2021 GMC Sierra 1500 problems

“The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 45 MPH, there was an abnormal knocking sound coming from the vehicle. The vehicle started hesitating, and there was a loss of power that became worse over time. Additionally, the “Service Engine” and “Power Train” warning lights were illuminated. The messages “Loss of Steering Assist - Be Alert” and “Service Parking Brake” were displayed. The following day, the vehicle was driven in LIMP Mode to the dealer and was diagnosed with engine failure. The contact stated that there was an ongoing NHTSA investigation associated with the 6.2L engines. The failure mileage was approximately 34,000.”

“GM has a known issue with coolant control valves that can cause vehicles to go into reduced power mode creating drive-ability and safety concerns in busy traffic situations. They have issued a TSB (N252508341) for certain VIN numbers but have ignored similar issues in other VINs.”

“The infotainment system inadvertently shuts down and restarts which creates a unsafe situations while using the navigation system, backing up using the backup camera and while trailering. In a 30 mile drive it might do it 10 times and it might do it 30 times and eventually it doesnt restart until the vehicle is shut off. Each time it does it, it starts with the screen locking up which has resulted in me backing into my boat trailer 3 times while backing up to put the trailer on the hitch and numerous near misses with pedestrians and other vehicles in parking lots. Research on the internet indicates it is a known issue across several GMC platforms and has been since 2016. I took my truck to the dealer, they did a software update which was unsuccessful, then they did a global reset, charged me $240.00 and told me it was fixed. It shutdown 2 times before I got out of their parking lot.”

“The contact owns a 2021 GMC Sierra 1500. The contact stated that while attempting to start the vehicle, the engine failed to turnover. The vehicle was towed to the residence. The contact stated that the vehicle was inspected and it was determined that the engine had seized. The engine was rebuilt and the vehicle was repaired. The manufacturer was notified of the failure. The contact associated the failure with NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The failure mileage was 142,767.”

“My 2021 GMC 1500 Sierra has the 6.2L motor that has significant known issues with catastrophic engine failure involving the camshaft and lifters. The engine in my truck has suffered the same failure but for some reason my VIN is not included in the recall of nearly 600,000 GMC trucks. I called GMC Customer Service and was told bluntly the recall was VIN specific and I would have to bear the 14,000 dollar repair. This is unacceptable since GMC is under federal investigation for knowingly and negligently manufacturing a flawed motor.”

“Vehicle Safety Hazard Summary: This complaint concerns an incomplete, non-compliant post-collision structural repair on a 2021 GMC Sierra 1500 (VIN: [XXX]). It has resulted in immediate vehicle tracking failure, dangerous steering drift, and a compromised cabin safety cage following a passenger-side side-impact collision. 1. Severe Suspension and Tracking Misalignment • Electronic Alignment Failure: The post-repair electronic wheel alignment documents a Rear Thrust Angle of 0.17°. General Motors OEM specifications require a maximum allowable thrust angle of 0.10° or less for this 4WD Crew Cab chassis. The system printed a critical warning: "One or more values are not within specification. Tire wear, handling and safety problems may result." • Physical Wheelbase Displacement: Physical cross-measurements confirm a 1.25-inch tracking variance between the rear wheel wells. This proves the solid rear axle has shifted along the leaf springs due to a sheared centering pin or a bent axle/spindle assembly. • Road Hazard Handling: The truck exhibits a severe right-hand steering drift. The driver must hold the steering wheel significantly off-center to prevent the vehicle…”