2020 GMC Sierra 2500

These are unverified consumer reports filed with NHTSA, shown as submitted.

• 12/23/2022· UNKNOWN OR OTHER

  1. The Engine Block heater sparked and created a small flash underneath the truck. It can be inspected whenever you would like. 2. Electric spark/fire 3. The problem has not been reproduced nor inspected by the dealer. I would not dare to plug it back in. 4. There were not any warning messages. It happened the first time the engine block heater was plugged in. February of 2022.

• 12/20/2025· ELECTRICAL SYSTEM,SERVICE BRAKES,FORWARD COLLISION AVOIDANCE

  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

• 12/19/2024· POWER TRAIN

  The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was contacted. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

• 12/17/2021· VEHICLE SPEED CONTROL

  While driving Truck was setting Cruise Control at approx 100km/hr. The cruise would set but at approx 70km/hr. Tried to set multiple time throughout the trip but no change. Recorded video and sent to dealer. They brought truck in to check it out, but said that since they can't duplicate the problem they cannot diagnose it. This has happened multiple times and have recorded video each time. Again dealer said they can't do anything unless they see it themselves.

• 12/17/2021· FORWARD COLLISION AVOIDANCE

  Was driving truck down driveway at about 5km per hour and the parking brake automatically engage bringing the vehicle to a sudden and unexpected hard stop. Brought to dealership, then said they cannot duplicate the problem and therefore there is no action to be taken.

• 12/15/2023· TIRES

  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.

• 12/13/2025· STEERING

  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!

• 12/09/2020· ELECTRICAL SYSTEM

  WENT OUT TO MY VEHICLE THAT HAS BEEN SITTING IN MY DRIVEWAY FOR 24 HOURS AND ATTEMPTED TO UNLOCK IT WITH THE KEY FOB. NOTHING. TRIED THE OTHER FOB. NOTHING. USED THE KEY TO UNLOCK THE DOOR AND GET IN TO PUSH BUTTON START AND NOTHING. I PLUGGED BOTH BATTERIES INTO CHARGERS AND THEY WOULD START TO CHARGE, THEN DISCHARGE AFTER THE BATTERIES GOT UP TO ABOUT 20% I CALLED GMC ROADSIDE ASSISTANCE AND THEY SENT SOMEONE OUT. THE SERVICE GUY SHOWED UP ABOUT 45 MIN LATER AND HOOKED UP A JUMP BOX TO EACH BATTERY. STILL NO LUCK IN GETTING IT STARTED. HE SAID IT MUST HAVE SOME MAJOR ELECTRICAL ISSUES. SINCE WE COULD NOT GET IT TO SHIFT TO NEUTRAL, HE COULD NOT TOW IT AND I AM NOW WAITING FOR A TOW IN THE MORNING. THIS TRUCK HAS LESS THAN 10,000 MILES ON IT. I'M DEALING WITH THIS LESS THAN 5 MONTHS INTO OWNERSHIP AND THIS COMES AFTER I HAD TO TAKE IT INTO SERVICE THE SECOND DAY OF OWNING THE VEHICLE BECAUSE I HAD A DEF SENSOR CRYSTALLIZE AND GO BAD. SO, I OWNED THE TRUCK FOR LESS THAN 24 HRS AND HAD TO PUT IT IN THE SHOP FOR A WEEK. NOW, IT GOES BACK. THIS IS RIDICULOUS FOR A $81,000 TRUCK THAT HAS LESS THAN 10K MILES.

