GMC Complaints

Took dealer 3/26 for Sam issue Engine Power reduced after already cause me hit curb. Got it out 4/1/26 Now 4/5/26 it happened again same codes after they claimed they fixed it. Also keep having Emergency services come on a caused my dashboard out. My issues is car keeps stalling losing power. Same codes as week ago after dealer fix. Also 4 time took for noises in my car from passenger side. They keep telling me they can’t replicate it, but you can clearly see where the door is not lined up. This has been going on for over 30,000 miles for that. Like some of these issues have been going on since the 36,000 but now I’m having issues where I’m losing power like this is insane all before 60,000 miles which I’m about to hit. It’s gonna end up getting me killed on the interstate. My vin also says it’s fwd it’s awd AT4 . Called dealer said only to update software clearly not the issue. My doors are off and they have refused to fix those for over 30,000 miles now. It won’t let me attach any pics for some reason I’ve tried since yesterday

Had recently turned 40,000 miles and was driving down a highway; ,lost all power had to get towed to dealership. Was told engine went out, and had to get another. Would be weeks, still no engine. Was towed 3/2/2026. Common problem finding out, was a 90k vehicle unacceptable!

What component or system failed or malfunctioned, and is it available for inspection upon request? Horn began sounding unexpectedly and intermittently while driving and parked. How was your safety or the safety of others put at risk? The uncontrollable horn startled surrounding motorists and pedestrians, causing confusion and defensive reactions. While removing the fuse temporarily stopped the noise, it eliminated a critical safety feature. The horn remains inoperable as of 4/6/26. Has the problem been reproduced or confirmed by a dealer or independent service center? GMC Dealership. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? GMC Dealership. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No prior warning. Issue began Jan 31, 2025 (66 days after purchasing the brand new vehicle). Timeline of events: Jan 31, 2026: Horn began sounding unexpectedly and intermittently while driving and parked. Per dealership advice, the horn fuse was removed to allow for safe travel. Feb 5, 2026: First service visit. Service advisor reported a "kinked wire" was found and repaired. Feb 15, 2026: Issue recurred; horn sounded continuously while driving. Fuse was removed again to disable the horn; it has remained inoperable since. Feb 26, 2026: Second service visit. Dealership diagnosed the issue as a faulty steering wheel and placed an order (ETA: 7–10 days). Mar 3, 2026: Follow-up call. Advised the part was under “national control” with an additional 10-day delay. Mar 13, 2026: Dealership notified me that the steering wheel request was denied by GM because the part is restricted and the cause remained unproven. Mar 18–20, 2026: Third service visit (loaner provided). New diagnosis identified an internal failure in the SIR coil. Part was confirmed as backordered.

I was driving my vehicle on the highway doing normal highway speed, when I began to hear an odd noise coming from the engine area. I slowed down and moved into the slow lane at which time the noise became worse. The vehicle then lost power and I wasn’t able to get the vehicle to do over 40mph. I was able to exit the highway and limp my vehicle home. I had the vehicle towed to a GMC dealership the following morning. After about ten days, I was contacted by the dealer and was advised that I had an engine failure and that my vehicle required a new engine.

Nothing has happened yet. However, after only 308 miles… my 2026 Denali is knocking and ticking very loud. Why? How is this possible? We’ve only had it 2 weeks! I have only driven it 5-6 times in the past 14-15 days, too worried that this might happen. But I was reassured by the dealership it wouldn’t. But here I am now. I am so disappointed. Being a Disabled Vet I thought we could have something that we both liked. Now I am upset because I feel betrayed and lied to. I did a video but it’s too large to upload so I can’t get it under 10MB.

The motor on my 2026 GMC Sierra stalled 2 weeks ago with a p0016(crankshaft position sensor issue). Was able to clear code and limp home. Vehicle did stall on a busy road and stop abruptly. Scheduled service and was advised to drive it in. Was experiencing irregular idle when warmed up, and a slight hesitation in the pedal. Service advisor started the vehicle and claimed no codes, and everything appear OK. Later in the afternoon the service advisor called to inform me that the vehicle had a siezed engine and had siezed during a test drive on the highway. Currently waiting on warranty information, and engine replacement information but i've been informed it will require a whole new engine. This is the same 6.2l L87 V8 that has been in near constant recalls from GMC over the last 6 years.

Took dealer 3/26 for Sam issue Engine Power reduced after already cause me hit curb. Got it out 4/1/26 Now 4/5/26 it happened again same codes after they claimed they fixed it. Also keep having Emergency services come on a caused my dashboard out. My issues is car keeps stalling losing power. Same codes as week ago after dealer fix. Also 4 time took for noises in my car from passenger side. They keep telling me they can’t replicate it, but you can clearly see where the door is not lined up. This has been going on for over 30,000 miles for that. Like some of these issues have been going on since the 36,000 but now I’m having issues where I’m losing power like this is insane all before 60,000 miles which I’m about to hit. It’s gonna end up getting me killed on the interstate.

In the 2026 Yukons, almost all physical buttons have been replaced by the giant center touchscreen. When starting my vehicle, about a third of the time the screen will not come on, and can’t be turned back on by any means. It will randomly come back on after a few more trips/restarts. This renders several critical systems inoperable. All HVAC does not work, defrosters aren’t available, back up cameras and parking assist is not available, and control of any navigation functions or options (ie heated/cooled seats) are not possible. There are no physical buttons for these items, so there are no other options. Voice commands do not function properly when the screen is black, so no option there. After my third visit to the dealership and an open case with GM, they are finally authorizing a screen replacement. We will see if this fixes it. However, my previous explanations from GM pointed to a nebulous future software release, with no date or detail.

On March 13, 2026 I purchased a 2023 GMC Sierra AT4 Pickup with 3.0 Diesel Engine. While driving on a state highway in a 35 mph zone I started to accelerate as the speed zone changed. The truck suddenly had the rear wheel lock up for a brief time about quarter to half second then the truck proceeded on. This happened as the transmission was downshifting. Then on or about March 24, 2026 I was using the same truck and towing a 4,000 pound enclosed trailer. This trailer was hooked up within all recommended hookup requirements. In a 225 mile trip I experienced the same rear wheel lock up happen 4 random times during the trip. Once this happened at 65 miles and hour had there been snow or ice on the highway the truck may have crashed. This lock up happened while using the truck in tow haul mode. Two times it happened while the truck was being towed with cruise control active and two times it happened while not using cruise control. Truck was brought to Authorized GM Dealer and inspected and truck had no stored codes from transmission related issues. Dealer blamed this for using cruise while towing. I informed dealer this happened while not using cruise as well. Was told to turn off adaptive cruise when towing. I was unable to find anything in the GMC Manual regarding not using cruise while towing. This appears to be an issue with the valve body in the transmission and customer explained this to the dealer but they denied this claim. When these quick moment lockups happen no codes or engine lights show everything on dash appears normal. Customer is bringing truck to another GM Dealer to be tested and examined.

Driving approximately 30mph, the engine shut down. Vehicle shifted into neutral until stopped and shifted to park. Unable to place in neutral to pull off the road. Check engine stated transmission needed service. Dealership states seized engine. Engines are on back order. Vehicle has 2980 miles on the odometer. I'm active duty Navy and have a permanent change of station this summer and no vehicle to move in and I also haven't gotten a rental.