WenmarOpen by Wenmar Pro

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
01-06-01-011P2024-09-05. Service bulletin. ENGINE. This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
PIP5832A2024-09-04. Service bulletin. ENGINE. This Preliminary information communicates to the dealer an issue where a vehicle may be exhibiting an engine noise condiion. The dealer is instructed on how to isolate the noise to a specific area of the engine for further diagnosis.
23-NA-0112024-08-30. Service bulletin. ENGINE. This Informational bulletin advises the technician of possible areas the oil may leak from the engine.
18-NA-0982024-08-30. Service bulletin. ENGINE. This informational bulletin provides information for the technicians on where to look on the Duramax engine for coolant leaks.
00-06-01-012N2024-08-30. Service bulletin. ENGINE. This service bulletin advises about the possible issues that may occur when using a scotch brite pad or highly abrasive disk on gasket sealing surfaces or reused parts.
21-NA-2712024-08-28. Service bulletin. ENGINE. This bulletin advises the technician of a possible kinked coolant hose that might be causing the customers concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P026A Set.
20-NA-0902024-08-28. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This informational bulletin provides a way for the technician to identify if the ECM has been modified.
18-NA-1032024-08-24. Service bulletin. FUEL/PROPULSION SYSTEM; ENGINE. This service bulletin provides service information for customer concerns of an in-tank fuel pump whining noise, engine hard to start and/or stalls and Malfunction Indicator Lamp (MIL) is illuminated that may be caused by gelling of fuel in cold temperatures.
PIT5689H2024-08-16. Service bulletin. ENGINE. This Preliminary information communicates that some customers may comment that after an auto-stop event the engine does not restart and to inspect the engine ground strap. Temporarily on hold while PIE0572 is active. PIE0572 has now ended and reinstating the PI.
20-NA-0822024-08-16. Service bulletin. ENGINE. This informational bulletin explains why more DEF is being used in diesel engines due to new emission standards.
PIP59902024-08-16. Service bulletin. ENGINE. This Preliminary information communicates a part restriction for certain MY 2.7 L3B service engines
12-01-37-001G2024-08-13. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information to dealership personnel on a new refrigerant (R1234yf) for A/C service.
PIP5712C2024-08-13. Service bulletin. ENGINE. 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.
20-NA-2032024-07-30. Service bulletin. ENGINE. This informational bulletin explains how the regen works for the DEF system and how it works at different levels.
17-NA-1572024-07-30. Service bulletin. ENGINE. This service bulletin explains the difference in oil filters for gas engines with new oil pump control systems and the possibilities of what may happen using the incorrect filter.
24-NA-1242024-07-26. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This technical bulletin provides repair information to correct a customer concern of Malfunction Indicator Lamp Illuminated, Stall, or No Start with DTC P2534, U3023, P0700, P129D, P10DB (w/ L5P Diesel), P103B, P17E0.
23-NA-0022024-07-22. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This technical bulletin provides repair information to correct a customer concern of Charge Air Cooler (CAC) Icing, Check Engine Lamp Illuminated, Possible P0299, P2227, and/or P0300 DTCs Set.
24-NA-1232024-07-18. Service bulletin. ENGINE. This service bulletin advises the technician that the purge pump part number has changed and limited supply.
16-NA-3832024-07-16. Service bulletin. ENGINE; FUEL/PROPULSION SYSTEM. This service bulletin advises of a new fuel injection cleaner kit used for decarbonizing the intake valves to correct conditions of rough idle, Crank no start, extended crank or misfire, MIL with DTCs, and explains how Top Tier fuels should be used to reduce carbon build-up.
19-NA-2182024-06-28. Service bulletin. ENGINE. This service bulletin provides a service procedure to correct a condition of a Ticking Noise from the Engine.
18-NA-1252024-06-28. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information for engine oil life monitor operation calculation.
23-NA-0322024-06-18. Service bulletin. ENGINE; ELECTRICAL SYSTEM. The informational bulletin advises the tech to use the glow plug bore cleaner to reduce the chance of soot building up on the glow plug causing a premature failure.
18-NA-1252024-06-08. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information for engine oil life monitor operation calculation.
22-NA-1502024-05-28. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This technical bulletin provides a procedure to program the Reductant Control Module and Setup and Perform the Reductant Fluid Tank Level Reset.
15-00-89-004G2024-05-15. Service bulletin. ENGINE; SUSPENSION; POWER TRAIN. This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.

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