GROUNDWORK — 21V496000: Electrical systems and batteries recall for GMC SIERRA 3500 and 3 other models GMC SIERRA 3500 and 3 other models: check the listed vehicles, the reported issue and the manufacturer remedy for 21V496000. Keep the official status and service answers in one private record. Campaign: 21V496000 Official record checked: 2026-10-19T20:40:23.112Z Official campaign: https://api.nhtsa.gov/recalls/campaignNumber?campaignNumber=21V496000 Official VIN lookup: https://www.nhtsa.gov/recalls LISTED VEHICLES (VIN confirmation required) 2019 GMC SIERRA 3500 2019 CHEVROLET SILVERADO 2500 2019 CHEVROLET SILVERADO 3500 2019 GMC SIERRA 2500 2017 GMC SIERRA 2500 2017 GMC SIERRA 3500 2017 CHEVROLET SILVERADO 2500 2017 CHEVROLET SILVERADO 3500 2018 CHEVROLET SILVERADO 2500 2018 CHEVROLET SILVERADO 3500 2018 GMC SIERRA 2500 2018 GMC SIERRA 3500 OFFICIAL REPORTED ISSUE 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. OFFICIAL REPORTED CONSEQUENCE An electrical short-circuit can increase the risk of a fire. OFFICIAL REPORTED 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. OFFICIAL 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. OWNER PREPARATION Keep existing warnings or observations for service. This guide does not ask you to probe wiring, disconnect a battery or open a high-voltage assembly. REMEDY TIMING IN THE DATED SOURCE Confirm current remedy arrangements The source does not explicitly establish current remedy availability. Ask the manufacturer about the applicable remedy, required parts or software, appointment arrangements and any interim instructions. Current availability for your VIN: unconfirmed. YOUR SERVICE QUESTIONS 1. Does the manufacturer confirm that campaign 21V496000 applies to this VIN, including the report’s equipment and production restrictions? A matching model and year is only a starting point. The official lookup or manufacturer must establish the individual vehicle’s status. Discussion status / answer: __________ 2. What remedy, required parts or software, and appointment arrangements are currently available for this VIN, and which interim instructions apply? The source does not explicitly establish current remedy availability. Ask the manufacturer about the applicable remedy, required parts or software, appointment arrangements and any interim instructions. Discussion status / answer: __________ 3. Which electrical component or software function is covered, and what interim charging, parking or use instructions does the manufacturer give? Compare the answer with the reported component: EQUIPMENT:ELECTRICAL:ENGINE BLOCK HEATER. Discussion status / answer: __________ 4. Which items in the reported replacement remedy for 21V496000 were replaced, and are they identified on the work order? Keep the replaced items and the campaign number together so that a later visit can distinguish recall work from other repairs. Discussion status / answer: __________ 5. How does this campaign relate to 19V328000, and does work recorded under an earlier campaign satisfy the current remedy? Show any earlier work order. Related recall numbers can describe expanded or repeated work; ask the manufacturer to reconcile the records. Discussion status / answer: __________ 6. What dated document records the remedy performed under 21V496000, and what should I do if the reported concern remains? Keep campaign completion and unresolved symptoms as separate questions. A saved worksheet or booked appointment does not establish a repair. Discussion status / answer: __________ OFFICIAL LOOKUP DECISIONS Not checked or unavailable: eligibility remains unconfirmed; use the official lookup or manufacturer. Campaign listed as open: confirm current instructions, availability and remedy arrangements. Campaign not listed as open: reconcile repair history and lookup coverage with the manufacturer if needed. A zero-open result does not diagnose symptoms. Work order records completed recall work: keep the exact campaign and dated remedy record; report unresolved symptoms separately. YOUR RECORD Check date: __________ Official lookup result: __________ Service arrangement: __________ Existing observation: __________ Questions and work-order notes (no VIN or plate needed): __________ LOOKUP LIMITS A model/year match does not establish VIN eligibility. The official lookup may omit completed recalls, some recent campaigns or recalls outside its coverage. The listed defect does not prove the cause of a symptom on your vehicle. This guide supports owner preparation and does not provide a repair procedure.