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.
Power train, Jul 1, 2025
My 2021 GMC Sierra 1500 Diesel Truck is displaying the Check Engine Light which I was told by the local Mount Vernon GMC Dealership is a failed Temperature Control Valve affecting the transmission. I also get a warning message of "Reduced Engine Power". I am told that it is OK to drive the vehicle but at reduced power. The dealership told me they ordered a replacement part which is covered under warranty on May 7, 2025, but showed on "Back Order". Every time I call to follow up on the status, I'm told it is still on "Back Order", and they cannot do anything to improve the delivery. Why does a customer, owning a "Denali" truck under warranty, can't get the problem resolved? I have a recall notice from GMC dated January 2025 about this very problem and have shown it to GMC dealerships during regular services, and still have the problem. Since I have bought this truck, I have experienced a failed right running board that cost $1,500 to repair a few months ago which is failing again. The driver side mirror now vibrates when I put the truck into drive after being in reverse, and I cannot get any idea on when this transmission valve problem will be fixed which is causing me serious delays in using the truck to pull a trailer. Prior to this problem I had the dealership replace my brakes which required 2 follow-up repairs due to the "GMC original rotors" being warped that required machining to make them not vibrate which to me, now makes them "used". This means I paid full price for "repaired" parts! I thought that by buying a GMC "Denali" 1500 Sierra truck I was buying the "top of the line" in pick-up trucks but now finding out it's a lemon. I love the truck, but not the problems. What do I need to do to get this fixed? [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Engine, Jun 28, 2025
It started with a emergency brake light coming on, shortly (2 miles) later it started misfiring on cylinder #1 after replacing coil pack plug wire and plug. It then started smoking bad out of the exhaust. I knew GM was having recalls on the 6.2 engines so I hauled it to the dealer. They told me it was a bad engine and since it had aprox.62,000 miles on it and no recall it wasn't covered. Since then the dealer called the factory service rep. and he agreed to replace the engine at a 50% reduction in the price, but had no idea when they could get me a replacement engine. After a few days of research on my part I called the dealer again to get a price on how much it was going to cost me? The owner of the dealership ask me to give him a few more days to ask the rep. if he would agree to 100%. My problem now is I don't have it to drive, I can't sell it. and no idea how long it will be before it can be repaired. Plus I am still making payments on it. It is available for inspection at the dealer. If I had of continued to drive, it could have locked up causing a catastrophic accident. In my research it looks like these problems started in 2019 not late 2020 when mine was built. NC has lemon law complaints going back to 2019 that have been paid out. I currently own a #1 2007 GMC Yukon Denali 6.2 with aprox.389,000 miles and only replaced the transmission recently. #2 A 2008 GMC Sierra Denali 6.2 with 279,052 miles, new transmission. #3 A 2011 GMC Yukon Denali 6.2 with 234,361 miles and #4 a 2017 Cadillac Escalade 6.2 with aprox. 102,000 miles. All of these are working and driving on a daily bases. I have a lot of faith in these 6.2 engines until now, I will no longer be buying any more of these engines even though 1 out of 5 aint bad. Thank you for your consideration and for what you do. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Engine, Engine and engine cooling, Jun 26, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated that occasionally while attempting to start the vehicle, the engine hesitated to turn over. The contact stated that the failure progressed, and the vehicle no longer started as needed. The check engine warning light was illuminated. The contact stated that two local dealers were contacted; however, the contact was advised that to diagnose or repair the vehicle, might take several months. The vehicle was towed to a local independent mechanic, where it was diagnosed with camshaft sensor failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 83,000.
Engine and engine cooling, Jun 25, 2025
The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING); however, the part to do the recall repair was not yet available. The contact stated that while driving 70 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. No warning lights were illuminated. The contact stated that several minutes later the vehicle functioned as designed. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. 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 failure mileage was approximately 38,000. VIN tool confirms parts not available.
Engine and engine cooling, Jun 25, 2025
The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING); 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 manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.
Engine, Jun 25, 2025
Safety recall, unsafe
Service brakes, Jun 24, 2025
On March 10, 2025, I was driving down a residential street, about 40 mph, when the "Brake System Failure, 42 miles top speed," indicator light came on. Seconds later, I was approaching a stop sign and pressed down on the brake pedal. The brakes failed and the brake pedal went directly down to the floor. Luckily there were no other vehicles around and i was able to coast through the stop sign. I continued to coast until the truck stopped on its own and I was able to shift the gear into park. I've checked for recalls on my truck for this issue and did not find any. There is a similar issue with the GMC 2500 and 3500 series. Perhaps the issue is broader than expected.
