2025 GMC Sierra 1500 Problems

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving approximately 5 - 10 MPH, the vehicle went into LIMP Mode and failed to properly accelerate, and the transmission unexpectedly downshifted. There was an electrical malfunction, which caused the transmission to downshift. An unknown message was displayed on the instrument panel. The contact stated that the network was not operating at the correct voltage due to the wiring harness. The engine light illuminated after the failure. The vehicle was towed on two occasions to the dealer to attempt to duplicate the failure. The dealer was unable to determine how to repair the vehicle. The vehicle was driven to the dealer in LIMP Mode. The manufacturer, General Motors, was contacted by the dealer, and the contact also reported the failure to the manufacturer. A General Motors service engineer had inspected the vehicle. The failure mileage was approximately 34,637.

When updating the vehicle as prompted by the entrainment system the next day when attempting to start the vehicle it did not start. Vehicle had to be jumped then 6 warning lights came on and disappeared shortly after driving.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving approximately 5 - 10 MPH, the vehicle went into LIMP Mode and failed to properly accelerate, and the transmission unexpectedly downshifted. There was an electrical malfunction, which caused the transmission to downshift. An unknown message was displayed on the instrument panel. The contact stated that the network was not operating at the correct voltage due to the wiring harness. The engine light illuminated after the failure. The vehicle was towed on two occasions to the dealer to attempt to duplicate the failure. The dealer was unable to determine how to repair the vehicle. The vehicle was driven to the dealer in LIMP Mode. The manufacturer, General Motors, was contacted by the dealer, and the contact also reported the failure to the manufacturer. A General Motors service engineer had inspected the vehicle. The failure mileage was approximately 34,637.

When updating the vehicle as prompted by the entrainment system the next day when attempting to start the vehicle it did not start. Vehicle had to be jumped then 6 warning lights came on and disappeared shortly after driving.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving approximately 5 - 10 MPH, the vehicle went into LIMP Mode and failed to properly accelerate, and the transmission unexpectedly downshifted. There was an electrical malfunction, which caused the transmission to downshift. An unknown message was displayed on the instrument panel. The contact stated that the network was not operating at the correct voltage due to the wiring harness. The engine light illuminated after the failure. The vehicle was towed on two occasions to the dealer to attempt to duplicate the failure. The dealer was unable to determine how to repair the vehicle. The vehicle was driven to the dealer in LIMP Mode. The manufacturer, General Motors, was contacted by the dealer, and the contact also reported the failure to the manufacturer. A General Motors service engineer had inspected the vehicle. The failure mileage was approximately 34,637.

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

Super cruise was engaged on I-95 and attempted a lane change. Another vehicle was in a position along side my vehicle that would have resulted in an accident if I had not noticed it and manually grabbed the steering wheel to override the super cruise. I have an appt with the dealer next week. The vehicle is also is occasionally displaying a "service driver assistance system" message

I own a 2025 GMC Sierra 1500 Denali equipped with the 6.2L V8 L87 engine, VIN [XXX]. The vehicle had approximately 35,000 miles when the engine experienced a catastrophic engine failure. Prior to/during the failure, the vehicle experienced abnormal engine noise and a loss of power. Multiple warning/alarm lights appeared on the dashboard, including the Check Engine and Traction Control warning lights. The engine failure resulted in a loss of motive power and made the vehicle unsafe to operate. PHONE# [XXX] The sudden loss of engine power while driving created a serious safety hazard because the vehicle could no longer operate normally in traffic and could potentially cause a crash. I am requesting that NHTSA document and investigate this engine failure as a potential safety defect involving the GM 6.2L L87 engine. I am also requesting that NHTSA determine whether 2025 GMC Sierra 1500 vehicles equipped with this engine should be included in an appropriate safety recall or other corrective action. The vehicle is a 2025 GMC Sierra 1500 Denali with approximately 35,000 miles. The engine failure and warning lights occurred during normal vehicle operation. The vehicle and repair records can be made available for inspection, and I can provide dealer repair orders, diagnostic information, photographs, and other documentation concerning the failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Cruise control activates at speeds between 1-5mph, which frequently happens while turning, parking, or going through a drive-through. The cruise control activates by a toggle on the left spoke of the steering wheel, which can be easily bumped while doing low-speed maneuvers like parking. When bumping the toggle, the cruise indicator shows a set speed of 15-18 mph, and the vehicle surges forward trying to attain that speed. Since this occurs while maneuvering to park, it creates a dangerous situation if anyone is nearby and you are unable to react in time. This is an ongoing problem that can be duplicated at will. Rear backup camera very dark at night it’s unusable.

The contact owns a 2025 GMC Sierra 1500. The contact stated that while the defroster was activated to clear the windshield, the blower vents on the passenger’s side started making an abnormal hissing sound, and air produced by the blower motor decreased and was inadequate to clear the windshield. There was no warning light illuminated. The contact stated that the failure occurred while there was light snow covering the hood and on the outside vents underneath the windshield. The contact had taken the vehicle to a local dealer several times, and the dealer was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 3,000.

