2025 GMC SIERRA 1500 Unknown Or Other Problems

Onstar telecommunications module failed within 5 months of ownership. GPS and in car navigation goes crazy showing incorrect position which is distracting on the infotainmet screen. Been almost 4 weeks with no estimate of part availability from GM.

Onstar telecommunications module failed within 5 months of ownership. GPS and in car navigation goes crazy showing incorrect position which is distracting on the infotainmet screen. Been almost 4 weeks with no estimate of part availability from GM.

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.

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.

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.

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.

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.

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.

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)

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)

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.

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.

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.