GMC Complaints

I have a 2023 GMC Yukon AT4. The OnStar/telematics system stopped working. The blue OnStar button does not function and the vehicle no longer communicates with the myGMC app, resulting in loss of connected and OnStar services. A GMC dealership diagnosed a failed OnStar/telematics module and advised that the module must be replaced at a cost of approximately $1,200. I am concerned because this failure affects access to OnStar communication and emergency-related services. I have found reports from other GM owners describing similar telematics/OnStar module failures, and GM has issued service information addressing K73 telematics-module communication faults. I have also opened a case with GMC Customer Assistance. I am reporting this because I believe the repeated failure of a system used for emergency communication warrants investigation.

The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving 45 MPH and depressing the accelerator pedal, the vehicle slowed down unexpectedly. The vehicle then lost power while stopped at a traffic light. No warning light was illuminated. The vehicle was turned off and restarted, and the vehicle operated as intended. The vehicle was taken to the dealer, where it was diagnosed and determined that there were metal shavings inside the oil pan and the engine needed to be replaced. The engine was replaced twice. The manufacturer was not notified of the failure. The approximate failure mileage was 3,202.

Transmission Valve Body failure. - Caused wheels to lockup momentarily and killed the engine with sudden loss of propulsion. Link to video of incident: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Push on accelerator truck barely would go, shifted hard, codes check engine lights flashing, engine sounded bad

2021 6.2L GMC Sierra Denali. Has the L87 engine that is recalled but yet my truck doesn’t fall under the recall although the recall is for 2021-2024 engines. Everything that the engine recall states is the issue with my truck, I have service report from dealership stating that there is wear/breakage of cam shaft/crank shaft amongst other things including cylinder 3 and 5 misfiring , bearings broken , filings in the oil , banging in the engine and safety lights on. My local GMC dealership recommended that the only acceptable action was to replace the engine at my cost of course. This is unacceptable of a supposed reputable large corporation not caring about the “little guy”. The truck only has 136000 kms on it and I was only going 60 km/hr when this happened. Please help as I feel GM knows this engine is faulty but somehow has managed to escape a recall on my vin number

The OnStar module in the truck is broke it affects all communications. The truck has including things like let me know what the speed limit is. It happened after they did a software update, which seems a little fishy because there was nothing wrong with it before I understand. Some people were having problems with this module, causing their batteries to die, but now I’m the one having issues and they won’t seem to fix it unless I pay them $900.

On [XXX] I was driving my 2024 GMC Sierra 1500 Vin # [XXX] on a major highway in Houston when without warning the engine shut off, stranding me in the middle of busy traffic. I was able to get to the shoulder and restart the truck, but no warning lights came on so I continued on my drive when approximately 20 minutes later, while still on a busy freeway, the engine shut off again. I was able to restart the truck and within another 15 minutes the check engine light appeared, the engine lost power and started making a loud rattling noise. Roughly 2 minutes later, as I was attempting to pull over to the shoulder and safety, the truck shut off and would not restart. This was the 3rd time for it to stall out on a busy freeway which was very dangerous for myself and the other drivers. I contacted the local Chevy dealership and they sent a tow truck out to tow the truck back to their dealership service center. I was later contacted by a service advisor that said they found a code P0016. He informed me that the engine would need to be replaced. As of today 8/11/26, they are still waiting on backordered parts to arrive before they can even start on any repairs. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ABS Randomly turns on with the traction control light… All windows except for driver window will not go down and sometimes it does not unlock or lock sometimes. It started the beginning of 2022 and has got worst over the years. It is available for inspection. Safety has been and issue because whenever it rains it can lose control on the road haven’t had the money to fix it so don’t really drive it right now.

I was driving doing about 60 mph. All of a sudden the engine stopped and the truck just coasted. I was able to find a safe spot on the side of the road and pull over. Called a tow truck and had it taken to the GM dealership nearby. The trucks engine was just fixed in October of 2025 for the camshaft and lifter rods. It’s currently in the shop and I’m waiting for the diagnostics.

The contact owns a 2024 GMC Yukon XL. The contact stated that upon taking the vehicle to the dealer to be repaired under NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling), the contact was informed that the vehicle passed the inspection and no repair was needed. However, the vehicle experienced engine failure approximately seven months later. While driving 50 MPH, the vehicle lost motive power. There was no warning light illuminated. The driver pulled over, restarted the vehicle, and resumed normal driving. The vehicle was taken to the dealer the following morning, where the Electronic Control Module was replaced under warranty; however, the failure recurred while driving 70 MPH three weeks later. No warning light was illuminated. The driver pulled over, restarted the vehicle, and resumed driving; however, the vehicle failed to exceed 40 MPH and shut off. The vehicle failed to restart and was towed to the dealer, where it was diagnosed and determined that the engine, radiator and seal kit needed to be replaced. The vehicle was not yet repaired. The contact was concerned that the recall remedy failed to prevent the failure. The manufacturer was notified of the failure and a buyback was requested, but the request was denied, and the contact was referred to the dealer for additional assistance. The failure mileage was approximately 27,800.