2021 GMC Sierra 1500
Problems, recalls and owner-reported issues
Engine is the leading concern among 572 owner complaints filed for this model year. This is the 5th highest complaint count among 26 Sierra 1500 model years with reports.
Of the 2021 reports, 5 involved a crash and 6 involved a fire. 2 people were injured.
What owners report most often
Recalls and investigations
Power train, automatic transmission, control module, softwareFeb 12, 2026
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.
Rear wheel lock up increases the risk of a crash.
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.
Campaign 26V083000 on NHTSA.gov
Engine and engine cooling, engine, hard parts internal/mechanicalApr 24, 2025
General Motors LLC (GM) is recalling certain 2021-2024 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, and Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles equipped with a 6.2L V8 gas engine. The connecting rod and/or crankshaft engine components may have manufacturing defects that can lead to engine damage and engine failure.
Engine failure increases the risk of a crash.
Dealers will inspect the engine, and as necessary, repair or replace the engine. For vehicles that pass inspection, dealers will add higher viscosity oil, install 6 oil fill cap, replace the oil filter, and update the owner's manual. Repairs will be performed free of charge. Owner notification letters were mailed June 18, 2025. Owners may contact Cadillac customer service at 1-800-333-4223, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-800-462-8782. GM's number for this recall is N252494000.
Campaign 25V274000 on NHTSA.gov
Power train, automatic transmission, control module, softwareOct 24, 2024
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.
Rear wheel lock-up can increase the risk of a crash.
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.
Campaign 24V797000 on NHTSA.gov
Tires, temporary/emergency spare tireDec 16, 2021
General Motors (GM) is recalling certain 2019-2021 GMC Sierra 1500 and Silverado 1500 vehicles equipped with certain accessory road tires and a 17" spare tire. The 17" spare tire provided with the vehicle is not compatible for use with the accessory wheels, which can cause the anti-lock brake system (ABS) to not function properly under certain conditions.
An ABS system that does not function properly can increase the risk of a crash.
Dealers will provide a new 17" spare tire and wheel assembly that is compatible with the accessory wheels, free of charge. Dealers will also apply a new spare tire information label, and provide owners with an owner's manual insert clarifying which spare tire to use with the accessory road tires and with the 17" original tires. Owner notification letters were mailed February 7, 2022. Owners may contact GM customer service at 1-800-462-8782 or GMC customer service at 1-800-462-8782. GM's number for this recall is N212346510.
Campaign 21V985000 on NHTSA.gov
Seat beltsDec 23, 2020
General Motors, LLC (GM) is recalling certain 2020 Chevrolet Bolt EV and 2021 GMC Canyon and Sierra 1500, 2500 and 3500, Yukon, Yukon XL, Cadillac Escalade and Escalade ESV and Chevrolet Blazer, Camaro, Colorado, Equinox, Silverado 1500, 2500 and 3500, Suburban and Tahoe vehicles. Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle. If an incorrect bolt was used, the seat belt may not be properly attached to the vehicle.
If a seat belt assembly is not properly attached to the vehicle, the seat belt may not properly restrain an occupant in the event of a crash, increasing the risk of injury.
GM will notify owners, and dealers will replace the suspect bolts, free of charge. The recall began January 29, 2021. Owners may contact GMC customer service at 1-800-462-8785, Cadillac customer service at 1-800-458-8006, or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202322230.
Campaign 20V811000 on NHTSA.gov
Seat beltsDec 17, 2020
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.
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.
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.
Campaign 20V792000 on NHTSA.gov
TiresNov 5, 2020
General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5, GMC Acadia and Chevrolet Traverse vehicles and 2020-2021 Chevrolet Silverado 1500, GMC Sierra 1500 vehicles. The vehicles may have been manufactured with Continental tires that were overcured.
Overcured tires may experience a carcass break in the sidewall resulting in a sudden air loss or could develop a belt edge separation which could lead to partial or full tread/belt loss. Either condition increases the risk of a crash.
GM will notify owners, and dealers will inspect vehicles and replace tires that have DOT number and production mold number combinations identified by Continental, free of charge. The recall began December 17, 2020. Owners may contact GMC customer service at 1-888-988-7267, Buick customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N202319030.
Campaign 20V684000 on NHTSA.gov
Representative owner complaints
572 reports, newest first.
