2020 GMC Sierra 2500 Problems

While driving down a highway doing between 45 and 55 mph the transmission suddenly and completely faulted causing the truck to come to a complete stop. Just enough power to get to the shoulder luckily. The transmission had basically completely blown out, fluid everywhere. The insurance company did not find any comprehensive damage. The entire transmission needs to be replaced. There were no indicators showing any problems, no alerts, no warning whatsoever. Mechanics said there was a lot of metal coming out of the transmission. The truck is currently in a mechanic shop awaiting the new transmission, so at this time it is available for inspection. The safety issue here is that it happened on a busy highway, and the vehicle was no longer drivable so it needed to be towed causing more time spent on the side of the road.

A couple times I heard loud clanking coming from rear brakes. One time in particular I was trying to stop and it felt line someone had ran into my truck but must have been the rear wheel locking up

The contact owns a 2020 GMC Sierra 2500. The contact stated that the check engine warning light was illuminated, and the message "Reduced Power" was displayed. The vehicle was taken to the dealer, where the turbo actuator and wastegate position sensor A-circuit were replaced; however, the failure persisted. The vehicle was taken back to the dealer, and the contact was advised that another diagnostic test was needed. The contact declined to pay for the diagnostic test. The vehicle was taken to a retired GM mechanic, who diagnosed the vehicle with turbo charger failure. The vehicle was not repaired due to the cost. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 100,000.

Catastrophic engine failure after taking it in for the April 2025 recall. Complete engine replacement needed

The main tailgate will not go down or function properly and it says online there is a national recall for this, but does not come up when I search my vehicle. When I turn on my left turn signal the brights flash for no reason and this is a known major issue with the vehicles as well. The trucks computer is telling me low on coolant even though it is not that has already been fixed through a 3rd pARTY WARRANTY Parking brake was stuck on when I bought the vehicle and had been for a long time you could tell and I had to pay over $1100 to fix it at GM. The Ford collision system does not work properly and the cameras will come on at certain times when they're not supposed to be and not come on when they are supposed to be

Tires locking up while driving. NOT SAFE TO DRIVE

The main tailgate will not go down or function properly and it says online there is a national recall for this, but does not come up when I search my vehicle. When I turn on my left turn signal the brights flash for no reason and this is a known major issue with the vehicles as well. The trucks computer is telling me low on coolant even though it is not that has already been fixed through a 3rd pARTY WARRANTY Parking brake was stuck on when I bought the vehicle and had been for a long time you could tell and I had to pay over $1100 to fix it at GM. The Ford collision system does not work properly and the cameras will come on at certain times when they're not supposed to be and not come on when they are supposed to be

The rear defroster massively overheated. It started heavily smoking and eventually exploded the rear windows. Only warning sign was the smoke which we noticed quickly because the windows were up. Had the windows been down we might not have noticed before a fire started. I'm taking it to a dealership now. This module also triggers on from a remote start. Extremely dangerous!!!

The main tailgate will not go down or function properly and it says online there is a national recall for this, but does not come up when I search my vehicle. When I turn on my left turn signal the brights flash for no reason and this is a known major issue with the vehicles as well. The trucks computer is telling me low on coolant even though it is not that has already been fixed through a 3rd pARTY WARRANTY Parking brake was stuck on when I bought the vehicle and had been for a long time you could tell and I had to pay over $1100 to fix it at GM. The Ford collision system does not work properly and the cameras will come on at certain times when they're not supposed to be and not come on when they are supposed to be

Vehicle was parked in a school parking lot. Rear Trailer Harness and modules in back short circuited causing an electrical fire that expanded to the driver’s taillight rear bumper, and bed of truck.

Bad vibration and bad wobble in steering wheel and front end components. This is the 3rd or 4th time my truck has been back to the dealer because of the same issue!

I have taken the vehicle to my local dealership six times. The tailgate started opening and the headlights were blinking on and off. This happened 3 months after I bought it. The dealership told me they changed the tailgate switch and they said there wasn’t anything wrong with my lights. Two weeks after the dealership said they changed the tailgate switch, the tailgate started opening and closing. The lights also stopped working driving down the road at night. This happened 3 different times at night. The tailgate opened when I was pulling a trailer and it caved in and I had to pay to have it repaired. The dealership said it wasn’t their problem. During this time the power steering fluid was leaking under my steering wheel and ruined my carpet. The dealership has yet to acknowledge that problem. I still have to put power steering fluid in the truck every week and my interior is ruined. The tailgate is still opening on its own. I had to start charging my batteries up every morning because they were dead. I got up one morning and the batteries were dead and the truck wouldn’t start. I had to buy a new $300 key. Took it back to the dealership for an appointment. The truck sat there for a week and I called for an update and they didn’t even remember the truck was there. It still sat there 4 days after that. They told me the truck needs new batteries and it wasn’t under warranty. I spent $1000 on 2 batteries. Tailgate is still going down. The lights are still going on and off. And then the lights and the locks will go on and off while the truck is parked and turned off. And now the new batteries are becoming weak and I am having to get the truck jumped off several times. I have had the truck at the dealership 6 times and they still haven’t fixed anything. When they have my truck I am losing money because I am a business owner and I use my truck for work. I lost all of my tools. I have lost time and money because the dealer has yet to help and do their job. I need help GM

