2020 GMC Sierra 3500HD

What owners should know

Covers 2020–2026 · 6.6L Duramax L5P diesel and 6.6L V8 gas · Updated 2026-10-01

Researched from owner forums and NHTSA complaints and written by Know Your Truck. These are patterns in what owners report, not a guarantee about any particular truck.

Common failures & how to fix them

Parts and video buttons search for your 2020 GMC Sierra 3500HD. Always confirm a part fits using your VIN. Brakes, steering, fuel and airbag work affects your safety, so if you're not sure, have a qualified mechanic do it.

• 10-speed transmission valve body failure

  Dealer (recall)

  Signs: Sudden hard downshifts, limp mode, or rear wheel lock-up on diesels.

  Fix: Covered by GM recalls on 2020–2022 diesels. Other repairs are usually under warranty on newer trucks. Ask a dealer for all open recalls and bulletins.

  May be covered free by recall 24V797000 / 26V083000. Check the VIN at nhtsa.gov/recalls.

• Trailer brake controller warnings

  Easy DIY

  Signs: 'Check trailer wiring' or 'Trailer brakes disconnected' messages that cut the trailer brakes.

  Fix: Clean and inspect the 7-pin trailer connector and the trailer's wiring first. If it continues, have a dealer check for bulletins and module updates.

  Shop: 7 pin trailer connector▶ How-to videos

• Power tailgate opens unexpectedly

  Dealer (recall)

  Signs: The tailgate unlatches by itself, often after water gets in.

  Fix: Covered by GM recalls on 2020–2024 trucks with power-unlatching tailgates.

  May be covered free by recall 24V060000 / 24V894000. Check the VIN at nhtsa.gov/recalls.

• Steering gear shaft can break (2024)

  Dealer (recall)

  Signs: Loose steering or a clunk. In rare cases loss of steering.

  Fix: Covered by a GM recall on some 2024 trucks.

  May be covered free by recall 23V549000. Check the VIN at nhtsa.gov/recalls.

Recalls

A recall doesn't mean a truck still has the problem. Enter the truck's VIN at nhtsa.gov/recalls or ask a dealer to see whether the repair was done.

• Power Train:Automatic Transmission:Control Module:Software

  Feb 2026 · #26V083000

  General Motors, LLC is recalling certain 2020 Chevrolet Silverado 2500, 3500, GMC Sierra 2500, 3500, and 2020-2022 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles that may have been repaired incorrectly under recall 24V797. The transmission control valve may fail and cause the rear wheels to lock up.

  Risk and fix

  Risk: Rear wheel lock up increases the risk of a crash.

  Fix: Dealers will inspect the vehicles and update the transmission control software, free of charge. Owner notification letters were mailed March 6, 2026. Owners may contact GMC customer service at 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N252516560. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on February 12, 2026.

• Power Train:Automatic Transmission:Control Module:Software

  Oct 2024 · #24V797000

  General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.

  Risk and fix

  Risk: Rear wheel lock-up can increase the risk of a crash.

  Fix: Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242454440.

• Latches/Locks/Linkages:Tailgate:Latch

  Feb 2024 · #24V060000

  General Motors, LLC (GM) is recalling certain 2020-2024 Chevrolet Silverado 2500, 3500, GMC Sierra 2500 and 3500 vehicles equipped with power-unlatching tailgates. The tailgate's electronic gate-release switch may short circuit due to water intrusion, which can result in the tailgate inadvertently unlatching while the vehicle is in park.

  Risk and fix

  Risk: An unlatched tailgate may open while driving and result in a loss of unsecured cargo, creating a road hazard and increasing the risk of a crash.

  Fix: Owners are advised to check that the tailgate is closed and latched before driving. Dealers will replace the exterior touchpad switch assemblies, free of charge. Owner notification letters were mailed May 17, 2024. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is N232426400.

• Seat Belts

  Dec 2020 · #20V792000

  General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.

  Risk and fix

  Risk: If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.

  Fix: GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.

• Air Bags:Side/Window:Curtain:Inflator

  Jul 2020 · #20V446000

  General Motors, LLC. (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5 and XT6, Chevrolet Blazer, Silverado 1500, 2500 and 3500 and Traverse and GMC Acadia and Sierra 1500, 2500 and 3500 vehicles. The diffuser component of the Roof-Rail Air Bag (RRAB) inflator may not have been properly crimped to the inflator and could separate from the inflator during air bag deployment.

