NHTSA lists 5 safety recalls and 20 owner complaints for the 2021 GMC Sierra 3500. Most complaints involve power train (7) and service brakes (5).
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.
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.
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.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
“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.”
“The contact filed the complaint on behalf of the owner of a 2021 GMC Sierra 3500. The contact stated that while the vehicle owner was driving at an undisclosed speed, the driver noticed that the rear wheels were attempting to lockup. The contact stated that the failure was noticeable while driving forward and while reversing. No warning light illuminated. The vehicle was taken to the independent mechanic, where it was diagnosed with detached rear brake pads and detached rear emergency brake shoes. In addition, the rear brake caliber had seized. The vehicle owner was informed that the rear brake pads and the rear emergency brake shoes needed to be replaced, and the rear brake caliber needed to be repaired. The vehicle was repaired. The dealer was made aware of the failure. The contact was advised to contact the NHTSA Hotline to report the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 140,606.”
“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.”
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
5 safety recalls as of Oct 28, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
Owners filed 20 complaints with NHTSA. The most-cited components are power train (7), service brakes (5), electrical system (4). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.