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, Apr 2, 2025
P1098 coolant Control Valve malfunction and out of stock
Power train, Mar 27, 2025
I own a 2021 GMC Sierra 1500 Duramax diesel. At around 60,000 miles, I received an engine coolant system alert through OnStar and retrieved a P1098 trouble code, which indicates a failure in the coolant control valve. This issue causes the engine fan to run excessively, creating loud noise, reduced fuel economy, and possible drivability concerns. After researching owner forums and talking to multiple service departments, I discovered this is a widespread problem among 2020–2022 GMC/Chevrolet Duramax 3.0L diesel owners. In many cases, the coolant control valve is failing prematurely, and the replacement part is on national backorder, suggesting a high failure rate. GM has not issued a recall or service bulletin to address the issue, and many customers are being told to pay out of pocket despite the systemic nature of the failure. This component is tied to engine temperature control, and failure could pose a safety risk if the engine overheats or derates unexpectedly. I am filing this complaint to document the issue and request NHTSA investigate this as a potential defect.
Power train, Engine, Mar 27, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 30 MPH, there was an abnormal knocking sound coming from the engine compartment, after which the vehicle lost motive power. The contact was able to pull over to the side of the road. No warning lights were illuminated. The vehicle was taken to a dealer, who determined that the engine needed to be replaced. The vehicle was repaired. The contact stated that prior to the engine failure, the transmission was replaced. The manufacturer was not notified of the failure. The failure mileage was approximately 20,000.
Power train, Mar 25, 2025
The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the dealer was unable to complete the recall and returned the vehicle to the contact in a worse condition than when the contact had dropped the vehicle off at the dealer. The contact stated that while attempting to drive the vehicle off the dealer parking lot, the check engine and reduced power warning lights flashed on the instrument cluster. The contact stated that he returned the vehicle to the dealer and was informed that the vehicle could not be repaired. The manufacturer was not made aware of the issue. The failure mileage was approximately 114,000.
Power train, Mar 19, 2025
Truck started to lose power or slip on quick acceleration on highway Truck would jolt or shudder. 63000 miles. Dealer diagnosed truck needs Torque converter and a valve body replacement. No warning lights Contacted GM. Have a case number, was told to take to dealer. It’s at dealer now, getting repaired. I’m wondering if GM has a bigger problem with transmission recall
Power train, Engine, Mar 18, 2025
After 2 years of owning the vehicle, after every oil change, it would indicate low oil just before an oil change causing for us to add an additional a quart of oil to keep it running smoothly. We informed the service technician of the situation on multiple occasions and no further inspection was completed, and just an oil change was serviced. After a few months we noticed the engine was running rough and a white smoke coming out of the exhaust on acceleration then the check engine light came on. We brought the car to get tires replaced and to service the check engine light, the technician stated that the check engine light a failure in the catalytic converter. We brought the vehicle to the local GMC service center, where they indicated that the we required a replacement engine because of catastrophic engine failure. We reported that the check engine light was due to catalytic converter failure. The service technician ensured that the priority was the replacement of the full engine not indicating what was the main cause of engine failure stating that the catalytic converter could have led to the failure of the engine as well. We replaced the engine, and after 3 months of vehicle being in the shop the engine was replaced. Three days after receiving the vehicle, a check engine light came on. We did not drive the vehicle until we had to return it back to the service center. The service technician stated that it is due to a lack of communication from the engine to the ECU. The technician called the following Monday stating that the check engine light was due the catalytic converter. We told the technician that was the primary reason that the customer the vehicle in the first place. We asked if there was an alternative to replacing the catalytic converter since we already paid 12k for the engine replacement. We asked if they had taken apart the catalytic converter to confirm its not a sensor issue. They replied that the codes indicates its the whole converter.
Power train, Mar 18, 2025
See attached document for complaint.
Power train, Mar 17, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving approximately 75 MPH, the rear wheels locked up. The failure had occurred on several occasions. The contact stated that several unknown warning lights were illuminated. The vehicle was towed to a dealer where it was diagnosed and determined that a software update was needed. The vehicle was repaired under an NHTSA Campaign Number: 24V797000 (Power Train); however, the failure persisted. The manufacturer was not notified of the failure. The failure mileage was approximately 35,000.
