tjonesdfw

There's no consistency with this generation, so check it out closely and look at the repair history. I know someone who's had '19, '22 and now '24 6.2 trucks with minor warranty issues, and then another who had a '21 that blew two 6.2 motors. My '21 5.3 was in the shop more than I drove it for the first few years with multiple rear window leaks, camera issues repeatedly, mirror replacements, several parking sensor failures, check engine lights, wiring harnesses under the hood and in the rear, stereo/touchscreen failures, coolant leaks and more. All GM gave me for my "trouble" was a small discount on a new truck if I bought before the end of '25.

The last time I contacted GM Customer Service about the long list of electrical issues with this truck, the experience was less than satisfactory and took many months and emails to get to what amounted to an insulting resolution.

Has anyone had a message in the cluster say that the rear cross traffic alerts are disabled? When you toggle that system on and off in the touchscreen, it says "on" or "off" so this seems to be an error in the system. No mud, dirt, rain, or freezing temps... and was just sitting in the driveway as the message randomly popped up several times in the cluster.

They have replaced sensors in the front bumper twice, sensors in the rear bumper once, and various connections in the wiring harness in the rear. Unfortunately after all repair attempts, the Park Assist still goes out from time to time. Now I'm also getting messages that the rear cross traffic alert system is disabled. I'm about convinced these are just poorly designed systems, with no real fix.

Not to discourage you, but I opened a case with GM customer care too, and their offers were insulting at best after all the electrical problems we've had with our truck. Plus, it took over 4 months of constantly hounding them before anything came of it. When the truck had a repeat issue before resolving the customer care case, they put the offers on hold and told me I had to take the truck back to the dealer before they would do anything more. We weren't sure if trading for the same brand would accomplish anything because ours is a '21 and we've seen reports from '22-'24 owners of the same issue. When you stop the truck and re-start does the black screen cure itself or is it still stuck? Sometimes that would cure our issue temporarily, and during other failures it would not.

Agree with this. We've had to go back to the dealer again after each of the last three alignments we've had them perform because they have left our truck pulling or the steering wheel off center worse than it was when it went in for an alignment in the first place.

In our case it unfortunately was one of the smaller family owned dealers left in our area that we purchased this truck from. There are only two family owned GMC dealers left in our area, one of which is even worse, and the other is not taking any vehicles for service that weren't purchased from their dealer because they are so backed up with repairs. The owner of our current GMC dealer recently told a business partner of mine that they can't find decent mechanics, and complained about turnover being their primary issue. I call that at least partial BS, because from my experience, there is clearly a lack of proper management and quality control measures. I recognize the dealer's aren't responsible for faulty designs and product, but they ARE responsible for the multiple times they've returned my truck to me with other parts broken or damaged, or incomplete repairs, OR when they diverge from proper means and methods. I despise every time I'm in for service and overhear an advisor telling (primarily women) that they need a fuel injection service on year old vehicles.

To me its clear GM has an issue with reliable electrical systems if it takes this many repairs and they keep throwing different parts at the system. Since our last camera system repair we haven't had a camera failure yet, but the parking sensors have failed for the fifth time and will be going back for repairs at the next service visit.

We have owned multiple 5.3 and 6.2 trucks but never a 3.0 LM2 or LZO. I've driven one around town but never out on open country highways. I keep reading that some consider passing power with the 3.0 LZO to be inadequate compared to the 5.3 or 6.2. You have to wind the 5.3s up pretty good to pass but they always handle what I need, and the 6.2 is just a rocket. I know I'll get comments about just taking it slower, but most of the rural highways we travel are 75mph, with some 80 and 85. Driving slower or being unable to safely pass are dangerous themselves in some areas.

