Most common 2021 GMC Sierra 2500 problems
Share of the 52 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
GMC Sierra 2500 complaints by model year
Best Sierra 2500 years: 2012, 2014, 2013. Years to avoid: 2024, 2025, 2020, 2021, 2022. Compare all years →
2021 GMC Sierra 2500 recalls (6)
Power train › Automatic transmission › Fluid/lubricant › Valves/valve body
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.
Remedy: 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…
Latches/locks/linkages › Tailgate › Latch
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…
Remedy: 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.
Service brakes, hydraulic › Power assist › Electric › Control module
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.
Remedy: 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.
Tires › Temporary/emergency spare tire
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).
Remedy: 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.
Seat belts › Critical fasteners
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.
Remedy: 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…
Seat belts › Critical fasteners
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.
Remedy: 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.
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 2021 GMC Sierra 2500:
Air Bag Malfunction
On April 9, 2021, the Office of Defects Investigations (ODI) opened PE21-010 to investigate instances of air bag malfunction indicator light (MIL) illumination and potential for frontal air bag non-deployment in several vehicles manufactured by General Motors (GM).
What 2021 GMC Sierra 2500 owners say
Transmission & drivetrain
The contact owns a 2021 GMC Sierra 2500. The contact stated that while driving at 50 MPH, the contact was pulling a trailer that he had loaded, and he drove around a curve, the gear shifted down independently, and the trailer pushed the vehicle off the right side, causing him to crash into a post and embankment. The contact mentioned he was able to shift the gear into Four Wheel Drive to get back on the road. The contact mentioned he pulled over to the right side of the road, exited the vehicle to inspect, and noticed damage to the vehicle and the trailer. The contact stated no air bag deployed. The contact stated that he sustained injuries left arm and neck, causing his muscles to tighten. No medical attention was required. The contact stated no police report was filed. …
The contact owns a 2021 GMC Sierra 2500. The contact stated while driving 40-55 MPH, the vehicle started losing motive power. The contact stated while pulling into a nearby independent mechanic shop, the vehicle started jerking significantly and stalled midway. The check engine warning light was illuminated. The mechanic diagnosed the vehicle with transmission failure. The vehicle was towed to the residence. The local dealer and several unknown dealers were notified of the failure and informed the contact that the transmission assembly was not available and could not be ordered. The vehicle was towed to CJ's Transmission, where the transmission was taken apart. The mechanic determined that the transmission needed to be replaced. The vehicle was being repaired with a rebuilt transmission. …
Lights
On 11/21/24 noticed passenger headlight day light running light flickering. On 11/22/24 right turn indicator intermittent fast blink, dash message stated turn indicator failure. Once home, inspected passenger headlight assembly. Found DRL, turn signal, and low and high beam head lights were inoperative. On 11/25/24 went to GMC dealer/service. Staff seemed aware of issues and stated they are common, that they carry the $1,400 sealed assebly in stock. Vehicle is 4 months over warranty, but only has 29,000 miles. There is no visible damage to the assembly, but there is visible condensation inside the lens. GM has a published service bulletin, 01-08-42-001P, that specifically addresses this issue for my vehicle. The earliest date the issue could be diagnosed/service date is 12/10/24. A complete failure of this non-servicable headlight assembly is an absolute safety issue. …
The front left headlamp assembly low beam light unexpectedly began to flicker repetitively until the vehicle was turned off. In addition, the left front turn signal was failed, but an indication of the failed turn signal was not always present. The headlamp assembly was taken in for replacement at a local GMC dealership promptly due to safety concerns of operating the vehicle on public roadways with this condition. The safety of others was at risk due to the strobing effect of the flickering lights and not being able to drive the vehicle during conditions where headlights are necessary. The flickering/strobing condition of the headlamp was highly distractive and puts other drivers are risk. In addition, due to the natural height of the vehicle the cast of the beam is closer to the rear view mirror height of the majority of vehicles. …
Engine & cooling
The contact owns a 2021 GMC Sierra 2500. The contact stated while driving 40-55 MPH, the vehicle started losing motive power. The contact stated while pulling into a nearby independent mechanic shop, the vehicle started jerking significantly and stalled midway. The check engine warning light was illuminated. The mechanic diagnosed the vehicle with transmission failure. The vehicle was towed to the residence. The local dealer and several unknown dealers were notified of the failure and informed the contact that the transmission assembly was not available and could not be ordered. The vehicle was towed to CJ's Transmission, where the transmission was taken apart. The mechanic determined that the transmission needed to be replaced. The vehicle was being repaired with a rebuilt transmission. …
The contact owns a 2021 GMC Sierra 2500. The contact stated that the vehicle was equipped with an engine block heater that he plugged into the vehicle when the weather was below 32 degrees to start the vehicle. The contact stated that he noticed that the engine block heater was causing the GFCI outlet in his residence, to experience an electrical short circuit. The dealer was notified of the failure and informed the contact that it was a known failure. An appointment was scheduled for diagnostic testing. The vehicle was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 19V328000 (Engine) however, the VIN was not included. The manufacturer was notified of the failure and a case was opened. The failure mileage was approximately 55,000.
Frequently asked questions
Is the 2021 GMC Sierra 2500 a good car?
Based on 52 owner complaints filed with NHTSA, the 2021 Sierra 2500 rates avoid: 2.5× as many complaints as a typical year of the Sierra 2500 at the same age. It is one of the Sierra 2500 years we suggest avoiding. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2021 GMC Sierra 2500?
The transmission & drivetrain — 13 complaints, 25% of all complaints for this model year, most often about automatic transmission › fluid/lubricant › valves/valve body. Next are the lights (9) and engine & cooling (8).
How many recalls does the 2021 GMC Sierra 2500 have?
There are 6 recalls for the 2021 GMC Sierra 2500, the most recent from October 24, 2024 (valves/valve body). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the GMC Sierra 2500?
The best years by complaints, compared at the same age, are 2012, 2014 and 2013. Years to avoid or approach with caution: 2024, 2025, 2020, 2021 and 2022. See the full GMC Sierra 2500 years comparison.
At what mileage do 2021 GMC Sierra 2500 problems happen?
The median mileage reported in complaints is about 53,000 miles; 33% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.