Power train, Electrical system, Engine, Mar 12, 2025
[XXX], I PURCHASED A 2021 GMC SIERRA 1500 FROM FAULKNER CHEVROLET IN BETHLEHEM, PA. I TEST DROVE THE VEHICLE BEFORE PURCHASE AND IT SHOWED NO INDICATION OF ANY MECHANICAL ISSUES THAT I WAS ABLE TO DETECT. I WAS SHOWN BY THE DEALERSHIP THE CARFAX AND WAS INFORMED THAT THERE ARE CURRENTLY NO RECALLS FOR THE VEHICLE. I WAS LED TO BELIEVE THAT THE VEHICLE WAS IN GOOD CONDITION AND SAFE TO DRIVE AND, THEREFORE, AGREED TO PURCHASE THE VEHICLE FOR THE AFOREMENTIONED PRICE (INCLUDING TAX AND TITLE FEES). I PURCHASED THE VEHICLE WITH 60,077 MILES ON IT, AND AFTER DRIVING IT NORMALLY FOR ONLY 5 DAYS (ON [XXX]) IT BROKE DOWN AND I WAS STRANDED ON THE HIGHWAY 16 HOURS FROM HOME. I WAS ABLE TO GET THE VEHICLE TOWED AND PAID $1,200 FOR THE STARTER TO BE REPLACED, WHICH IS WHAT THE MECHANIC SUGGESTED BUT THIS ENDED UP BEING ENTIRELY UNNECESSARY AS THE REAL ISSUE WAS DUE TO A CATASTROPHIC DEFECT IN THE ENGINE. AFTER THE STARTER WAS REPLACED, I WAS DRIVING THE VEHICLE ONLY A FEW DAYS LATER (ON [XXX]) AND IT SUFFERED A CATASTROPHIC ENGINE FAILURE WHILE DRIVING 70MPH ON THE HIGHWAY. I LOST CONTROL OF THE VEHICLE AND NEARLY GOT IN A COLLISION WITH ANOTHER VEHICLE. I WAS ABLE TO GET THE VEHICLE TO THE NEAREST AUTO SHOP AND AFTER INSPECTING THE VEHICLE THEY INFORMED ME THAT THERE IS A SERIOUS ENGINE ISSUE RELATING TO A SEIZED BEARING AND THE ENGINE WILL NEED TO BE REBUILT ENTIRELY. AT THIS POINT IT HAD BEEN ONLY 12 DAYS SINCE THE PURCHASE AND THE ODEMETER READ 61,662 (1,585 MILES DRIVEN SINCE PURCHASE). DUE TO THE FAULTY VEHICLE, I WAS FORCED TO PAY TO HAVE THE VEHICLE SHIPPED FROM THE LOCATION WHERE IT BROKE DOWN TO THE DEALERSHIP WHERE I ORIGINALLY BOUGHT IT (AROUND $1,200). FAULKNER CHEVROLET KNOWINGLY SOLD ME AN UNSAFE VEHICLE THAT THEY WERE WELL AWARE HAD A DEFECTIVE 6.2L V8 ENGINE. THIS DEFECT IS CURRENTLY UNDER INVESTIGATION BY THE NHTSA AND FAULKNER CHEVROLET PURPOSEFULLY OMMITTED THIS CRUCIAL INFORMATION UNTIL AFTER THE VEHICLE WAS SOLD. CLEARLY, THIS IS AN UNETHICAL BUS INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Power train, Engine, Feb 28, 2025
Subject: Complaint Regarding Recurring Engine Failure in 2021 GMC Sierra AT4 Dear National Highway Traffic Safety Administration, I am writing to formally express my concern regarding recurring engine failures in my 2021 GMC Sierra AT4 (6.2L engine). At 23,000 miles, the vehicle suffered a complete breakdown due to failure of cylinder #8, lifters, and push rods. General Motors covered the repairs at that time. However, at 97,000 miles, the exact same issue reoccurred, resulting in significant engine damage. The dealership diagnosed a misfire in cylinder #8, leading to the removal of the right cylinder head, where they found a bent push rod, spun lifter, damaged camshaft lobe, and lifter roller. The repair estimate totals $9,746, but GM has refused to cover the costs, despite us having an extended warranty purchased from the dealership. This recurring failure raises serious concerns about engine reliability and manufacturing defects in General Motors vehicles. I urge the NHTSA to investigate this issue, as multiple GMC and Chevrolet owners have reported similar problems with the 6.2L engine lifter and camshaft system. This is not just a costly repair but a potential safety hazard that GM has failed to properly address. Thank you for your attention to this matter. I appreciate any guidance or action the NHTSA can take to hold GM accountable and ensure consumer protection.