Engine, Mar 22, 2026
I am filing a complaint regarding a catastrophic engine failure in my 2021 GMC Sierra 1500 equipped with the 6.2L V8 engine. While driving under normal conditions, the engine suddenly failed without warning and threw a connecting rod, rendering the vehicle inoperable. There were no prior warning signs such as knocking, overheating, oil pressure issues or even a check engine light. The vehicle has been properly maintained, including regular oil changes using manufacturer-recommended 0W-40 oil. This failure created a serious safety concern due to the sudden loss of power while driving, which could have resulted in a dangerous situation, especially at highway speeds or in traffic. I am aware that General Motors has issued a recall and/or is aware of similar failures involving the 6.2L engine in certain 2021 vehicles. However, my vehicle’s build date falls just outside the currently defined recall range, despite experiencing the exact same type of catastrophic failure described in those cases. My build date is 12/20 and the recall was issued for 3/21. Given the similarity of this failure to known issues, I believe this defect extends beyond the currently identified recall population. This raises concerns that additional vehicles, including mine, are at risk of sudden engine failure without warning. I am requesting that National Highway Traffic Safety Administration investigate this issue further and consider expanding the recall to include additional affected vehicles outside the current build date range.
Power train, Fuel/propulsion system, Mar 20, 2026
The DEF tank in my truck is defective and its the second time in the last 14 months it has broke. The part is now back ordered and according to the dealership this is a nationwide issue regarding these specific trucks. I have contacted around 10 dealers in my area and all tell me the same thing that they have multiple trucks waiting on the same issue. I have not had my truck for over 2 months and have no idea when i will be getting it back due to dealership having no idea when the part will be released due to the back order. This seems to a huge issue with these trucks and GM is doing nothing to help resolve it. I've reached out to GM directly and get no assistance and now have made 2 payments on my truck and the dealership refuses to give me a loaner vehicle. i am looking for some help or relief on what to do to go about my issue
Other or unspecified, Mar 19, 2026
When my android auto does not connect, it essentially disables the whole infotainment system which is incredibly distracting and dangerous while driving. I am requesting that this be fixed so that I can still use some of the infotainment system but they are redusing to to do anything to fix the issue. The dealer has advised that they are unable to fix the issue because it is software related but yet the software team is saying it is a dealer issue. Please help me get a resolution to this issue!
Engine and engine cooling, Mar 18, 2026
The contact owns a 2021 GMC Sierra 1500. The contact stated that on Aug. 14, 2025, the PICO engine test was completed on the vehicle under NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The dealer stated that the engine had passed the test, and the engine oil was changed to a higher viscosity oil, and the oil cap, oil filter, and the page in the Owner’s Manual were updated. The contact stated that the vehicle was making abnormal sounds while idling, and the fuel consumption had increased. The dealer was contacted and advised the contact to bring the vehicle back to have the engine test performed again; however, the contact refused. The vehicle was not repaired. The contact stated that the engine test had not been performed on the vehicle and that the vehicle was unsafe. The manufacturer was informed of the failure and informed the contact that the vehicle was repaired. The failure mileage was approximately 44,000.
Engine, Mar 17, 2026
at roughly 5,000 miles had lifter failure which caused loss of power. That was repaired under warranty. Same issue at 86,000 miles - loss of power. New engine which I had to pay for. Same issue at 126,000 miles. New engine required. Covered under warranty. Side note. New engine will only have balance of warranty from 2nd engine or about 5,000-6,000 miles. first incident Feb 2001, second incident about Nov 2004, third incident Mar 2026.
Engine, Mar 16, 2026
Loss of power, and knocking from the engine while driving. Check brake system, check srs, check parking brake and check engine light flashing came on at the same time. The problem has been reproduced at a mechanics shop and has been determined that cylinder 6 is dead.