  Risk and fix

  Risk: If the diffuser separates from the inflator during deployment, RRAB performance may be degraded, increasing the risk of injury in a crash.

  Fix: GM will notify owners, and dealers will replace the suspect RRAB modules, free of charge. The recall began September 3, 2020. Owners may contact Chevrolet customer service at 1-800-630-2438, Cadillac customer service at 1-800-333-4223, or Buick customer service at 1-800-521-7300. GM's number for this recall is N202305380.

• Structure:Body:Hood

  Jun 2020 · #20V324000

  General Motors LLC (GM) is recalling certain 2020 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles previously recalled under 20V-142. Some of the vehicles in 20V-324 were not part of Recall 20V-142 but received defect parts during another service (typically during collision repair). The hood-latch striker wires on replacement hoods installed for Safety Recall 20V-142 may not have been heat-treated properly, possibly causing them to fracture.

  Risk and fix

  Risk: If a striker wire fractures, the hood may open unexpectedly while driving, increasing the risk of a crash.

  Fix: GM will notify owners, and dealers will replace the hood assembly, free of charge. For hoods sold over the counter, dealers will contact customers with instructions for hood replacement. The recall began July 7, 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N202306490.

• Latches/Locks/Linkages:Hood:Latch

  Mar 2020 · #20V142000

  General Motors LLC (GM) is recalling certain 2020 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The hood-latch striker wires may not have been heat-treated properly, possibly causing them to fracture.

  Risk and fix

  Risk: If a striker wire fractures, the hood may open unexpectedly while driving, increasing the risk of a crash.

  Fix: GM will notify owners, and dealers will replace the hood assembly, free of charge. The recall began April 13, 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192284960.

• Seat Belts:Pretensioner

  Nov 2019 · #19V814000

  General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500, and 2020 Silverado 2500, Silverado 3500, Sierra 2500, and Sierra 3500 vehicles equipped with carpet floor covering. When the front seat belt pretensioners deploy, hot gas may vent through an opening in the pretensioner bracket, possibly igniting the carpet.

  Risk and fix

  Risk: A vehicle fire could result if materials ignite inside the vehicle.

  Fix: GM will notify owners, and dealers will close off the opening in the pretensioner bracket, free of charge. The recall began December 13, 2019. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192270600.

Owner complaints by area

Reports owners filed with NHTSA. They aren't verified, and one complaint can mention more than one area. Tap an area to read the most recent ones.

• Power Train18

  3 involved a crash

  • Filed Jul 2025

    The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently went into LIMP Mode. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the transmission valve body sensor had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The approximate failure mileage was 130,000.

  • Filed Jul 2025

    The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving at 60 MPH, the rear differential seized, in addition, the contact was hauling a median size tracker on top of a flat bed. The flat bed jackknifed and hit the left side of the contact's vehicle. The vehicle was able to come to a stop. The air bags did not deploy. There was no warning light illuminated. A police report was filed. There were no injuries sustained. The vehicle was towed to a towing yard. The trailer was towed to the residence. The tractor was damaged in the accident. The vehicle was diagnosed by an independent mechanic. The contact was informed that the transmission had failed. The vehicle was not repaired. The insurance company was contacted. A claim was filed with the insurance company, and it was canceled a few days later by the insurance company. The manufacturer was not notified of the failure. The failure mileage was approximately 108,000.

  • Filed Apr 2025

    Valve body failed while pulling my camper down the interstate. Transmission began to have issues and locked up on us while driving. Luckily i was able to avoid any accidents. Had truck towed to a private Transmission shop to have the transmission repaired. Shop advised the failure was due to the faulty valve body.

