Chevrolet and GMC Heavy-Duty Pickup Trucks Recalled Due to Short-Circuit Concerns

Diesel-powered 2017-2019 models equipped with an engine block heater are affected

2017 GMC Sierra Denali 2500HD Photo: GM

General Motors is recalling 2017-2019 Chevrolet Silverado and GMC Sierra heavy-duty pickup trucks equipped with an engine block heater due to concerns that the optional heater cord could develop a short circuit. This action includes only 2500/3500-series trucks fitted with the 6.6-liter diesel engine. 

The announcement follows the previous report of problems in early 2019 (NHTSA campaign 19V328, GM number N182206310). Since then, GM received 122 related complaints and 24 reports of potential, related fires, between December 3, 2019, and May 28, 2021. (Ford also had a recall over faulty engine-block heaters in 2019.)

GM is still developing a remedy. The company advises that owners who have this feature disabled as a remedy to the safety condition will be offered replacement block heaters and heater cords under a separate customer satisfaction program. 

Should a problem develop, the automaker says that owners may notice smoke or a burning smell; poor performance from the engine block heater; or coolant from the block heater pooled under affected trucks. When in use, the block heater may blow vehicle fuses or trip a circuit breaker.

Dealerships have been directed to remove the engine block heater cord on both customer trucks and those in their inventory.

GM will notify owners in mid-August, then follow up with directions when a true remedy is available.

The Details

Vehicles recalled: 2017-2019 Chevrolet Silverado 2500/3500 and GMC Sierra 2500/3500 pickup trucks with the 6.6-liter diesel engine and optional engine heater, built from July 18, 2016, to May 10, 2019. A total of 331,274 trucks are included in this action.

The problem: A short circuit can occur if a block-heater coolant leak develops and coolant contacts the block-heater cable terminals while the cable is plugged into an energy source. Contamination of the sealing surface of the block-heater heating element during assembly can allow coolant leaks to develop.

The fix: For now, dealerships will remove the engine block heater cord.

How to contact the manufacturer: Owners may contact Chevrolet customer service at 800-222-1020; and GMC customer service at 800-462-8782.

NHTSA campaign number: 21V-496. GM’s number for this recall is N212329840.

Check to see whether your vehicle has an open recall: NHTSA’s website will tell you whether your vehicle has any open recalls that need to be addressed.

If you plug your car’s 17-digit vehicle identification number (VIN) into NHTSA’s website and a recall doesn’t appear, it means your vehicle doesn’t currently have any open recalls. Because automakers issue recalls often, and for many older vehicles, we recommend checking back regularly to see whether your vehicle has had a recall issued.

Stay informed about recalls that might affect your vehicle by using our Car Recall Tracker. Create a free account now to become a CR member.

2017 GMC Sierra Denali 2500HD

Photo: GM Photo: GM


Jeff S. Bartlett

A New England native, I have piloted a wide variety of vehicles, from a Segway to an aircraft carrier. All told, I have driven thousands of vehicles—many on race tracks across the globe. Today, that experience and passion are harnessed at the CR Auto Test Center to empower consumers. And if some tires must be sacrificed in the pursuit of truth, so be it. Follow me on Twitter (@JeffSBartlett).