GMC Sierra 3500 · model year

2021 GMC Sierra 3500

27 NHTSA complaints, and 5 recall campaigns listed for this cohort. A VIN lookup is required to determine whether a specific vehicle has an unrepaired recall.

NHTSA overall rating

Not crash-tested

New Car Assessment Program

Complaints
27
Recalls
5

The verdict

The 2021 GMC Sierra 3500 posts above-average complaint volume among its own model-year siblings.

43rd pctile
complaint volume, own model years
5
recall campaigns

The 2021GMCSierra 3500 carries 27 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 0 crashes, 0 fires, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.

The most frequently selected component label in reports for the 2021 Sierra 3500 is power train with 7 filings, followed by service brakes (4) and electrical system (4). Complaint categories reflect owner reports and intake categorization; they do not establish a defect pattern or cause. This cohort has 5 NHTSA recall campaigns listed below. Enter a VIN in NHTSA's official recall lookup to determine whether a specific vehicle has an unrepaired recall.

NHTSA currently has 2 investigation files overlapping the 2021 Sierra 3500. Owners comparing this cohort against neighboring years should read the complaint-by-year trend as report volume, not a causal diagnosis. Use the related-complaint feed and the official recall lookup when researching a specific vehicle.

27
Complaints
0
Crashes
0
Fires
0
Injuries
0
Deaths
F
PlainCars Safety Score
0/100
2021 GMC Sierra 3500

PlainCars' own composite of NHTSA NCAP crash-test ratings and rollover-risk assessment, each dimension normalized against the federal scale or the full national model-year corpus. Not an official NHTSA figure, and not a substitute for a specific vehicle's VIN-level recall check.

NHTSA Overall Rating N/A
Not rated
NHTSA New Car Assessment Program overall crash-test rating.
Front Crash N/A
Not rated
Frontal barrier crash-test rating.
Side Crash N/A
Not rated
Side barrier and pole crash-test rating.
Rollover Resistance N/A
Not rated
Static stability factor + dynamic rollover test rating.
Rollover Risk N/A
Not reported
NHTSA single-vehicle rollover probability, dynamic test.

Total Complaints

27 filings

Crashes Reported

0 reports

Source

NHTSA ODI

Federal complaints database

Complaints vs. fleet median (215)

At or below the fleet median complaint volume.

Complaints by Component

ComponentCount
POWER TRAIN7
SERVICE BRAKES4
ELECTRICAL SYSTEM4
ENGINE3
UNKNOWN OR OTHER3
FUEL/PROPULSION SYSTEM2
STRUCTURE:BODY1
TIRES:TREAD/BELT1
BACK OVER PREVENTION1
VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM1

Recalls (5)

21V75800029/09/2021

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. The bolts that attach the brake pressure modulator valve (BPMV) assembly may not

24V79700024/10/2024

POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE

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 caus

20V81100023/12/2020

SEAT BELTS

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 m

20V79200017/12/2020

SEAT BELTS

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 fram

24V06000001/02/2024

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

Recent Complaints

20251124POWER TRAIN

During takeoff the transmission acted as if it was in neutral while I was crossing traffic luckily, the semi truck that was coming towards me was able to stop. I had the vehicle towed to a shop. After the vehicle was towed to the shop the transmission acted normal when the mechanic searched the VIN number. There was a service bulletin issued by General Motors for this exact problem. Had the semi not been able to stop. It could’ve very well killed me or my children. I suppose if it would’ve killed someone, maybe general motors would finally do a recall for this very disappointed in general motors and the NHTSA, the fact that this is an ongoing problem and has not been fixed and as a customer, I was not even notified that this problem existed is very alarming.

20250908ELECTRICAL SYSTEM

The contact owns a 2021 GMC Sierra 3500. The contact stated that while his wife had the vehicle idling with the rear defroster activated, shortly afterwards, she observed smoke coming from the plastic on the rear sliding window. After a visual inspection, the contact's wife observed that the plastic was melting, prompting her to deactivate the rear defroster. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 26,000.

