2020 GMC Sierra 3500 Problems, Recalls & Reliability
Verdict
AvoidComplaint Index
87/100
#3 most-complained of 16 Sierra 3500 years
The 2020 GMC Sierra 3500 has a Complaint Index of 87 and ranks 3rd worst out of 16 model years, earning an Avoid rating. It logged 51 complaints, 8 recalls, 4 crashes, and 2 fires, with Transmission & Powertrain the top problem area at 37% of complaints.
- Complaints
- 51
- Recalls
- 8
- Crashes / fires
- 4 / 2
- Injuries / deaths
- 4 / 0
- NHTSA overall rating
- Not rated
- EPA combined MPG
- —
Top 2020 GMC Sierra 3500 problems
NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.
- Transmission & Powertrain19 (37%)
- Electrical System10 (20%)
- Brakes7 (14%)
- Engine7 (14%)
- Fuel System6 (12%)
- Other6 (12%)
- Structure & Body6 (12%)
- Suspension, Wheels & Tires5 (10%)
- Visibility & Wipers2 (4%)
- Airbags1 (2%)
What owners report
- Transmission suddenly locks up or bangs loudly at highway speed, sometimes locking the rear brakes and forcing the truck onto the shoulder.
- Rear differential seizes at 60 mph while towing, in one case causing the trailer to jackknife into the truck.
- Dash computer malfunctions and disables trailer brakes while loaded, sometimes several times per day, occasionally paired with reduced power.
- Transmission unexpectedly downshifts from 10th to 5th gear at 75 mph.
- Steering wheel shakes or shimmies at speeds above 50 mph and persists after repeated dealer repair attempts.
- Electrical system develops a progressive pause on startup that eventually leaves the vehicle unable to start at all.
2020 GMC Sierra 3500 recalls
8 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 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.
- NHTSA 24V060000Feb 1, 2024Structure & Body570,434 vehicles
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 is in park.
Risk: An unlatched tailgate may open while driving and result in a loss of unsecured cargo, creating a road hazard and increasing the risk of a crash.
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. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-800-462-8782. GM's number for this recall is N232426400.
2020 compared with other Sierra 3500 years
Frequently asked questions
- Is the 2020 GMC Sierra 3500 a good year to buy?
- NHTSA data ranks it 3rd worst among 16 model years with a Complaint Index of 87 and an Avoid verdict, so it is one of the weaker years for this model based on owner complaints and recalls.
- What are the most common problems with the 2020 GMC Sierra 3500?
- Transmission & Powertrain issues lead with 19 complaints (37% share) and a median failure mileage of 108,000 miles, followed by Electrical System (10 complaints, 20%) and Brakes (7 complaints, 14%).
- Does the 2020 GMC Sierra 3500 have transmission recalls?
- Yes. NHTSA lists two transmission-related recalls covering the 2020 Sierra 3500, including software updates to the transmission control module reported in 2024 and 2026.
- How many recalls does the 2020 GMC Sierra 3500 have?
- NHTSA lists 8 recalls for the 2020 Sierra 3500, covering transmission control software, tailgate wiring, hood latches, airbags, and seat belts, none of which are do-not-drive recalls.
- Which GMC Sierra 3500 years are rated best based on NHTSA data?
- Among the years listed, 2012, 2014, and 2018 carry the lowest Complaint Index scores (7, 13, and 20) and are rated Best, compared to 87 for 2020.