• 12/07/2025· ENGINE

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

• 12/04/2024· WHEELS,SERVICE BRAKES

  Tires locking up while driving. NOT SAFE TO DRIVE

• 11/27/2019· TRACTION CONTROL SYSTEM,SERVICE BRAKES

  TL* THE CONTACT OWNS A 2020 GMC SIERRA 2500. WHILE DRIVING 5 MPH, THE BRAKES ENGAGED AUTOMATICALLY AND THE TRACTION CONTROL WARNING INDICATOR ILLUMINATED. THE VEHICLE WAS TAKEN SEVERAL TIMES TO CARL BLACK CHEVROLET BUICK GMC (LOCATED AT 1110 ROBERTS BOULEVARD NORTHWEST, KENNESAW, GA 30144, (888) 457-2417). THE DEALER DIAGNOSED THAT THE SPEED SENSOR NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED, BUT THE FAILURE CONTINUED. THE DEALER DIAGNOSED THE VEHICLE AGAIN AND STATED THAT THE WHEEL HUBS NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED, BUT THE FAILURE RECURRED. THE DEALER DIAGNOSED THE VEHICLE A THIRD TIME AND STATED THAT AN UNKNOWN STEERING ANGLE SENSOR NEEDED TO BE UPDATED. THE VEHICLE WAS REPAIRED, BUT THE FAILURE CONTINUED. THE MANUFACTURER WAS INFORMED OF THE FAILURE. THE FAILURE MILEAGE WAS 571.

• 11/24/2025· ELECTRICAL SYSTEM,STRUCTURE,VISIBILITY/WIPERFire

  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!!!

• 11/22/2023· UNKNOWN OR OTHER

  The rear window of my 2020 GMC Sierra developed major water leaks across the entire window in 2021. GM has documented this issue with a service bulletin and the dealership has documented their resolution to the first repair under warranty. GM knows of this manufacturing issue and continued to install a faulty back window. Not only did the back window leak large amounts of water into the cab causing a potential dangerous mold issue, the security and integrity of the back window breaking or falling onto rear passengers is a major safety hazard. The integrity of the back window falling out into traffic is another safety hazard to consider. GM issued a service bulletin for leaking back windows for their Sierra trucks due to the known problems. GM has documented their problem and remedied a quick inexpensive solution. Many other GM Sierra truck owners have documented their issues and frustration with GM, and the BBB. GM has invested this issue and found the rear window plastic frame was installed or will develop stress cracked in the frame. GM’s remedy is to use a silicon window caulk and apply the silicon between the outside top section of the glass to the cab. This did not address the safety aspect of the situation. It only delayed the issue temporarily until vehicle owners were out of warranty. GM’s solution usually only last for one or two years before the issue develops again. After GM and the dearship siliconed the rear window per the service bulletin in 2021, my vehicle once again developed the same leak as before. The dealer ship once again inspected the rear window, but this time told me the issue and replaced the entire rear window because of the “stress cracks”. It’s amazing that GM wants to replace the rear window at the customer’s expense since I am out of warranty. It preposterous that GM knew of this safety issue and created a temporary correction that would last a short time until vehicle owners are out of warranty and stick them with a bill.

• 11/20/2024· POWER TRAIN

  The contact owns a 2020 GMC Sierra 2500. The contact stated while driving approximately 65 MPH, the vehicle lost motive power. The contact stated that he had not depressed the brake pedal. The contact was towing a 20-foot flatbed trailer with a load of lumber of approximately 4,000 lbs. in weight. The contact stated there was no warning light illuminated. The contact pulled over with the vehicle still running and attempted to shift into drive(D) and reverse(R); however, the vehicle failed to respond. The contact stated that after shifting into drive(D), several unknown warning lights were illuminated. The contact had the vehicle towed to a local dealer; however, the vehicle was not diagnosed or repaired. The contact researched online and related the failure to NHTSA Campaign Number: 24V797000 (Power Train). The manufacturer was informed of the failure. The failure mileage was approximately 100,000.

• 10/14/2025· POWER TRAIN

  Torque converter in my transmission we out, causing my gears to grind and lose power. Slight rumbling sound under the front passenger seat, First dealer (Palmen Motors, Kenosha WI) told me there was nothing wrong with the vehicle and no transmission error codes exist. Second dealer (Parks GMC, Greenville SC) indicated that i need a complete new transmission. Part is on backorder for the last 4 weeks and I am without my vehicle. No ETA for new part or any information on why it failed prematurely.

• 10/07/2025· STEERING,ELECTRICAL SYSTEM,EXTERIOR LIGHTING

  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

• 10/02/2020· ELECTRICAL SYSTEM,EXTERIOR LIGHTING,ENGINE

  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.

• 09/29/2023· UNKNOWN OR OTHER

  Rear sliding window leak and has saturated seat and carpet causing an unhealthy environment. Spoke with dealer and was told it is a design flaw and repairs are not covered under extended warranty. I was also told it is only a temporary fix and “ leak will reoccur”. I only realized of the problem when soap residue was seen on the inside of the widow. Dealer gave estimate of repair.

