Chevrolet Silverado 2500, Chevrolet Silverado 3500, Gmc Sierra 2500, Gmc Sierra 3500, model years 2017 to 2019. Filed by General Motors, LLC and reported to NHTSA on 1 July 2021. 338,020 vehicles potentially affected.
What the notice says 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 …
Is your vehicle included? Check with your VIN at NHTSA, or ask a dealer. This page is an independent copy of the notice, kept so you can see what changed after it was published. It is not the authority, and the authority’s own text is the one to act on.
General Motors's own number for this recall: N212329840. That is the number on the owner letter and on the dealer paperwork. 21V496 is the number NHTSA gave the same campaign, and the number this page is filed under. They are one recall, written two ways.
What owners ask about this recall
- Which vehicles does recall 21V496 cover?
- Chevrolet Silverado 2500, Chevrolet Silverado 3500, GMC Sierra 2500, GMC Sierra 3500, model years 2017-2019.
- What is wrong with them?
- 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.
- What can happen if it is not put right?
- An electrical short-circuit can increase the risk of a fire.
- Is there a fix yet?
- Yes, and it is free. 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.
- What should I do now?
- Check your own vehicle by its VIN with NHTSA, which is the record to act on. General Motors calls this recall N212329840, which is the number on the owner letter and the dealer paperwork.
Answered from the register this site holds. NHTSA is the record to act on.
What the authority says can happen if this is not fixed: “An electrical short-circuit can increase the risk of a fire.”
affected
in the notice
caught
| Campaign | 21V496 |
|---|---|
| Filed by | General Motors, LLC |
| System at fault | Equipment:Electrical:Engine Block Heater |
| Reported to NHTSA | 1 July 2021 |
| Model years | 2017-2019 |
| Vehicles named | CHEVROLET SILVERADO 2500, CHEVROLET SILVERADO 3500, GMC SIERRA 2500, GMC SIERRA 3500 |
What the notice says today
The consequence
An electrical short-circuit can increase the risk of a fire.
The 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.
What it said before
This campaign is in the register but not yet in the dated wording archive, so we cannot yet say whether its text has moved. It enters the archive on the next pass.
This is one of 2,632 notices in the record whose component field names equipment. Across that group the median wait before owners were written to was 29 days.
Last checked . No change has been recorded in the wording.
The models named here, across their whole recall history
- Chevrolet Silverado 2500 recalls: 37 US campaigns
- Chevrolet Silverado 3500 recalls: 37 US campaigns
- GMC Sierra 2500 recalls: 35 US campaigns
- GMC Sierra 3500 recalls: 36 US campaigns
How to cite this record
Quoting the wording on this page means quoting a version, so the date belongs in the citation:
CarsMultiverse, recall 21V496, wording as read on 16 September 2026. https://carsmultiverse.com/recall/21v496/
The cross-border matches used on this site are deposited as a citable dataset: doi:10.5281/zenodo.22087136. The recall wording itself is published by the national authority named above and is theirs, not ours.
The recall record and its wording are published by the US National Highway Traffic Safety Administration and are US Government public domain. The dated archive, the comparison and any before-and-after above are CarsMultiverse. How fresh every engine behind this page is, is public on the status page. To check a specific vehicle, use NHTSA’s own VIN lookup.
Other General Motors notices we hold
- 26V530: 2024-2025 Chevrolet Silverado 2500 and GMC Sierra 2500
- 26V496: 2026 Chevrolet Silverado EV and GMC Sierra EV
- 26V494: 2026 Cadillac Escalade IQ, Escalade IQL, GMC Sierra EV, and Chevrolet Silverado EV
- 26V399: 2025-2026 Express, and 2025-2026 Savana
- 26V394: 2026-2027 Cadillac Vistiq
- 26V345: 2026 Chevrolet Express and GMC Savana
- 26V329: 2015 Cadillac Escalade, Escalade ESV, XTS, 2015-2016 Cadillac ATS, CTS, and SRX
- 26V325: 2018 Chevrolet Silverado 1500, GMC Sierra 1500, 2019 Chevrolet Silverado 2500, Silverado 3500, GMC Sierra 2500, and Sierra 3500
All 474 General Motors campaigns we hold · Every manufacturer in the record
The fingerprint of this notice
We take a SHA-256 of each of the three blocks of text the authority publishes and keep the first eight characters. As we last read campaign 21V496 on 23 August 2026, they were:
- Defect summary
b3db4de1 - Consequence
10ce3782 - Remedy
86cb1e44
We first read this notice on 21 August 2026. It has not moved since. If it ever does, these characters will not match, and the change will be dated here.
The wording we hold for 21V496 · how the whole register is watched
This notice names one vehicle among several registers that have written about it. Every notice this site holds for the Chevrolet Silverado 2500, in all seven, is kept on that vehicle's own page, with the newest in each.
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