  • Filed Mar 2025

    Greetings. In December 2024, I brought my vehicle in for the rear end lock up recall. The recall reprogrammed the transmission control module. As admitted, by yourself and GM this doesn't fix the problem. In addition, if the lockup occurs and a new valve body is required, GM is on back order with no date for delivery. Also, it is replacing it with the same valve body, i.e. you will have the same problem in the future. Nextgen Drivetrain has a valve body for around $1000 that fixes the problem. [XXX] . Please read the attached blog from Nextgen, they explain in detail, the problems and the fixes. I am scared to death to pull my travel trailer out of state with this looming problem. Please give us a better solution. Thank you. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

  • Filed Mar 2025

    The contact owns a 2020 GMC Sierra 3500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The contact was concerned about the remedy repair not being adequate to repair the vehicle. 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 made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

  • Showing the 5 most recent of 18.
• Electrical System9

  1 involved a fire

  • Filed Feb 2024

    Vehicle will not start due to known GM issues. This failure left my family stranded in cold dark unsafe area once already. If we were in the flow of traffic or had to leave an area immediately we would have been unable too. Known GM issue, engine fault code P12A6 fault code. Bulletin: PIP5719A discusses this issue. I am being told by the dealer there is a newer bulletin which advises ECM update. GM dealer is stating ECM software upgrade is required to resolve at owners expense. Owner is responsible for diagnostic fee in addition to repair costs. If the issue is not resolved vehicle may continue to experience starting failure and or other electrical problems. The night the vehicle left us stranded instrumentation was erratic and not reading properly on the instrument cluster. Very unsafe and GM should reach out to customers to inform them a software update is needed and it should not be at the expense to the consumer if the consumer is out of the bumper to bumper warranty.

  • Filed Nov 2022

    Plugged in engine block heater and the car erupted in flames. Total loss.

  • Filed Jun 2022

    The component that failed was the passenger side or main battery. Our safety was compromised when the design of the HVAC system and the battery location allowed the hydrogen sulfide gas into the passenger compartment of the vehicle. The issue has not been confirmed by a deal or independent service center. The battery(s) and vehicle are available for inspection to confirm the issue. I have uploaded pictures of the battery and one can visually see the swollen battery with liquid leaking out of it. There were no warning messages or other symptoms prior to the failure. The rotten egg smell started shortly after the truck was started and my three young children were in the truck for about 10-15 minutes while I was loading items in the bed of the truck. When I entered the vehicle, the smell was extremely strong and my eyes started burning. I opened all the windows to air out the passenger compartment and thought it was possible off gassing from the nearby septic field. Once driving with the windows now closed, the smell came back instantly and very strong. My children started complaining of headache and nausea. For the next part of the trip, we drove with the windows down. When we arrived at our destination, I was able to determine the smell was coming out of the HVAC system while in normal "Auto" mode. Opening the hood, I went to smell around the engine compartment and when I got over the passenger side main battery, the rotten egg smell was so strong that my nose and eyes instantly started burning. We then drove the truck home with the windows closed and the HVAC system in recirculate but the smell still entered the passenger compartment. All four of us had symptoms of hydrogen sulfide poisoning with my son being the worse with multiple vomiting episodes immediately upon exiting the vehicle. Poison Control was notified and all four of us were evaluated in our local Emergency Department for Inhalation Toxin. The truck is all OEM.

  • Filed Nov 2021

    Infotainment system AND center instrument cluster went completely black - six times over the course of one month. I took the truck to Alan Webb Chevrolet in Vancouver Washington. Their service technician was aware of infotainment system “Black Screen of Death - BSD” problems due to previous repair work on several different GM models. However, on the way to their Service Department to get this fixed, I rolled down the driver’s side window about 6 inches to get some fresh air and rolled it back up. Out of nowhere the Infotainment system AND the center instrument cluster came back to life. No rhyme, no reason and both stayed on (illuminated). Their Service Technician could NOT recreate the BSD. They had my truck for more than one week AND said they were working with GM engineers to resolve this issue. GM case number SR 9-7065134382. I’m driving and towing my 5th wheel blind without a remedy for this electrical issue.

  • Filed May 2021

    The computer lite up the dash and reduced power, plus took the trailer brakes off line. This happened while loaded. To reset the system you have to pull over and turn the vehicle off. This happens 2-3 times per day. This was a problem at 600 miles. The transmission shifted from 10 gear to 5th gear while driving 75 miles per hour. The truck had 75,000 miles on it . Had to send another truck out to pick up the load in Santa Rosa New Mexico. The dealer Glenn Polk in Sanger has been working on for the last 4 months There is never a warning until the lights come on with a system failure.

  • Showing the 5 most recent of 9.
• Service Brakes7

  1 involved a crash

  • Filed May 2025

    Engine started skipping, then service parking brake light came on, then service engine light came on and speed dropped to 44 mph.