Turned on vehicle and an alert popped up "Brake system control module malfunction", limited speed to 43 miles per hour, no power breaks worked. I have had no issues with brake system for the first 11k miles. I contacted my local GMC dealership (Banks Chevrolette in Concord, NH) and was told that I would not be able to get an appointment until the 2nd week of November. I told them this was a break system issue covered under warranty and they told me I was welcome to DRIVE to their dealership (14 mi away on INTERSTATES and CITY STREETS) and wait to see if there was any time to plug it in, but they would not guarantee there would be time on their end. I spoke with the service manager and was told the same and that his advice was to "not drive it until November". I was able to take the truck to a shop in town 2 mi away , and they printed off the following codes: P25A U160F U1610 U2418 U2419

I was driving in town when all lights on the dash lit up, and I mean all of them. I was approaching a traffic light in low traffic in the 20-30mpg range. I went to apply the brakes and almost had none. If I was going to estimate how much braking was available, it would be in the 10% range. I drove at 20mph to the nearest dealer. They verified the issues. They reflashed the computer, drove the truck afterwards, and pumped the brakes. They told me they recommended an immediate master cylinder replacement. They had seen this twice already in the month of August. Both times prior to mine the reflash initially worked, but the problem returned within a week, and the master cylinders had to be replaced. The master cylinder replacement was a $2600 repair.

While driving at highway speed, my 2025 GMC Sierra suddenly began slowing down without warning and lost propulsion. When I pressed the accelerator, there was no acceleration response. The vehicle felt like it was braking or dragging instead of accelerating, creating a serious crash risk in traffic. A warning message appeared instructing me to “Put in neutral and restart truck.” I followed the instruction, but the vehicle would not restart. It sounded like it was attempting to start, but it would not start normally. A “Service ESC” warning also appeared. The vehicle was towed by AAA to a GMC dealership and remains available for inspection. The dealership provided a diagnostic trouble code report showing active codes: C2A07 Engine Control Module Indicated Torque Signal Malfunction; U0101 Lost Communication with Transmission Control Module; U0131 Lost Communication with Power Steering Control Module; U0140 Lost Communication with Body Control Module; U0146 Lost Communication with Central Gateway Module; U160F Lost Communication with Brake System Control Module 1 on CAN Bus 1; U1611 Lost Communication with Engine Control Module on CAN Bus 2; and U3003 Battery Voltage Circuit Voltage Below Threshold. The vehicle had approximately 22,000 miles at the time of the incident. The failure has not been repaired at the time of this complaint. The concern appears to involve a safety-related electrical, propulsion, powertrain, ESC/brake, and module communication failure that caused sudden loss of propulsion, no acceleration response, warning messages, and a no-start condition.

While in the parking lot of a local grocery store, I shifted the vehicle into reverse, at which point all dashboard warning lights immediately illuminated and the braking response became significantly weakened and nearly unresponsive. I placed the vehicle back into park, paused, and then attempted to shift into reverse again, but the dashboard alerts and brake issue persisted. This created a very unsafe driving situation because the brake system was very unresponsive. Despite the unsafe condition, I cautiously drove to my home 2miles away at a speed of under 20 MPH, requiring excessive brake pressure to bring the vehicle to a stop. I parked the vehicle in my driveway and left it there overnight. The next morning, I tested the brakes, and they seemed to return to normal so I drove 5 miles to my local GMC service center. Service Tech confirmed Check Engine Light On and reported code P0700 and P00FF in the report.

The truck when put in parking it still roll forward a little bit. Back up camera can’t not see during night time. Dealership stated they will not solve that problem and tell us to do manually by turn around look back. The suspension really bouncy but the tech stated that is normal. Spoke to other 3rd party tech they said that not normal at all.

Backup camera is not usable at night, you cannot see anything on the camera unless it is a brightly it area. This causes safety concern for people and property. Dealer confirmed no issues with the camera and that is how it is. Had to add external light to ensure I could see at night.

--Radio power button inoperative --Radio channel change buttons, to left of steering wheel inoperative (everyday) --Radio volume inoperative -just stops working (sometimes) --Radio “HOME” button, left of radio power button inoperative --Driver door mirror wobbles when above 50 MPH (very distracting when driving) --Driver door hard to close and out of alignment --Dealership is selling the vehicles KNOWING some of the issues are present, but not advising the buyer. My safety is/was at risk due to having to move my hands off the steering wheel to touch the radio display to make any changes while driving. A certified GM service dept confirmed all my issues and could not repair. They quoted a PIT 6408. However, this particular PIT does not address my issues/concerns.

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.

Heated steering wheel reaches temps of 137 - 143 degrees. Should have the ability for the owner to select a lower temperature setting the same as the heated seats.

Heated steering wheel gets so hot it almost burns to touch it. IR Thermometer readings at the 10 and 2 o'clock positions read between 119 and 125 degrees Fahrenheit. Bottom of the steering wheel is 127-130 degrees. Have made an appointment to have the dealer check for issues.

2025 GMC Sierra, purchased new, is showing signs of severe dry rot on 3 of the 4 original tires. The vehicle has less than 8000 miles currently. This level of Dryrot poses a safety hazard for a vehicle that is less than 1 year old.

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.

The truck when put in parking it still roll forward a little bit. Back up camera can’t not see during night time. Dealership stated they will not solve that problem and tell us to do manually by turn around look back. The suspension really bouncy but the tech stated that is normal. Spoke to other 3rd party tech they said that not normal at all.

I purchased a 2025 GMC Siera Denali Ultimate in December 2024. Approximately 2 weeks after purchasing the vehicle, I was driving down the road I received a message that said, "Service Suspension". I was able to call OnStar for diagnostic and the truck was throwing code C2A0A. I took the truck into the dealership to see what the issue was. The dealership said that I apparently ran something over and it must have flown up and broke a plastic sensor cover on the lower rear left shock. I never hit anything but have no way to prove. So, I had to pay $526 for a new shock. Even if I did run over something if that area of the shock is that sensitive it should be better protected especially if it's not covered under warranty.