Dead battery and check engine light

Colossus · April 1, 2020

On 3/26/2020 at 8:18 AM, GMC 2018 said:

wow I had the same exact thing happen to me yesterday, Traded in my 19 AT4 5.3 for a 2020 AT4 with the 6.2 and with only 2 miles on it i go to start it and it was slow to turn over. when it did the check eng light came on. I looked at vehicle diagnostics and it had a few voltage codes. so i drove around for about 30 min turned it off waited 20 min and restarted started right up and the check eng light was gone. I was a service advisor for 4 years at a chevy store and from my experience anytime you have a dead or dieing battery you will get a slew of erroneous eng codes b/c there are so many computers on these thing and they are very sensitive to how much voltage they get and will fault if its not exactly right....

what is the dealer telling you ?

EXACTLY, well said.

whitesierraRT · April 1, 2020

12 hours ago, Colossus said:

EXACTLY, well said.

I now believe you are correct. Not driving much right now and not having the problems mentioned before. I know my truck sat for several months before I bought it with the AGM battery that died. Now that it's been replaced the problem seems to have gone away. If only I knew how to remove the old P25A2 code produced. My Autel code reader wont remove it.

Fireman02 · April 6, 2020

Unfortunately I can add my name to this list. Yesterday pulled my truck out of the garage to do a big spring cleaning. A couple hours later pulled it back in, it stumbled a little pulling it in which I thought was odd. About 9pm I went to move it out again so I could get to something I needed in the garage and it was dead. Only thing that would work was lock/unlock on the key fob. Hooked it up to battery tender/ charger all night, and it still wasn’t showing it charged this morning, but it did start. It had a bunch of codes, check engine, check brakes, etc... so I drove it to my dealer. It ran funny on the way, lag/ hesitation off the line, brake pedal clicked every time I presses it, shifted funny, which my truck hasn’t done any of these previously. To the dealers credit, without any appointment they took in my truck and gave me a loaner Tahoe. We’ll see what they come back with.

Also, it’s a 2020 Rst with 750 miles.

Edited April 6, 2020 by Fireman02
Added text

Pinnacle · May 21, 2020

4 hours ago, [email protected] said:

2020 RST 1200 Miles. Wife just went to go out and Key Fob was not working......grabbed the spare.....nothing. Popped the hood battery was at 5v........WTF! I looked at he alternator cable connection per the recall but everything looked great.

To me it seems there is a parasitic draw in these trucks as this is happening abit at a dealership Im at. Acura had the same problems would drain the battery turned out to be the Bluetooth modual in those.

2020GMC truck · June 4, 2020

2020 GMC Denali 96 days old and was introduced with a dead battery yesterday morning. GM roadside assistance was no help. Had to call AAA to jump start the truck which the battery was completely dead 0% charge. GM dealer did not have any advice other than bring it in. OnStar sent two notices about the low battery charge.

Jsharpe · June 15, 2020

Having the same issue right now with my 2020 RST 6.2L. 2125 miles on it. Battery dead and won’t start. It’s the second time it’s happened. I had an airbag kit with compressor installed and thought that may be the issue but doesn’t sound like from other posts that this is the issue.

HarleypsychRN · June 17, 2020

My 2020 Silverado is back at the dealers (for the second time) dead battery. Second time on the flatbed with only 1700 miles on the Odometer. Not a happy camper. I was a Ford guy who switched to Chevy...

Edited June 17, 2020 by HarleypsychRN

HarleypsychRN · June 17, 2020

On 6/15/2020 at 4:32 PM, Jsharpe said:

Having the same issue right now with my 2020 RST 6.2L. 2125 miles on it. Battery dead and won’t start. It’s the second time it’s happened. I had an airbag kit with compressor installed and thought that may be the issue but doesn’t sound like from other posts that this is the issue.

So the Tow truck guys arrives and says to me "Yea, I tow a lot of these 2019 and 2020 Silverados" (honestly, I'm not making this up).

Edited June 17, 2020 by HarleypsychRN

Brandon Boles · July 13, 2020

Have the 2020 1500 AT4 3.0 now for 4 months and have loved it. Came out this morning and same issue. Not a blip of power. no dome lights, nothing. Had a 2015 2500 Dsl denali that started giving me fits way too early. GM needs to get their act together.

shellbunner · July 14, 2020

2020 AT4 3.0. 2200 miles. Dead battery and drove the truck a few days ago and it was just fine. Hope I can get it started and then I'm going to take it to the dealer and see what they say. Frustrating as hell to have a dead battery on a 3 month old truck.

