2026 GMC Sierra 1500: check engine light

Filed Oct 23, 2026 · Electrical, Engine · NE

Three different times now (most recent: 10/22/2026), I have had my truck completely shut off when coming to a stop on the highway/interstate. I always have auto start/stop disabled when I drive. When it happens, a message shows on the dash that says press start button. No other codes or check engine light. Thankfully it has started every time, but this is obviously a serious safety concern. After the second time it happened, I had the dealer (Woodhouse Buick GMC Omaha) look at it on 9/14/2026, but they couldn't find anything since there were no codes. I'm not sure if it is an electrical issue or this is related but my audio will stop working at times as well. Nothing from the radio or any blinker sounds. Sometimes it's static with a high pitch noise. 2026 GMC Sierra Elevation 5.3 EcoTec3 v8 10 speed

Filed Oct 21, 2026 · Engine · NE

I had driven about 30 minutes on the Interstate at highway speeds and had just exited the Interstate and the truck made a horrible noise, shut off, and the transmission threw itself into park at about 10 mph. At this time, the engine did not want to restart, but did eventually and I had a check engine light on, but I was able to move the truck out of the intersection so that I could be towed to the dealership. Prior to the incident, there were no check engine lights and the vehicle had only been serviced at a GMC dealership. I was very uncomfortable with the way the truck stopped and slammed into park. I am happy that no one was behind me, but it could have been bad. The vehicle has not been inspected yet to my knowledge.

Filed Oct 21, 2026 · Electrical, Engine · IL

While driving the truck it randomly shuts down, message on dash says shift to park to restart. No check engine light comes on or any other message. When it does this, the truck goes into park. It has been to the dealership 3 times and has not been fixed!

Filed Sep 27, 2026 · Engine · MI

I purchased this vehicle on May 28th 2026. At that time I was told there were no problems with the 6.2L engine. The problems they have had didn't affect the 2026 Denali 1500 6.2L's. After hearing about numerous 25's and 26's engine failures I decided to have my first oil change at 1540 miles. I asked the dealership to give me the oil filter so I could open it and examine it. I found excessive metal in the filter, indicating to me that the engine is failing. I contacted the dealer, they told me to go to GM Customer service. They told me there is nothing they can do unless the check engine light comes on or there is noise in the engine or it blows up. In which case people have reported traffic hazards getting to the side of the road without power or even the rear wheels locking up. One incident shows the vehicle had a fire and completely burned up. I made a vacation trip without incident and put another 825 miles on the truck, at which time I swapped out the oil filter and opened it up and found more metal particles. Common sense tells me that the engine is self destructing and will at some point fail. The manner in which that happens is the safety issue. I have reported this issue to the dealer and GM and they say just keep driving it. Putting myself and my family at risk. I know I am not the first one to have a bad engine in my new GMC Denali. There are just way too many defective engines in these vehicles to feel safe after buying such and expensive vehicle. Don't get me wrong, I love the truck!! I just would like to know it has a dependable engine to keep me safe while driving it!!

Filed Sep 23, 2026 · Fuel system · VA

Fuel Filter and High pressure Rail System The truck started shuddering and began to go into limp mode also shifted into neutral byitself No It was inspected by the dealership shop and now insurance Check engine light came on and code P1089

Filed Aug 25, 2026 · Engine, Fuel system · ID

Bought the vehicle brand new at the end of april. 2 weeks later and at 557 miles, the engine had a lifter failure and needed to be replaced. One day after picking it up after the engine replacement, a fuel injector went bad and needed to be replaced. About 2 days ago, the check engine light lit up, and the GMC app said it was a code for the transmission system (popped on after attempting to remote start the vehicle, although the light did shut off on its own the next day after a software update on the vehicle)

Filed Aug 25, 2026 · Engine, Fuel system · ID

I bought the vehicle brand new in april 2026. On May 3rd, approximately 2 weeks after I bought it, I experienced a lifter failure that caused metal to get into the oil pan/engine and the engine needed to be replaced. About a month later after repairs were complete, I picked up my vehicle on a Friday night, and the very next morning, had issues again. Took it back to the dealer and a fuel injector went bad and needed to be replaced. I recently attempted to use the remote start feature and as soon as it fired up, the engine cut out. I went to start it again and the check engine light came on. My GMC app said the code was transmission related, although it cleared on its on the next morning after a software update.

