GMC Complaints

THE PARK ASSIST WOULD GO ON WHEN I WAS AT A STOP LIGHT AND NO ONE WAS IN FRONT OF ME AND AUTO STOP WAS OFF ALL THE TIME. TWO GROUND STRAPS WERE CORRODED. THERE IS A RECALL ON THEM FROM 2019 TO 2024. MY TRUCK DID NOT HAVE A RECALL ON IT. I JUST WANT TO LET YOU KNOW AND MAYBE IF ENOUGH PEOPLE COMPLAIN, YOU WILL PUT ALL TRUCKS ON THE RECALL.

Incident Summary: On 2/2/2026, my vehicle was serviced under Safety Recall 25V-274 at an authorized GMC dealership. The service technician performed the mandated diagnostic protocol (including the PicoScope test) and informed me that the engine had "passed" inspection. No internal components were replaced; the remedy was limited to an oil change to a higher-viscosity oil (0W-40) and a new oil filler cap. The Failure: Approximately 48 hours after this "successful" recall remedy, the vehicle suffered a catastrophic engine failure while in operation. The engine failed entirely. The vehicle lost all propulsion while in motion, creating an immediate safety hazard for myself and other motorists. Diagnostic and Risk: The failure has been confirmed by a GMC dealer, who subsequently performed a full engine and radiator replacement. In the 48-hour prior to failure, there were no warning lamps or symptoms; the vehicle had just been cleared by the manufacturer's own diagnostic tools as safe and free of defects. Systemic Concern: This incident demonstrates that the current diagnostic protocol for Recall 25V-274 is insufficient to identify terminal manufacturing defects in the connecting rods and crankshaft of the L87 6.2L V8 engine. The "remedy" of higher-viscosity oil failed to prevent the exact catastrophic loss of propulsion the recall was intended to address. The replaced engine is available for inspection upon request by the NHTSA Office of Defects Investigation.

The contact owns a 2022 GMC Sierra 1500. The contact stated that while driving at various speeds, the driver's side seat vibrated, and the automatic high beam feature disengaged, and the lane change indicator became inoperable. The message " Crash Sensor System Inoperable" was displayed. The dealer was notified of the failure and advised the contact to temporarily disconnect the battery. The contact followed the instruction; however, the failure recurred a day later. The vehicle was taken to the dealer, where it was diagnosed, and determined that there was a glitch in the crash sensor system. The dealer determined that the system needed to be updated. The vehicle was repaired out-of-pocket. The manufacturer was contacted and informed the contact that the failure was a maintenance issue, and the repair was at the owner's expense. The failure mileage was approximately 51,000.

The contact owns a 2022 Safe Haven 12-foot Flatbed Trailer. The contact stated that while driving approximately 10 MPH and towing the unloaded trailer with a 2024 GMC Sierra 2500, while slowing down to make a right turn, the trailer detached from the tow hitch ball. The contact stated that there were no warning lights illuminated. The contact stated that the aluminum arms on the hitch adjoined to the frame of the trailer was loose. The contact stated that because of the design of the hitch, the receiver that rests on the trailer hitch was not flush, and there was room for the trailer receiver to move up and down, causing the bolts to loosen. The contact called the manufacturer and was informed that it was the normal of the bolts. The trailer was taken to an authorized dealer, and the contact was informed that the trailer was attached incorrectly. The vehicle was not diagnosed or repaired. The failure mileage was approximately 1,200. The VIN was not available.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving on several occasions at various speeds, the vehicle started shaking and slipped in and out of gear, with the message "Idle Transmission" displayed. The vehicle was pulled over and shifted into park(P) and then to drive(D). There was a loud banging sound coming from the rear of the vehicle. The vehicle was towed to an independent mechanic, where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be repaired. The vehicle was not yet repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 80,000.

The contact owns a 2023 GMC Yukon XL. The contact stated that the vehicle was losing oil, and the engine was running rough. There was an abnormal burning odor after driving the vehicle. The vehicle received an oil change; however, two weeks later, the oil warning light illuminated. The vehicle was towed to the local dealer, where it was determined the oil level was approximately 2 quarts low, and another oil change was performed. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 70,000.