Mileage: 26,000

20250908VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM

The contact owns a 2021 GMC Sierra 3500. The contact stated that while his wife had the vehicle idling with the rear defroster activated, shortly afterwards, she observed smoke coming from the plastic on the rear sliding window. After a visual inspection, the contact's wife observed that the plastic was melting, prompting her to deactivate the rear defroster. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 26,000.

Mileage: 26,000

20250814BACK OVER PREVENTION

The contact owns a 2021 GMC Sierra 3500. The contact stated that while reversing, the back over prevention camera screen displayed an image of the ground. The contact stated that the image was approximately ten feet behind the vehicle. The vehicle was taken to the dealer; however, the failure was not duplicated. The dealer replaced the back over prevention camera system, however, the failure reoccurred. The contact stated that the original back over prevention camera was installed in another vehicle, and the back over prevention camera system worked as designed. The contact was informed that the back over prevention camera was not the cause of the failure. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 70,000.

Mileage: 70,000

20250512UNKNOWN OR OTHER

There is a known issue with these trucks with the infotainment screen blacking out, which renders the backup cameras inoperative. This is a huge safety risk and its astounding to me that this hasn't been recalled yet.

20250308ELECTRICAL SYSTEM

When carrying the electronic key in my pocket the vehicle will lock/unlock presumably due to the remote contacting other items in the pocket. I have owned well over a dozen GM vehicles and never had this issue. I believe the remote design has the lock/unlock buttons too proud of the surrounding surface

20250308UNKNOWN OR OTHER

Vehicle is put into park after driving. Shift to Park warning comes on while vehicle is in park. Vehicle will not shut off due to this warning and must be left running unoccupied.

20250127POWER TRAIN

The contact's son owns a 2021 GMC Sierra 3500 Commercial Vehicle. The contact stated while her son was driving at an undisclosed speed uphill, the vehicle failed to shift to a gear higher than 5th gear. Additionally, the rear wheels locked up, causing the vehicle to come to a stop. The driver attempted to resume driving, but the vehicle failed to exceed 10 MPH. The contact was unsure whether a warning light had been illuminated. The vehicle was towed to the residence of the driver's girlfriend. The vehicle was then towed to the dealer, where it was diagnosed that the failure was related to NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. Additionally, the dealer informed the contact that the transmission needed to be replaced, but the part was not available. The vehicle was not repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware

Mileage: 133,000

20250118POWER TRAIN

Transmission had to be replaced from the dealership. Hard shifting dealership said truck was 23 days out of warranty. I couldn’t get into the dealership that truck was purchased from for 3 weeks. Had to go to the Jeff Gordon dealership, which is Chevrolet. And I had to replace the transmission.

20241101ENGINE

Multiple instances of diesel engine emissions system parts and software failure. While driving, towing or not, the DIC would randomly display a message that the DEF level is low and reduced speed will occur in x-amount of miles and that mileage would then begin a visible countdown on the DIC, sometimes much more quickly than the actual speed I was traveling. In other words, it might at first state 500 miles remaining, but then be counting down from 500 miles by one mile per second of time, or faster. Each instance, I would park and attempt to refill the DEF tank, only to discover that the tank is already full or near full. My truck’s DEF tank has now been replaced twice under warranty with the latest tank being installed at only 35,460 miles on the odometer. During the latest replacement, the technician also diagnosed and replaced the electrical wiring harness related to the DEF tank, stating that one of the connector pins was not reading the required voltage. There was also a faulty

20241101UNKNOWN OR OTHER

Multiple instances of diesel engine emissions system parts and software failure. While driving, towing or not, the DIC would randomly display a message that the DEF level is low and reduced speed will occur in x-amount of miles and that mileage would then begin a visible countdown on the DIC, sometimes much more quickly than the actual speed I was traveling. In other words, it might at first state 500 miles remaining, but then be counting down from 500 miles by one mile per second of time, or faster. Each instance, I would park and attempt to refill the DEF tank, only to discover that the tank is already full or near full. My truck’s DEF tank has now been replaced twice under warranty with the latest tank being installed at only 35,460 miles on the odometer. During the latest replacement, the technician also diagnosed and replaced the electrical wiring harness related to the DEF tank, stating that one of the connector pins was not reading the required voltage. There was also a faulty