• 09/28/2020· SERVICE BRAKES

  MY BRAKES ARE SQUEAKING VERY LOUDLY THEY HAVE BEEN SINCE AUGUST. I WAS DRIVING DOWN THE ROAD ON US1 AND PREPARED TO STOP TO MAKE A TURN AND MY TRUCK WOULD NOT STOP. I WAS MAKING A RIGHT TURN AND ENDED UP IN THE OTHER LANE OF ONCOMING TRAFFIC SIDEWAYS BECAUSE I TRIED TO TURN MY TRUCK TO SLOW IT DOWN. I COMPLAINED ABOUT MY BRAKES SEVERAL TIMES TO THE DEALERSHIP THEY ORDERED ME NEW BRAKES WITHOUT EVEN LOOKING AT MY VEHICLE AROUND AUGUST 8TH. WE ARE NOW AT THE LAST TWO DAYS OF SEPTEMBER AND THEY STILL DO NOT KNOW WHEN THE BRAKES WILL COME IN. THIS IS A SERIOUS SAFETY ISSUE AT THIS POINT. I HAVE NO OTHER VEHICLE TO DRIVE. I BOUGHT A 70,000 TRUCK AND MY AND MY FAMILY'S SAFETY IS ON THE LINE. GMC NEEDS TO FIND ME A COMPARABLE LOANER VEHICLE UNTIL MY TRUCK IS REPAIRED.

• 09/24/2020· SERVICE BRAKES

  TL* THE CONTACT OWNS A 2020 GMC SIERRA 2500. THE CONTACT STATED THAT WHILE DRIVING AND TOWING A TRAILER, SHE DISCOVERED THAT THE BRAKES WERE OVERHEATING. THERE WAS A STRONG BURNING HOT ODOR COMING FROM THE BRAKES. THE CONTACT PULLED OVER AND DISCOVERED ALL FOUR BRAKE ROTORS WERE EXTREMELY HOT. THE CONTACT DROVE AND DROPPED OFF THE TRAILER. THE CONTACT DROVE 20 MPH AND DOWN SHIFTED TO CONTROL THE SPEED TO GET BACK HOME. THE DEALER DAVE ARBOGAST BUICK-GMC (3540 S CO ROAD 25A, TROY, OH 45373, (937) 335-0068) STATED THAT INCORRECT BRAKE PADS WERE INSTALLED ON THE VEHICLE FROM THE FACTORY AND THERE WAS A TECHNICAL SERVICE BULLETIN FOR THE FAILURE. THE VEHICLE WAS NOT REPAIRED DUE TO THE REPLACEMENT PARTS NOT BEING AVAILABLE. THE MANUFACTURER WAS CONTACTED AND PROMISED TO PROVIDE A CALLBACK. THE FAILURE MILEAGE WAS 500.

• 09/21/2020· STEERING,ELECTRICAL SYSTEM,ELECTRONIC STABILITY CONTROL (ESC)

  2020 GMC SIERRA DENALI DURAMAX 3000 MILES TRIED TURNING ON TRUCK THIS MORNING TO GO TO WORK AND WOULD NOT EVEN CRANK IT IS A PUSH START OPTION HAVE NO CLUE ON HOW IM GOING TO TAKE IT TO THE DEALERSHIP IF I CANT GET IT OF PARK INTO NEUTRAL FOR A TOW TRUCK AT LEAST ! TRUCK DOES NOT CRANK IT THROWS ME A TON OF MESSAGES STABILITY TRAK DSC ABS POWER REDUCED 4WD CHECK TRAILER LIGHTS. BUNCH OF MESSAGES I TOOK VIDEO OF IT AND SO TRUCK DOESN'T EVEN TRY TO START. I TOOK A VIDEO OR THE PROBLEM

• 09/20/2024· UNKNOWN OR OTHER,SERVICE BRAKES

  I HAVE A 5TH WHEEL WITH SOLAR AND MY BRAKE CONTROLER STOPS WORKING PERIODICALLY. I HAVE A CASE# WITH GM 9-13676268071. I ALSO HJAVE AN EXTENDED WARRANTY WITH GM AND IT'S NOT COVERED DUE TO MY VIN# NOT BEING ON A BULLENTIN# 23-NA-149. GM ALSO HAS A CUSTOMER SATISFACTION PROGREAM # N232414840 AND STILL WON'T COVER IT. THIS IS A MAJOR SAFETY ITEM AND CONCERN FOR ME.