Just FYI, they replaced several camera modules behind the rear seat before they dug deeper and said the rear window was leaking on the modules, requiring yet another replacement. However, on another visit after that they said the rear camera that had already been replaced before had developed an internal short, and the factory wiring harness also had shorts in it. Our truck was bought new, stays in a southern climate, has never been wrecked, and is all dealer maintained, so in my opinion it has to be design flaws in the electrical systems on these trucks. The electrical issues alone in our truck have been a nightmare, let alone the other warranty repairs. I initially chalked it up to being a Covid era build that sat around in Mexico or a railyard for months, but I'm seeing the exact issues posted here on '22-'24 trucks.

I'm convinced GM doesn't have a solution at this point. Our truck has had the reprogram, several rear cameras replaced, a new driver side mirror camera, at least three replacement camera modules behind the rear seat, and most recently they replaced the entire wiring harness in the ass end of the truck. 46K miles and the problems continue to pile up with no permanent fix.

Had to use this dealer due to an ongoing GM customer service situation but I definitely won’t be going back anymore!

Dealer just passed the buck and said they couldn't find anything wrong with the seat base and that everything is tight. Really frustrating to drive around in a truck that costs this much with a drivers seat that clunks side to side at every bend in the road!

The cooling system failed a pressure test yesterday indicating a leak, then dealer claims it passed a pressure test today. They pulled a vacuum on it, filled it up, and said come get it. Wonder how long it takes to drop again.

Finally got the truck back to the dealer and they say the cooling system failed the pressure test, yet they can't locate where the leak is yet. The saga continues...

That's what I've seen too but my dealer has already told me they dont think our GM Platinum Plan extended warranty covers anything with the seat base, but I'm still waiting on my service appointment to see what they say. Agreed on the dealer 100%. Working through some repeat warranty issues with GM customer service that this dealer has worked on several times, so I'm stuck with this dealer at least until those items are resolved. Then again, I'm not sure there are any GMC dealers in this area that give a sh*t from my experience.

No, its not the seat shaker. Its a distinct clunk and shift of the seat when my weight shifts in the seat while turning the truck.

45k miles, well maintained, so was surprised to see it so low absent a leak.

After overfilling did you run it with the cap on and sealed, or with the cap off to burp air out of the system? I understand and have had air pockets in a cooling system before, but not sure how that correlates with the coolant level dropping without there being a leak somewhere.

Recently, at startup on a 2021 Sierra 1500 with the 5.3, I’m hearing a loud waterfall/rush of water sound in the passenger side dash. I’m assuming it’s air pockets in the heater core, but it’s unusually loud. The cooling overflow tank is low… about half way between the full line and the bottom of the tank. There’s a sludge line or darker dried line of coolant slightly above the fill line where it appeared to have been at one time, and it was at the fill line a year ago. No visible leaks anywhere or any coolant on the ground at the moment. Can these trucks eat that much coolant or do I need to ask the dealer to pressure test the cooling system? Are there any common leak spots to look for?

Amen to that, not much pride or honesty left in any industry it seems!

The ground strap was one of the first things we checked and continue to check each time it acts up, but everything looked good at last check. We're down south and pretty dry, but I have heard the ground strap can be an issue on trucks that see salted roads. Ours has been at the dealer multiple times since new for misfires, check engine lights, shorted wiring harnesses, shorted cameras, shorted modules, faulty sensors, you name it. I like the creature comforts, but this truck has been a nightmare especially electronically.

Yeah, I was hoping someone might be aware of a TSB or diagnostic/repair method I could point my dealer to as they usually don't dig very deep unless I hand them a bulletin or GM known fix for an issue. Wasn't sure if it was the seat itself or one the components buried in it... cooling fan, buzzers, etc. Just got ours out of the dealer for a 2 week long repeat electrical repair... guess its time to go back again and see if they can replicate this issue.

In the last few hundred miles, the driver seat feels like the base itself or some kind of internals in the base are moving and clunking to one side or the other during turns. It does not shift forward or rearward. We have the safety package with buzzers and cooled seats if that makes a difference. Has anyone experienced this and knows what the fix is?

Unfortunately this is a repeat occurrence in this truck and not just after its been in for service. It lights up the dash as well.