2021 GMC Sierra 1500 Problems, Recalls & Reliability
Verdict
CautionComplaint Index
73/100
#5 most-complained of 16 Sierra 1500 years
The 2021 GMC Sierra 1500 has a Complaint Index of 73, ranking 5th worst out of 16 model years, earning a Caution verdict. Engine problems dominate at 62% of complaints, with 7 recalls filed and a median failure mileage of 50,000.
- Complaints
- 570
- Recalls
- 7
- Crashes / fires
- 5 / 6
- Injuries / deaths
- 2 / 0
- NHTSA overall rating
- 5 / 5 ★
- EPA combined MPG
- 17
- 15.5 city / 21 hwy
Top 2021 GMC Sierra 1500 problems
NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.
- Engine351 (62%)
- Transmission & Powertrain136 (24%)
- Electrical System75 (13%)
- Other42 (7%)
- Fuel System36 (6%)
- Steering33 (6%)
- Brakes24 (4%)
- Structure & Body22 (4%)
- Suspension, Wheels & Tires18 (3%)
- Collision Avoidance & Cameras9 (2%)
What owners report
- Engine bay fires and explosions reported while driving or shortly after parking, sometimes with flames visible under the hood.
- Sudden brake system failure with a 'brake failure' warning message, in one case leading to a rear-end crash in stop-and-go traffic.
- Engine failures involving lifter and piston rod damage, with one owner reporting two separate engine replacements.
- Right front suspension failure causing steering and brakes to lock up while merging lanes.
- Airbags failing to deploy during a rear-end crash despite smoke appearing in the cabin.
- A sharp interior structural piece near the front seats caused a hand injury when reaching for a dropped object.
2021 GMC Sierra 1500 recalls
7 NHTSA recall campaigns list this model year.
- NHTSA 26V083000Feb 12, 2026Transmission & Powertrain1,055 vehicles
Power train:automatic transmission:fluid/lubricant:valves/valve body
General Motors, LLC is recalling certain 2020 Chevrolet Silverado 2500, 3500, GMC Sierra 2500, 3500, and 2020-2022 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles that may have been repaired incorrectly under recall 24V797. The transmission control valve may fail and cause the rear wheels to lock up.
Risk: Rear wheel lock up increases the risk of a crash.
Remedy: Dealers will inspect the vehicles and update the transmission control software, free of charge. Owner notification letters were mailed March 6, 2026. Owners may contact GMC customer service at 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N252516560. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on February 12, 2026.
- NHTSA 25V274000Apr 24, 2025Engine597,571 vehicles
Engine and engine cooling:engine:hard parts internal/mechanical
General Motors LLC (GM) is recalling certain 2021-2024 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, and Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles equipped with a 6.2L V8 gas engine. The connecting rod and/or crankshaft engine components may have manufacturing defects that can lead to engine damage and engine failure.
Risk: Engine failure increases the risk of a crash.
Remedy: Dealers will inspect the engine, and as necessary, repair or replace the engine. For vehicles that pass inspection, dealers will add higher viscosity oil, install 6 oil fill cap, replace the oil filter, and update the owner's manual. Repairs will be performed free of charge. Owner notification letters were mailed June 18, 2025. Owners may contact Cadillac customer service at 1-800-333-4223, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-800-462-8782. GM's number for this recall is N252494000.
- NHTSA 24V797000Oct 24, 2024Transmission & Powertrain463,295 vehicles
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.
Risk: Rear wheel lock-up can increase the risk of a crash.
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 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. GM's number for this recall is N242454440.
2021 GMC Sierra 1500 fuel economy and fuel cost
- City
- 15.5 MPG
- Highway
- 21 MPG
- Combined
- 17 MPG
- Annual fuel cost (EPA)
- $3,800
- 15,000 mi/yr
- Fuel
- Regular
- Current regular gas
- $4.32/gal
- national avg.
EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.
2021 compared with other Sierra 1500 years
Frequently asked questions
- Is the 2021 GMC Sierra 1500 reliable?
- Compared to other Sierra 1500 model years, 2021 ranks 5th worst out of 16 years tracked, with a Complaint Index of 73 and a Caution verdict.
- What is the biggest problem with the 2021 GMC Sierra 1500?
- Engine problems make up 62% of complaints (351 of 570), with a median failure mileage of 56,901 miles. NHTSA also logged 6 fire reports.
- Does the 2021 GMC Sierra 1500 have recalls?
- Yes, NHTSA lists 7 recalls for the 2021 Sierra 1500, covering transmission control software, the 6.2L V8 engine, seat belt bolts, and spare tire/wheel compatibility.
- How does 2021 compare to other Sierra 1500 years?
- The 2021 model (Complaint Index 73) ranks better than 2022, 2023, and 2024, which are rated Avoid with indices of 93, 87, and 100, but worse than years like 2018 (index 20, Best).