Problems after update last weekend

Matt001 · February 11

Hi everyone. I’m new here and looking for some direction. I have a 2024 Sierra 2500 Denali which I love. Last weekend it had an over the air update (Saturday). Since then I noticed a couple of things but yesterday had an actual issue.
1. immediately after the update, the adaptive cruise started spontaneously disengaging. Not a big issue, just kept driving and turned it back on later. I figured a sensor got dirty because I was on a long trip.

2. The truck has started idling oddly. It has always been rock solid at idle, now it is continuously changing by a couple hundred rpm’s while idling. It’s not rough at all, just changing.

3. Yesterday while driving home (again with the adaptive cruise control on) we came to a stop in traffic. The adaptive cruise did its job and the truck stopped as normal. Then all of a sudden it started accelerating hard while the car in front was still stopped. I hit the brakes and all is well, but that’s an issue.

I’ve put on some miles and the truck is over 40,000 so I’m out of factory warranty and under the extended warranty that I got, but I don’t think I should have to pay for the copay for the extended warranty when it only started after a Gm update.

has anybody else seen these problems?

thanks

Matt

Another JR · February 11

I have a 2021 GMC 3500 HD. From the beginning, based on experiences I had with other vehicles, I actively resisted allowing GM to update the software in my truck. The few times I have taken it in for service, I have made explicitly clear that they are not to update any software without my express permission, and I insisted that a statement to that effect was captured in the service paperwork. I make clear that I own the truck, and am not leasing or licensing it from them. I keep the truck inside a building that does not have adequate cell reception to allow software updates. After three years they seemed to have given up on pressing me to accept software updates. My truck is working fine.

My tailgate has a recall on it for uncommanded opening due to water ingress. It is in a crate in my garage because I have a truck camper installed. Every time I have brought it to the dealer they freak out about wanting to do that recall (installing a new switch of the same design as the original), and I tell them that until there is a redesign I don’t want them touching my truck. They get all indignant, and I laugh at them.

Chuck FB · February 12

First off that is very alarming to say the least and not only the dealer but GM corporate should be contacted AND I would suspect that NHTSA be contacted to ensure that GM corporate doesn't try to hide this. And then there is your idle issue and could be tied to the same glitch as well.

Do you know what the code to the latest software update is that you received and can post it here as I am guessing from doing my own search on what updates I am missing ( I'll get to why that is ) this latest update as well as probably three others. In fact would you be able to list off all the codes for the updates your truck has had since new if it isn't too much of a pain to do.

So why my truck which was built in Jan of 2025 didn't get any updates after the middle of Feb of 2025 that the dealer must have done before I bought the truck, I did not realize that I had to be doing something at the dealer to accept the onstar connected terms as I had not subscribed to onstar and its all technology that is unfamiliar to me and over my head and so when the month of so called free onstar ran out, I did not realize what of it would remain ( 2025 models have 8 years of a limited connected services ). I also had no idea that it had to be connected manually to wifi by putting in a wifi code as I assumed it must be happening over cell towers. Every time I thought I was checking for updates manually it said there were no updates but duh .. it was never connected to the internet to see and the system is too stupid to tell a person if its connecting properly and searching for real vs the circle of pretend happening on the screen. So a few weeks ago I started having a glitch with the infotainment system where if the vehicle was moving I could not choose a new screen, music, home, camera etc until the vehicle was at a standstill as a warning would come up if I tried to do such. Talked to the dealer and figured out from that, my truck was not able to connect to onstar and had to set that up myself so I did that to contacting onstar. Then about a week after going through that process I got update N25-250380 and seems like that has taken care of that glitch I had and was apparently a fairly major update that came out in the summer of 2025. Since then when I try to find more updates it isn't and yet I know there are probably 3 more updates according to a search of a list I found. Because I have not had any issues that I am aware of since that update I was able to get months after the fact, I haven't seen a reason to go through the pains of going to the dealer yet to get them to force the rest of the updates and from your experience I am wondering what I should even allow it to update at this point.

One of the updates I found listed during my internet search list is one that says was released in Jan of 2026 and they refer to it as an engine and system calibration ( N25-250403 ) but explains it as updating the accuracy of the engine check light and refines the behavior of the aero shutter system. I don't have that update or two others that my search listed off but I am wondering if that is the code to your last update ?

Matt001 · February 20

Well, starting to think than mine was the only one affected by the update.

Chuck FB · February 20

24 minutes ago, Matt001 said:

Well, starting to think than mine was the only one affected by the update.

Has the dealer looked at it and like you said its out of GM warranty but you do have the extended warranty which I suppose has a cost attached to it any time its worked on. I am only guessing that they could undo that update and see if the truck snaps out of it and then reinstall the update in the shop and see what happens.

GMCustomerService · February 26

Your safety is extremely important to us and we'd like to investigate this further with you. Please send us an email to [email protected]. Be sure to include your Username and Forum in the subject line with additional details. We look forward to your email.