2021 Gmc Sierra 2500 problems, complaints & recalls
Most-reported problem areas: Power Train (12) · Exterior Lighting (8) · Service Brakes (6)
🧭 Reliability snapshot
Compared against other Gmc Sierra 2500 model years — complaint volume vs the model's median year, recalls and severity. How we score →
Safety recalls (6)
Power Train:automatic Transmission:fluid/Lubricant:valves/Valve Body 2024-10-24 · campaign 24V797000 · 463,295 vehicles
Defect: General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.
Risk: Rear wheel lock-up can increase the risk of a crash.
Fix: Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020.
Latches/Locks/Linkages:tailgate:latch 2024-02-01 · campaign 24V060000 · 570,434 vehicles
Defect: General Motors, LLC (GM) is recalling certain 2020-2024 Chevrolet Silverado 2500, 3500, GMC Sierra 2500 and 3500 vehicles equipped with power-unlatching tailgates. The tailgate's electronic gate-release switch may short circuit due to water intrusion, which can result in the tailgate inadvertently unlatching while the vehicle is in park.
Risk: An unlatched tailgate may open while driving and result in a loss of unsecured cargo, creating a road hazard and increasing the risk of a crash.
Fix: Owners are advised to check that the tailgate is closed and latched before driving. Dealers will replace the exterior touchpad switch assemblies, free of charge. Owner notification letters were mailed May 17, 2024. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is N232426400.
Service Brakes, Hydraulic:power Assist:electric:control Module 2021-09-29 · campaign 21V758000 · 3,241 vehicles ⚠ PARK OUTSIDE
Defect: General Motors, LLC (GM) is recalling certain 2021-2022 Chevrolet Silverado 2500, Silverado 3500, GMC Sierra 2500, and Sierra 3500 vehicles with electronic brake control modules (EBCM) replaced during vehicle assembly. The bolts that attach the brake pressure modulator valve (BPMV) assembly may not be properly tightened, which could fail to seal the two sub-assemblies and allow water intrusion.
Risk: Water in the BPMV may cause an electrical short circuit and increase the risk of fire.
Fix: Owners are advised to park outside and away from other structures until the recall repair is completed. Dealers will replace the BPMV assembly, free of charge. Owner notification letters were mailed on October 20, 2021. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is N212349181.
Tires:temporary/Emergency Spare Tire 2021-07-29 · campaign 21V578000 · 86 vehicles
Defect: General Motors, LLC. (GM) is recalling certain 2020-2021 Chevrolet Silverado 2500 and GMC Sierra 2500 vehicles equipped with a 17" spare tire (RPO ZHQ or ZXT) and either the 20" accessory road tire (RPO REM) or the 18" accessory road tire (RPO Q2V). Operating the spare tire with other 20" or 18" tires can prevent the Anti-Lock Braking System (ABS) from engaging.
Risk: An ABS system that cannot control the rear wheels independently increases the risk of a crash.
Fix: Dealers will provide the appropriate spare tire and apply a new spare tire information label, free of charge. Owner notification letters were mailed on October 18, 2021. Owners may contact Chevrolet customer service at 1-800-222-1020; GMC customer service at 1-800-462-8782. GM's number for this recall is N212329780.
Seat Belts:critical Fasteners 2020-12-23 · campaign 20V811000 · 470 vehicles
Defect: 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.
Risk: 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.
Fix: 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.
Seat Belts:critical Fasteners 2020-12-17 · campaign 20V792000 · 624,216 vehicles
Defect: General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.
Risk: If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.
Fix: GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.
Service bulletins (1,062)
Technical service bulletins are repair instructions manufacturers send dealers for known issues. Unlike recalls, the fix is not automatically free — but naming the bulletin at the service desk can save diagnosis time and support goodwill repairs.
Unknown Or Other 2026-10-26 · GM Update N25-250552 · Over The Air
• improvements to onstar functionality.
Unknown Or Other 2026-09-26 · PIT5698F · Service Bulletin/Repair Instructions
this pi provides diagnostics tips on how the lin bus works and how to diagnosis it.