Other or unspecified, Engine, Fuel/propulsion system, Jun 24, 2025
Engine experiences missing when accelerating in lower speeds ...also now, and since driving for a few thousand miles, f umes are entering cabin frequently and causing nausea, 'headaches and burning of mouth, lips and eyes .....all the time. My youngest granddaughter got sick and so did my oldest son just this past weekend! As far as I know , police or dealership never inspected , nor did they acknowledge it! No warning lamps appeared
Power train, Jun 24, 2025
In December of 2024 the engine started not being able to reach full power. This would happen intermittently and there would be a check engine light that would come on when this was happening. In January of 2025 I had the code pulled up by a mechanic at a local shop and this mechanic actually spoke to the service manager of the GMC dealership who said it was covered under the 100,000 mile power train warranty. I took it to the dealership who then told me the diesel mechanic was backed up and I would have to schedule repair for February. I had also received a recall notice in the mail for another issue so asked about taking of both things at the same time. I made the appointment for mid-February so had to deal with reduced engine power for several weeks.The dealership had my truck for several days and a recall was fixed and I thought the reason for the reduced engine power had been fixed also. I had received a phone call from the service representative about an issue that would cost over $1200 that I declined. I did not realize that this was actually for the main issue. I was still thinking the reduced engine power was under warranty. I got my truck back but then the next day the check engine light came on again and the engine power was reduced again. I immediately called the service representative who then told me only the recall had been fixed and that the reason for the reduced engine power was not fixed because I had declined the service. I was totally confused and didn’t understand what happened. This is when I was told that the reason for the reduced engine power was due to a coolant control valve, which was not under the powertrain warranty. I pushed the issue and wanted answers as to why the service manager himself told the mechanic that it was under warranty and was told that the service manager is not a technician and they rely on what the technician says is the problem. And this problem was not covered. I finally gave in and got it fixed and paid $1788.
Other or unspecified, Jun 20, 2025
When I am in park my engine shuts off the light goes from green to orange which indicates it’s still on electrically. I have to turn on/off my vehicle multiple times for it to turn off fully. It’s an intermittent problem.
Power train, Jun 18, 2025
coolant control valve failure activating check engine light, reduced power mode and fan running continuously. Truck has been in the shop for 3 weeks already with no part available.
Engine, Jun 18, 2025
I heard a ticking in the engine and noticed multiple warning lights in the dashboard. I called the GMC dealer and was told the next opening was several weeks away. I was also told that it would be OK to drive the vehicle which I did (~10 miles) and parked the truck in my driveway until I could get the truck in for a diagnostic evaluation. The service department at the GMC dealer where the vehicle was purchased identified a defective camshaft/lifter as the source of the noise and lights. The service manager recommended either an engine rebuild at their shop or purchase a replacement motor from the GMC inventory network. The serial # of the old motor is: 126852545. The serial # of the new motor is: 40208378. The cost of the new motor, replacement of required fluids and parts and labor was $12,360. 100% of the repair was paid by myself. The .pdf of the service record (RO #: 9189240) exceeds the 10 MB limit and cannot be uploaded. I have a hard copy if needed. The dealership where the vehicle was purchased and serviced is: TULLEY Buick - GMC - BMW - Mazda P.O. Box T 147 Daniel Webster Highway South Nashua, New Hampshire 03060 (603) 888-0550 www.tulley.com
Engine, Jun 17, 2025
I had an engine warning warning light on my dash around May 5th. A notice of reduced speed also lit up my dash while I was on the freeway. I scheduled a service for May 15th and was told the engine coolant flow control valve needed to be replaced. I was also told there was a backlog of other vehicles waiting for the same part. It has been over a month and I am still unable to drive my truck which I use for work.
Engine and engine cooling, Jun 17, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds, the check engine warning light illuminated, and the engine fan activated and operated at a very high velocity. Additionally, the message "Engine Power Failure" message was displayed, and the vehicle stalled. The vehicle was taken to the local dealer who diagnosed that the engine coolant control valve was faulty and needed to be replaced. The contact was informed that the parts were on backorder and no repairs were performed. The manufacturer was not yet contacted. The failure mileage was 45,000.
Power train, Jun 17, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated upon starting the vehicle and shifting to drive(D) in the morning, the transmission hesitated to shift to second gear and then shifted harshly. There was no warning light illuminated. The vehicle was taken to the dealer, where it was test-driven, but the failure could not be duplicated. The contact stated that the failure occurred once a day on first start-up of the vehicle and upon shifting to drive(D). The vehicle was taken back to the dealer over the weekend, and the dealer was able to duplicate the failure on first start-up of the vehicle and upon shift to drive(D). The dealer related the failure to TSB Number: 16-NA-361; and informed the contact the manufacturer had not made a repair available. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to file a complaint. The failure mileage was unknown.
Engine and engine cooling, Jun 17, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at various speeds, the check engine warning light illuminated, and the engine fan activated and operated at a very high velocity. Additionally, the message "Engine Power Failure" message was displayed, and the vehicle stalled. The vehicle was taken to the local dealer who diagnosed that the engine coolant control valve was faulty and needed to be replaced. The contact was informed that the parts were on backorder and no repairs were performed. The manufacturer was not yet contacted. The failure mileage was 48,000.
Engine, Jun 11, 2025
My Truck has been consuming oil since new, latest documented consumption test was 1.25 quarts in 1967 miles. GM dealership said that is normal and no further diagnosis is required. GM says acceptable consumption is 1 quart per 2,000 miles. This truck has a 6.2L engine that is not under the current recall ( N252494000 ). The engine problems affect more vehicles that the current recall and should be investigated.
