When going up my 5% grade driveway the truck has slammed into “park” while moving two times. The car turns off as it slams into park and a “ service transmission” warning is on the dash. It leaves small skid marks from doing this while moving. It has 1790 miles on it. Dealer has had it a week and says they cannot duplicate the issue. Google search seems to indicate many trucks have had the same issues going up an incline.

I bought the truck with 2 miles , shut off on me within 1,300 miles wouldn’t turn on , supposedly it was a bad fuse that was burned out , Second time it shut off on me again , all my sensors were going off and on and truck wouldn’t turn back on , they told me they couldn’t figure out the problem evaczue they had disconnected the battery and it erased all the codes 3rd time , they changed my oil and they forgot to torque the screw back correctly and all the oil spilled and cost my engine to lock up and mess up , they replaced the motor with a new one 4th time , supposedly it needs a replacement for a catalytic converter which is being replaced now as we speak or sometime this week

I bought my 2026 GMC in April. Several times the audio doesn't work work. When this happens audio related safety technology is affected too including turn signal sounds and back camera audio also. A person walking behind the truck can be seen on the screen but no warning beeps are heard. When backing up the warning for getting too close to an object also doesn't work. I called the dealer in early May and was told that this was a known issue and that it needed a software update. took the truck to the dealer on May 8th and the software update was performed. When the update had been completed when I started the truck after the update there was no audio. I told the service advisor it was currently happening and she took it back to the technician. They disconnected the battery cables to reset the system and told me to do that in the future until the issue is resolved. I opened Case #100978480 with GM on June 1st because I wanted to be sure that GM was also informed of the issue. I was hoping they would be proactive and report back to me what they were doing to resolve this issue. Instead I was told that I need to call the dealer and the dealer would call GM because an update might be available but dealers wouldn't be informed and wouldn't check unless I called.

My motor has a catastrophic failure. Started sputtering and Squealing.

2026 GMC Sierra 1500 AT4X with 3898 miles. Driving 71mph on state highway on flat grade road. Lost power and vehicle shut down after pulling off the road. No previous lights or warning signs prior to power loss. Vehicle would not start afterwards. OnStar Diagnostics sent ECM Engine and Transmission System code P0016. Had vehicle towed 100miles to GM dealership. Upon inspection of vehicle, the Service Department contacted me the following day and said the the vehicle needed an entire engine replacement according to GM cooperate. I asked if it had anything to do with the 6.2L V8 L87 engine problems from previous recall years of 2021-2024. Service tech stated yes it was more than likely the same issue. Very unhappy with my new GM vehicle purchase. Will have to have a full engine replacement BEFORE my first oil change!