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: power train
137 reports, newest first. Show all
Power train, Engine, Fuel/propulsion system, Apr 16, 2026
While driving into work, I noticed a knocking sound from the outside of the vehicle. Once parked, upon further inspection I narrowed down the area of the noise to the bottom rear of the engine/front of transmission. Fortunately, I was able to park in front of my office building and wasn’t stranded on the side of the road but under different circumstances it could've been the side of a busy highway or hours from home. I had the vehicle towed to the dealership I originally purchased from, the dealership was able to duplicate the issue with me present. Later that afternoon I was informed that the engine had failed and a replacement would be ordered. There was no prior indication of a problem or warning/CEL’s. The engine failed after the dealership had completed the engine recall ( pico test and 0-40W oil change ) related to the vehicle. I am reporting this in hopes that it helps with the investigation. This has been very disappointing for me as I have supported the brand of vehicle for many years. Only to have many issues under 80,000 miles and to lose confidence in the vehicle I purchased and the company.
Power train, Engine, Apr 13, 2026
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving approximately 45 MPH, the transmission inadvertently shifted from drive (D) to first gear. The check engine warning light was illuminated. The vehicle was pulled over to the side of the road and then towed to the dealer, where it was diagnosed, and it was determined that the valve body needed to be replaced. The vehicle was not repaired because parts were not available. The manufacturer was notified of the failure. The failure mileage was approximately 103,000.
Power train, Engine, Apr 8, 2026
I have a 2021 GMC Sierra 1500 AT4 3.0L diesel pickup truck with 98,500 miles. The coolant control valve failed on my vehicle and for some reason it is not covered under GM's special bulletin that covers this part 15yr/150,000. Ridiculous.
Power train, Mar 31, 2026
I believe the torque converter is failing. While driving approximately 38 mph and also 48 mph up to 51 mph the vehicle have a vibration feeling like driving on a rumble strip. If you maintain the same speed, the vibration continues if you speed up, slow down, or let off the gas it goes away. There are so many detailed explanations on forums and social media from other customers experiencing the same problem, but not seeing any recall made by GMC.
Power train, Mar 23, 2026
I've been to the dealership a few times due to the truck jerking violently under very light acceleration when its trying to shift gears. also there was a few times that the rear wheels have locked up while driving.
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
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.
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.
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.
Power train, Engine, Feb 10, 2026
The engine has been burning oil since purchased but really highlighted when at 47k miles I got a dashboard message saying “reducing power to engine” I checked the oil and it didn’t register in dipstick. I added 3quarts of oil to show up on dipstick. When I changed the oil which I did at my own garage only 2.5qrt came out including what was in filter. It’s since take an average of 2.5qrt between oil change at 7500. Also the transmission is slipping which happened after warranty expired at about 69k miles and I don’t want it to repair or repair until gm fixes these issues which they know are problem in2020-2021 models but they haven’t addressed it. My truck has been serviced at the dealership except fo 3 oil changes. The issue are noted but the answer is car burn oil typically between changes. Yeah they do if it was 20yrs old not 3yrs. The issue lies with GM. It’s Needs to be addressed.
Power train, Wheels, Jan 25, 2026
4 months after bring my truck back to the dealership for a body valve issue on the 10 speed transmission. The truck went into limp mode while I was driving.
Power train, Engine, Fuel/propulsion system, Jan 22, 2026
On the afternoon of 01/20/26, I was merging onto the highway in my 2021 GMC Sierra 1500 when a loud bang was heard from the engine compartment at approximately 60 mph. Immediately after the ban was heard, several indicator lights on the dashboard were illuminated, including the ESC, check engine light, and parking brake light. A power loss was felt when attempting to accelerate and the banging noise worsened anytime the accelerator was depressed. I was able to drive the vehicle to the nearest GM dealership that coincidentally was at the closest exit off of the highway I was traveling on. The dealership performed diagnostic and determined that the damage was caused due to the ongoing GM recall associated with Safety Recall N252494000. My vehicle had previously been inspected as part of the recall and was found to have passed. Vehicle had been driven approximately 4,000 miles after recall was performed.
