Home › Chevrolet › Silverado 3500 › 21V496000
Silverado, Sierra Block Heater Cord Fire Risk
critical How serious is it? About this label
An electrical short-circuit can increase the risk of a fire. The notice does not tell owners to stop driving.
Key facts
| NHTSA campaign number | 21V496000 |
|---|---|
| Reported to NHTSA | Jul 1, 2021 |
| Manufacturer | General Motors, LLC |
| Part affected | Equipment:electrical:engine Block Heater |
| Vehicles covered | 8 model/year combinations, model years 2018–2019 |
| Do-not-drive advisory | No |
| Park-outside advisory | No |
| Repair | Free at any franchised dealer |
What's wrong, in plain English
Certain Duramax diesel Chevrolet Silverado and GMC Sierra trucks equipped with the optional engine block heater cord can develop an electrical short-circuit. This can happen in the heater cable itself, or in the terminals that connect the cable to the block heater. A short-circuit in this wiring increases the risk of a fire starting in the vehicle.
What you should do
2. Contact a GMC or Chevrolet dealer at 1-800-462-8782 to schedule a free inspection.
3. The block heater and cord will be replaced at no cost.
Where do I find my VIN, and what do I tell the dealer?
Your VIN is the 17-character code on the lower left of the windshield, on your registration and usually on your insurance card. Enter it at nhtsa.gov/recalls to see whether this recall is still open on your car. When you call the dealer, say you have an open safety recall and give them NHTSA campaign number 21V496000. More in how recalls work.
Affected vehicles (8)
Who to contact
Chevrolet — official Chevrolet recall lookup
Customer service: 1-800-222-1020
GMC — official GMC recall lookup
Customer service: 1-800-462-8782
The bigger picture
- Chevrolet Equipment Recalls Cover Heater Cords, Jacks, and Missing Manuals · all 6 Chevrolet recalls in this area
- GMC Equipment Recalls Address Block Heater Fires and Missing Information · all 4 GMC recalls in this area
Other Chevrolet Silverado 3500 recalls
- May 21, 2026Chevrolet Silverado, GMC Sierra Roof Air Bag Inflator Riskhigh
- Mar 19, 2026Chevy Silverado and GMC Sierra Roof Air Bag Defecthigh
- Mar 5, 2026Silverado and Sierra 3500 Fuel Pump May Stall Enginehigh
- Feb 26, 2026GM vehicles may be missing the electronic owner's manuallow
- Feb 12, 2026Chevrolet Silverado, GMC Sierra Transmission Wheel Lockup Riskhigh
- Nov 25, 2025Chevrolet Silverado Trucks Missing Owner's Manuallow
Official notice
- Component
- EQUIPMENT:ELECTRICAL:ENGINE BLOCK HEATER
- 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.
- Safety risk
- 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.
Verify your specific vehicle by VIN at nhtsa.gov. Recall repairs are free of charge by law.