  • Filed Jul 2024

    driving approximately 50 mph when vehicle suddenly made loud bang and locked up rear brakes for 25' coming to a stop in road side ditch, numerous vehicles had to make evasive actions to avoid me and other vehicles. flat spotted tire abut no visible physical damage. sat on side of road for transmission temp to cool down then drove to shop without repeat. called dealer was told the earliest appt was a month away. have not been able to repeat incident so far. this has happened a few times and is becoming more frequent, mfg has tsb issued but indicates they cant assist because my warranty has expired so i will have to pay 225 per hour diagnostic fee. this is untenable and dangerous. this needs a recall and repair ASAP.

  • Filed Jan 2023

    Rear tires locking up out of no where almost made me jack knife.

  • Filed May 2021

    The computer lite up the dash and reduced power, plus took the trailer brakes off line. This happened while loaded. To reset the system you have to pull over and turn the vehicle off. This happens 2-3 times per day. This was a problem at 600 miles. The transmission shifted from 10 gear to 5th gear while driving 75 miles per hour. The truck had 75,000 miles on it . Had to send another truck out to pick up the load in Santa Rosa New Mexico. The dealer Glenn Polk in Sanger has been working on for the last 4 months There is never a warning until the lights come on with a system failure.

  • Filed May 2021

    The computer lights up dash reducing power and taking the trailer brakes away. This almost caused a wreck when the truck shut off and the brakes failed. This truck has been in the shop at least once per month trying to fix the issues, from computer and brake failure to injector failure. Glenn Polk Chevrolet in Sanger has been working on this since the truck was new. Also we have case open with General Motors without resolution. The dash lights up at the same time as the brakes fail.

  • Showing the 5 most recent of 7.
• Unknown or Other5

  1 involved a crash · 1 involved a fire

  • Filed May 2025

    Engine started skipping, then service parking brake light came on, then service engine light came on and speed dropped to 44 mph.

  • Filed Dec 2024

    The tailgate automatically opened while I was driving. I was sure the tailgate was shut and latched properly prior to the incident.

  • Filed Jul 2024

    driving approximately 50 mph when vehicle suddenly made loud bang and locked up rear brakes for 25' coming to a stop in road side ditch, numerous vehicles had to make evasive actions to avoid me and other vehicles. flat spotted tire abut no visible physical damage. sat on side of road for transmission temp to cool down then drove to shop without repeat. called dealer was told the earliest appt was a month away. have not been able to repeat incident so far. this has happened a few times and is becoming more frequent, mfg has tsb issued but indicates they cant assist because my warranty has expired so i will have to pay 225 per hour diagnostic fee. this is untenable and dangerous. this needs a recall and repair ASAP.

  • Filed Mar 2022

    In short, the Diesel Exhaust Fluid (DEF) reductant heater failed which requires the entire DEF tank assembly (part 85138746) to be replaced on my 2020 GMC Sierra 3500. This cause the truck to go into "limp" mode where it will not travel above 65 mph, and after another period, the speed continues to be reduced down to 25 mph. Prior to the speed being reduced, there is a warning message that appears stating "Service DEF System See Owner's Manual" and a warning light illuminates in the gauge cluster. Any severe reduction in speed that can cause the truck to go "limp" is a safety concern. In addition to being a safety concern, some quick internet research reveals that this has been a known problem with GM's DEF system since at least 2019. The electrical connections are too small for the current which supplied the DEF tank heater, causing the system to short and trigger the truck into limp mode which renders it useless. The replacement part is on national backorder, and it has been on backorder for years. My truck is completely useless until this part (or a better-engineered replacement) arrives at the dealer, and there are hundreds if not thousands of people waiting on this same, defective part to get their trucks back on the road. People are losing their livelihood and the means by which they support their families. GM has known about this defective part for years and has done nothing- neither engineered a better part nor issued a recall with some kind of workaround. They haven't even been able to stock the defective part, and this is not just a supply chain issue as new trucks are still being built. This problem was not inspected by any police or insurance agency as it did not cause an accident or injury in this case.

  • Filed Jul 2020

    WHILE TOWING A FIFTH WHEEL CAMPER, THE EXHAUST WAS SO HOT IT MELTED THE CAMPER DIRECTLY BEHIND IT. WAS CAUGHT IN SIDE MIRROR BEFORE ANYTHING CAUGHT ON FIRE.

