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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

By topic

Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
18NA0982020-12-21. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This informational bulletin provides information for the technicians on where to look on the Duramax engine for coolant leaks.
PIP5752G2020-12-14. Service bulletin. ENGINE; EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates A Vehicle may have a concern of service engine light, misfire and engine noise with possible of DTC P0300 P0106 P0506, Possible valve spring concern
PIP5733F2020-12-14. Service bulletin. ENGINE. This Preliminary information communicates Possible Crank no start or extended crank with DTC p12A6 set current or history. Under Investigation
PIP5759A2020-12-14. Service bulletin. ENGINE. This Preliminary information communicates 6.2L engine restriction, Contact TAC
PIE05902020-12-07. Service bulletin. ENGINE AND ENGINE COOLING. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards check to the engine lamp being illuminated on the drivers information center (DIC).
19NA1872020-11-30. Service bulletin. ENGINE; POWER TRAIN; EQUIPMENT. This bulletin provides additional information on how to graph a cylinder misfire and a possible diagnostic cause.
18NA3612020-11-30. Service bulletin. FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING:ENGINE:DIESEL. This technical bulletin provides a procedure to flush the cooler lines to validate if there is excessive debris in the fuel system caused by a failed part.
18NA1502020-11-30. Service bulletin. ENGINE AND ENGINE COOLING; FUEL SYSTEM, OTHER. This informational bulletin provides information on 6.6L Duramax Possible Oil Leak Path Information.
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.
17NA3932020-11-30. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE. This informational bulletin explains how to check the NOx Catalyst Reductant-Load Adaptive Values using GSD2.
16NA3802020-11-30. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. This informational bulletin provides a procedure on how to perform a quick test to check if the DPF is the cause of excessive soot from the tailpipe.
16NA3762020-11-30. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:DIESEL; FUEL SYSTEM, DIESEL. This informational bulletin provides information on higher than expected oil consumption.
16NA3722020-11-30. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:ENGINE:DIESEL; FUEL SYSTEM, DIESEL. This bulletin provides information on common diesel engine tick noises and how they are considered part of normal operation and no parts should be replaced for these normal operating conditions.
16NA2222020-11-30. Service bulletin. ENGINE. This bulletin provides information on Engine Concerns that could result from lack of scheduled maintenance, improper service or aftermarket calibrations.
PIP5711A2020-11-16. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This Preliminary information communicates to the dealer technicians a warm engine knock noise has no short or long term effects on the engine. Do not attempt repairs for this noise.
PIP5752F2020-11-16. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates A Vehicle may have a concern of service engine light, misfire and engine noise with possible of DTC P0300 P0106 P0506, Possible valve spring concern
PIP5750A2020-11-16. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates the possibility of the having dtc p06DD P06DA P06DB due to engine wiring harness concerns.
PIP5733E2020-11-16. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates Possible Crank no start or extended crank with DTC p12A6 set current or history. Under Investigation
PIE0574A2020-10-26. Service bulletin. FUEL SYSTEM, OTHER; ENGINE. This engineering informational bulletin is requesting information from technicians to inspect for engine oil leak and contact the engineer listed.
PIP5733D2020-10-19. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates Possible Crank no start or extended crank with DTC p12A6 set current or history. Under Investigation
PIP5733C2020-09-14. Service bulletin. ENGINE. This Preliminary information communicates Possible Crank no start or extended crank with DTC p12A6 set current or history. Under Investigation
PIP5733B2020-09-14. Service bulletin. EQUIPMENT; ENGINE. This Preliminary information communicates Possible Crank no start or extended crank with DTC p12A6 set current or history. Under Investigation
PIE05742020-09-08. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE. This engineering informational bulletin is requesting information from technicians to inspect for engine oil leak and contact the engineer listed.
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.
20NA0832020-05-26. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This technical bulletin provides a procedure to check the oil level for correct reading and oil pressure switch is in working order.

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