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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

Bulletins, newest first
22-NA-2462024-02-06. Service bulletin. POWER TRAIN. This service bulletin advises the technician that the possible cause may not be from a faulty clutch piston or extension housing and to perform testing on transmission for other possible issues, but it still may be possible on high mileage vehicles that orifices in housing may have come dislodged, causing the same customer concern.
22-NA-1122024-02-05. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This technical bulletin provides repair information to correct a customer concern of 2020 - 2022 Silverado and Sierra Equipped with Diesel Engine Setting DTCs P20BB or P20C3.
21-NA-1202024-02-05. Service bulletin. EQUIPMENT; POWER TRAIN. This service bulletin provides a Diagnostic Tip for Noise, Vibration, and/or Harshness Issues/Clunk Noise Heard During Coast Down Event after the transfer case was removed from the transmission and reinstalled during a recent repair.
18-NA-0992024-02-02. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This bulletin provides information for use on a Product Assistance Claim (PAC), which is formerly known as a Product Allegation Resolution (PAR) claim.
PI1394B2024-02-02. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This PI bulletin advises the technician on the proper way to install the pistons in an engine.
PI0592I2024-02-02. Service bulletin. ELECTRICAL SYSTEM. This preliminary information (PI) provides information om Service Programming System (SPS) Error Codes (E4398, E4399, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491 or E6961).
PIT5386J2024-01-29. Service bulletin. BACK OVER PREVENTION; ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician about vehicles that are found to have a back-up alarm inoperative during the Pre-Delivery Inspection. On trucks equipped with the Back Up Alarm (RPO 8S3), the alarm will be intentionally left disconnected from the assembly plant. Technician will reroute the harness and plug it in.
PIT5074P2024-01-29. Service bulletin. EQUIPMENT. This Preliminary Information communication provides information to the technician about the use of J-35616-64B terminal test probe, replacement terminals, and terminated leads. The J-35616-64B is the latest test probe released for checking tension or probing the .64 series terminals. The test probe terminal has been released in the terminal repair kit (J-38125-620H) located in Lear Tray 7 part number 963716-2. There are 5 terminated leads in a package part number is 13505346, which can be ordered through your normal General Motors Customer Care and Aftersales parts channel.
PIT5962A2024-01-29. Service bulletin. ELECTRICAL SYSTEM:HAND HEATER:WIRING HARNESS; UNKNOWN OR OTHER. This Preliminary information communicates a GM part number for reflective high temperature heat or insulating tape when repairing wiring harnesses.
PIT6097B2024-01-29. Service bulletin. EQUIPMENT:ELECTRICAL; EQUIPMENT:ELECTRICAL:WIRELESS CHARGER/CRADLE. This Preliminary information communicates an issue where the vehicles wireless charger no longer works with the latest ISO update on Apple 15 phones.
PIT6097A2024-01-29. Service bulletin. EQUIPMENT:ELECTRICAL:WIRELESS CHARGER/CRADLE. This Preliminary information communicates an issue where the vehicles wireless charger no longer works with the lastest ISO update on Apple 15 phones.
PIT60972024-01-29. Service bulletin. EQUIPMENT:ELECTRICAL:INFOTAINMENT:SOFTWARE; EQUIPMENT:ELECTRICAL:INFOTAINMENT. This Preliminary information communicates an issue where the vehicles wireless charger no longer works with the lastest ISO update on Apple 15 phones.
PIT60962024-01-29. Service bulletin. EQUIPMENT:ELECTRICAL; POWER TRAIN. This Preliminary information communicates a diagnostic tip for the 110 /120 volt power outlets being inoperative and dealerships should try a battery disconnect to see if the concern goes away.
21-NA-1552024-01-19. Service bulletin. TRAILER HITCHES; EQUIPMENT; ELECTRICAL SYSTEM. This informational bulletin advises the technician to check for faults that may be caused by the trailer otherwise found by a possible faulty trailer connector.
02-08-42-001J2024-01-19. Service bulletin. EXTERIOR LIGHTING. This informational bulletin provides information for dealers/technicians on Headlamp, Tail Lamp, License Lamp or Fog/Driving Lamp Damage.
23-NA-1852024-01-19. Service bulletin. POWER TRAIN; EQUIPMENT; STEERING; ELECTRICAL SYSTEM. This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases - Service 4WD on DIC, Intermittent Failures, Noise Concerns, Driveline/Steering Vibration/Shudder, Intermittent DTCs/MIL Illuminated, Engagement/Disengagement/Ratcheting Concerns.
22-NA-1502024-01-19. Service bulletin. ELECTRICAL SYSTEM; FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING. This technical bulletin provides a procedure to program the Reductant Control Module and Setup and Perform the Reductant Fluid Tank Level Reset.
21-NA-2382024-01-19. Service bulletin. POWER TRAIN. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak.
18-NA-1802024-01-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Warranty Administration Bulletin Provides High Voltage Battery Exchange Process Information.
22-NA-1502024-01-13. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; FUEL SYSTEM, DIESEL. This technical bulletin provides a procedure to program the Reductant Control Module and Setup and Perform the Reductant Fluid Tank Level Reset.
19-NA-2182024-01-13. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides a service procedure to correct a condition of a Ticking Noise from the Engine.
16-NA-3612024-01-13. Service bulletin. POWER TRAIN; EQUIPMENT. This service bulletin provides service /diagnostic information to aid with a Transmission Harsh 1-2 Shift Upon First Start Up/Shift of the Day Under Light Throttle.
PIT5099G2023-12-26. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This Preliminary Information communication provides information to the technician about vehicles that the Heater-Vent-Air Conditioning blows warm air. Before calling General Motors Technical Assistance Center technician will need to have high and low pressures, outside temperature, humidity, and vent temperature.
PIT5950A2023-12-26. Service bulletin. EQUIPMENT; WHEELS. This Preliminary information communicates an issue of the wrong part number WSS being installed during a service procedure and to warn dealership tech to make sure the correct part number WSS is installed.
PIT5698D2023-12-26. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus.

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