Power train, Jan 20, 2026
1-At approximately 40,000 miles, my transmission was replaced under warranty. It had been failing since approximately 2000 miles having a very hard time shifting between first and second gear. It was finally replaced at 40,000 miles. 2- At approximately 45,000 miles I took my truck into the dealership for this latest recall on the 6.2 L failure for inspection. Vehicle is inspected and I was told I would need to have an engine replacement. I was told that there was no ETA on when a replacement engine would be available and that I would be contacted when one was. Afterwards I was sent back home in the truck they just inspected for potential engine failure and said had a bad engine. As of now, I’m still waiting on a word of a new engine and my truck is still operating, but leaves me concerned that it could fail at any moment while driving it.
Power train, Jan 10, 2026
Unexpected rear wheel lock-up at 29000 miles. While engine braking from highway speed onto an off-ramp at approximately 50 mph, the rear wheels unexpectedly locked up. Due to prior rear brake actuator issues, I suspected the emergency brake had activated without my input. It was only momentary, and no fault codes or warnings were displayed. It happened again under the same circumstances two months later, with no fault codes. On May 9, 2025, the check engine light came on, and I scheduled service. The dealer addressed a recall regarding the transmission by installing software. In August 2025, I received a letter from GM regarding recall N242454440 for excessive wear in the transmission control valve, which was causing rear-wheel lockup. On October 31, 2025, while towing a small enclosed trailer at 70 mph on the highway with cruise control engaged, the truck suddenly decelerated, and I was nearly rear-ended by a semi-truck (no brake lights to warn them). The truck would not go over 50 mph unless I was going downhill. The transmission would not shift into higher gears. I returned it to the dealer, who checked the computer and found no record of the incident, so they said there was no problem. They informed me that the new software was designed to limit the truck's speed if a potential lockup was detected. This recall did not fix the transmission problem or the safety issue. It was simply a way to avoid costly repairs. There is a problem with the physical transmission valve that, for me, resulted in an extremely dangerous situation. The NHTSA needs to take this issue seriously and require GM to replace the prematurely worn valves in the affected vehicles.
Power train, Engine, Jan 3, 2026
I own a 2021 GMC Sierra 1500 equipped with the 6.2L L87 V8 engine and 10-speed transmission. The vehicle exhibits the following issues: Persistent lifter ticking noise audible from the driver-side wheel well, even when the engine is warm. Rough idle that is noticeable at stops and low-speed conditions. Transmission shifting problems, specifically harsh or delayed shifts when downshifting from 3rd to 2nd gear during deceleration. These symptoms raise concerns about potential lifter failure and transmission defects. I am aware of GM’s recall (25V-274) and NHTSA Engineering Analysis EA25007, but my vehicle’s build date (January 2021) currently falls outside the official recall window. Given the similarity of symptoms to those under investigation, I believe my vehicle may be affected by the same defect. Safety Concern: The rough idle and shifting hesitation could lead to unexpected loss of power or unsafe driving conditions, especially during deceleration or merging. Request: Please include this complaint in EA25007 and consider expanding the recall to cover earlier builds. I am willing to provide service records, videos, and additional documentation upon request.
Power train, Fuel/propulsion system, Dec 22, 2025
Transmission valvebody failure, causing rapid, repeated rear wheel lock ups. Videos can be provided. These happen almost daily at highway speeds. This will cause a very bad accident
Power train, Engine, Dec 3, 2025
On 10/21/2025 as I was traveling on the highway in Kansas at 60 mph, the vehicle lost power and the engine went into limp mode immediately reducing the speed dramatically. Multiple warning lights flashed on the screen. I was able to get the truck to the side of the highway. The vehicle never started again. I was informed by the dealer that the vehicle would need a new engine.
Power train, Fuel/propulsion system, Nov 10, 2025
I was driving on the freeway and my gmc Sierra at4 received a notification that I could could no longer accelerate. I pulled off to the side as safely as I could in a slanted hill in a major freeway with no shoulder. I sat on the side of the road for 45 min and then ran out of diesel gas waiting for the tow truck. We took into gmc and they said nothing was wrong, we were out of gas. But I ran out of gas waiting for the tow truck. The truck never shut off and ac still going, I just couldn’t accelerate. We’ve had the truck in the shop every single month for the past year for sensor issues and replacements and have all the documentation of the last few years of similar issues. No extensions of warranty’s nothing. Well we started to smell something burning this week and now we were told today we have a faulty fuel pump that will cost us $1,000 to fix and is not covered under our warranty. The truck is still under warranty, so why is something in relation to the power train not covered? There is a current t recall on other gmc models of this year for this fuel pump issue and the safety recall is EXACTLY what happened to us on the freeway and the issue we have now. Why has this not been extended to other GMCs????? My entire family could have died on the side of the freeway!!