Transport CanadaCritical
2017 GMC SIERRA HDTransport Canada Recall #2021407
The official notice
Defect
On certain vehicles, a small coolant leak could cause the engine block-heater cable to short circuit while plugged in. Note: This recall only affects trucks equipped with a 6.6 L diesel engine and an optional block-heater power cable. This recall replaces Transport Canada Recall # 2019-204. All vehicles repaired under that recall require a second repair.
Safety Risk
A short circuit could cause damage to engine components and create the risk of a fire.
Remedy
General Motors will notify owners by mail. The corrective actions for this recall are under development. Do not use your engine-block heater until the repairs are performed.
36,376 vehicles affectedMfr ref: N212329840Updated June 10, 2026