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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.

About P0308 on the 2021 GMC Sierra: what the code means, and the bulletins and recalls about the same components.

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Only bulletins with trouble code: P0308 are shown. Show all

Bulletins, newest first
23-NA-0432024-03-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides a procedure to replace the valve lifter and guides to correct customer concerns of Poor Engine Performance, Engine Misfires, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 Set.
PIP5628G2023-09-18. Service bulletin. ENGINE. This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D
23-NA-0432023-05-16. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides a procedure to replace the valve lifter and guides to correct customer concerns of Poor Engine Performance, Engine Misfires, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 Set.
PIP5628F2023-05-15. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D
23-NA-0432023-05-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides a procedure to replace the valve lifter and guides to correct customer concerns of Poor Engine Performance, Engine Misfires, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 Set.
PIP5628E2023-03-13. Service bulletin. EQUIPMENT:ELECTRICAL:ACCESSORY GENERATOR:OUTLETS/RECEPTACLE. This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D
PIP5628E2022-01-24. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D

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