While driving a "Service Transmission" message appears on the information center. The truck shifts slowly, sometimes slamming into gear, doesn't seem to have smooth acceleration through the gears until a high gear is reached. Unusual sounds occur during the shifting sequence. The vehicle was dropped off at the dealer for service. Dealer claims that since they were not able to duplicate the conditions reported to them, the vehicle was fine and not in need of any further investigation or service. Transmission problems are a known concern with vehicle as recalls have been expanded to include this class of truck in the recall but GM is not including this vehicle.

On [XXX], at approximately 4:10 PM, I was at the McDonald’s drive-through located at [XXX] and [XXX] in Springfield, Missouri. I was stopped at the final service window. As I pulled away from the window, I approached a 90-degree left turn heading south. I removed my foot from the accelerator pedal to allow the truck to coast slowly around the corner, as the area is heavily pedestrian and requires caution. While coasting with my foot completely off the gas pedal, the truck suddenly and rapidly began to accelerate on its own. I immediately applied the brakes, and the unintended acceleration stopped right away. At that point, I called Thompson GMC in Springfield, Missouri, at 4:17 PM to report the incident. This was the second time this has occurred. The first incident happened several months ago on [XXX] north of Strafford, Missouri. While navigating a curve, I lifted my foot off the accelerator to coast, and the truck again experienced sudden, hard acceleration. I quickly applied the brakes, and the acceleration stopped immediately. I called Thompson GMC at that time as well. They advised me that I could bring the vehicle in for inspection, but without a check engine light or warning light illuminated, and without the issue occurring while a technician was driving, it might be difficult to diagnose. I did not bring the vehicle in after the first incident. Yesterday, a Thompson GMC employee scheduled an appointment for me to have the truck inspected. No warning lights or check engine lights were illuminated on the dashboard during either incident. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I purchased this vehicle in June 2024 as a demo vehicle with approximately 7,000 miles on it. Within one month of ownership, the vehicle began experiencing serious problems that have continued to worsen. The vehicle currently has approximately 34,000 miles, and the issues have been ongoing from the time of purchase through the present. Since purchasing the vehicle, it has been in the dealership multiple times for the same recurring problems, including but not limited to: * Powertrain issues and loss of power * Reduced acceleration while driving * Complete electrical failure while driving * Engine and electrical warning lights repeatedly turning on * Vehicle running excessively hot * Water pump replacement * Replacement of sensors * Thermostat replacement * Ongoing engine and electrical system malfunctions Despite these repairs, the same problems continue to reoccur. Each time I return the vehicle for service, I am informed that it is a “different issue,” even though the symptoms remain unchanged. This strongly indicates a defective powertrain and/or electrical system that has not been properly repaired. The most serious concern occurred while I was driving on public streets, when the vehicle lost acceleration, electrical power shut off, and the vehicle completely shut down, nearly causing me to be hit by other vehicles. This incident created an extreme safety hazard for myself, my passengers, and other motorists. I have made several formal complaints directly with GMC, and more than four case numbers have already been created regarding this vehicle. Despite these complaints and repeated repair attempts, the problems persist. Given the repeated failures, numerous repair attempts, documented safety risks, and the fact that these issues began shortly after purchase, I believe this vehicle qualifies for relief under applicable lemon laws and consumer protection laws. Incident (Critical)Vehicle lost acceleration and electrical power and completely stalled while roads

The truck currently has 48000 miles. The 6.2L L87 engine was replaced at 17000 miles. A few weeks ago, I parked it, went to a ballgame, came back 4 hours later and started the truck. Drove it approximately 500 feet and lights started flashing on the dash. It was running rough, had loos of power, and sounded like a diesel. I immediately shut it off and had it towed to a dealer. The lifter on the number 3 cylinder stuck and bent the pushrod. The dealer replaced all lifters on that side of the engine. This all happened after it was checked for the recall and the thicker oil was put in.