Other or unspecified, Engine, Jun 6, 2025
Dealer keeps ignoring engine knock noise states its normal , mpg is down dramatically . Shift to park , vehicle only has 34k miles and dealer does not want to repair under warranty due to vehicle being a 2021 Battery keeps draining for no reason , new battery added still does the same thing
Fuel/propulsion system, Jun 4, 2025
- #5 injector failure, no. - Once the injector failed, the vehicle would violently shake when trying to accelerate. - Yes, was not covered under factory warranty but replaced by third-party extended warranty. -Yes, replaced by the dealership. -No warnings prior, once the injector failed warning for brake system check and vehicle mileage limits set in warning.
Engine and engine cooling, Jun 3, 2025
The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The dealer was not contacted and confirmed that parts were not yet available. The manufacturer was not made aware of the failure. The contact had not experienced a failure. VIN tool confirms parts not available.
Power train, Jun 3, 2025
received my truck back after replacement of the front transmission pump and idle gear, the same day the transmission had horrible down shifts, sometimes it would just downshift into neutral and bounce off the rev limiter. the service advisor told me that my transmission had to "relearn" my driving habits when I called him and would take 200-400 miles.. i drove it one more day and drove it back to the dealer to have them drive it. the agreed that something was wrong, but didn't know what and had to contact gm engineers. 2 days later they told me that the valve body needs to be replaced. I dropped it off to find out that it had been ordered with zero ETA of when they will receive it.. so now im stuck with a loaner and no ETA on when parts will be available.
Engine, Jun 2, 2025
Engine seized while at idle speed and has to be replaced. It was a catastrophic event, but not covered under the current recall for 6.2L L87 engines.
Air bags, Wheels, Jun 2, 2025, crash
• The airbag system failed to deploy during a collision that resulted in the total loss of the vehicle. Additionally, the vehicle was operating with a 17” spare tire (undersized compared to the standard 20” wheels), which may have contributed to the accident. The vehicle has been totaled and is currently in the possession of the insurance company, but may be available for inspection upon request. • Despite the severity of the collision, none of the airbags deployed, which could have resulted in serious injury if the circumstances were different. The use of an undersized 17” spare tire may have affected the vehicle’s stability, braking, or performance, contributing to the crash. • No. The vehicle was declared a total loss and has not been evaluated for defect reproduction by a dealer or service center. However, I am aware of related recalls and lawsuits regarding both improper spare tire sizing and airbag non-deployment in 2020–2021 GMC Sierra models. • The vehicle has been inspected by the insurance company during the total loss evaluation. A police report was also completed at the scene of the accident. To my knowledge, the manufacturer (GM) has not inspected the vehicle at this time. • No. There were no warning lights, messages, or symptoms prior to the crash. The vehicle gave no indication of any issue with the airbags or tire compatibility leading up to the accident. I was involved in an accident in my 2021 GMC Sierra. At the time, the vehicle was operating with a 17” spare tire installed, which I later discovered may be significantly undersized compared to the standard 20” wheels. During the crash, the impact was severe enough to total the vehicle, but none of the airbags deployed. Fortunately, there were no injuries, but I believe the non-deployment of the airbags represents a critical product safety defect. I’ve since learned that GM has recalled similar vehicles for incorrect spare tires, and that lawsuits have been filed regarding calibration issues.
Steering, Service brakes, Engine, Jun 1, 2025
While traveling on the interstate the vehicle lost all propulsion and started to rapidly decelerate. Shortly after propulsion was lost the engine turned off completely affecting the steering and braking of the vehicle. The vehicle was towed to the GMC dealership that we purchased it from. repairs have not begun so I assume it would be available for inspection. We were traveling on a three lane interstate up a grade at 80 MPH. Had I not been able to safely get the vehicle stopped and out of traffic or had we lost control going down a grade we would not have been able to stop the vehicle and there would've potentially been a catastrophic accident most likely resulting in injury or death. No the dealership has not diagnosed the failure physically. The service writer did suggest that it sounds like the failure reported from the recall not being addressed. I did contact the dealer about the recall on Saturday May6th. At which time I was informed there was not a solution for the vehicle for my vehicle at that time. There were no warning prior to the incident. After the engine stopped operating there was a warning produced on the instrument panel that read "Engine Oil Hot" and the instrument panel no longer registered any oil pressure.
Visibility/wiper, Jun 1, 2025
I don't believe this needs to have an investigation, but i would like it documented and brought to GM's attention for future body designs. I have never had as many rocks/debris hit my windshield as I have with this truck. I have had one chip in a windshield in 30+ years of driving, until this truck where I have had several that needed repairs, and this last one has created a Crack large enough where my windshield needs replaced. It may be bad luck, but I've talked to multiple other Sierra owners and most of them have had the same issue. A couple have had the windshield replaced almost yearly. Please at minimum inform GM engineers to possibly determine the cause (I assume aerodynamics) so they can incorporate the flaw (if there really is one) into future designs. The photo I included happened almost immediately after the impact. The crack has grown several inches since as expected.