Electrical system, Engine, Mar 10, 2026
Following the remedy of the engine recall in 2025, the truck started having intermittent electrical issues (i.e. warning lights on dash turn on/off: service 4WD, Loss traction Control, etc) come one while the truck is being driven. If the truck is turned off while the dash warning lights are on, it will NOT Start for about 24 hours. If the warning lights are ignored, eventually they will go off on their own. Additionally, the truck is having "no-start" problems (randomly the truck does not start, then after a few days it starts). A New development, when backing up there is a scraping/squealing sound (possibly universal joint). Truck has been back to the dealership that replaced the engine block for the recall and they have failed to identify any issues as these problems are intermittent. Engine Recall Replacement Invoice (Attached)
Engine, Mar 9, 2026
Took it to dealer for engine sound said nothing was wrong 4 days later rod bearing went out while driving. Truck no longer able to drive
Suspension, Power train, Mar 8, 2026
Transmission Shuttering which was confirmed from from GMC dealership , but refused to do any repairs after confirmation or diagnostic and test driving. Demanded a 220$ fee be paid before releasing my vehicle back. Also gave GMC Bulliten # 25-NA-148 which states the same issues I'm currently having.
Power train, Engine, Mar 8, 2026
Driving down the road and engine shut off and would not start back. Had it towed to dealer and it needed a motor replacement. Waited over a month for the shop to finish it. New motor has 3k miles on it and is making noise, transmission is stuttering hard and the air conditioning quit working all around the same time. Had to take the truck back to the dealer after the replacement motor was installed because of a faulty “new” starter.
Other or unspecified, Engine, Mar 8, 2026
[XXX] we bought our 2021GMC Sierra 1500 from Dealer with 39842 on it. we drove the truck 2910 miles when we checked the oil it was 2 quarts low at 42752. we added oil at that time and called our local dealer to make appointment . appointment at Bowser route 51 Pleasant Hills PA 15236 They informed us they would have to charge us for an oil change to start an oil consumption test on 10/23/25 miles 43829. 11/24/25 brought back to Dealer they said the oil was full yet i checked it in morning it was1/4 low. 1/7/26 brought back to dealer this time they let our truck sit over night the best way to check it and found it to be 3/4 low with only 1,698 miles driven also the antifreeze reservoir was low also they topped off both. 3/8/26 I Checked it ,its now 1 quart low with 1,097 miles driven milage on truck now is 46,623. Summarize GMC will not even look into why my truck is using oil not once my truck is still under warranty where is the consumer protection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Electrical system, Other or unspecified, Mar 7, 2026
Rear tailgate on my 2021 Sierra opens or drops when wet. This seems to only happen in a heavy rain or after a truck wash. This problem has been recognized by the manufacturer and the dealer. There is no warning other than the constant clicking of the electric switch allowing the tailgate to drop. This problem has been recalled on the 3/4 & 1 ton trucks but not the 1/2 ton. The tailgate and switches are the same on all 3. Because my vin# does not show for this recall I had to pay for the replacement
Engine, Fuel/propulsion system, Mar 6, 2026
Engine developed a low knock type noise just above idle while beginning to move in the parking lot. It was also noted pulling away from an intersection at low rpm under light acceleration. Oil pressure was normal, 30 psi and approximately 50-60 at cruising speed. Low level knock began earlier in the day but no other symptoms. Oil level was checked and found to be at proper level. At mile 2 into my trip a chirping/ squeak type noise was heard under light throttle and light load at approximately 1500 rpm. The noise stopped when accelerator was released. Rough running sensation followed the noise under the load. Noise returned when the accelerator was pressed and then the engine stopped running while traveling 45-50 mph. Placed the shifter to neutral and attempted to restart, engine rolled slowly for a brief moment and then locked up entirely. Starter only clicks when attempted after that. Vehicle left me stranded with no heat on the shoulder of the highway in the dark in Northern Michigan on March 5, ambient temp was 28 degrees. Vehicle towed to closest dealership which is also where it was purchased for inspection on 3/6/2026. General motors customer care contacted and case opened. No assistance with repair at time of callback.
Power train, Mar 6, 2026
The valve body failed, brought it in to a GMC dealership 3 months ago they told me the valve body is on back order. Last week they received the new valve body installed it and tried to program it. While programming it, the brand new valve body failed. So now I am stuck again with no ETA of when a new valve body will be sent to the dealership to fix the issue. this is obviously an issue with the make and model and in my opinion should be a recall. I do not feel safe if I ever get my truck back from this issue due to ongoing valve body failures nation wide and two on my end.