Power train, Engine, Feb 24, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 55 MPH, the vehicle started making a knocking sound. There were no warning lights illuminated. The contact picked up his son from school and drove the vehicle to the dealer. The contact stated that while depressing the accelerator pedal, the knocking sound became louder, and the vehicle was losing motive power. The vehicle was taken to a dealer and diagnosed with engine failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 58,522.
Power train, Feb 20, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at various speeds up an incline, the vehicle was vibrating and shuddering. The failure persisted over time. There were no warning lights illuminated. The vehicle was taken to the local dealer, but the vehicle was not diagnosed or repaired. The vehicle was taken to a transmission shop, and it was determined that the transmission needed to be replaced. The manufacturer was not contacted. The approximate failure mileage was 68,000.
Power train, Feb 11, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds and depressing the accelerator pedal, the vehicle hesitated to respond and shuddered. The vehicle was taken to the dealer, where the fuel tank was cleaned, and the contact added fuel treatment to the fuel, as recommended by the dealer; however, the failure recurred. The contact stated that while driving from a complete stop, uphill, and while driving 50 MPH, the vehicle shuddered and experienced erratic transmission shifting. The check engine warning light was illuminated. The vehicle was taken to Dixie Buick GMC (14565 S Tamiami Trl, Fort Myers, FL 33912); where it was determined that the vehicle was experiencing a abnormal shudder. The dealer replaced the transmission fluid; however, the failure persisted. The contact stated that the failure had become progressively worse and mostly occurred at 1,200 RPM. The dealer was contacted, and an appointment was scheduled for diagnostic testing. The vehicle was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 24V797000 (Power Train); however, the VIN was not included. The manufacturer was notified of the failure. The failure mileage was approximately 8,000.
Power train, Vehicle speed control, Engine, Feb 2, 2025
On the morning of 1/19/25, my 2021 GMC Sierra 6.2L AT4 went into limp mode heading south on HWY 207 in Leavenworth, WA at approximately 60 m.p.h. Fortunately, I was able to avoid a rear end collision. I quickly turned the truck off in the middle of the road and restarted it with a CEL. When I returned home almost 180 miles away, my local mechanic diagnosed a code P0303 and cleared it. Since, the truck has continued to shutter at various speeds without throwing a code. It is currently at Haselwood GMC in Bremerton, WA being scanned, recorded, and findings set to GM waiting for resolve. I have notes, exact dates, times, call records, return voice mail messages, and dealership personnel spoken to, etc. The dealer’s lead technician and I were able to replicate the shutter on a road test together on 1/27/25 at 3 p.m. after having driven just 10 miles. During my visit on the morning of 1/30/25, the lead technician stated he has since been able to replicate the shutter seemingly getting worse. I was strongly encouraged by the service manager, service writer, and lead technician their collective “personal recommendation” was to not take the truck back. Haselwood has had the truck since 1/27/25. Still awaiting a response and resolution.
Power train, Jan 31, 2025
The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the contact believed that the remedy offered would cripple the vehicle and interfere with his work. The contact works in Alaska and the remedy involved the transmission being limited to fifth gear, preventing the possibility of a wheel lock up condition, which could occur while downshifting from eighth gear. The manufacturer was made aware of the issue and advised the contact to find a dealer that could repair the transmission. The contact had not experienced a failure. Parts distribution disconnect.
Power train, Jan 30, 2025
The engine locked up with no warning I called the dealership and they said it was out of warranty as it has 77000 miles. upon further investigation I found that the front main bearing on the engine had gone bad and caused the engine to lock up. GMC refused to accept any responsibility for the failure.