• Engine5

  1 involved a fire

  • Filed May 2025

    Engine started skipping, then service parking brake light came on, then service engine light came on and speed dropped to 44 mph.

  • Filed Jan 2025

    Engine Coolant Low error constantly appears. GM Service provider states that engine coolant level is fine, but sensor may be defective.

  • Filed Nov 2024

    The contact owns a 2020 GMC Sierra 3500. The contact stated while driving approximately 60 MPH, the vehicle jerked, lost motive power, and almost stopped unintendedly. There was no warning light illuminated. The contact was able to pull into a parking lot, where the vehicle shut off. The contact stated that while attempting to restart the vehicle, the diagnostic trouble code: P129F was displayed, and the vehicle failed to restart. The vehicle was towed to the residence. The local dealer was contacted and advised the contact that the failure might be related to the fuel pump control module and that the part was on backorder. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 19,000.

  • Filed Nov 2022

    Plugged in engine block heater and the car erupted in flames. Total loss.

  • Filed May 2021

    The computer lights up the dash reducing power and turning off power to trailer brakes. This has almost caused an accident on several occasions . It happens a couple of times per trips. This vehicle has been in the shop a couple of times per month since it was put into service. Glenn Polk Chevrolet has worked on it each time and the problem is still there. This truck has also had several injector issues. There is an open case with this vehicle with General Motors with no resolution. I have filled out forms on each of my 2020 GMC's 3500's.

• Fuel/Propulsion System5

  • Filed May 2025

    My IntelliBeam function stops working sometimes, I can still use the lights as normal but the IntelliBeam function stops every so often and starts working after about 2 to 10 mins. Lane departure warning stops every so often and will start working after 1 to 10 mins, I have noticed that when it stops working at night time then the IntelliBeam function stops working also. When I press the on/off button for lane departure then it will say that lane departure is unavailable right now. I have been getting a p20ee code showing something is wrong with SCR nox sensor 2. Scan tool reveals that the sensor works normal and then stops. Once I clear the code then it works good for a few days.

  • Filed Mar 2025

    Def heater connection on the tank will arc and melt down causing engine derate and costly repairs. Gm know and has released a service bulletins in 2022. Bulletins N212342980. But even with bulletins done still fails. And talking todealer ships it a very common problem and there is a shortage in parts.

  • Filed Feb 2025

    I was towing my 44'camper entering the highway and during excellration there was a loud bang and the truck shuddered no lights on the dash. Pulled over and did a visual check of the vehicle and did not see anything out of ordinary. Continued on our journey and during the the week noticed clunking noise when shifting into park and into drive with no camper. We shortened our trip and returned home with no futher incidents. Received recall letter from GM in December, called the dealer and was told Gm has not released my VIN number yet. Called twice in January 2025 and the software was done on February 20, 2025. Truck seems to run as it should. I use the truck for business and to tow my camper. The software is only a patch. My fear is I'm out traveling with my 44' camper and the truck goes into limp mode limiting to fifth gear. Then I have to get the truck towed home and the camper. I travel with 3 dogs too. GM has known about this issue and has failed to fix the problem leaving me and my family at risk of a serious accident. I can not work without my truck and GM does not care about me or my family. I have several camping trips scheduled for this year and I'm considering canceling them because I don't feel comfortable with the software update.

  • Filed Jun 2024

    Fuel Pump Driver Module

  • Filed May 2021

    The computer malfunctions. It is available for inspection. The computer lights up and causes failure in the trailer brakes. Glenn Polk the dealership in Sanger Texas has been working on a fix but has yet to come up with one. I have spoken with General Motors Representatives several time trying to resolve the problem without result. I also emailed the CEO last Friday and have heard nothing. There were no warning lights until seconds before failure.

• Structure4

  1 involved a fire

  • Filed Jul 2025

    The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving 45 MPH with passengers seated in the rear seats, the passengers became aware that water was entering the vehicle between the window and frame. There were no warning lights illuminated. The vehicle was taken to the local dealer, who informed the contact of Technical Service Bulletin: 18-NA-383. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed that there was no special coverage or warranty coverage on the vehicle. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 50,000.