• 09/15/2025· ENGINE

  The catalytic converter failed at 93,000 miles, and 64 months. GM says it is out of warranty.

• 08/29/2023· ENGINE

  Low coolant light keeps coming on and dealership checks and confirms coolant is not low. The end result is the sensor In the resivor is bad and requires the entire tank to be replaced rather than just the sensor

• 08/11/2025· POWER TRAIN

  The contact owns a 2020 GMC Sierra 2500. The contact stated that while driving approximately 70-80 MPH, the transmission downshifted, and the rear wheels locked up. The contact was able to coast to the side of the road. The contact was unsure if a warning light had illuminated. The vehicle was towed to the dealer, where it was diagnosed and determined that the transmission had failed and needed to be replaced. There were metal shavings found mixed in with the transmission fluid; however, the vehicle remained with the dealer unrepaired. The contact was informed by the dealer that the warranty had expired, and the vehicle could not be repaired. The manufacturer was notified of the failure but declined to assist in covering the cost of the repair. The failure mileage was approximately 166,000.

• 08/07/2024· PARKING BRAKE,SERVICE BRAKES

  The contact owns a 2020 GMC Sierra 2500. The contact stated that while driving 65 MPH, the message "Check Service Brakes Now" was displayed. The vehicle was taken to an independent mechanic, where it was diagnosed with electric parking brake malfunction. The mechanic informed the contact that the electric parking brake had been engaged unintendedly, causing the rear driver's side brake calipers to seize. The vehicle was repaired; however, the failure recurred on the rear passenger's side while driving. The vehicle was taken to the dealer, where it was diagnosed with electric parking brake circuitry failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 62,000.

• 08/04/2022· TIRES

  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.

• 07/29/2020· UNKNOWN OR OTHER

  PART #19419266 TONNEAU WAS INSTALLED 07/16/2020 AND LEAKS TERRIBLE IN THE RAIN

• 07/18/2024· UNKNOWN OR OTHER

  Well, we ended up having a problem with our transmission in our 2020 truck. I am the wife and I was driving down the highway and all of a sudden the truck started bucking and went down to 35 mph. I was in a middle lane on the highway when this happened which Was very scary! Then I was stranded along side the highway until I could get help. Here we found that our transmission went out already only after four years, which is crazy. Very crazy! We bought this truck because we were told with the weight of this truck and all that it would pull out 42 foot fifth wheel we have. So of course we did use this truck to pull our trailer and now four years later we have been without a truck because we cannot even find a transmission with our transmission code of OMEF. Now today we found a possibility which is going to cost $7000 which is Love Ludacris! We buy a $65,000 truck just for years ago and now had to put $7000 out for a transmission. Is there anything we can do to rectify this situation??

• 07/07/2025· POWER TRAIN

  The contact owns a 2020 GMC Sierra 2500. The contact stated that while her husband was driving 30 MPH, the rear wheels locked up and the vehicle skidded to a complete stop. No warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission had imploded and needed to be replaced. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 24V797000 (Power Train); the VIN was included but the vehicle had not been repaired. The manufacturer was not notified of the failure. The failure mileage was 125,000.

• 06/30/2026· ENGINE AND ENGINE COOLING

  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.

• 06/29/2023· UNKNOWN OR OTHER

  When towing a trailer a notice to service trailer brakes comes on and the trailer brakes are disabled

• 06/24/2025· POWER TRAIN

  What component or system failed or malfunctioned, and is it available for inspection upon request? - Transmission Valve Body resulting in a P0700 & P0747 code. Yes currently installed in vehicle. How was your safety or the safety of others put at risk? - When the vehicle goes into a limp mode to protect the transmission and rear-wheel lock up, the truck shuttered and hard downshifted. Speed limit is restricted to 5th gear only. I've been instructed by GM to continue driving and using the vehicle until the problem happens again, knowingly putting myself and others at risk on a second failure that could happen at any time. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes this is a common problem with a recall #N242454440, NHTSA 24V-797. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Mine has been rejected by GM. Although I documented and photographed the failure codes, I cleared them from the vehicle in order to attempt to safely get to the dealer and prevent further damages. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? At the time of failure yes, check engine light and codes from an engine monitor coinciding with the known problems. Engine speed / power was reduced to allow only 5th gear.

