GMC Complaints

While driving my 2019 GMC Terrain on local roads, the vehicle suffered a sudden and complete failure of the braking system. The brake pedal became extremely hard to press, and the dashboard displayed a critical error message stating 'Engine Power is Reduced.' during this frightening safety incident i felt lucky to bring the car to a stop without an accident. The vehicle had to be flatbed towed to a repair facility. This sudden loss of power braking is a known, documented defect matching the engine-driven brake vacuum pump failures currently subject to federal class-action litigation (Thieme v. General Motors). I am requesting a formal safety investigation into why the GMC Terrain was excluded from previous GM vacuum pump recalls despite posing an identical, life-threatening risk to occupants."

The car suffered a long crank, then stalled completely while moving on a public road, which is a severe safety hazard.

My 2023 GNC Sierra 1500 has experienced a recurring electrical and safety-related malfunction on multiple occasions while driving. The dashboard and warning lights intermittently flash on, and off and numerous warning messages appear simultaneously. During previous occurrences, warnings included power steering service, safety restraint system, check engine and transmission related messages, including a message instructing me to pull over and shut the vehicle off. During one occurrence, the electric power steering assist stopped working while I was driving. The vehicle was taken to an authorized GMC dealership multiple times while under the factory warranty. The dealer replaced the Brake System Control Module and performed vehicle-wide software/programming updates. When the problem continued, the dealer contacted GM Technical Assistance. The Dealer subsequently diagnosed an intermittent open circuit involving the electric power steering rack-and-pinion/steering gear assembly and replaced the complete steering gear assembly. Despite these repairs, the malfunction has occurred again, during another occurrence while driving on the freeway, the dashboard flashed on and off and multiple warning lights and messages repeatedly appeared, similar to the condition that occurred before the steering gear was replaced. The vehicle currently has approximately 55,000 miles. The condition remains intermittent despite multiple repair attempts. I am concerned that this recuring electrical or vehicle communication failure could again cause loss of power steering assistance or affect other safety-related vehicle systems while driving.

Catastrophic failure of drivers side rear tire. Complete delamination of tire causing severe vehicle damage. Tire and vehicle is available for inspection upon request. Tire exploded causing serious risk to passengers at highway speeds. Tire has not yet been inspected due to date of incident being on Saturday. Immediately prior to incident a small vibration was noticed in the rear approximately 1 minute before failure. Tire pressure was at 80 psi when troubleshooting vibration while traveling. Tire size 275/65 R20

2026 Denali, 6.2, failed after getting off express way while on my way for a fishing get away and pulling my boat. NO warning lights, noises, nothing. Came to a stop sign and at the last second slammed into park. Dash went black, 10 seconds later would come back on and try to start, then the dash goes black. Sheriff pulled up 20 or so minutes later and told my wife to get back into the vehicle as she was directing semis and other cars to go around. Towed to a chevy dealership 13 miles away. After Running tests on the truck, came up blown engine. 7600 miles. 5 hours later we left with a loaner and able to continue on with our plans. I do thank the dealership for their help and loaner. 23 business days later they delivered my truck to my house and returned in the loaner. After all my investigating on these engines, I will not be buying another one. Time for GM to invest some of their profits into finding the problem!

While driving southbound on Interstate 95 in Florida, the front upper grille molding/deflector completely detached from my 2023 GMC Sierra 1500 SLE at highway speed and separated from the vehicle, creating a potential road hazard for other motorists. Prior to the complete separation, I noticed that the upper grille molding was becoming loose and lifting away from the vehicle. I stopped and photographed the component and its attachment areas. The photographs show failed/broken attachment points while the molding was still partially attached to the truck. Later, while driving on I-95, the remaining attachments failed and the entire molding separated from the vehicle. The part could not safely be recovered from the interstate. The vehicle recently underwent dealer service involving the active grille shutter/damper area near this component. I cannot determine whether that service contributed to the failure, so I am reporting it as part of the vehicle's recent service history rather than asserting it as the cause. I subsequently became aware that NHTSA Recall 25V-060 / GM Recall N242490120 addresses separation of a front upper grille deflector on certain GMC Sierra 1500 vehicles due to fractured attachment points. My vehicle is a 2023 model and does not presently appear to be included in that recall. Because my vehicle experienced a similar failure mode resulting in the exterior component completely separating at highway speed, I am submitting this complaint so NHTSA can determine whether this condition may extend beyond the vehicles currently covered by the recall. Photographs documenting the component and failed attachment areas before its complete separation are available.

Vehicle: 2023 GMC Sierra 1500 SLE VIN: [XXX] While driving southbound on [XXX] near exit [XXX], the front upper grille molding/deflector completely detached from my 2023 GMC Sierra 1500 SLE at highway speed and separated from the vehicle, creating a potential road hazard for other motorists. Prior to the complete separation, I noticed that the upper grille molding was becoming loose and lifting away from the vehicle. I stopped and photographed the component and its attachment areas. The photographs show failed/broken attachment points while the molding was still partially attached to the truck. Later, while driving on [XXX] to work, the remaining attachments failed and the entire molding separated from the vehicle. The part could not safely be recovered from the interstate. The vehicle recently underwent dealer service involving the active grille shutter/damper area near this component. I cannot determine whether that service contributed to the failure, so I am reporting it as part of the vehicle's recent service history rather than asserting it as the cause. I subsequently became aware that NHTSA Recall 25V-060 / GM Recall N242490120 addresses separation of a front upper grille deflector on certain GMC Sierra 1500 vehicles due to fractured attachment points. My vehicle is a 2023 model and does not presently appear to be included in that recall. Because my vehicle experienced a similar failure mode resulting in the exterior component completely separating at highway speed, I am submitting this complaint so NHTSA can determine whether this condition may extend beyond the vehicles currently covered by the recall. Photographs documenting the component and failed attachment areas before its complete separation are available. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Driving on the highway near Rockport, WA, when vehicle suddenly loss propulsion, engine light appeared, and vehicle went into transport mode enabled. Without causing an accident, I was able to pull to the side of the road. Once I put vehicle in park, it shut off and displayed, “Tranport Mode On. Vehicle would not start and was towed home. My son-in-law was able to disable transport mode, but vehicle still will not start. Will notify dealership on Monday.

Driving on the highway near Rockport, WA, when vehicle suddenly loss propulsion, engine light appeared, and vehicle went into transport mode enabled. Without causing an accident, I was able to pull to the side of the road. Once I put vehicle in park, it shut off and displayed, “Tranport Mode On. Vehicle would not start and was towed home. My son-in-law was able to disable transport mode, but vehicle still will not start. Will notify dealership on Monday.

My 2022 GMC Terrain left me on the side of the road today with a fuel pump module failure. After having it towed to the dealership I began looking to see if this is a known problem. I see that there was a recall for the 2022 GMC Terrain, but my VIN is not listed on that recall. MY FUEL PUMP MODULE FAILED! I think that my VIN was left off of recall list. GMC should pay to repair this!