GMC Complaints

The vehicle has the L87 GM engine. It lost complete power and the engine seized up and would not start again. Fortunately I was able to roll into a neighborhood and get off the main road with no issues. The dealer has confirmed the seized engine and a replacement engine has been ordered with no ETA. There was no prior warning of the failure, besides a shuddering, like I was running out of gas, and then a lose of complete power.

Engine knocking, constantly kicking into limp mode, shaking when driving. Taken to GMC and local repair shops. Limp mode will not stop kicking on. Now other issues will mean total engine replacement needed. Mechanic says it’s not worth repairing at this point. Only 109k miles on it.

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle vibrated and felt as if the transmission was going to unexpectedly downshift. No warning light was illuminated. In addition, there was an abnormal sound coming from the rear wheels. The contact stated that it felt like the rear tires were driving in the wrong gear. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The contact stated that the failure persisted and became a worsening failure. The manufacturer was not notified of the failure. The failure mileage was approximately 75,000.

The onstar module of my 2023 GMC Yukon has failed. This is a wide spread issue with recent model GMC's. There are thousands of reports of the same thing happenings. When an onstar module fails, the vehicle loses its safety features. No lane departure, no collision detection or pre-collision braking, no critical system checks. Even the gas and mileage components stop working correctly.

The 8-speed automatic transmission (Hydra-Matic 8L90) on this 2017 GMC Yukon SLT 5.3L V8 has failed. This is a repeat failure — the transmission was previously rebuilt in 2020 under a GM recall/service action for the same known defect affecting this transmission type. The transmission has now failed again in 2026, approximately six years after GM's prior repair. Prior to failure, the vehicle exhibited hard shifting, shuddering during acceleration, and hesitation between gear changes — symptoms consistent with the known defect pattern documented across 2015–2019 GM vehicles equipped with this transmission. The failure was confirmed by a service center. The vehicle is currently not safely drivable. Safety concern: erratic and unpredictable gear changes, including sudden lurching and hesitation during acceleration, create a dangerous condition for the driver, passengers, and other vehicles on the road. GM has been contacted through their Customer Assistance Center (case opened). GM's initial position was that they cannot assist because the vehicle is out of warranty. However, this is a repeat failure of a previously repaired known defect. GM issued 13+ technical service bulletins on this transmission and has been aware of the root defect since at least 2018. A federal class action (Speerly v. General Motors, E.D. Michigan) covering this exact vehicle type and transmission has been certified and upheld by the Sixth Circuit Court of Appeals. The prior GM repair did not remediate the underlying defect.

The contact owns a 2015 GMC Sierra 1500. While traveling on a two-lane highway at approximately 55 MPH, another vehicle suddenly turned into the contact's lane, resulting in a severe frontal "T-bone" collision. The force of the impact caused the other vehicle to be propelled into a ditch, while the contact's vehicle remained on the roadway. Despite the significant nature of the crash and the speed involved, no air bags deployed. The dealer was notified of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 218,000.

the rear lights do not function they quit working and there is no parking lights tail lights brake lights

I was traveling on the I70 West around the 210 mile marker. I was in the passing lane at high speed when the vehicle without warning switched itself off. The dash showed the “press start” warning, but the vehicle would not restart. I was fortunate that I was around 1/2 a mile from a rest stop area. I was able to glide the vehicle into the rest area. As I slowed close to a stop the vehicle suddenly stopped and applied the park brake. I am a very experienced driver, if my wife was driving, the vehicle shutting down completely in the fast lane could have been catastrophic. The road was busy. The vehicle was locked up in Park and was unrecoverable. It had to be dragged sideways out of the area that it had come to a stop, and then dragged onto and off the tow truck. The following morning the dealership confirmed the engine was seized. When I purchased the vehicle, the dealership confirmed that the historic failures on the L87 6.2L V8 engine were resolved. Clearly not the case.

The contact owns a 2017 GMC Sierra 2500 Denali. The contact stated that while driving at an undisclosed speed, the vehicle went into LIMP Mode. There was no warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that the knock sensor had failed and needed to be replaced. The vehicle was not repaired. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 209,000.

I purchased my used GMC YUKON from a used car dealership 3/28/26. I signed the papers for the agreement while I was driving the vechicle home I lost power and it wouldn't go forward with gas applied. The check engine light came on, I pulled the suv over and it was towed. The code that popped up 0700 and 02723 both codes having to do with the transmission.