2025 GMC Sierra 1500

First occurrence was 02/27/2026 - onstar detecated a critical issue, the check esc, check tsc words came on in the center dash, then the orange lights came on and my truck went into limp mode at a stop light. I had to limp mode a mile to the nearest dealer. Where nothing was repaired just reset. Second occurrence - exhaust flap valve failed creating chirping noise resulting in a muffler replacement on 04/28/2026 - picked the vehicle up on 04/30/2026 Third occurrence - 05/01/2026 came out after a wedding to start my truck which it immediately repeated the first occurrence, check esc, check tsc with the orange lights and chugging. recorded on camera now the trucks been at the dealership awaiting updates.

The contact owns a 2025 GMC 1500 equipped with Bridgestone Tires, Tire Line: Dueler, Tire Size: 275/60/R20. While washing the vehicle, the contact became aware that the sidewalls on all four tires were cracked. The tires were the original equipment. The dealer was contacted and made aware of the issue; however, the contact was informed that the tires were not under warranty. The tires were not replaced. The manufacturer was not informed of the failure. The approximate failure mileage was 12,000. The VIN was not available.

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.

I am reporting a serious safety issue involving unintended acceleration in my vehicle. The vehicle accelerates unexpectedly without driver input (specifically without pressing the “resume” function), requiring immediate braking to regain control. This issue has occurred numerous times over the past 4–5 months. Incidents have primarily happened at low speeds (approximately 20–25 mph or less), including while making turns, exiting parking lots, and once in our yard, where the vehicle nearly struck our home. The problem has occurred both when adaptive cruise control was active and when it was turned off. In the most recent incident, adaptive cruise control was off, and the vehicle suddenly accelerated while traveling in about 20–25 mph on the main street. The driver had to apply the brakes forcefully to avoid a collision with the vehicle in front. There have been no warning lights, alerts, or messages prior to these events. During at least one incident, a “braking required” message appeared only after the unintended acceleration had already begun. The vehicle has been taken to a GMC dealership multiple times, but the issue has not been duplicated by them. The dealer suggested the possibility of accidental activation of the “resume” button; however, this did not occur. The vehicle is currently at the dealership (since April 6) and is available for inspection. This defect presents a significant safety hazard to the occupants of the vehicle and to others on the road.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the engine made abnormal knocking sounds. No warning light was illuminated. The vehicle was taken to the dealer, who discovered metal shavings inside the engine oil and determined that the crankshaft bearings had failed. The contact was informed that the engine needed to be replaced. The vehicle was not yet repaired and remained with the dealer. The manufacturer was made aware of the failure. The failure mileage was 26,634.

I stopped at a stoplight and my truck shut off, the doors unlocked and then immediately restarted and then came up with a bunch of errors telling me that my brake system failed and to get the traction control serviced. I then had no power braking. This is the second time my truck has shut off at a light and restarted, but I don’t lose my brakes the first time.

I was traveling on the I70 West around the 210 mile marker. I was in the passing lane at high speed when the vehicle without warning switched itself off. The dash showed the “press start” warning, but the vehicle would not restart. I was fortunate that I was around 1/2 a mile from a rest stop area. I was able to glide the vehicle into the rest area. As I slowed close to a stop the vehicle suddenly stopped and applied the park brake. I am a very experienced driver, if my wife was driving, the vehicle shutting down completely in the fast lane could have been catastrophic. The road was busy. The vehicle was locked up in Park and was unrecoverable. It had to be dragged sideways out of the area that it had come to a stop, and then dragged onto and off the tow truck. The following morning the dealership confirmed the engine was seized. When I purchased the vehicle, the dealership confirmed that the historic failures on the L87 6.2L V8 engine were resolved. Clearly not the case.