2025 GMC Sierra 2500 Problems

My 2025 Sierra 2500HD repeatedly displays “Trailer Brakes Disabled—Service Required” with a lithium- and solar-equipped trailer. The truck passes the EL-52641 simulator, but the failure occurs intermittently while towing and resets after Park or reconnecting the trailer. This closely matches the higher-trailer-battery-voltage/backfeed condition described in N232414840. Please open a TAC case and determine whether my 2025 has the revised Trailer Brake Power Module or whether GM engineering authorizes module replacement.

Normal driving 40mph brake failure and power steering loss. Towed vehicle to dealership

Normal driving 40mph brake failure and power steering loss. Towed vehicle to dealership

Power steering pump failed when decelerating after 9500 miles. When power steering pump fails, power assisted braking also fails. Upon deceleration, I could not turn the steering wheel at all or stop the vehicle without extreme pressure on the brake pedal. I narrowly avoided impact with a concrete barricade at the entrance to a parking lot. GM issued a technical bulletin (DCS7112) on January 16, 2025 identifying the problem and failure and directing dealerships to replace the pump on inventory vehicles. No mention was made to repair or notify owners of the potential problem.

Component / System Failure The exhaust system, specifically the exhaust manifolds and previously the EGR system components, appear to have failed or malfunctioned, allowing exhaust gases to enter the passenger cabin. The dealer initially replaced the EGR cooler diverter on December 23, 2025. However, the condition persisted. On February 3, 2026, cracked exhaust manifolds were identified by the dealership, and a major front-end teardown was advised to complete the repair. The vehicle is currently available for inspection upon request. ⸻ How Safety Was Put at Risk The malfunction allowed exhaust gases, including carbon monoxide, to enter the passenger cabin during vehicle operation. Carbon monoxide readings inside the cabin reached up to 50 parts per million (ppm) while driving. Carbon monoxide is a toxic gas that can cause: •Headaches •Dizziness •Impaired concentration •Nausea •Vision disturbances Because carbon monoxide is odorless and colorless, this presents a significant safety risk, particularly at highway speeds where driver alertness is critical. The exposure occurred while operating the vehicle in normal driving conditions. This created a potential risk of driver impairment and increased risk of collision. ⸻ Has the Problem Been Reproduced or Confirmed? Yes. The vehicle was presented to the dealership three times for the same exhaust intrusion concern: •December 16, 2025 •December 29, 2025 •February 3, 2026 During the February 3 visit, the dealership confirmed cracked exhaust manifolds requiring major disassembly for repair. The carbon monoxide readings were observed during vehicle operation. The exhaust odor and intrusion symptoms were consistently present following the first attempted repair. ⸻ Has the Vehicle Been Inspected by Manufacturer or Others? The vehicle has been inspected by the authorized dealership on multiple occasions. Two manufacturer customer care cases were opened.

Burning an unusual amount of oil. Have seen several instances of blue smoke in the exhaust. Have had to add over a quart of oil twice in less than 6500 miles.

The transfer case leaked out all the fluid while driving over a period of time and damaged internal parts before the first oil change. This has happened 2 times now, and is currently leaking again with less than 10k miles.

transmission locked up 8 times from 1,050 miles to current 3,885 miles. It has happens each time around 40 mph. Each time it’s like hitting the brakes. The 8th time it locked really hard like slamming on the brakes. I’m worried with winter months what will happen on snow/ice covered roads. Called dealership and was told GM refuses to do anything until it completely fails. It seems they know what the problem is but refuse to fix till the truck stops moving during complete failure. No warning lamps and dealer ship says they can’t replicate it.

The contact owns a 2025 GMC Sierra 2500. The contact stated that the front driver’s side door handle failed to operate as needed, and the contact was unable to exit the vehicle through the driver’s side door. The vehicle was taken back to the dealer, and a new handle was ordered. The part was replaced under warranty. Soon after the repair, the liftgate failed to open or close as needed and became inoperable. The vehicle was taken back to the dealer for the liftgate to be serviced under warranty. The manufacturer was not notified of the failure. The vehicle remained with the dealer unrepaired. The failure mileage was approximately 300.