Power train, Jan 21, 2025
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at approximately 20 MPH, the vehicle lost motive power. The contact stated that the accelerator pedal was depressed; however, the vehicle failed to respond as needed. The contact moved the transmission lever from drive(D) to neutral(N) to reverse(R) several times and was able to drive back to the residence. The contact stated that the check engine warning light was illuminated. The contact had the vehicle towed to a local dealer. The dealer diagnosed the failure and determined that the transmission control valve had failed and needed to be replaced. The vehicle was repaired; however, the contact stated that the failure had reoccurred. The vehicle was taken back to the same dealer who advised that the transmission control valve had failed, but the parts needed to complete the repair were on back-order. The vehicle was not repaired. The contact had asked the dealer what the possibility of the same failure reoccurring after the second replacement of the control valve and the dealer advised that the valve would fail again. The vehicle was awaiting repair. The manufacturer was informed of the failure. The failure mileage was 27,676.
Power train, Jan 20, 2025
The control valve system on my 2021 gmc has malfunctioned and this is the second time, currently sitting at Nelson GM Dealer in Fergus Falls MN. I have to drive back to TN as thats where I live and the mechanic said this issue will happen again. This vehicle hasn't had recalls but I believe it was missed since this is the second time with this same issue. This is a GM wide issue as I have researched.
Power train, Engine, Jan 20, 2025
We had to replace the transmission at 70,000 miles even though problems were reported to the dealer at 53,340. This repair costed $2300 on a 1 year old truck. Then we needed to replace a solenoid circuit which was not covered under warranty. We repaired this 2x (the second time covered). Then at 147,000 miles 9/24, there was a cylinder misfire which bent the push rod and collapsed lifter. This engine repair cost $8300.00 dollars. Who has to replace an engine on a truck that's 3 years old. This is a defect. Please help us. We have spent over $10,000 on repairs. We faithfully do our changes and service.
Power train, Engine, Jan 18, 2025
L87 engine problems. I have had failed lifters, on top of transmission issues and a current oil consumption issue where I have to add two quarts of oil (sometimes more) without any indication of low oil. I took my vehicle into the local dealership and the technician asked if I had gotten any low oil indicator and I stated no. He proceeded to tell me it had little to no oil in it. Imagine this at highway speeds and sudden engine seizure.
Power train, Jan 16, 2025
Transmission has a hard shift when coming out of each gear. 2nd to 1st shifts hard and jolts entire vehicle a head. Feels like a slip or difficulty in shift.
Power train, Service brakes, Engine, Dec 21, 2024
I received a notice of a recall for a known problem with GMC transmissions. it is very well known that these transmissions lock up and cause problems with braking and can cause the vehicle to slide off the road when the tires lock up. it also causes hard shifting, which I have experienced. GMC said they will not fix the transmission, they instead will add a device to monitor the transmission, so when the transmission locks up and causes an accident, it will let me know that it was the transmissions fault!!! How is this legal? they will let me know that their transmission caused the accident after the fact? why not fix it? typical of government to do nothing about safety... and instead make laws that allow big corporations and government to make money off of peoples deaths!
Power train, Dec 20, 2024
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving at various speeds and downshifting, the rear wheels locked up with the parking brake warning light flashed on the instrument panel. The vehicle would resume normal operation soon after the failure. The vehicle was taken to a dealer where the contact was informed that there was a pending NHTSA Campaign Number: 24V797000 (Power Train) on the vehicle for the failure. The contact was informed that there was a temporary fix on the vehicle to repair the defect. After the temporary fix was performed, the contact experienced the failure twice within a week. The contact received a call that the permanent fix was available; however, soon after the repair was performed, the failure immediately occurred upon leaving the dealer. The manufacturer was notified of the failure, and the contact was informed that he would receive a callback. The vehicle was not repaired. The failure mileage was approximately 75,000.
Power train, Dec 16, 2024
The contact owns a 2021 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that the transmission was shifting hard while driving. The local dealer was notified of the failure. The cause of the failure was not yet determined. The manufacturer was not made aware of the issue. The failure mileage was 120,000. VIN tool confirms parts not available.
Power train, Dec 12, 2024
transmission has a shudder when accelerating and after shifting through all gears (8speed) during cruise mode when going on an incline as in overpass it starts to shudder and seems like it is trying to find the right gear to go into .