2021 GMC Sierra 2500 Problems and Top Complaints – Is Your Car A Lemon?

Airbag, brake, and tire issues are among the top complaints received by the NHTSA from vehicle owners

Updated on Author: Brian Jones | Editor: Rita Roberts | Reviewer: Sergei Lemberg

When drivers want to experience plenty of style mixed with capability, they often look at 2021 GMC Sierra 2500 heavy-duty trucks. After all, the automaker claims these offer a “powerful performance.” But owners aren’t so sure. They complain about airbags that don’t deploy, brakes that dealerships can’t fix, and all kinds of other problems.

Click on other model year to view more problems: 2022

Commonly Reported Issues

There aren’t a huge number of complaints about the 2021 GMC Sierra 3500, but there are complaints about many of its components and systems. There are four recalls and an investigation on file with the National Highway Traffic Safety Administration (NHTSA).

Taking all of this into account, the most common problems relate to airbags, brakes, and tires. Other components and systems identified as problematic include backover prevention, the engine, exterior lighting, forward collision avoidance, powertrain, seat belts, and the structure of the 2021 Sierra 2500.

2021 GMC Sierra 2500 Complaint Summary

Complaint CategoryNumber of Complaints
Exterior Lighting
Air Bags
Electrical System
Service Brakes
Unknown Or Other
Back Over Prevention: Warnings
Forward Collision Avoidance: Warnings
Parking Brake:driveline:hydraulic:actuator


The four recalls that involve the Sierra 2500 are for tires, brakes, and seat belts.

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The most serious is NHTSA Campaign Number 21V758000 that relates to the brake pressure modulator valve (BPMV). The bolts that attach the BPMV assembly may not be properly tightened, which may not seal the two sub-assemblies. Then, if water gets into the BPMV, it can cause an electrical short circuit, which increases the risk of fire. General Motors, LLC (GM) has identified 3,241 vehicles that may be affected. These include 2021-2022 GMC Sierra 2500 and 3500 vehicles, as well as 2021-2022 Silverado 2500 and 3500s.

Because the issue is so serious, affected owners have been advised to park outside and away from other structures, including their homes, until the repair is completed.

Seat Belts

There are two recalls because of seat belt issues. The first implicates 624,216 GMC and Chevrolet vehicles, including the 2020-2021 GMC Sierra 2500. The problem is that front center seat belts may not have been properly secured. If these vehicles crash, there is a real danger of injury.

The second applies to relatively few (470) Chevrolet, Cadillac, and GMC vehicles including the 2021 Sierra 2500 — 18 model and model years in all. This recall involves incorrect bolts used to attach seat belts. Again, the seat belts may not restrain those in the vehicle in a crash, which increases the risk of injury.


The tire recall also increases the risk of a crash for 86 2020-2021 GMC Sierra 2500 and Chevrolet Silverado 2500 vehicles. The issue relates to incompatibility of the tires on the vehicle with spare and accessory road tires. Essentially, “operating the spare tire with other 20″ or 18″ tires can prevent the Anti-Lock Braking System (ABS) from engaging.” This, too, increases the risk of crashing.

Airbag Problems

The most dramatic complaint lodged with the NHTSA about airbag problems with the 2021 GMC Sierra 2500 is from an owner in Michigan. The vehicle was hit in the driver-side tire. The airbags didn’t release, and the “truck then went up in flames.”

Nothing more is said in the complaint. However, there was a longstanding NHTSA investigation into several GMC vehicles, including the 2021 Sierra 2500. It was opened in April 2021 by the NHTSA’s Office of Defects Investigations (ODI). Their brief was “to investigate instances of airbag malfunction indicator light (MIL) illumination and potential for frontal airbag non-deployment in several vehicles manufactured by General Motors (GM).”

It cites rust particles in the connection terminal interface of the driver airbag inflator housing as the cause of the airbag MIL illumination. This can result in a non-deployment of the frontal driver air bag during a frontal collision and increase a risk of injury for drivers.

The investigation was eventually closed on August 24, 2023, because there hadn’t been reports of fires, crashes, injuries, or fatalities related to this issue. However, the ODI stated that “this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take additional action if warranted by new circumstances.”

It is interesting that this complaint was in August 2022, a year before the investigation closed — and there was certainly the report of a fire.

Brake Problems

Complaints about the 2021 Sierra 2500’s brakes don’t relate to the recall. Rather, there are other issues that single out brakes that squeak and squeal. Dealers identify this problem as being brake pads that need replacing. But it’s not that simple.

An owner from Tennessee states in an NHTSA complaint that when the Sierra 2500 brakes started squeaking, the dealer said the brake pads needed to be replaced. But the new brake pads did the same thing. The owner went to another dealer, and they replaced the caliper on the front driver’s side. That didn’t help either. A third dealer was aware of the issue but said “there was no recall for the failure.” At the time, the failure mileage was only 800.

“Excessive squealing” was the reason for an NHTSA complaint from an owner in Virginia. “Squealing implies incorrect pressure to the rotor to stop the vehicle, which highly concerns me as an operator.” In this case, the dealer said, “there is a technical bulletin that approves replacement of the brake pads for free if reported in (the) first 7500 miles.” But this incident happened at 15,000 miles, and the dealer refused to cover the repair costs. The owner then had to pay $1,500 to replace the brakes “or risk my safety. I believe this should be a recall.”


An owner from Idaho reports in a complaint how, after having Walmart install new tires with “road hazard and lifetime balance,” one of the tires failed. “I can see the fibers around the issue area and soft spongy for approximately 14 inches sounds like glue not sticking when I push around the bead area.” Walmart told him that it was defective and coming apart.

They didn’t take responsibility and referred him to the manufacturer, which he did “without any positive results.” All they did was deny the claim. “This tire needs to be Inspected and I want a new one, this for sure is defective.”

Other Problems

An owner from Tennessee states that the passenger headlight fills up with “moisture.” This results in the high intensity discharge (HID) filling up with water and shorting out. “The high beam starts flashing when you try to use your turn signal and eventually the headlights completely stop working. Is a known problem, but GM won’t do anything to help if you’re outside of the 3-year/36,000-mile warranty.” Worse still, the owner was “unable to get a new headlight because of the ongoing strike.”

Another owner had a serious powertrain issue when the Sierra 2500 had 47,000 miles on the clock. While driving 70 mph, the RPM revved up to 6,000 RPM and the vehicle lost motive power. The vehicle was taken to the dealer, who informed the owner that the transmission needed to be replaced.

Lemon Law Legal Rights

Lemons are a reality when it comes to vehicles. The challenge is recognizing and identifying which ones are lemons. If you think you have bought a lemon, you don’t have to accept your fate. But it’s a good idea to get knowledgeable advice before going head-on with billion-dollar manufacturers.

Because the law makes GM pay lemon law legal fees, Lemberg Law will assess your problems free of charge. All you have to do is call our Helpline or fill out a contact form to request a free evaluation.

Brian Jones

About the Author:

Brian Jones spent more than 30 years working as an ASE Certified Master Tech and Parts Specialist at multiple dealerships. Brian has become an authority in the industry, traveling across the country to consult for car dealerships and contributing his expertise as a writer for several major automotive publications. In his spare time, Brian enjoys working on pickup trucks, muscle cars, Jeeps and anything related to motorsports.

See more posts from Brian Jones

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