NHM25 · July 14, 2020

Hey guys, reposting from another thread:

7/6/20: I may have everyone beat on my timeline to frustration. Just purchased new 2020 GMC AT4 from Van GMC Buick in Scottsdale 3 DAYS AGO! The assembly date is June 20, 2020! It ran great the first two days... day 3, won't start. Total of 170 miles on the truck. Same issues that everyone has noted. Came outside, tried to open her up with the key fob and the battery was completely dead. Had to open manually. Push start did not function, no power whatsoever... basically a $65k brick in my driveway.

Connected battery to wife's Explorer and got the dash to light up but it wouldn't start. Tons of error messages. Kept trying to start it and it finally lights up... but was running very rough with knocking. This morning, started it up and it ran great. Dropped it off at dealer and they tell me there are no codes, it's running fine, the alternator and the battery look good. So I send them the videos below and a link to this thread... No word yet but will keep you all posted. So incredibly frustrating. Love the truck but now have to worry about this... what happens if it doesn't start when my family and I are in the middle of the woods camping/hunting? Ridiculous. 2020 could not get any worse.

Truck not starting when connected; charged for 20 min. https://www.youtube.com/watch?v=wEV5n6ZbkXU

Truck won't start after charge: https://www.youtube.com/watch?v=_78kJthwf58

TRUCK FINALLY STARTS: https://www.youtube.com/watch?v=8xEFiD66ZIM

Truck starts, idle is off:  https://www.youtube.com/watch?v=xGd-6nNTU58&t=8s

7/8/20: UPDATE: Dealer thinks they found the problem: Loose UBEC Bolts. There was a recent bulletin posted on 6/26/20 about this that may be the cause for this issue as a whole. Ask for document ID 5628169 or the following title for the GM bulletin: #PIT5756: Various Electrical Concerns (Inspect UBEC Bolts for Being Loose) - (June 26, 2020). SEE ATTACHED

Condition: Some customers may comment on any number of electrical related symptoms. The following are some of the known reported ones:

no crank
no start
starter grinds or re-engages after engine starts
SES MIL
IPC guages sweep/fluctute and/or various IPC warning lights or messages
High or low system voltage
May have any of the following DTC's: B1325, B2750, B305D, B297B, C0049, P0562, P0700, U0100, U0101, U0102, U3006
some of these concerns may be noticed with powertrain movement, like when accelerating or braking.

Cause: These concerns could be caused by the X50A underhood fuse box bolts being loose. The X50A has built in indicators which pop up as the X50A bolts are tightened down, to inidcate the X50A is fully installed. In some cases, even if these green indicators are popped up, the bolts may still be loose.

Correction: Inspect the X50A Underhood Fuse Block bolts and verify they are properly torqued to 53 lb in (6Nm)

Dealer stated that my box was indeed loose (that's what she said). Has not been able to replicate issues. Really hoping this is the fix for my truck and all of yours. Will update forum either way. Best of luck.

UPDATE: 7/14/20. I have had no issues with the truck so far. I start and drive it every day. I really hope this was the simple fix; hopefully you guys give it a try and it works. You can do this fix yourself. I've attached the bulletin for everyone here. Good luck.

BUELLTIN (1).pdf

Colossus · July 16, 2020

On 7/13/2020 at 1:44 PM, Brandon Boles said:

Have the 2020 1500 AT4 3.0 now for 4 months and have loved it. Came out this morning and same issue. Not a blip of power. no dome lights, nothing. Had a 2015 2500 Dsl denali that started giving me fits way too early. GM needs to get their act together.

My friend, the battery issue is not limited to GM, it's all across the automotive board. Too many computers onboard, too many gadgets to control.

HarleypsychRN · July 16, 2020

12 hours ago, Colossus said:

My friend, the battery issue is not limited to GM, it's all across the automotive board. Too many computers onboard, too many gadgets to control.

With all due respect (and I was just talking to a neighbor about this the other day), they are putting too much electronic crap on these vehicles. I've had trucks (63'Int, 87 Dodge Dakota, 07' F-150) that I actually had to open and close the tail gate myself (Gasp). With the importance of the 1500 segment to the sustainability of these companies, they are all racing to have the most and greatest features and it's coming back to bite them in the a**.

When I spend over $50K on a new truck, I expect it to start.

Colossus · July 17, 2020

Doesn't matter how much you spend. Even high end crap like Benz and BMWs and Lexus are having the same engine. How much you spend doesn't mean crap anymore.

Cpl_Punishment · July 17, 2020

On 7/13/2020 at 1:44 PM, Brandon Boles said:

Have the 2020 1500 AT4 3.0 now for 4 months and have loved it. Came out this morning and same issue. Not a blip of power. no dome lights, nothing. Had a 2015 2500 Dsl denali that started giving me fits way too early. GM needs to get their act together.

If your 2015 Sierra was junk, why did you buy another one? With customers like you, what incentive does GM have to actually improve their products?