20241101ELECTRICAL SYSTEM

Multiple instances of diesel engine emissions system parts and software failure. While driving, towing or not, the DIC would randomly display a message that the DEF level is low and reduced speed will occur in x-amount of miles and that mileage would then begin a visible countdown on the DIC, sometimes much more quickly than the actual speed I was traveling. In other words, it might at first state 500 miles remaining, but then be counting down from 500 miles by one mile per second of time, or faster. Each instance, I would park and attempt to refill the DEF tank, only to discover that the tank is already full or near full. My truck’s DEF tank has now been replaced twice under warranty with the latest tank being installed at only 35,460 miles on the odometer. During the latest replacement, the technician also diagnosed and replaced the electrical wiring harness related to the DEF tank, stating that one of the connector pins was not reading the required voltage. There was also a faulty

20241001POWER TRAIN

While driving 55mph on a 2 lane road, pulling a 5th wheel camper, the truck transmission downshifted by itself to a low gear. This caused a scary and immediate deceleration from 55 to 25mph. The trailer wanted to push into the oncoming lane the deceleration was so fast. The truck is at a dealership and they acknowledge the issue but not a fix other than putting back in the failed part. There was no warning and my readings say many others are having same issue. The small dealership we left the truck with (yemm Chevrolet in Galesburg Il) said they had 3 trucks with the same issue. The truck has been with the dealership for 7 weeks now.

20240419SERVICE BRAKES

When starting the vehicle, I got a message to service the parking brake (this is the second time I’ve had this warning appear in the 21,000 miles I’ve owned it, first was approximately 5,000 miles ago). When this warning is active the parking brake does not engage, and can’t be used to stop the vehicle when the brakes fail as they did today. With 42,774 miles on the vehicle, and the onboard monitor for brake wear showing remaining brake life at 94% front and 96% rear, brake fluid reservoir between Max and Min the brake pedal went soft and the vehicle would not stop. I resorted to putting the vehicle in neutral and pumping the brakes until the pedal got hard. As soon as I let off the brake my vehicle began to roll backwards, stepped on the brake pedal again and the pedal again went to the floor without stopping or slowing the vehicle (pumping the brakes got it stopped again inches away from running into my house). The myGMC app notified me that I need to service the ABS system. I

20230524TIRES:TREAD/BELT

The right rear tire (Goodyear Wrangler 275/65R20) separated and blew out on the highway, the truck was very difficult to control however it was safely stopped and there were no injuries. There was no observed warning prior to the blow out. The tire separation caused damage to the right rear quarter panel. The spare was installed and finished the trip safely. A tire shop found a second tire with evidence of separation on the left front corner. The tire that blew out on the highway is (DOT PJOT JB1V 0721) and the other 3 including the one with evidence of separation is (DOT PJOT JB1V 0821). The blown tire has been returned to Goodyear in Ohio by the auto repair facility at Goodyears request. Goodyear is refusing to assess the other 3 tires unless I bring them to an authorized service center which is not possible with only 3 functional tires including the spare. The 3 remaining tires are at the auto repair facility.

20220403FUEL/PROPULSION SYSTEM

Part Number: 85138746 - DEF tank assembly, heater, pump, reservoir. I was told there were issues with the heater and pump. The heater turns high or the heater won’t work; and there are issues with the connector.02/24/22: My truck has 16,000 approx. miles. The check engine light came on and displayed message that I had so many miles until truck would be restricted to 65MPH. I took my truck into Kendall dealership in Nampa, Idaho and was told there was myself and another person who had the same issue. A couple weeks go by and I call the dealership back and was told that I was 5th in line and there were 20 behind me. I was told that there were 11,000 parts already spoken for and 6,000 parts on backorder. I was one of the backorder individuals. I was also told that they do not have a ETA on when they would receive parts and that parts show up unexpected. They told me that I would have to contact GM customer service for assistance. The dealer called me back March 31st to see if I