Filed Aug 21, 2026 · Engine, Fuel system · CT

I bought a new GMC Sierra 1500 Denali with the 6.2L V8 engine in December of 2025. 7 months later, I was driving home from work. When the car started, it sounded a little louder, but not out of the ordinary. I started driving and got a strange rattle when I was getting on the highway at around 65MPH. I pulled off at the next exit and checked my fluids, checked under the car to see if anything was caught that was causing the rattle. All pressures and fluids were normal. I had Onstar run a system diagnostic. The diagnostic read normal. I got back on the highway and drove about 20 miles at 75mph. The rattling continued. 20 miles later, the check engine light came on. I had onstar run a diagnostic and came back stating “engine and transmission system problem” with two error codes. One code said “An issue has been detected in the Variable Valve Timing System adjust the timing of fuel delivery for more efficient engine operation”. The other code said “An issue has been detected in the Ignition System which oversees the timing and spark necessary to ignite fuel in your engine” Both error codes said to fix within one day. The GMC dealership was on the way home so I was going to stop there and see what they could do. I never made it to the dealer. About 2 minutes after the diagnostic, while doing 75mph on the highway, I hit the accelerator and the car did not speed up. The engine then shut off while I was in the left lane doing 75 mph. The electronics stayed on and the dash stated “press start to start engine.” I pulled over to the side of the highway and put the car in park and attempted to restart the engine. The engine never turned over again. I could not get the engine to start. I could not shift the car to neutral to have it rolled up on to the tow truck. My truck was towed to the GMC dealership and they are now replacing the engine under warranty. Will upload any maintenance paperwork once engine is replaced.

Filed Aug 20, 2026 · Acceleration, Engine · AR

Vehicle: 2026 GMC Sierra 1500 AT4 (3.0L LZ0 Duramax Diesel) Current Mileage: ~16,500 miles Check Engine Light Status: NO Check Engine Light active Description of Incident & Symptoms: •Interstate Incident: While driving at highway speeds, a severe drivetrain vibration occurred (felt like a rear wheel weight flew off). •Dashboard Warnings: Within 5 minutes, intermittent "Traction Control" and "Forward Collision Warning" alerts appeared on the dash, accompanied by a sudden drop in engine power. •Engine Noise & Idle: Once safely pulled over, the engine exhibited a loud mechanical knock and a very rough, unstable idle. •Extended Crank: After shutting the engine off and waiting a few minutes, restarting the truck took roughly twice as long as normal (long crank/delayed start)

Filed Aug 9, 2026 · Engine · WA

Driving on the highway near Rockport, WA, when vehicle suddenly loss propulsion, engine light appeared, and vehicle went into transport mode enabled. Without causing an accident, I was able to pull to the side of the road. Once I put vehicle in park, it shut off and displayed, “Tranport Mode On. Vehicle would not start and was towed home. My son-in-law was able to disable transport mode, but vehicle still will not start. Will notify dealership on Monday.

Filed Aug 9, 2026 · Engine · WA

Driving on the highway near Rockport, WA, when vehicle suddenly loss propulsion, engine light appeared, and vehicle went into transport mode enabled. Without causing an accident, I was able to pull to the side of the road. Once I put vehicle in park, it shut off and displayed, “Tranport Mode On. Vehicle would not start and was towed home. My son-in-law was able to disable transport mode, but vehicle still will not start. Will notify dealership on Monday.

Filed Apr 5, 2026 · Engine · WA

Driving approximately 30mph, the engine shut down. Vehicle shifted into neutral until stopped and shifted to park. Unable to place in neutral to pull off the road. Check engine stated transmission needed service. Dealership states seized engine. Engines are on back order. Vehicle has 2980 miles on the odometer. I'm active duty Navy and have a permanent change of station this summer and no vehicle to move in and I also haven't gotten a rental.