2025 GMC SIERRA 2500

SERVICE BRAKES, HYDRAULIC

The contact owns a 2025 GMC Sierra 2500. The contact stated that while depressing the brake pedal to come to a complete stop, the brakes made a loud whistling and squealing sound. There were no warning lights illuminated. The vehicle was taken to the dealer, Bellamy Strickland Chevrolet GMC (145 Industrial Blvd, McDonough, GA 30253); who was unable to determine the cause of the failure. The dealer informed the contact that it was a known issue with no fix for the failure. The vehicle was not repaired. The vehicle was taken to a second dealer, who was also unable to diagnose the vehicle. The manufacturer was not informed of the failure. The mileage was approximately 5,000.

STEERING

While towing a less than 2000 lb trailer I had total loss of power steering when speeds dropped below about 5 mph. I got off interstate and was turning right at the end of exit ramp and I could barely turn the vehicle. At the next stop sign it did the same thing. I stopped turned off the vehicle and restarted it and it continued this for the next few miles. Then just as suddenly as it started it stopped doing this and worked fine the rest of my trip.

SERVICE BRAKES

We noticed that the brakes were really soft. We literally had to push on the brakes with excessive force. We took it to Lynch - West Bend, WI for a service call and was told that nothing was wrong with it. After leaving the dealership we did our own research (the hubby is a certified master technician himself). Come to find out through GM, contacts through TBM brakes and Duramax Forum.com "brake pedal effort" we found the issue and a solution and we fixed it ourselves. This truck is brand spanking new and the dealership threw their hands in the air with a safety issue and let us drive out of the parking lot. Imagine driving away after being told no issue to end up in an accident due to failed brakes. Who's to blame for that? Certainly not the customer. It was only when the new car sales manager took the truck for a drive, he agreed that there was a problem. - too late we took it home and fixed it ourselves. This problem needs to be looked into seeing its a known issue!

SUSPENSION

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.

STEERING

The contact owns a 2025 GMC Sierra 2500. The contact stated that while driving at an undisclosed speed, after driving over a small pothole on the road, the alignment was dramatically altered, causing the vehicle to slightly veer out of the intended lane even though the steering wheel was centered. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The contact stated that he previously owned another vehicle of the same year, make, and model that had experienced the same failure and a case was filed with the manufacturer for the vehicle, resulting in a buyback. The failure mileage was 2,000.

STEERING

Experienced loss of power steering, loss of brakes

SERVICE BRAKES

Experienced loss of power steering, loss of brakes

POWER TRAIN

Transmission fluid overheating, which is a known issue in other GM models with 6.6L diesel with 12 speed allison transmission. Confirmed by warning message received on dashboard and transmission fluid temperature gauge. This occurred within 3 weeks of purchase. Dealer confirmed “Valve” needs to be replaced. Part is on back order with no arrival eta. Service advisor indicates the truck is not safe to drive and remains in the service department.

UNKNOWN OR OTHER

The truck is not even 2 weeks old and driving down the road at less than 50mph the sunroof exploded. Nothing fell on the sunroof and no other vehicles were near the truck at the time the sunroof busted.

VEHICLE SPEED CONTROL

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.