GMC Complaints

The contact owns a 2021 GMC Sierra 2500. The contact stated that on several occasions, the automatic power side-out step failed to extend as designed. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was 93,726.

The contact owns a 2012 GMC Acadia. The contact stated that while reversing, the liftgate unexpectedly opened, even though the liftgate was properly closed. There was no warning light illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 125,000.

I took my 2020 GMC Sierra in for an oil change. The engine seized when it the technician tried to restart the car. We had it towed to GMC where they confirmed the engine seized. The oil repair shop then replaced the engine and when doing so confirmed the original threw a rod which is the same recall issue that is occurring with the 2021-2024 models. I have since taken the car to GMC for a full inspection and made additional repairs. The vehicle is available for future repairs. My safety and others are at risk as the engine could seize leaving my family stranded or endangering others on the road if the seizure occurs while driving. Yes the vehicle was inspected at the GMC dealership and the shop where the engine was replaced with another L87 engine. there was no warning the engine seized after an oil change.

Engine started with a rough idle, I attributed this to mileage. Check engine light did not come on until days before scheduling service. Per diagnostic from Chevrolet service department: Lifter roller damaged and camshaft damaged on lobe. need to replace camshaft and lifters. this has been diagnosed by Chevrolet dealer mechanics at Ferman Chevrolet North Tampa, in Tampa Florida. Check Engine Light came on 4 days before I took it for diagnostic. Chevrolet and GMC have issued a recall on 2021+ but this remains outside that recall. I'm quoted for an $11,343 repair on a vehicle that has gotten regular synthetic oil changes at the dealership since I bought it with approx 80k miles on it. Metal was not noticed in the prior oil changes, latest which was

The contact owns a 2021 GMC Sierra 1500. The contact stated that while her son was driving 55 MPH and depressing the brake pedal, the vehicle failed to slow down as intended. The driver attempted to use the parking brake to slow the vehicle, but the vehicle failed to slow down. The message “Braking System Failure” was displayed. The driver pulled over to the side of the road, and the passenger’s side front wheel detached and started leaning to the right before the vehicle came to a stop. The driver exited to inspect the vehicle and became aware that the front passenger’s side wheel was lying on the ground. The vehicle was towed to an independent mechanic, but was not diagnosed. The vehicle was then towed to another dealer, where it was diagnosed, and it was determined that the passenger’s side upper and lower control arms, ball joints, rack and pinion, brake rotor and pads, hub, outer tie rod, brake line, speed wheel sensor, wheel and tire, and suspension parts needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 77,000.

On April 7, 2026, I was driving my 2023 GMC Yukon Denali Ultimate on the interstate at approximately 70 mph, accelerating to pass a car so I could get off on my exit. Without warning, the dashboard displayed "Engine shut off, press start button" and the engine lost power. I coasted off the interstate to the shoulder safely. I was alone in the vehicle. I thought it was a battery issue and had a coworker attempt a jump. The vehicle would not restart. I called Moses GMC of Huntington, WV, and they dispatched a tow through GMC Roadside Assistance. I waited approximately 2 hours on the shoulder for the tow. After the tow, Pete, the Moses GMC service manager, called and said nothing was wrong with the vehicle, that it only needed an oil change. He said it started right up and he drove it into the bay. Moses performed the oil change. When the technician test drove it afterward, the engine fully shut down on the hill leaving the dealership property. My husband Zach happened to drive past and saw the Yukon stopped with hazard lights on at the top of the exit. Pete called that evening and said, "I think there actually is something wrong with it." On April 10, 2026, Pete confirmed the failure is the GM 6.2L V8 L87 engine defect covered under NHTSA Recall 25V-274 (connecting rod/crankshaft manufacturing defect). Full engine replacement required, estimated 6-7 weeks. This vehicle was previously inspected by Moses GMC under Recall 25V-274 in August 2025 and cleared at that time, approximately 8 months before the April 7 shutdown. Vehicle had ~38,000 miles, garage kept, full maintenance records, no prior engine issues or warning signs. No crash, no injury, no other vehicles involved in any of the three failure events.

There is a recall on my 2015 GMC Yukon, that I am not the original owner of. The recall is for the brake booster and says that it expired. I have had the car checked by two different shops (both confirmed it was this), and one of them was the local GMC dealership by my house. I called to make an appointment for the recall to be fixed, to which they said they needed to order parts and it would take a few weeks. I dropped the car off three weeks later per their request for then another person to call me and say they won't fix it because it is expired. It is a safety matter that the breaks don't work occasionally.

Reverse lamps are not bright. Camera does not brighten area either. Very unsafe to reverse in the dark. Have to touch the brake pedal to be able to see while backing. Also have tried the LEDs in the mirrors while backing- although the LEDs are bright- lights to see while backing are insufficient on the stop lamps.

Issue: Repeated failure of safety-critical module Description: The Side Blind Zone Alert system on my 2015 GMC Acadia has failed multiple times over the life of the vehicle. The system becomes inoperative and displays “Side Detection System Unavailable.” A local GMC dealer has diagnosed the issue as a failure of the SBZA module due to loss of communication. This failure has occurred repeatedly, approximately every two years, despite prior repairs and replacement of the module at my own expense. This is a safety-critical driver-assist feature, and the repeated failure pattern suggests a defect in the design or durability of the module. The system is unreliable and cannot be depended on for safe lane-change operation. GM Customer Assistance has declined to provide support or escalate the case further, despite the safety implications and documented repeat failures. I am reporting this because the failure affects safe operation of the vehicle and appears to be a recurring defect affecting multiple owners of this model.

Hard as rock brakes Long response time Mechanic friend says it’s break booster.