Unknown Or Other 2026-09-04 · PIP4902W · Service Bulletin/Repair Instructions
this preliminary information advises a dealer on how to email gds2 session logs into technical assistance.
Unknown Or Other 2026-08-27 · PIP6127A · Service Bulletin/Repair Instructions
this document assists gm dealer technicians with diagnosing torque converter concerns to ensure torque converter replacement is necessary. the torque converter part number will be placed on order restriction, and the technician will be asked to follow 25-na-148 before requesting a part through pqc.
Unknown Or Other 2026-08-20 · PIC6551C · Service Bulletin/Repair Instructions
this preliminary information communicates to dealer to perform a mec reset for wireless projection issues
Unknown Or Other 2026-08-07 · PIT6031B · Service Bulletin/Repair Instructions
this preliminary information communicates an issue where an aftermarket autostop device or rear taillights is causing a dead battery.
Showing the 6 most recent of 1,062 bulletins. Search all of them free at nhtsa.gov.
What owners report
2026-10-02 · Power Train:automatic Transmission:fluid/Lubricant:valves/Valve Body · 38,000 mi“the contact owns a 2021 gmc sierra 2500. the contact stated that while driving at an undisclosed speed, the transmission unexpectedly shifted out of first gear and the vehicle failed to accelerate as needed. the failure had occurred twice. the vehicle was towed to the dealer, who determined that the valve body needed to be replaced. the failure mil…”
2026-08-05 · Service Brakes“ the left rear internal "top-hat" parking brake shoes suffered a total manufacturing bonding failure, causing the friction lining to completely delaminate and detach from the metal backing plates inside the rotor hub. this triggered diagnostic trouble code (dtc) c060b (left park brake actuator circuit). the failed components were replaced by the se…”
2026-07-30 · Fuel/Propulsion System“after finishing a long drive south, i shut the engine off and a yellow engine code popped on. i connected my computer to it and revealed a p129f code (fuel pump control module). i have noticed that other gmc models have been included in a recall concerning this problem. the 2021 gmc 2500 denali should be also since it is the same problem. this …”
2026-06-26 · Power Train“i am reporting repeated failures involving both the transmission and diesel emissions (def) system on my 2021 gmc sierra 2500hd denali equipped with the 6.6l duramax diesel engine and allison 10-speed automatic transmission. while under warranty, the truck required replacement of the aftertreatment fuel injector and later the reductant control mod…”
2026-06-01 · Power Train“we keep getting an error message that shows we need to service def system, it also started to limit my mph and is now locked at 55 mph. initial check of the def system shows a malfunctioning module. it has been happening over the last year to 18 months. they would reset it or it would sometimes go away on its own after having to drive it in order f…”
2026-04-23 · Structure:body:step/Ladder · 93,726 mi“the contact owns a 2021 gmc sierra 2500. the contact stated that on several occasions, the automatic power side-out step failed to extend as designed. the vehicle was not diagnosed or repaired. the manufacturer was notified of the failure. the failure mileage was 93,726. …”
2026-04-22 · Unknown Or Other“xxx power assist step reversing i have a 2021 gmc sierra 2500hd that the local dealership (ozark mo 65714) is stating has expired and not covered by the warranty. i researched online and as i understand this recall falls under saftey recalls and is to be fixed and doesn't expire? it requires no parts but the reprogramming of the k4 assist step c…”
2026-04-01 · Engine · 77,000 mi“the contact owns a 2021 gmc sierra 2500. the contact stated that while driving at 55 mph, the vehicle stalled unexpectedly. there were no warning lights illuminated. the vehicle was taken to the local dealer, where it was diagnosed, and determined that the engine needed to be replaced. the engine was replaced; however, the failure recurred. while a…”
2026-03-24 · Power Train“while driving on the highway at normal speed, my vehicle was operating completely normally with no warning lights, messages, or prior issues. without any warning, the vehicle suddenly lost the ability to accelerate and felt as if it had been shifted into neutral. i immediately had to pull over to the side of the highway, as this created a dangerous…”
2026-02-03 · Engine“80,000 miles, complete engine break down. 12,000 to repair …”
Excerpts of consumer complaints filed with NHTSA, lightly truncated. They are owner statements, not verified findings.