The rear defroster massively overheated. It started heavily smoking and eventually exploded the rear windows. Only warning sign was the smoke which we noticed quickly because the windows were up. Had the windows been down we might not have noticed before a fire started. I'm taking it to a dealership now. This module also triggers on from a remote start. Extremely dangerous!!!

Vehicle was parked in a school parking lot. Rear Trailer Harness and modules in back short circuited causing an electrical fire that expanded to the driver’s taillight rear bumper, and bed of truck.

Tires locking up while driving. NOT SAFE TO DRIVE

THE VEHICLE PULLS TO THE RIGHT OR LEFT INTO ONCOMING TRAFFIC WITHIN 800 FEET OR SOONER DEPENDING ON SPEED. THIS OCCURS ON CITY STREETS OR INTERSTATE. GM AND GM APPROVED DEALERSHIPS SAY THIS IS DONE TO GM SPECIFICATIONS. THE FIRST 7000 MILES, IT DIDN'T PULL. AFTER GM SHOP ALIGNED, AND 3 MONTHS LATER, IT IS UNSAFE TO OPERATE.

The contact owns a 2020 GMC Sierra 2500. The contact stated that the vehicle was under NHTSA Campaign Number: 24V797000 (Power Train) and the vehicle was repaired. The contact stated that after the recall repair, the transmission started shifting hard. The vehicle was taken to the dealer, and the contact was informed that the transmission module would reprogram and adjust independently. The contact stated that a week later, while driving approximately 45 MPH, the vehicle started to run rough, and the message engine power reduced was displayed. The transmission fault, parking brake system alert, service parking brake, and the check engine warning light illuminated. The vehicle was towed to the dealer, who diagnosed the vehicle and determined that the fuel injector was open, causing high resistance in the connector for cylinder #4. The transmission could not be diagnosed until the injector was repaired. The manufacturer was informed of the failure and opened a case. The failure mileage was 125,000.

DEF tank system failure. Vehicle is under warranty, 18 months old, (purchased 08/20) with 20,000 miles. 6 WEEKS AGO I took to dealer who informed me that there are no DEF tanks available and don't know when they will be available. This is a hazard: if I am on a trip and the system shuts off I could be stranded anywhere with the reduced speed that the DEF system creates. If this system is designed to shut off (with warning) there should be ample supplies at all GMC dealers for repair. If there aren't ample supplies the system should NOT shut the truck down. THIS IS A SAFETY HAZARD THAT IS PREVENTABLE!

I have taken the vehicle to my local dealership six times. The tailgate started opening and the headlights were blinking on and off. This happened 3 months after I bought it. The dealership told me they changed the tailgate switch and they said there wasn’t anything wrong with my lights. Two weeks after the dealership said they changed the tailgate switch, the tailgate started opening and closing. The lights also stopped working driving down the road at night. This happened 3 different times at night. The tailgate opened when I was pulling a trailer and it caved in and I had to pay to have it repaired. The dealership said it wasn’t their problem. During this time the power steering fluid was leaking under my steering wheel and ruined my carpet. The dealership has yet to acknowledge that problem. I still have to put power steering fluid in the truck every week and my interior is ruined. The tailgate is still opening on its own. I had to start charging my batteries up every morning because they were dead. I got up one morning and the batteries were dead and the truck wouldn’t start. I had to buy a new $300 key. Took it back to the dealership for an appointment. The truck sat there for a week and I called for an update and they didn’t even remember the truck was there. It still sat there 4 days after that. They told me the truck needs new batteries and it wasn’t under warranty. I spent $1000 on 2 batteries. Tailgate is still going down. The lights are still going on and off. And then the lights and the locks will go on and off while the truck is parked and turned off. And now the new batteries are becoming weak and I am having to get the truck jumped off several times. I have had the truck at the dealership 6 times and they still haven’t fixed anything. When they have my truck I am losing money because I am a business owner and I use my truck for work. I lost all of my tools. I have lost time and money because the dealer has yet to help and do their job. I need help GM

AS I WAS DRIVING HOME MY CHECK ENGINE LIGHT CAME ON AND ALL OF MY LIGHTS WENT OUT. I HAD NO TAIL LIGHTS AND THE RADIO STARTED SAYING NO SIGNAL DETECTED. THE DASH SCREEN WAS SAYING SERVICE KEYLESS ENTRY SYSTEM. AND I HAD NO RUNNING LIGHTS BUT MY HEADLIGHTS. PRETTY SCARY THINKING NO ONE COULD SEE ME AS THEY WERE DRIVING BEHIND ME AT A HIGH RATE OF SPEED. MY TRUCK ONLY HAS 200 MILES ON IT SO THIS IS REALLY SCARY TO BE HAVING ISSUES SO EARLY IN THE OWNERSHIP OF THIS TRUCK. I'VE ALWAYS HAD FORDS BUT THIS TRUCK CAUGHT MY EYE AND I STEPPED OUT OF MY COMFORT ZONE AND NOW WISHING I WOULD HAVE STAYED IN IN.