• 06/22/2020· UNKNOWN OR OTHER

  THE FRONT PARK ASSIST SENSORS ON THIS TRUCK DO NOT OPERATE AS INTENDED, OR AS ON PRIOR YEARS OR AS ON OTHER VEHICLES. THE SENSORS DID NOT PICK UP PARKING BOLLARDS IN FRONT OF A CONVENIENCE STORE AND RESULTED IN A MINOR DING THAT COST OVER $1300 TO REPAIR. WHEN BUMPER WAS REPAIRED THE SERVICE PERSON SAID SENSORS WERE FIXED, YET, TO HIS SURPRISE, WE WERE ABLE TO INCH UP TO A CAR DIRECTLY INTERSECTING THE FRONT OF THE CAR AND IT DID NOT PICK IT UP. I DID A SIMILAR TEST WITH A BRAND NEW/UNSOLD VEHICLE ON DEALER LOT IND IT FAILED TO SENSE THE LARGE TRUCK DIRECTLY IN FRONT OF IT. THIS I BELIEVE CAN BE A VERY DANGEROUS SAFETY ISSUE AS THE TRUCK HOOD SITS VERY HIGH IMPEDING VIABILITY AND A SMALL PERSON OR PET CAN EASILY GO UNDETECTED. THESE VEHICLES HAS ALSO HAD NUMEROUS RECALLS INCLUDING ONE FOR THE POSSIBILITY OF THE HOOD FLYING OPEN WHILE OPERATING. I HAVE SOLD THE TRUCK AS ALL OF THESE ISSUES HAVE DEVALUED THE VEHICLE, IT REMAINS UNSAFE AND GM RESPONSE HAS BEEN LESS THAN FAVORABLE.

• 06/21/2024· STRUCTURE

  The contact owns a 2020 GMC Sierra 2500. The contact stated that when the vehicle was parked, the contact's husband noticed that rainwater had entered the rear interior of the vehicle. The contact stated that the rainwater had entered through the rear sliding window. In addition, the contact stated that the aluminum casing around the rear window had fractured. The contact stated that due to the failure, the interior of the vehicle had a moldy odor. The vehicle was taken to the dealer where it was diagnosed with a fractured window frame. The contact was informed that the rear window and frame needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The contact was informed that the repair would not be covered under warranty. The failure mileage was approximately 69,000.

• 06/17/2024· FORWARD COLLISION AVOIDANCE

  The contact owns a 2020 GMC Sierra 2500. The contact stated while driving 60 MPH, the vehicle independently slowed and dramatically decelerated. The vehicle returned to normal functionality, but the failure became a regular occurrence. The contact stated that when the failure occurred, the gear shifter position indicator light flashed, and once the vehicle returned to normal functionality, the light remained solid. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the Forward Collision Avoidance warning sensor. The vehicle was repaired, but the failure reoccurred. The manufacturer was not notified of the failure. The failure mileage was 102,000.

• 06/17/2021· STEERING,SERVICE BRAKES

  While driving my 2020 GMC 2500 Denali with the Duramax Diesel engine, the power assist for the steering and brakes failed without any warning. This made the truck nearly impossible to steer and stop. Luckily, I was able to avoid a collision and get the truck stopped in a safe location. The truck is currently being towed to Rivard GMC in Tampa, Fl. Doing an internet search, I found this problem has happened to others as well. Please ask GM to rectify this extremely dangerous defect.

• 06/02/2022· ENGINE

  I took my vehicle into the local dealership two weeks ago for the DPF emissions voluntary recall. Prior to the service I was getting 16.6 mpg for the 42000 miles on my truck. After the service, for the ~200 miles driven on same route and conditions commuting to and from work I have only been able to achieve ~13 mpg. There has been no other changes to my vehicle or operating conditions. When I took the vehicle in the advisor mentioned that it may take awhile for the service because “we have to download the update wirelessly.” While researching this issue the recall document specifically warns against wireless download of the update. I am not sure if this may be the result of not following the correct process or not and I am headed back to the dealer today. I also found several others posting on the diesel forums about similar significant loss of mpg after the update. Losing almost 25% fuel efficiency after the update is unacceptable and reflects the my previous experience of efficiency loss during an actual regeneration cycle prior to the update. The vehicle is acting as if it is running in a constant regeneration cycle. Unsure if this may lead to dangerous driving condition due to excessive stress and wear on the affected parts and engine.

