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Service bulletins for the 2021 GMC Sierra

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

1649 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

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Only bulletins with component: Cooling system are shown. Show all

Bulletins, newest first
20NA1662022-05-31. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:COOLING SYSTEM:HOSES/LINES/PIPING/FITTINGS. This informational bulletin advises the technician of possible coolant entering the areas of the engine, either through failed parts or defects in the castings, that may be the cause of the concerns related to the MIL or the engine running rough.
21NA2372022-02-14. Service bulletin. UNKNOWN OR OTHER; ENGINE AND ENGINE COOLING:COOLING SYSTEM. THis technical bulletin provides a procedure to perform a cooling system flush to remove possible debris from the cooling system pipes.
21NA2572021-12-27. Service bulletin. ENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This service bulletin provides a service procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3075 Set.
21NA2372021-12-27. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:COOLING SYSTEM:HOSES/LINES/PIPING/FITTINGS. THis technical bulletin provides a procedure to perform a cooling system flush to remove possible debris from the cooling system pipes.
18NA1032020-11-30. Service bulletin. FUEL SYSTEM, GASOLINE; ENGINE AND ENGINE COOLING:COOLING SYSTEM:PUMP. This service bulletin provides information to correct a customer concern of an in-tank fuel pump whining noise, engine hard to start and/or stalls and Malfunction Indicator Lamp (MIL) is illuminated.
PIP5684B2020-08-10. Service bulletin. ENGINE; ENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT. This Preliminary information communicates the use of air leak diagnostic test tool CH-52250 in addition to the information found in the service manual.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.