shellbunner

Thanks! Appreciate your help diagnosing it.

Perfect, no issues! After they flashed the newest firmware it’s been rock solid. Tried setting off the sensor and draining the battery overnight when I park on an incline but truck has been great since. Slowly falling back in love but still don’t feel 100% confident.

Had a similar issue. Wife connected her phone via Bluetooth which worked fine, but the AUX input didn't work. Don't have a solution for you, but hoping you get an answer.

Dealer called me back after I asked for an update. Hooked up to machine overnight and this morning and everything shows 100%. He said the BSCM recall/bulletin was already done a few months ago but they redid it at my request. Gonna pick it up this afternoon and try to drive it a ton this week to see if it happens again before our roadtrip next week. Here's hoping I don't have to do this again.

Great ideas. I took videos based on your previous advice but thankfully I guess it died on them a couple times so they know I wasn’t exaggerating. I’m a big fan of documenting everything so I will reach out to customer care the next time the truck dies. I have a feeling I’m going to get to know the service department very well. I’m hoping for a response from my survey but not gonna hold my breath. As much as I’m afraid to drive it I told my wife to drive the truck as much as possible so that we can see if the issue pops up again sooner rather than later and have a better chance of Lemon Law’ing it if needed.

That's such a BS response. I didn't drive the truck for 6 or 7 days last month and it was just fine. Went 3 days this past week and it was dead. Clearly not from not driving it enough. These dealers are just dense. I'm going to pick up my truck tonight hopefully and cross my fingers I don't have to take it back in. If/when it dies again I'm calling corporate and starting a case as well. Really love this thing but I'm not going to keep a truck that may or may not start. I think GM's new slogan should be "It might start, or not".

Thanks. Appreciate your help with all of this. I have 2 jump starters that I'm going to bring with me on our trip next week, and I'm going to ask for a list of the codes that it threw to dig into those more so that I can be somewhat prepared in case it acts up again. I have no confidence in this truck either, and I wrote a page long response to a survey from GMC about my issues and disappointment in them. Doubt it's going to do anything, but figured I better document everything in case I have to Lemon Law this eventually. Also noticed the truck kept engaging the parking brake when the tow truck was trying to pull it up on the flatbed. Him and I messed around with it for 15 minutes to get it to disengage since it would randomly reengage for whatever reason. This damn thing is possessed.

Dealer had the truck all day yesterday. Called me before they closed and kinda gave me an update. They attempted to start the truck to move it to the service area. Wouldn't start. Tried jumping it and couldn't get it to start. Eventually got it running, and moved it. They tried to start it again to move it into the service bay and it was dead again. Eventually got it jump started. He told me my truck is "weird". Not very reassuring to hear, but I'm obviously aware there is an issue somewhere, duh. Checked the battery, all connections, computers and everything is 100% and showing fine. Didn't give me exact error codes when I asked him, but did mention that the truck was saying low voltage somewhere. Told me it's running fine now and I could pick it up. I read him the BSCM bulletin since I park on an incline and mentioned that could have POSSIBLY been my cause and he said it very well could have caused the battery to die. I told him nothing was left on, but he kept asking if I maybe left a light on or something. I mentioned that the truck has a battery saver function built in and the lights will auto shutoff for that very reason. He said "oh yea you're right". He asked if I wanted to pick it up and I told him unless he could assure me it wasn't going to fail on me and that everything is fixed that I wasn't comfortable taking it home without some further diagnosing. He offered to put it on a Parasitic machine?? to see if any of the computers are draining the battery overnight and he'll call me today. Fun stuff.

Yea it's been frustrating. My wife is pretty stressed about taking the truck anywhere once it gets fixed. She's worried that we'll get stranded with the kids on a roadtrip or she'll get stuck somewhere by herself. The 3 months we've had it have been GREAT and we all love taking it everywhere, but now that our trust in it is shaken it's really hard. Had to cancel our roadtrip for next week and the kids are going to be bummed when I break the news to them. Couldn't get a loaner from the dealer since they're out of them supposedly and they suggested I front the money for a rental car and GM would most likely reimburse me. Wasn't willing to take that chance so now we're down to 1 car for the foreseeable future. Have had 4 new cars in the past 7 years and EVERY one has had its fair share of issues. But none has just flatout failed to start and left us waiting for a tow. Really hope GM gets their ****** together and we can get back to enjoying our truck.

Checked the UBEC bolts and they are all tight so probably not my issue. Checked the wire on the battery and tight as well. Tried jumping the truck to no avail. Charged the battery for an hour and still wouldn't start. Called Roadside Assistance and they couldn't get it started. Guy said it was the 1st vehicle in recent memory that he couldn't start. Called for a Tow after and he was just laughing about how many of these trucks he's towed recently. He said EVERY truck that he's towed had "computer" issues and clearly wasn't impressed with these. Appt at the dealer is in an hour so can't wait for the phonecall about how they will "fix" it when I'm sure I'll be dealing with this issue again.

WIll do. I feel the same way. Supposed to take a road trip on Monday so we're nervous that we'll be stranded. Hoping it's either the UBEC bolts or the Brake Module that maybe got stuck on and drained it over the weekend. Dealer seemed receptive to the info and I'm making sure to bring 2 battery jump starters in the truck until I know for sure this is fixed.

Talked them into an appt tomorrow morning so crossing my fingers I can get it started and to the dealer. Thanks for the info. I forwarded the bulletin to them so they added it to my notes and we'll see what happens. Cheers!

Still running fine? My truck is Dead in my driveway and can't get an appt for 8 days at the dealer. Hoping your fix is what fixes mine as well.

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.