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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
PIT5677E2021-05-17. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This Preliminary information communicates the following issues and directs dealership to inspect the engine harness for shorting. Some customers may comment on any of the following concerns: - SES MIL - No Start - No Crank - Engine runs rough - Reduced engine power - Erratic speedo - Blown Fuse(s): F46UA, F47UA, F51UA, F78UA, F85UA, F86UA, F87UA, and/or F90UA When checking for DTC's any combination may be found: C15AA P001A P2B00 P2B01 P2B03 P2B96 P001B P003D P0107 P018C P01E5 P01E6 P01E7 P0237 P0340 P0341 P0355 P0365 P037C P03F0 P0521 P0522 P0532 P0616 P077C P07BF P0707 P1101 P112F P146D P159F p16A0 p16A2 P171B P2122 P26E5 P2812 P2814 P2B53 P2C05 P2C08 P2C09 P2C0C P2C0D P2C10 P2C12 P2C15 P2C16 P2C19 P305E P3084 P3089 P308E P3093 P3094 P3095 P3098 P30B0 P30B3 P30CF U0073 U0100 U0101 U0140 U0644 U0672
PIP5775B2021-05-17. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This Preliminary information communicates to dealership technicians that a P11D5 may be cause by a software anomaly, check to see if campaign N212331790 applies, reflash the ECM and release the vehicle.
PIP5752L2021-05-17. Service bulletin. ENGINE. 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
21NA0812021-05-10. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This technical bulletin provides a procedure to locate a possible short in the engine wiring harness.
PIE06172021-05-03. Service bulletin. ENGINE AND ENGINE COOLING. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to why is Engineering seeking more details on what is driving Engine Oil Cooler replacements through the warranty system.
21NA0562021-05-03. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin provides a procedure to correct the condition of Information on Vehicles Engine Shuts Off After 30 or 60 Minutes of Idling.
21NA0022021-05-03. Service bulletin. ENGINE AND ENGINE COOLING. This informational bulletin provides a test procedure, for a possible faulty DEF Heater.
20NA1382021-05-03. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. This bulletin provides information on Policies Applicable to All U.S. Dealers for Engine and Transmission Assembly Replacement Under Warranty, Policy or Customer Enthusiasm and information on Submission of Warranty Transaction in Global Warranty Management.
20NA0822021-05-03. Service bulletin. ENGINE AND ENGINE COOLING. This informational bulletin explains why more DEF is being used in diesel engines do to new emission standards.
PIP5212C2021-04-19. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary Information communication provides information to the technician about vehicles that have run hot and or has a tick noise. Technician should inspect the head gaskets to ensure are not installed backwards. Technician should replace the head gasket if they are found installed backwards.
PIP5712B2021-04-19. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:CRANK/CAMSHAFT POSITION SENSOR; POWER TRAIN. This Preliminary information communicates to the technician a service Diagnostic / Repair tip to avoid causing the crankshaft sprocket to disengage from the crankshaft during crankshaft balancer or cam drive system component related service procedures.
PIP57912021-04-19. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates to dealership technicians to perform a sweep of the coolant flow control valve and test the circuits before replacing the Engine Coolant Flow Control Valve, and to assist engineering in root causing the P2B60.
PIP5712A2021-04-19. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:CRANK/CAMSHAFT POSITION SENSOR. This Preliminary information communicates to the technician a service Diagnostic / Repair tip to avoid causing the crankshaft sprocket to disengage from the crankshaft during crankshaft balancer removal.
PIT58192021-04-19. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE. This Preliminary information communicates in temperatures below freezing, it may be noticed that exhaust is only exiting from the right hand exhaust tailpipe. The cause of this condition is a low point in left side tailpipe which results in condensation building up at the low point in the tailpipe. In low temperatures the condensation can freeze and form ice limiting the flow of exhaust out of the left tailpipe. Dealers are to drill a small hole in the left tailpipe to allow condensation to drain.
PIE06092021-03-08. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ELECTRICAL SYSTEM; EQUIPMENT; ENGINE AND ENGINE COOLING. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to a noise heard from the engine compartment, loss of charging and/or reduced alternator output.
PIE06022021-03-08. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to Service Engine Soon Lamp Illuminated On Driver Information Center (DIC), DTC P208B Set.
PIE0590A2021-03-08. Service bulletin. ENGINE; EQUIPMENT; ELECTRICAL SYSTEM:INTERIOR LAMPS/BULBS. This engineering informational bulletin 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).
21NA0072021-03-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. This technical bulletin provides a procedure to program the reductant fluid module if found the cause of the customers concern.
21NA0062021-03-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. This bulletin provides a possible location of a bad connection at the reductant fluid tanks electrical connector.
21NA0022021-03-01. Service bulletin. EQUIPMENT:ELECTRICAL:ENGINE BLOCK HEATER; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); FUEL SYSTEM, DIESEL. This informational bulletin provides a test procedure, for a possible faulty DEF Heater.
20NA2032021-03-01. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin explains how the regen works for the DEF system and how it works at different levels.
18NA0732021-03-01. Service bulletin. ENGINE. This service bulletin provides graphics, information and guidelines for engine component wear to assist service personnel as a guideline to perform necessary engine repairs and prevent unnecessary engine replacement.
PIE0601A2021-03-01. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Service Engine Soon Lamp being illuminated.
090604026S2021-03-01. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE; EQUIPMENT. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
010601011L2021-03-01. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION; EQUIPMENT. This informational bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.

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