AT4ChapinSC

Very glad to hear you guys found some workarounds for this issue- I know how frustrating it is to have a brand new very expensive truck not work properly. If it were as simple as keeping it on a battery tender I'd probably have gone that route, but I am parked for days at a time deep in the wilderness for large parts of the winter so that just wasn't feasible. Basically a safety issue at that point. Couldn't keep an unreliable truck in what easily could be a life and death situation. Fortunately I was able to sell the truck for what i paid for it, so really thankful for that. I do feel for the poor soul that ends up buying that truck though. Fortunately it's still under warrantee. Going to give Ford a shot now. Been a Chevy/GMC guy my whole life- but after 2 new GMC trucks in the last 10 years basically being lemons, gonna have to give someone else a shot. Good luck to you guys getting a permanent and reliable fix achieved with these trucks-I hope it works out well. I know GMC was of ZERO help and my dealer just kept replacing batteries without addressing the root of the problem.

I had my 4th dead battery since March last week. Truck is in the shop again. After the third, the Service Advisor at the dealership kind of blamed my winch (Warn Zeon 12) and/or the pedal commander I had hooked up. I did a little research and called both companies. Pedal commander said it was impossible- their product doesn't actually drain any power- it just changes computer settings when it is on (it hadn't been used in months). Warn said it wasn't likely- but they put a power switch on this model. I actually had the power switched off before the 3rd battery died, but when the dealer replaced that battery they disconnected the warn winch anyway- so it couldn't possibly have contributed... Also took the pedal commander out anyway just to be certain. Now the truck is in the shop for the 4th battery- and they are at a loss. They actually admitted this time they think some module is coming on that shouldn't be- and are doing more tests. I hate to say i was glad that it happened again, but after blaming my winch and pedal commander it was somewhat redeeming that those weren't the problems. Anyway- hopefully they figure this issue out. I forwarded this thread on to the dealers service manager so they are definitely at the very least aware that its not an isolated issue. E

Out of curiosity- is anyone having this problem using a pedal commander? https://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwjFpNeBoKzyAhWhCIgJHbrMAboYABAIGgJxbg&ae=2&ohost=www.google.com&cid=CAESQeD2nufMyDKEvQ5sIlaO5L6QIrmNOFA7fKA96Y37lMK1ms-Vdaf8Mq_VIw06mqjygo24oEAPc9rL2HPKLSOYGs2q&sig=AOD64_2mON5-PBxQz-ecOBXmSbkb-DTOLw&q&adurl&ved=2ahUKEwilvM6BoKzyAhVxSDABHT7QD6UQ0Qx6BAgDEAE&dct=1 Thanks fellas Elliott

Second dead battery in under a month. I drove my truck yesterday. No problems. Got up this morning to a totally dead battery- too dead for a jump box or cables to another truck to start. Dead. Overnight. Good lucking truck but its a lemon

I've had the same issue now twice. I bought a 2020 AT4 in October. I drove to see my wife in British Columbia (from South Carolina) for a few months this winter/spring). My truck sat for 4-5 days not started (in 30-40 degree weather) and went out one morning to start it- didn't start. Got my jump box out and it started, but took it to the dealership to replace the battery because it didn't start again without the jump box after i drove it around for a bit. The dealer in BC said they think i got a defective battery. OK. I figured since it was cold outside at least that may have contributed to it. Fast forward to last week (July 18, 2021). Back in South Carolina. My truck sat again for 4-5 days (80-90 degree weather) without my starting it. Go out to the garage and key fob won't even unlock doors. I have a bakflip tonneau cover on my truck that unlocks from the inside... Go to try to pop my "multi-pro" tailgate to get my jump box or jumper cables- no dice. Fortunately this time I was somewhere I had access to another truck to use to try to jump it. Hooked up jumper cables and boom- every error message there was flashing by. Unfortunately the battery was actually dead.. wouldn't start with another truck jumping it. So i had to get onstar to come tow it to the dealership. They called me a couple days later and said it was a bad battery... I basically told them i didn't think thats what it was- it's happened before. He looked into my records and realized it had happened in March. They kept it for another couple days and said to come and get it, it was a bad connection to the battery terminal. Very nice guys and i certainly don't blame them, but all i did was spend 30 seconds on the computer googling "sierra 2020 dead battery" and it brought me here to tons of examples of the same issue, so it would be difficult to convince me that GMC is trying very hard to figure this out. I think the multi-pro tailgate is absolute garbage and poorly designed. Not having any way to manually open your tailgate seems idiotic to me at least. I asked the dealer about that and he looked into it and said there was no way to open it with a dead battery... his response was "get a different tonneau cover that locks from the outside". I called GMC north america to ask them- i was informed if my battery goes dead and my cables/jump box are locked in my bed that I cant access it and I need to call roadside assistance and get towed. Well, unfortunately where my wife lives I could be somewhere very cold and remote in the mountains. It's absolutely a safety concern. I assume no one has found a real solution to this issue yet. I am going to go through this thread again more carefully- but i wanted to add this story. Hope you guys are having a good Monday. Thanks for all the information E