio 4 month's ago and it works perfectly but I suppose I can pull it out and put the old stuff back in and retest. I just pulled the 30 amp fuse for the radio amp and waited 2 hours and the draw was gone so it might be the radio causing this weird problem and waking up the amp which would be a expensive mistake. UGH

I would leave that fuse out for now while parked overnight and just see what happens if it goes back to normal then the radio is primary suspect.

 

[Gearz]

So I piggy backed the radio and amp fuse and went right to the source and the voltage drop is varying and large so the issue lies with the radio. It is possible that the radio may search for a GPS signal but will call Phoenix this week and see what they say. I don’t want to swap the radios if they have a software fix. I don’t think I would buy another AGM battery again because Geotrash may be correct about the charging system trying to charge a AGM battery.

 

[Gearz]

Hi all I’ve been hunting this thing down. It’s not the radio! I have never seen this happen but every hour the fluke meter on 10 amp scale would show 200 milliamp draw but that was only a average but I did catch it one time and it was almost 4 amps then trickle down to a normal 27-36 milliamps and stay there. I removed the #14 TCM fuse and it showed 4 amps on record then I reset it and the drain went away! I then disconnected the connector at the transmission and the drain came back in the same manor. I thing there is a I intermittent drain in the serial data line. FYI I installed my old factory radio and same issue. Is there a reflash for something like this I don’t have any access to TSB’S anymore..

 

[LiteUrEyes]

Hi everyone I'm new to the forum but am a retired GM tech. I have a strange problem with my 2011 Tahoe LTZ. The battery gets weak at times but the other day the battery was dead after sitting for 2 days. The AGM battery is 13 month's old and does recharge to full state. I preformed a parasitic draw test with my Fluke 87 multi meter on the amp setting and after the truck sat for 2 hours it read 20 milliamps with the meter in series but after another hour and the meter on min max it showed 200 milliamps on the high reading and went right back to 20MA. What the be causing this strange problem. It doesn't happen long enough to catch doing a voltage drop across the fuses. All doors are latched including the hood. I have been out of the dealer for 14 years so I have done what I can at this point other than buying a clamp meter but again I can't sit there for a hour just to see 200 milliamps come and go because the average is 30MA. Are there any bulletins out there that could explain this issue like a radio or radio amp or other module come on intermittently.

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.