• 05/20/2020· ENGINEFire

  TL* THE CONTACT OWNS A 2020 GMC SIERRA 2500. THE CONTACT STATED THAT WHILE DRIVING, HE NOTICED SMOKE ENTERING THE VEHICLE THROUGH THE AIR VENTS. THE CONTACT COASTED TO THE SIDE OF THE ROAD, EXITED THE VEHICLE SAFELY WITH HIS PASSENGER, UPON OPENING THE HOOD NOTICED THAT THE WHOLE ENGINE COMPARTMENT WAS ON FIRE. THE CONTACT STATED THAT THE FIRE DEPARTMENT ARRIVED BUT WAS UNABLE TO EXTINGUISH THE FLAMES AS THEY ALLOWED THE VEHICLE TO BURN UNTIL THE FIRE SELF EXTINGUISHED. THE DEALER NOR THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 2,800. VIN WAS NOT AVAILABLE.

• 05/17/2025· POWER TRAIN

  After the transmission recall was completed, I’m now having erratic shifting. Having the recall adding software monitoring for a hardware issue is inadequate. Now that I am out of warrentee, gm has not resolved the issue and now I am having shifting problems.

• 05/14/2025· UNKNOWN OR OTHER

  Cracks in the rear sliding window plastic upper rail glass guide causing Rear window leaking water and causing mold from water leaking. GMC has a service bulletin number 18-NA-383 knowing of this issue and not telling customers purchasing the GMC vehicle. The service bulletin was released in 2019 before purchasing the truck and they still didn't inform the customers. My child rides in the back in a car seat and now has been breathing in this mold and mildew for how long. I have had my vehicle in with Titus will Gmc in olympia multiple times for service and inspection of various recalls and still didn't inform me of this issue.

• 05/13/2025· UNKNOWN OR OTHER

  Tailgate unlatches unexpectedly. Has happened while parked and while driving. Almost caused accident to others.

• 05/01/2025· POWER TRAIN

  The contact owns a 2020 GMC Sierra 2500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

• 04/22/2021· AIR BAGSCrash

  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.

• 04/18/2025· ENGINE AND ENGINE COOLING,FUEL SYSTEM, DIESEL,POWER TRAIN

  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.

• 03/29/2024· SERVICE BRAKES,FORWARD COLLISION AVOIDANCE

  My vehicle inadvertently locks the rear tires at highway speeds and then releases and drives. In some instances it may brake several times causing the tires to burn rubber for a short distance causing rear traffic to either swerve to avoid rear ending me and in a couple instances causes the rear following traffic to abruptly change lanes to avoid rear ending me

• 03/28/2025· UNKNOWN OR OTHER

  I have a notice of a recall for the transmission control module and I took it to a GMC dealership and they are refusing to fix it. The transmission will not shift so I am unable to drive it

• 03/20/2025· STEERING

  The contact owns a 2020 GMC Sierra 2500. The contact stated that while driving at various speeds, the steering wheel was pulling to the left unintentionally. Additionally, the contact stated that there was significant play in the steering wheel. The contact stated that while driving 35-40 MPH and driving through a puddle of water, the vehicle veered violently at a 60-degree angle into the left lane while the contact was firmly grabbing the steering wheel, nearly causing a crash. The vehicle was taken to the dealer and was diagnosed with upper steering shaft failure. The contact was informed that the upper steering shaft needed to be replaced. The part was replaced. Additionally, the vehicle was taken to a Tire Shop, where the tires were replaced and alignment was performed. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 31,800.

• 03/20/2022· ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL,ENGINE

  DEF system failed. Wire harness burned out. Tank failure. Truck went into limp mode. I personally know 3 others with the same issue.

• 03/18/2025· POWER TRAIN,UNKNOWN OR OTHER

  ODI # 11646185 My truck on [XXX] leaked transmission coolant from the jumper line leak( which this part is recalled but not for my VIN #) $400.61 dollars and left me stranded in the middle of the highway and had to be towed. After the repair and checking the transmission was discovered it was ruined because of the leak. So now I have to have a new transmission installed at Jennings in Beardstown IL to the cost of $7363.39. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)