Power train, Mar 4, 2026
With the cruise set at 55-60 mph the Rpms will jump, along with a slight shudder feeling. Cruise control has turned off a few times due to this. Cruise set at 25mph and would shudder/lunge forward. Torque converter is showing it’s slipping and will need replaced. No check engine lights.
Power train, Mar 2, 2026
My vehicles transmission is part of a recall but my vin is not registered for this recall repair. Please assist.
Power train, Mar 2, 2026
Per GMC dealership, this vehicle suffered a Transmission valve body failure and they are recommending replacement of the entire transmission.
Power train, Feb 26, 2026
Engine coolant control valve failure. This is a widespread issue on 2020-2022 3.0L Diesel trucks and it hasn’t been addressed by GM, leaving owners to pay out of pocket for a faulty part.
Power train, Feb 23, 2026
Vehicle began to slip or shift hard when putting it in gear or coming to a stop. The next morning the vehicle would not move when put in drive or reverse.
Power train, Engine, Back over prevention, Feb 21, 2026
I was driving on a highway on my way home from work. Thank god there was not a lot of traffic because my truck just shut off lost all power, then I received a message on the dash to put on neutral and restart. I tried multiple times to turn it back on. It never turned on and had to get it towed to nearest dealership. It took them a week to inform that the engine locked up even though I tried to take it for the recall they told me to wait and reschedule the appointment. Never got a new appointment until the engine failed and I got it towed to the dealership and have also not received a new kind of loaner from GM. This will be my last GMC truck I purchase.
Engine and engine cooling, Feb 20, 2026
The contact owns a 2021 GMC Sierra 1500. The contact stated that while operating the vehicle, the check engine warning light illuminated and remained illuminated. While driving at various speeds, the vehicle entered LIMP Mode, causing the vehicle to decelerate. Additionally, the radiator fan was continually activated while operating the vehicle. The vehicle was taken to the local dealer, who diagnosed that the coolant control valve was inoperative and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 119,000.
Engine, Feb 18, 2026
The failed component is the engine coolant control valve on a 3.0L Duramax truck. The failure has been documented and confirmed by both an independent mechanic and an authorized dealership. The malfunction creates a significant safety hazard. Without warning, the truck will suddenly enter a reduced engine power mode while traveling at normal highway speeds. When this occurs, the vehicle will not allow acceleration beyond approximately 50 miles per hour. This is especially dangerous when operating on roadways with speed limits of 70+ mph, as the sudden and unexpected loss of power places myself and surrounding motorists at risk. The problem has been reproduced and confirmed by Steele GMC in Round Rock, Texas. In addition, the vehicle has been inspected by an independent mechanic, both of whom verified the coolant control valve failure. Prior to the initial occurrence of the failure, there were no warning signs. Once the malfunction occurred, the check engine light illuminated. General Motors has issued Service Bulletin #25-NA-185 (revised December 4, 2025), which addresses engine coolant control valve failures on 3.0L Duramax vehicles and outlines the proper diagnostic and repair procedures for this exact failure mode. This bulletin applies to 2021–2026 3.0L Duramax trucks. Additionally, GM has implemented Special Coverage program N252508341 for 3.0L Duramax coolant control valve failures, which extends coverage up to 15 years or 150,000 miles when diagnostics confirm the failure condition. Despite the fact that my vehicle’s documented failure matches the exact conditions described in the above-referenced service bulletin and special coverage program, I was informed by Steele GMC that my specific VIN is not included in the warranty. Given the documented safety risk, the confirmed diagnosis, and the existence of official GM guidance addressing this precise issue, I respectfully request this be reviewed and appropriate coverage or corrective action be authorized
Power train, Feb 17, 2026
I have had shuddering on the highway and a few hard random diwnshifts. Last week I went to start my truck and the transmission started grinding and rattling. I was told after towing to the dealer it needed a transmission due to pump not getting enough fluid and had failed. I was told I needed to pay, even though the part causing the problem had a extended 150,000 miles and the subsequent pump failure is a result of the control valve failure.
Engine, Feb 12, 2026
Had a P1098 code. The truck was diagnosed by a certified technician. Found to have a failing coolant control valve. GM has issued special coverage for this known failure. Special coverage is not including the VIN for this truck although it falls in the criteria for model, year, and engine model.
Engine, Feb 11, 2026
Engine failure without any warning. Car maintenance was kept up-to-date.