20220403POWER TRAIN

Problem: Unable to shift transmission from D to another position like R, P, N due to snow/slush being on shifter. I travel on Idaho state highways and County roads that are plowed. In February, I traveled state highway 14. Road conditions were plowed snow roads, broken snow floor, slush and pavement without slush or snow. I had a passenger with me on this trip from Elk City, Idaho to Grangeville, Idaho via SH-14. When I pulled into my storage unit, I could not shift from D to P or N or R. I could only drive forward. The temperature in Grangeville was mid 40s. I did not have any tremendous snow build up on the under carriage or wheel wells. I drove to the dealer Gortsema Motors and their service technician said that I needed to go to a car wash and blow out the snow buildup next to the transmission linkage shifter. When I pulled into the car wash, I still could not shift the transmission. My passenger got out and used the water to push out the snow buildup around the linkage sh

20220305ENGINE

The throttle body gets stuck wide open after the eninge gets up to operating temperature, it will give some warning with the throttle like on off throttle use and no codes show up at all. The risk of everyones is in extrem DANGER. The break are to soft and well not stop unless you put both feet on the break pedal down to the floor. Tranismission can NOT figure out what gear it needs to be in way too many gears and horrible fuel mpg for the 6.6L Duramax L5P. None of the GM dealership will look at the truck unless there is a code or it is happening right there when they look up the trucks VIN.

20220305SERVICE BRAKES

The throttle body gets stuck wide open after the eninge gets up to operating temperature, it will give some warning with the throttle like on off throttle use and no codes show up at all. The risk of everyones is in extrem DANGER. The break are to soft and well not stop unless you put both feet on the break pedal down to the floor. Tranismission can NOT figure out what gear it needs to be in way too many gears and horrible fuel mpg for the 6.6L Duramax L5P. None of the GM dealership will look at the truck unless there is a code or it is happening right there when they look up the trucks VIN.

20220305POWER TRAIN

The throttle body gets stuck wide open after the eninge gets up to operating temperature, it will give some warning with the throttle like on off throttle use and no codes show up at all. The risk of everyones is in extrem DANGER. The break are to soft and well not stop unless you put both feet on the break pedal down to the floor. Tranismission can NOT figure out what gear it needs to be in way too many gears and horrible fuel mpg for the 6.6L Duramax L5P. None of the GM dealership will look at the truck unless there is a code or it is happening right there when they look up the trucks VIN.

Compare 2021GMCSierra 3500 to Similar Vehicles

NHTSA Investigations

Vehicle Safety Guides

Frequently Asked Questions

How many complaints does the 2021 GMC Sierra 3500 have?
The 2021 GMC Sierra 3500 has 27 NHTSA complaints, 0 crashes, 0 fires, 0 injuries, and 0 deaths reported.
Are there any recalls for the 2021 GMC Sierra 3500?
Yes, the 2021 GMC Sierra 3500 has 5 recall(s). The most common affected component is SERVICE BRAKES, HYDRAULIC:POWER ASSIST:ELECTRIC:CONTROL MODULE. Recalls are issued by NHTSA and manufacturers must provide a free remedy.
What are the most common problems with the 2021 GMC Sierra 3500?
The most-complained component for the 2021 GMC Sierra 3500 is POWER TRAIN with 7 complaints. Other frequently reported areas include SERVICE BRAKES and ELECTRICAL SYSTEM.
Is the 2021 GMC Sierra 3500 safe to buy?
Review the complaint history, crash and fire reports, safety ratings, and recall status on this page to make an informed decision. No NHTSA crash test rating is available for this model year. Compare with other model years using the links above.
Where does this data come from?
All complaint, recall, and safety rating data is sourced from the National Highway Traffic Safety Administration (NHTSA). Complaints are filed by vehicle owners through NHTSA's Office of Defects Investigation.

Data vintage: August 2026. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.

Every figure on PlainCars is rendered directly from NHTSA complaint and safety data, no number is typed in by an editor. This year-specific record is rendered from NHTSA ODI, recall, and NCAP rows for the 2021 GMC Sierra 3500; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.