  • Filed Aug 2024

    There is a current safety recall N232426400 on GMC pickups including the year of my truck. GMC is saying that my VIN is not covered by the recall. However, I have the multi-pro tailgate and it came open about 6 months ago on its own as i was backing up and it caused me to run into my trailer with the tailgate. I put my tailgate up after moving my truck from under my trailer and then when i went to back up somehow the tailgate popped open and i didnt know and it contacted the top of tailgate while it was down.

  • Filed Dec 2022

    Rear window leaking on 2020 gmc truck due to faulty rear window seal and plastic slide. Known issue in 2020 models with a service bulletin already in place. Headliner saturated and black mold showing. Rear back liner has been saturated multiple times and gmc would not refund the cost of a whole new window to be put in and reimbursed. GM bulletin # is 18-NA-383

  • Filed Nov 2022

    Plugged in engine block heater and the car erupted in flames. Total loss.

• Tires3

  • Filed May 2023

    The contact owns a 2020 GMC Sierra 3500 equipped with Goodyear Tires, Tire Line: Wrangler Trail Runner, Tire Size: LT275/65/R20), DOT Number: (NA). The contact stated that while driving approximately 40-45 MPH, the vehicle exhibited the death wobble, causing the vehicle to become difficult to steer. The contact took the vehicle to the dealer to have the wheels aligned; however, the contact was informed of tread separation on the front driver’s side tire, and that the driver’s side rear tire had bubbles. The contact was informed that the passenger’s side front and rear had bubbles as well. The tires were replaced with a different brand tire. The manufacturer was not made aware of the failure. The approximate failure mileage was 29,400.

  • Filed Nov 2022

    Goodyear Wrangler Trailrunner AT, LT275/65R20, factory installed on a 2020 GMC Sierra Denali 3500. While traveling 60 mph pulling a fifth wheel in South Texas on a clear and dry day, the rear passenger tire unexpectedly lost its tread. As we slowed down, it completely lost tire pressure and we ran on the rim until coming to a complete stop. Immediately prior to the incident, the TPMS and other safety systems in the truck read normal. There were no system warnings and no objects in the road. It put us in a dangerous situation as we were stopped on the shoulder of the highway right before a bridge and had our 3 children in the backseat. We called the police, but they never sent anyone to help with traffic. The rear fender and the wheel well of the truck were badly damaged. We have the faulty tire and it is available for inspection.

  • Filed Sep 2022

    These tires are Good Year Wrangler Trail Runner AT size LT275/65 R20. My total mileage on these tires was 42,751. These were the original tires that were installed when the truck was purchased new. My Tires are rotated every 7,500 miles. Tire pressure is maintained at the exact pressure and in this case was just checked 4 days prior to the incident. I was driving on an interstate at 70 mph. A vibration started. I checked the Tire pressure monitors and all showed normal pressures. About 4 minutes later the vibration increased and I decided to pull over. I had slowed to about 45 mph and had my turn signal On, as I was intending to pull on to the right shoulder. Suddenly the left rear tire exploded, and tread had separated. My truck was damaged . All the components in the wheel well are gone or damaged. The left rear 1/4 panel/fender is bent. NO repair estimate yet. After the incident I saw zero pressure on that tire indicating on the TPMS.

• Visibility1

  • Filed Jul 2025

    The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving 45 MPH with passengers seated in the rear seats, the passengers became aware that water was entering the vehicle between the window and frame. There were no warning lights illuminated. The vehicle was taken to the local dealer, who informed the contact of Technical Service Bulletin: 18-NA-383. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed that there was no special coverage or warranty coverage on the vehicle. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 50,000.

• Exterior Lighting1

  • Filed May 2025

    My IntelliBeam function stops working sometimes, I can still use the lights as normal but the IntelliBeam function stops every so often and starts working after about 2 to 10 mins. Lane departure warning stops every so often and will start working after 1 to 10 mins, I have noticed that when it stops working at night time then the IntelliBeam function stops working also. When I press the on/off button for lane departure then it will say that lane departure is unavailable right now. I have been getting a p20ee code showing something is wrong with SCR nox sensor 2. Scan tool reveals that the sensor works normal and then stops. Once I clear the code then it works good for a few days.

• Lane Departure1

  • Filed May 2025

    My IntelliBeam function stops working sometimes, I can still use the lights as normal but the IntelliBeam function stops every so often and starts working after about 2 to 10 mins. Lane departure warning stops every so often and will start working after 1 to 10 mins, I have noticed that when it stops working at night time then the IntelliBeam function stops working also. When I press the on/off button for lane departure then it will say that lane departure is unavailable right now. I have been getting a p20ee code showing something is wrong with SCR nox sensor 2. Scan tool reveals that the sensor works normal and then stops. Once I clear the code then it works good for a few days.

