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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: Equipment and accessories are shown. Show all

Bulletins, newest first
19NA1042021-12-27. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This service bulletin provides information for dealers/technicians and customers on steam/vapor coming from the front grille or radiator area.
PIT58682021-12-13. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:HEATER CORE; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This Preliminary information communicates an issues will low or poor heater performance on the drivers side. Dealers are to inspect the HVAC temperature door linkage and if ok replace the heater core.
PIP5816A2021-10-25. Service bulletin. EQUIPMENT. This Preliminary information communicates A customer vehicle may have a concern of a P0300 setting after bulletin 21-NA-154 has been performed. Unknown Engineering is looking it to this concern
PIT5752B2021-10-25. Service bulletin. EQUIPMENT. This Preliminary information communicates multiple vehicle issues caused by an aftermarket device and it gives dealership information where to inspect for this device.
PIC6438B2021-09-13. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern.
PIC64442021-09-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates a possible SIM issue with vehicles in the middle east.
PIT3099U2021-09-13. Service bulletin. EQUIPMENT. This Preliminary Information communication provides information to the technician about installing General Motors Accessory parts/kits. Technicians should refer to Service Information for information regarding most accessories. Technicians may also contact PARTECH and/or the Techline Customer Support Center for additional support.
PIP5632E2021-09-13. Service bulletin. EQUIPMENT:ELECTRICAL:ACCESSORY GENERATOR:CONTROLS. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
PIP5776F2021-09-13. Service bulletin. ENGINE; EQUIPMENT. This Preliminary information communicates that a vehicle may exhibit a misfire condition resulting in misfire codes P0300-P308. Upon diagnosis it may be discovered the lifter has come apart. It is recommended to replace the lifter guide and the four lifters.
N2123368002021-08-09. Service bulletin. EQUIPMENT:ELECTRICAL; POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE); EQUIPMENT. Service Update. On certain vehicles, the thrust washer was not installed on the transfer case reduction carrier assembly. Dealers are to replace the transfer case.
N2023160202021-08-09. Service bulletin. EQUIPMENT:ELECTRICAL:INFOTAINMENT:SOFTWARE. Service Update - Radio Software Update (OTA) - Certain 2021 model year vehicles listed above, with an infotainment system, may have a condition where the infotainment system screen will appear black with no audio and no chime at key on during cold temperature conditions. Dealers are to verify radio software level and update if necessary.
N2123328202021-08-09. Service bulletin. EQUIPMENT:APPLIANCE:TV/RADIO/SPEAKERS; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM:SOFTWARE. Service Update. Certain vehicles may not be able to access Apps. A most notable improvement list this software update may correct is located at the end of this bulletin for conditions or concerns a customer may experience. Dealers will reprogram the radio.
PIE06482021-08-09. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; STEERING. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to a rubbing type noise heard while turning the steering wheel.
PIE06462021-08-09. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT ADAPTIVE/MOBILITY. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the trailer light message and/or trailer disconnect message on the infotainment screen.
PIE06452021-08-09. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT; POWER TRAIN. 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), Transmission Not Shifting Properly and/or Slipping, DTC P0796, P2714 Set.
PIE0642A2021-08-09. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards the Service Engine Soon (SES) lamp illuminated and/or Service Emission System Message on the Driver Information Center (DIC).
PIE0609A2021-08-09. Service bulletin. ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR:INTEGRATED STARTER(OTHER THAN PROPULSION); EQUIPMENT; ELECTRICAL SYSTEM; ENGINE. 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.
PIE0602C2021-08-09. Service bulletin. POWER TRAIN:DRIVELINE; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. 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 illuminated on Driver Information Center.
990420002L2021-08-09. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION; POWER TRAIN:AUTOMATIC TRANSMISSION; EQUIPMENT. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
110089002E2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. This service bulletin provides information on GM Accessories ? Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
080730035E2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
010842001N2021-08-09. Service bulletin. EXTERIOR LIGHTING; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This service bulletin provides information for dealers/technicians on Exterior Lamp Condensation and Water Leaks and Replacement Guidelines.
21NA1522021-08-09. Service bulletin. VISIBILITY:GLASS, SIDE/REAR; EQUIPMENT. This service bulletin provides information for dealers/technicians on glass ultraviolet (UV) Ray protection and tint percentage.
21NA0952021-08-09. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This technical bulletin provides a procedure to seal the exhaust at the UFSCR and Tailpipe flange.
120851002M2021-08-09. Service bulletin. EQUIPMENT. This informational bulletin provides technicians and dealership personnel with spray-in bed liner general information and repair procedures.

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