general problems of the 2025 GMC Sierra 1500

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.

I am writing to express my extreme disappointment and serious concern regarding a critical safety failure I experienced with my 2025 GMC Sierra 1500 denali unlimited (VIN: [xxx] ), which I purchased brand new in April 2025 from cavender GMC, san antonio, TX. On Friday, [xxx], with fewer than 9,000 miles on the vehicle, I was driving on the highway at about 65 mph, with my minor son in the vehicle when the dash suddenly displayed a traction control (trc) fault message, followed immediately by "acceleration is limited. " the truck experienced a severe and unexpected power loss, severely restricting my ability to accelerate or maintain safe highway speeds. I was forced to pull off the road abruptly to avoid a potentially dangerous situation. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The drivers side grab handle (a pillar trim piece) is cracked through completely at upper bolt mount location, causing the grab handle to be weakened and unable to safely support while using and could pull away from vehicle while in use potentially causing the driver to fall and become injured. I replaced the original with a genuine oem replacement from the dealership and it cracked in the exact same place. I posted an inquiry to a facebook group of fellow GMC owners and there were numerous reports of this having to them and having the dealership replace under warranty, only to have the issue occur again. This structural failure seems to happen with or without use of the grab bar.

Tailgate switch tailgate opened on its own with trailer attached while driving damaging the top of my tailgate. No notification inside cab. No console / fob / tailgate buttons were pushed. Discovered tailgate was down after I arrived home and had done a wide u-turn in my back yard. So far dealership has done very little diagnostic wise. Two trips to dealership so far with little to no results. Now I’m scared to use my trailer or utilize the bed of the truck to haul anything due to tailgate might open on its own at 75 mph on a major interstate/ 2 lane road hurting or killing the people in the vehicles behind me. Totally unacceptable from GMC / dealer for a 70k truck.

2025 GMC Sierra 1500 shifted from park to drive uncommanded, accelerated uphill, and crashed while idling, keyfob outside of vehicle, March 2025. Esis couldn't replicate and falsely claimed I didn't put it in drive, despite photos and no one inside.

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.