• Latches/Locks/Linkages1

  • Filed Dec 2024

    The contact owns a 2020 GMC Sierra 3500. The contact stated that while towing a trailer, the tailgate unintendedly opened while making a right turn. Due to the failure, the end of the tailgate was ripped in half. Upon investigation, the contact discovered NHTSA Campaign Number: 24V060000 (LATCHES/LOCKS/LINKAGES); which was linked to the failure. The vehicle was taken to a dealer and was informed that the vehicle was not included in the recall. The manufacturer was notified of the failure and referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 43,000.

• Fuel System1

  • Filed Nov 2024

    The contact owns a 2020 GMC Sierra 3500. The contact stated while driving approximately 60 MPH, the vehicle jerked, lost motive power, and almost stopped unintendedly. There was no warning light illuminated. The contact was able to pull into a parking lot, where the vehicle shut off. The contact stated that while attempting to restart the vehicle, the diagnostic trouble code: P129F was displayed, and the vehicle failed to restart. The vehicle was towed to the residence. The local dealer was contacted and advised the contact that the failure might be related to the fuel pump control module and that the part was on backorder. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 19,000.

• Diesel1

  • Filed Nov 2024

    The contact owns a 2020 GMC Sierra 3500. The contact stated while driving approximately 60 MPH, the vehicle jerked, lost motive power, and almost stopped unintendedly. There was no warning light illuminated. The contact was able to pull into a parking lot, where the vehicle shut off. The contact stated that while attempting to restart the vehicle, the diagnostic trouble code: P129F was displayed, and the vehicle failed to restart. The vehicle was towed to the residence. The local dealer was contacted and advised the contact that the failure might be related to the fuel pump control module and that the part was on backorder. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 19,000.

• Visibility/Wiper1

  • Filed Jan 2024

    Rear sliding window is leaking water into the cabin

• Air Bags1

  1 involved a crash

  • Filed Aug 2023

    The contact owned a 2022 GMC Sierra. The contact stated that while her husband was driving at an undisclosed speed, the vehicle collided head-on with another vehicle that ran a red light. The air bags did not deploy. No warning lights were illuminated. A police report was filed. No injuries were reported, but the contact and her husband sought medical treatment for various bruises caused by the seat belt at a later date. The vehicle was not taken to the dealer or an independent mechanic but was instead towed to a tow yard. The vehicle was not repaired. instead deemed a total loss. The manufacturer was not notified of the failure. The failure mileage was 25,000.

• Forward Collision Avoidance1

  • Filed Jan 2023

    Rear tires locking up out of no where almost made me jack knife.

• Steering1

  • Filed Dec 2019

    VEHICLE EXHIBITS STEERING WHEEL SHAKE / SHIMMY AT SPEEDS ABOVE 50MPH, SOMETIMES SEVERE. REPEATED ATTEMPTS AT REPAIR (CURRENTLY 4 DEALER VISITS), INCLUDING APPLICATION OF SERVICE BULLETIN 19-NA-240 DOES NOT CORRECT THE PROBLEM. GM HAS NOW INDICATED THIS IS A "NORMAL" CONDITION, AND WILL NOT AUTHORIZE FURTHER WARRANTY REIMBURSABLE LABOR FOR CORRECTION TO DEALER. THIS STEERING CONDITION AFFECTS SAFETY AS IT OCCURS IN VARYING SEVERITY AND WITH NO WARNING, ESPECIALLY DURING DRIVING OVER ROUGH PAVEMENT / BUMPS, AND HAS NEARLY LEAD TO A LOSS OF CONTROL OF THE TRUCK. THIS CONDITION WAS PRESENT AT DELIVERY OF TRUCK AT 221 MILES. TRUCK CURRENTLY HAS 1688 MILES.

Safety ratings

NHTSA 5-Star Safety Ratings from government crash tests. Ratings can differ by cab style and 2WD/4WD.

NHTSA hasn't published star ratings for this truck. Many heavy-duty pickups aren't included in NHTSA's crash-test program, so this doesn't mean the truck is unsafe.