I was travelling south bound on the highway at 70 mph when out of no where the left rear tire failed. The tread peeled back like an alligator skin and tore apart the side of my truck and caused me to fishtail all over the highway. I was able to avoid colliding with other vehicles on the road and miraculously made it to the shoulder of the highway. The tire is a Goodyear Wrangler TrailRunner AT in a size LT275/65/R20. I still have the remaining parts of the tire. My vehicle is still under manufacturer warranty, but the GMC dealer turned me away and told me I had to deal with Goodyear directly. I reached out to Goodyear to file a claim for the tire failure and damages related to it. They have been ignoring me for over a week, so I have filed a claim with my insurance company to handle the damages. I'm currently waiting to get my truck into the shop for repairs. There were no indications of any issues with the tire. I had them rotated as recommended by the manufacturer and kept the tire pressure at the recommended levels through the dealer when my vehicle was serviced. The TPMS light came on as soon as the tire failed and lost pressure showing the vehicle tire pressure monitoring system was working properly when the tire failed.

The contact owns a 2020 GMC Sierra 2500 equipped with Goodyear Tires, Tire Line: Wrangler Trail Runner, Tire Size: LT275/65/R20, DOT Number: PJ0TJB1V 2319. The contact stated that within a three-day period while hauling a camper on a road trip, all four tires experienced a failure. The contact indicated that the first failure occurred while driving approximately 60 MPH; the rear driver’s side tire experienced a blowout. During the failure, the driver’s side rear quarter panel was severely damaged. The contact stated that later on while driving at an undisclosed speed, the rear passenger’s side tire experienced a similar blowout causing damage to the passenger’s side rear quarter panel. Additionally, on another occasion while driving approximately 50 MPH on the same road trip, the front passenger’s side tire experienced tread separation. While at the service center the mechanic discovered that the front driver’s side tire had also experienced partial tread separation. The cause of the failure was not determined. The manufacturer and local dealer were notified of the failure. The failure mileage was 25,400.

The rear defroster massively overheated. It started heavily smoking and eventually exploded the rear windows. Only warning sign was the smoke which we noticed quickly because the windows were up. Had the windows been down we might not have noticed before a fire started. I'm taking it to a dealership now. This module also triggers on from a remote start. Extremely dangerous!!!

THE VEHICLE PULLS TO THE RIGHT OR LEFT INTO ONCOMING TRAFFIC WITHIN 800 FEET OR SOONER DEPENDING ON SPEED. THIS OCCURS ON CITY STREETS OR INTERSTATE. GM AND GM APPROVED DEALERSHIPS SAY THIS IS DONE TO GM SPECIFICATIONS. THE FIRST 7000 MILES, IT DIDN'T PULL. AFTER GM SHOP ALIGNED, AND 3 MONTHS LATER, IT IS UNSAFE TO OPERATE.

TL* THE CONTACT OWNS A 2020 GMC SIERRA 2500. THE CONTACT STATED THAT UPON DRIVING OVER A HILL AT 45 MPH, A VEHICLE WAS STOPPED IN THE MIDDLE OF THE ROAD. IN AN EFFORT TO AVOID HITTING THE VEHICLE, THE CONTACT DROVE THE VEHICLE OFF THE ROAD AND INTO A CONCRETE CULVERT AT THE END OF THE RAVINE. THE AIR BAGS DID NOT DEPLOY UPON IMPACT. THE AUTHORITIES WERE CALLED TO THE SCENE AND THE CONTACT WAS RUSHED TO A LOCAL HOSPITAL VIA AMBULANCE. THE CONTACT WAS DIAGNOSED WITH FRACTURED VERTEBRAE THAT MAY REQUIRE POSSIBLE SURGERY. A POLICE REPORT WAS FILED AT THE SCENE. DUE TO THE ACCIDENT, THE VEHICLE WAS TOWED TO AN INDEPENDENT MECHANIC WHERE THE VEHICLE WAS REPAIRED. THE DEALER NOR THE MANUFACTURER HAVE YET TO BE NOTIFIED OF THE FAILURE. THE VEHICLE WAS REPAIRED AND SOLD. THE FAILURE MILEAGE WAS APPROXIMATELY 15,500.