Anyone else ran into these Check engine code problems on 22 gmc sierra at4

[kkohne10]

Picking up today. Was told there was a "Calibration" issue with the emissions system. Apparently a reset is all it took.

 

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[CADGUY]

Sorry to read about these continual baby diesel problems. I loved my 2020 AT4 3.0, but when it was unfixed after a month in the dealership, stranding me for an extra month (was already gone for 4 weeks already as I was working out of state) with no fix in sight, I had to trade it.

GM needs to figure this crap out. I considered a 2023 AT4 HD diesel, but was reading about the similar issues with those also. Could have bought a 23 AT4 HD for almost the same price (probably a bit more expensive) than my 2023 AT4X, but I think I am done with GM diesels. Would love the have that 6.7 ltr AT4 diesel, its torque, power and yes, improved fuel mileage over my 6.2 AT4X (I do love the 6.2 but it is thirsty), but just don't need the headache of more possible issues with a more complicated fuel/emissions system that these diesels require. Hope those here with AT4 diesels are able to get GM to figure this crap out. It seems to happen to frequently, and often the same or similar issues people are having.

Did you work with GMC for a trade or did you trade it in and buy new?

 

[Teegunn]

Did you work with GMC for a trade or did you trade it in and buy new?

I did not work with GM or GMC. I did trade it in at the dealership who had it for a month, but unable to fix it.

I got high trade value, especially considering the tires were sorely needing replaced ($1500+ to do that), the windshiled literally got hit by a rock the week before the error codes happened, and broke all the way across the bottom and up the middle ($1000 at least to replace). I had some small dings in the tailgate (work related - it happens - $500 at least to fix) and a few other minor blemishes if one looked it over well enough that needed fixing. The leather of my rear passenger seat was ruined - had a kids car seat in that spot, but a kid spilled a citrus drink down that area and it sat that way for too long soaked (I didn't know this had happened or would have cleaned it up right away), ruining the leather on that seat bottom ($250 to fix). Also literally had 1% left for an oil change ($140 to do it at the dealership). Plus, of course, the mounting bills from being in the dealership service shop for 4 weeks (they replaced a bunch of sensors, and a couple other things), that bill was well over 2 grand by that point.

So I had all of that going on with the truck - which none of that were really an issue for me using it - but the fact that this "service emissions system" codes were constantly on (putting the truck in permanent limp mode), and all the stuff the dealership service dept was doing - costly enough stuff, and still not fixed at all, made the decision to trade it off sensible IF I was getting enough trade value, plus a good deal on the truck I was buying.

The problem was - this dealership, and really none close to where I was at (northeast Nebraska) - didn't have ANY trucks that I wanted. All of them were downgrades from my 2020 AT4 3.0. On January 4th, as I was speaking with the dealership manager telling him they HAD to figure out how to fix my truck, as this issue being unfixed had literally stranded me out of state for 4 extra weeks (I was already gone 3 weeks before those 4 weeks working, originally this is why I was in Nebraska, so I was gone out of state for 7 weeks total), the manager "promised" me they would figure it out by end of day (this was about 2PM), which I honestly don't have any confidence it was going to be fixed. As I was talking to him, I told him that if they had a new truck that I wanted and was not a downgrade from my 2020 AT4, I would be willing to look at trading. As I was talking to him, they had a semi come in with a load of new vehicles. One of those vehicles was a Dynamic Blue 2023 AT4X. The one I traded for that day.

The manager got the AT4X off the semi, and I test drove it a few minutes after that. Still had all the plastic, etc on the interior as the dealership didn't even have time to prep it. I knew right away that it was what I wanted, in a color I liked. I have a family friend that worked for GM and I get GM friends and family discount codes from this person. Most dealerships won't honor those discount codes anymore as just this past year GM made it so dealers could refuse to accept these codes. But the manager of this dealership honored my code (saved me a little over 4 grand off sticker price), plus gave me 45K in trade for my truck. I paid a tad over 50K almost 3 years prior for my 2020 AT4 3.0, so after almost 3 years I lost only 5 grand in value. Plus I figure I saved probably 5 grand or more on all the issues that would have needed to be addressed sooner or later on the truck.

I feel like it was as fair and good of a deal as I would have found anywhere, and the dealership manager treated me very well all things considered. Wasn't his fault they couldn't fix my 2020 AT4 3.0.

 

[SuthrnGMC]

Just saw this thread, had these similar engine codes show on my truck last week was driving home from dinner and truck started sputtering guess going into limp mode with ESC, low power mode and power steering mode lights going off, I could barely drive my truck to get off the road and had to have it towed. It's been at dealer since Thursday as they said they are backed up on vehicles, so hoping to hear something this coming week! 2020 with 24k miles no other issues it was driving great, although I did put it into sport mode about 15 minutes before it happened, not sure if that triggered it or not.

 

[Teegunn]

Just saw this thread, had these similar engine codes show on my truck last week was driving home from dinner and truck started sputtering guess going into limp mode with ESC, low power mode and power steering mode lights going off, I could barely drive my truck to get off the road and had to have it towed. It's been at dealer since Thursday as they said they are backed up on vehicles, so hoping to hear something this coming week! 2020 with 24k miles no other issues it was driving great, although I did put it into sport mode about 15 minutes before it happened, not sure if that triggered it or not.

Sorry to hear that! Sucks. Is your truck the baby diesel or 6.2?

 

[SuthrnGMC]

Sorry to hear that! Sucks. Is your truck the baby diesel or 6.2?

Yeah was a bummer! Mine is the 6.2. Other than the uncomfortable driver seat I love the truck! Hoping it’s just something simple like a software update vs lifters or something.

 

[CADGUY]

How did you get a hold of customer service? I have a 23 AT4 with a reoccurring NOx sensor issue (P22FE). Dealer replaced a sensor first, then a wiring harness but CEL just came back on. We called what I think is GM customer service and they basically said they can just schedule us an appointment with the dealer to look at it again.