Vehicle recall 21V496000 · July 1, 2021
GMC Sierra 2500, GMC Sierra 3500 and 2 more models
An electrical short-circuit may occur in the engine-block heater cable or in the terminals that connect the heater cable to the block heater.
Source: NHTSA data as of September 22, 2026. Last refreshed Sep 23, 2026, 2:43 AM UTC.
- Summary
- General Motors, LLC (GM) is recalling certain 2017-2019 Chevrolet Silverado 2500, 3500 and 2017-2019 GMC Sierra 2500 and 3500 vehicles equipped with a Duramax diesel 6.6 liter engine and an optional engine-block heater cord. An electrical short-circuit may occur in the engine-block heater cable or in the terminals that connect the heater cable to the block heater.
- Consequence
- An electrical short-circuit can increase the risk of a fire.
- Remedy
- Dealers will replace engine block heaters and heater cords. Vehicles that have this feature disabled as a remedy to the safety condition will be contacted and offered replacement block heaters and heater cords under a separate customer satisfaction program, free of charge. GM will provide free replacement block heaters and cords under a separate customer satisfaction campaign. For vehicles previously included in recall 19V-328, the heater cord will be replaced and rerouted, free of charge. Interim owner notifications were mailed on August 13, 2021. Owner notification letters are expected to be mailed on April 4, 2022. Customers may call GMC customer service at 1-800-462-8782. GM's number for this recall is 212329840.
- Notes
- Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.nhtsa.gov.
Recall details
- NHTSA campaign
- 21V496000
- Reported to NHTSA
- July 1, 2021
- Filed by
- General Motors, LLC
- Manufacturer campaign
- N212329840
- Owner notification
- April 4, 2022
- Vehicles potentially affected
- 338,020
- Initiated by
- the manufacturer
- Components
- Equipment › Electrical › Engine block heater
Vehicles covered
As listed by NHTSA. A recall usually covers only some vehicles of each model and year, often a production date range.
- Chevrolet Silverado 2500 (2017-2019): 2019, 2018, 2017
- Chevrolet Silverado 3500 (2017-2019): 2019, 2018, 2017
- GMC Sierra 2500 (2017-2019): 2019, 2018, 2017
- GMC Sierra 3500 (2017-2019): 2019, 2018, 2017
Has your Chevrolet been repaired?
Recalls here come from NHTSA’s records for the model and year. Not every vehicle of a model is included in every recall, and this site can’t see whether a repair has been done. Only a VIN lookup can tell you that.
NHTSA’s VIN search doesn’t show recalls that were already repaired, recalls more than 15 years old, or some small manufacturers’ recalls. A Chevrolet dealer can also check your VIN. Recall repairs are free.