The accident occurred when the tailgate opened without warning or any buttons being pushed while towing a boat trailer. The tailgate become bound between the truck and trailer. The tailgate was damaged and limited my ability to turn the truck. My truck is normally parked in a garage and doesn’t sit in the weather. This truck is my 3rd vehicle so it doesn’t really get driven unless it is pulling a trailer, I tow with it all the time but very rarely use the bed or tailgate. Monday June 16 – Drove from Gallatin, Tn – Eddyville, Ky – Paducah, Ky the weather was constantly heavy rain and wind. Tuesday June 17 – Drove from Paducah, Ky to Defeated, TN more of the same bad storm. There were 3 of us and no one opened the tailgate, we hooked up to my boat and drove less than a quarter mile to the boat ramp, when we arrived, the tailgate had opened and the stairs on the boat had impacted the small part of the tailgate during a right turn. Prior to leaving the driveway and after hooking up the boat I had to back up slightly and remove pressure to remove the chock block from the boat trailer tires. (I would have noticed that the tailgate was open) this happened with no warning, put me and my passengers at risk and did over $1000 dollars in property damage. I was expecting GM to replace the parts that were faulty and the small part of the tailgate that was damaged. I returned twice to Larry Stovesand GMC and had them access the switch. They have refused to supply paperwork from those visits and have become dismissive and deceptive. The contact there is Craig Morgan [email protected]

Had a minor wreck was to be two weeks to then it had to have a new frame they said it coun't be repair if a minor wreck can do this much damage there is a problem with subpar frames that any sudden stops or turns

The passenger side rear wheel went into a pothole while making a right turn on a city street. This resulted in the right rear leaf spring breaking at the forward mounting point. This caused thr rear axle to swivel impacting the rear of the wheel well. The ESC malfunction indicator and impact sensor malfunction llights illuminated appropriately 2-3 miles later after I was in a highway. This is a significant safety concern as I was at an increased speed in heavy traffic by the time the lights illuminated. This not only puts the vehicle occupants at risk, this is potentially a significant risk to other motorist. There were no noticeable indications of damage besides pulling until I was at appropriately 55mph on the highway. The vehicle is currently at a dealership for repair.

Reverse lamps are not bright. Camera does not brighten area either. Very unsafe to reverse in the dark. Have to touch the brake pedal to be able to see while backing. Also have tried the LEDs in the mirrors while backing- although the LEDs are bright- lights to see while backing are insufficient on the stop lamps.

The contact owns a 2025 GMC Sierra 2500. The contact researched online and became aware that there was a recent recall under NHTSA Campaign Number: 25V815000 (Equipment) for the Owner's Manual. The contact stated that the vehicle was sold without the Owner's Manual. The contact stated that the manufacturer was called and was advised that the recall was only related to the 2026 Chevrolet Silverado models and the vehicle was not the same year, make or model. The contact was attempting to retain a physical copy of the Owner’s Manual and thought that it was a safety issue since there was a safety recall. The contact had not experienced a failure.

See attached document for complaint.

The contact owns a 2025 GMC Sierra 2500. The contact stated that while driving at an undisclosed speed, the vehicle failed to accelerate as intended while depressing the accelerator pedal. The check engine warning light was illuminated. In addition, the contact stated that the RPM was fluctuating while driving. The vehicle was towed to a local dealer however, the vehicle was not diagnosed or repaired due to the warranty. The manufacturer was made aware of the failure. The failure mileage was approximately 600.

Component / System Failure The exhaust system, specifically the exhaust manifolds and previously the EGR system components, appear to have failed or malfunctioned, allowing exhaust gases to enter the passenger cabin. The dealer initially replaced the EGR cooler diverter on December 23, 2025. However, the condition persisted. On February 3, 2026, cracked exhaust manifolds were identified by the dealership, and a major front-end teardown was advised to complete the repair. The vehicle is currently available for inspection upon request. ⸻ How Safety Was Put at Risk The malfunction allowed exhaust gases, including carbon monoxide, to enter the passenger cabin during vehicle operation. Carbon monoxide readings inside the cabin reached up to 50 parts per million (ppm) while driving. Carbon monoxide is a toxic gas that can cause: •Headaches •Dizziness •Impaired concentration •Nausea •Vision disturbances Because carbon monoxide is odorless and colorless, this presents a significant safety risk, particularly at highway speeds where driver alertness is critical. The exposure occurred while operating the vehicle in normal driving conditions. This created a potential risk of driver impairment and increased risk of collision. ⸻ Has the Problem Been Reproduced or Confirmed? Yes. The vehicle was presented to the dealership three times for the same exhaust intrusion concern: •December 16, 2025 •December 29, 2025 •February 3, 2026 During the February 3 visit, the dealership confirmed cracked exhaust manifolds requiring major disassembly for repair. The carbon monoxide readings were observed during vehicle operation. The exhaust odor and intrusion symptoms were consistently present following the first attempted repair. ⸻ Has the Vehicle Been Inspected by Manufacturer or Others? The vehicle has been inspected by the authorized dealership on multiple occasions. Two manufacturer customer care cases were opened.