2024 GMC Sierra 1500

While driving on a divided two lane state highway at approximately 60mph my vehicle suffered a catastrophic engine failure causing immediate loss of power in traffic at highway speeds. I had to negotiate highway traffic to steer the vehicle onto a narrow shoulder and continue under reduced power to a location where the vehicle could remain stopped safely. There were no warning signs and no warning lights prior to the issue. The vehicle was towed to Faulkner GMC where it was eventually inspected and determined to be an engine failure consistent with the open recall affecting GM 6.2 L87 V8 engines. A replacement engine was installed under warranty. Additionally, a defective tailgate switch was discovered and replaced. A prior unrelated incident had occurred where the tailgate switch activated on its own lowering my tailgate while the vehicle was in motion. The tailgate lowered onto the tongue jack of a trailer I was towing causing damage to the tailgate. This issue occurred multiple times throughout my ownership of the vehicle until the switch was replaced. GM acknowledged the switch was found to be defective but refused to take responsibility for the damage.

My vehicle has experienced repeated and unresolved electrical system failures and unexpected loss of power steering assist. The problem involves multiple warning lights, module communication faults, drivability issues, and simultaneous malfunctions affecting systems including power steering, traction control, transmission, four-wheel drive, and other electronic controls. Repair records, diagnostic information, and videos documenting the failures are available for inspection upon request. The most serious incident occurred on August 23, 2026, when the power steering failed unexpectedly while I was driving. The sudden loss of steering assist made the vehicle difficult to control and nearly resulted in a collision with an oncoming vehicle. The failure created a significant safety risk because it impaired my ability to safely steer and control the vehicle. The condition has occurred multiple times over several months and has resulted in repeated dealership visits. Repairs have included replacement an HVAC controller, but the failures have continued. The vehicle has been inspected multiple times by an authorized dealer, and the manufacturer has been notified through an open support case. As of the most recent repair visit, no confirmed root cause or permanent repair had been identified, and the dealership was still working with engineering support to diagnose the issue. Prior to and during these failures, numerous warning lamps and service messages appeared, including warnings related to power steering, traction control, transmission, four-wheel drive, trailer brake system, steering column lock, and tire monitoring systems. In some incidents, the vehicle entered reduced-performance mode. These warning messages first appeared in November 2025 and have continued intermittently despite multiple repair attempts. The recurring and unresolved loss of power steering assist while driving creates an ongoing risk of crash or injury.

My 2024 GMC Sierra Denali Ultimate 1500 experienced a catastrophic powertrain failure that created a serious safety hazard. On XXX, while driving at highway speeds, the truck unexpectedly shifted into neutral, causing an immediate loss of propulsion. During this event, the electrical system was also affected. The battery power dropped, power steering assistance was lost, and due to the electronic push-button start system, the vehicle could not be restarted while in this condition. This placed me and surrounding motorists at significant risk of a crash. I initially brought the vehicle to Point GMC, where I was advised no issue was found. After the problem continued, I returned on XXX and a dealership technician rode with me. During the test drive on [XXX], the truck again shifted into neutral, confirming the defect. The vehicle was then towed to the dealership, where diagnostics revealed DTC P0016. I was informed the engine had seized and required a complete engine replacement. The engine was replaced by an authorized GMC dealership in New Jersey. After only about 2,000 miles, the check engine light returned and the vehicle began experiencing additional electrical issues. This is a Denali Ultimate, the highest trim level, with advanced electronic systems, making these recurring failures especially concerning. To date, the vehicle has been inspected by three authorized GMC dealerships, and I have opened multiple cases with GMC Corporate. Despite repeated repair attempts, the manufacturer has not provided a permanent resolution. I continue to experience recurring engine and electrical issues and no longer have confidence in the safety or reliability of this vehicle. Given the repeated failures, loss of propulsion, loss of steering assistance, inability to restart the vehicle, and lack of resolution after multiple dealership visits and an engine replacement, I believe this matter warrants investigation by NHTSA. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Check engine light illuminated with service transmission. The next day transmission started slipping and finally would not engage in reverse. Dealership Has it now and after diagnosis they advised that they had replaced the electronic control module to which, on the test drive, the gauge cluster blacked out and they got more codes. The cpdes that the vehical threw were the transmission valve body needed to be replaced.The truck has 24k miles on it.

My GMC sierra with 40000 miles The check engine light turn on and was steady on when driving on the highway I loose a power on the vehicle for a few seconds and almost a semi truck behind me hit me because I don’t have any power on the vehicle, I stop on a safe place and try to start the vehicle again immediately call dealer for appointment an start drive to home. The lady on General Motors say I can drive safe with my vehicle but I don’t feel safe because nothing on the onstar computer works the emergency button and GPS it’s not working at all.

The contact owns a 2024 GMC Sierra 1500. The contact stated while stationary or while driving, the vehicle unexpectedly shut off. There was no warning light illuminated. The vehicle stalled and lost electrical power. The battery was replaced five times and the BCM four times; however, the failure persisted. The contact stated that after opening the door causes an immediate parasitic drain on the battery, resulting in a total loss of electrical power. The vehicle was taken to a dealer however, the cause of the failure was not yet determined. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 48,000.

The contact owns a 2024 GMC Sierra 1500. The contact stated that there was an unknown failure with the front and rear cameras. The driver's and passengers' side mirror indicators remained illuminated but occasionally failed to operate. There was a glare that was shining into the vehicle while it was raining and driving at night. The vehicle was taken to the local dealer, where it was diagnosed that an unknown module was not operating as needed. The rear wiring harness was replaced. The seat module and transmission were repaired, but the failure recurred. The manufacturer was contacted, and a case was opened. The Attorney General was contacted and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 9,000.

The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving at 67 MPH, the transmission shifted to neutral(N) unexpectedly. In addition, the vehicle failed to accelerate as intended while depressing the accelerator pedal. The contact attempted to drive the vehicle off the road. A passerby slowed down and allowed the contact to move over to the side of the road. The engine seized, and the vehicle stalled between the shoulder and the line of the left lane. The check engine warning light illuminated, and the messages "Battery Low" and "Reducing Features to Save Battery" were displayed on the instrument panel. The contact called a friend who towed the vehicle to the dealer. The dealer was informed that the engine had failed and needed to be replaced. The vehicle remained at the dealer unrepaired. The contact stated that due to the failure, the contact no longer felt safe while driving the vehicle. The manufacturer was notified of the failure. The failure mileage was 52,680.