2026 GMC SIERRA 1500 Complaints

Three times this has happened. Most recently Pulling in drive and jumps out of drive to park with a jerk and stops.

The infotainment system keeps having the sound completely shut off. The radio, GPS, blinker system sound will not work.

The contact owns a 2026 GMC Sierra 1500. The contact stated that while slowly driving up a slightly inclined drive port and making a left turn, the vehicle shut off and the parking brake was activated or the vehicle suddenly decelerated. The contact stated that the failure had occurred on several occasions with three separate identical vehicles, including the loaner vehicle provided by the dealer. During the failure, the messages "Press Start" and "Service Transmission" were displayed. The vehicle was taken to the local dealer who was unable to determine the cause of the failure. The manufacturer was notified of the failure. The failure mileage was 29.

The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the transmission independently shifted to park or neutral. The contact stated that the failure had occurred while driving at slow speeds. The contact stated that during one failure, the brakes independently activated, and the vehicle shut off. The contact stated that while attempting to restart the vehicle, the vehicle started. The contact stated that the failure was persistent. The dealer was made aware of the failure by phone. The vehicle was taken to the dealer; however, the diagnostic result was not provided. The failure mileage was approximately 500.

XXX Pulling into Mason Park - Truck Shot down while driving. Went into Park (immediate stop) 2 of my Kids were in the truck at the time. Restarted truck and loud Noises. Immediately backed into parking space shut down and towed. Sent to dealership XXX Called spoke co/ Mark. [XXX] had tech. look at truck. expressed My concerns and Should Never occurred @ 6788 miles. Expressed Something Needs done. Recommend contact GMc. - Call GMC, Crated a Case #XXX. Engine replaced after 2 months. No one checked the transmission or had explained why it went into park while in operation.Refused to look at any other concerns. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Took ownership of this vehicle on XXX. 6.2 motor build date XXX at Tonawanda plant. Currently have 10,600 miles on vehicle. First and second oil changes at GMC facility T&T Coast Buick, GMC located in [XXX] First at 4,441 miles, oil part number 19420077. Second oil change at 8,379 miles, oil part number 19420077 This oil part number is for 5W-30. ACDelco bulk engine oil (Dexos1 Gen2 Full Synthetic 5W-30). The correct oil was not used. From what I have read this is a GM "oil trap" so if there is a problem with the motor GM can deny warranty coverage because the wrong oil was used. I have not adressed this with the dealership yet. If there is a 6.2 motor problem with my vehicle in the future am I going to be denied coverage? I am worried. I also have the extended warranty. Thank you. [XXX] [XXX] [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

We were told when we purchased our 2026 GMC Sierra 1500 that all the engine problems have been remedied. Purchased our new truck January 3, 2026 put 2001 miles on the truck went on June 29. The engine suddenly just stopped while driving on the highway. We were able to pull over unable to ever get it to start forced to have it towed to a nearby GMC dealer where it has been ever since were told it had to have a complete new engine put in we have corresponded with General motors on three different occasions we still sit with no offer as we did apply for a lemon law buyback but General Motors continues to sell these vehicles which is very deceptive and misleading as this situation was not remedied in any 25 or 26 models.

While driving through city traffic at approximately 35 mph the truck engine made a quick loud noise and then immediately shutoff. The power steering went out and then I was unable to pull off the road completely as the engine would not start back up. This truck is a 2026 with 9,000 miles, 6.2L motor. After being towed to a GM Service facility it was determined that the motor had blown up on the truck. A vehicle shutting off while driving down the road is an extreme safety concern in my opinion.

This truck has the GM L87 6.2L engine that is currently on recall for 2021- 2024 model years, but recently the NHTSA is looking into post engine replacement failures and 2025-26 model year issues. My engine at 7,000 miles failed for rod bearings. Same issues reported years ago and 100k engines ago. GM has not fixed the problem, its still happening.

The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving approximately 60 MPH, the transmission unexpectedly downshifted and the vehicle decelerated to 10 MPH. No warning light was illuminated. The contact pulled over to the shoulder of the road, and the vehicle was towed to a local dealer. The vehicle remained with the dealer for additional diagnostic tests and unknown recurring failure codes. In addition, the contact stated that the failure worsened and occurred while his wife, sister-in-law, niece, and child were present inside the vehicle. The vehicle was not repaired. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 7,500.