2025 GMC Sierra 1500

Safety Complaint – 2025 GMC Sierra 1500 Tailgate While driving our 2025 GMC Sierra 1500 and towing a trailer, the tailgate unexpectedly opened and dropped down while the vehicle was in motion. No one touched the tailgate button, key fob, or any other controls to activate the tailgate. We were unaware that the tailgate had opened. When we made a turn, the trailer contacted the tailgate and crushed/damaged it. This occurred without any intentional activation of the tailgate release. We believe this presents a significant safety concern because an unexpectedly opening tailgate while driving, especially while towing a trailer, could result in property damage, loss of cargo, or a more serious accident. We are requesting that this issue be investigated to determine whether there is a defect with the tailgate latch, release mechanism, or electronic controls on the 2025 GMC Sierra 1500.

ENGINE STARTED KNOCKING AT 18K MILES AND TOOK TO DEALER AND THEY FOUND METAL IN THE FILTER AND INSTALLED A NEW ENGINE AND ALSO REPLACED THE MIDPLATE GASKET ON THE VALVEBODY DUE TO A HARSH DOWNSHIFT WITHOUT CODES IN THE SYSTEM THIS ENGINE IS GOING ON 2K MILES AND IT SEEMS TO BE FINE NOW BUT THE PROBLEM WITH 6.2 WAS ONLY SUPPOSED TO BE ON THE 21-24 MODELS AND MINE IS A 25 MODEL AND ALREADY HAD A REPLACED AND NOTHING FROM GM WAS SAID TO EXTEND THE WARRANTY ON THIS MODEL AND POWERTRAIN

Either while stopping while driving or parking (forward or reverse) the engine RPMs go up thus wanting to move the vehicle in that direction causing the breaks needing to be applied harder. When you shift into neutral the RPMs go way up (3000). This has happened on this vehicle 3-4 times of which I have video of the latest occurrence. When put into R or D the RPMs are still over 1000. This also happened on the courtesy vehicle same make and model) I was given but on this one the RPMs went up to 5000 of which I also have a video. The dealership has not been able to duplicate the issue as of yet. My fear is that the vehicle will hit someone or something if the break isn't pressed to the floor. It happens very randomly. The dealer currently has my vehicle trying to figure it out. They say GM says there's nothing they can do. No warning lights or messages appeared.

Upon purchase of my 2025 GMC Sierra, it did not come with a physical manual. I asked the dealer about this and they said they did away with them, only providing the digital version. I contacted GMC recently as I saw the a recall dor 2026 models with this exact issue, but they did not seem to care and it was for 2026 models only. I find this to be a loophole GMC is following, and would just like a manual so I can log maintenance like a normal person without a phone or sitting in my vehicle. Thank you

I did not receive an owners manual when my vehicle was purchased new on January 15 2025. I reported it to the dealership and to GMC both times they said too bad, access it online. I contacted GMC again after recall N252540430 was issued but they still refuse to provide an owners manual because 2025 Sierra 1500 isn't listed it's only the 26 model year.

Safety Complaint – Delayed Acceleration from Automatic Engine Stop/Start I am reporting a safety concern regarding the automatic engine stop/start system in my GMC truck. During normal operation, the system shuts the engine off when the vehicle comes to a complete stop. When I release the brake and press the accelerator, there is a noticeable delay while the engine restarts before power is delivered to the wheels. This creates a hesitation between driver input and vehicle response. This delay presents a safety concern because it affects my ability to react quickly in situations that require immediate acceleration. I have experienced multiple real-world scenarios where this hesitation impacts safe operation: While stopped at an intersection preparing to turn, I observed oncoming traffic approaching faster than expected. When I attempted to accelerate to complete the turn, the delay caused by the engine restart reduced my ability to clear the intersection promptly. In stop-and-go traffic, I needed to move forward quickly to maintain safe spacing or respond to changing traffic conditions. The hesitation before acceleration limited my ability to react immediately. When pulling into traffic from a parking lot or side street, heavy traffic often creates small gaps that require prompt acceleration. Due to the delay in engine restart, it is difficult to accurately gauge and anticipate the truck’s response when pressing the accelerator. With this hesitation, safely merging into traffic in these conditions becomes extremely difficult and, at times, effectively impossible. In situations where a vehicle encroaches into my lane or a hazard develops unexpectedly, the delayed throttle response reduces my ability to maneuver out of the way quickly. This is not simply a convenience issue. The system introduces a delay between driver input and vehicle response, which can reduce reaction time in situations where immediate acceleration is necessary to avoid a potential hazard.

While driving in bumper-to-bumper traffic, my vehicle suddenly lost all engine power, the accelerator became unresponsive and the dash indicated "press start". There were no warning lights, no messages, and no prior symptoms before the failure occurred. I was in an active traffic lane when this happened, which immediately placed me and others at risk of being rear-ended. After several seconds, and pressing the start button, the vehicle regained power. But the odometer was indicating I was going 30+ mph when I was going less than 10 mph, so I pulled over to the side of the road. The vehicle is also was having issues with the lane keeping assistance was unavailable. This is is a new vehicle purchase directly from the dealer in August 2025, with approximately 4,500 miles at the time of the incident that occurred on, 11/18. The problem has not been reproduced by the dealership, and no diagnostic trouble codes were found. The vehicle has been at the dealer for inspection since 11/20, but I was informed that the issue would need to happen again before they could diagnose it. This type of sudden power loss while driving is a serious safety concern, especially because it occurred without warning and could happen again unpredictably. At this time, the cause it UNKNOWN, but the component or system responsible for the power loss should be inspected. The failure appears to be intermittent and without warning.

I’m filing this safety complaint in addition to a previous complaint, 11678151. which occurred on August 1, 2025. On Friday, August 22, 2025, I experienced a 2nd Traction Control alert and engine failure lights on my 2026 Sierra Denali Ultimate truck which again caused the acceleration to drastically decline while driving home from work. Thank God my kids were not in the car with me this time.  I am extremely appalled and confused as I've NEVER experienced this level of substandard operation from a new vehicle. I have informed the leadership team team at Cavender GMC West San Antonio, TX of the situation. The dealerships recommended (2) paths to exit the vehicle: GMC Customer Assistance and dealership trade-in.

Driving down interstate highway and sunroof “exploded”. Raising glass sunroof up about 2” above the body. Vehicle had 387 miles on it. This occurred at about 6:55 am and outside temperature was about 74 degrees. The rupture was loud and very startling and I exited the interstate pulling over to see what occurred. There was no damage whatsoever to any other body component and no “flying” debris was observed at anytime that could have struck the vehicle. I requested GMC dealer to look at onboard cameras and save video but they seemed dismissive. Had the interior sunroof shade not been closed I would have been showered in glass while driving.