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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: Transmission and driveline are shown. Show all

Bulletins, newest first
08-07-30-035H2024-06-07. Service bulletin. POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
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.
22-NA-2582024-04-09. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. This technical bulletin provides a procedure to program the TCM and replace the control valve body if the conditions are found to be the cause of the failure of the valve body.
22-NA-2582024-03-29. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. This technical bulletin provides a procedure to program the TCM and replace the control valve body if the conditions are found to be the cause of the failure you the valve body.
23-NA-1702024-03-19. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This bulletin advises the tech to inspect deeper into what may be the main cause of an engine failure.
PIP59682024-03-18. Service bulletin. POWER TRAIN. This Preliminary information communicates to have the dealer contact TAC with the transmission TUN number prior to transmission installation.
PIP59662024-03-18. Service bulletin. POWER TRAIN. This Preliminary information communicates Diagnostic aids for a no start or DTC'S following a transmission replacement
PIP59622024-03-18. Service bulletin. POWER TRAIN:AXLE ASSEMBLY. This Preliminary information communicates how to isolate a tick noise from the rear axle housing.
22-NA-1822024-03-06. Service bulletin. POWER TRAIN. This service bulletin advises the technician to check if the transmission cooler lines are twisted to correct customer concerns of Harsh Shift, Shudder, Surge, Stall, Transmission Overheating and/or High Transmission Fluid Temperature.
21-NA-2382024-02-29. Service bulletin. POWER TRAIN. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak.
23-NA-1852024-02-23. Service bulletin. STEERING; EQUIPMENT; ELECTRICAL SYSTEM; POWER TRAIN. 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.
16-NA-3382024-02-17. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This Warranty Admin service bulletin provides guidelines for Dealers Not Required and for Dealers Required to Contact the PQC for engine or transmission assembly replacement and explains the PQC process, GWM Transaction submission, vehicle service record retention and proper handling of assembly returns for Canadian Dealers only.
21-NA-2382024-02-14. Service bulletin. EQUIPMENT; POWER TRAIN. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak.
PIP5810B2024-02-12. Service bulletin. POWER TRAIN. This Preliminary information communicates that the tool for the HD transfer cases to install the input seal during a repair is incorrect and a new tool is in development.
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.
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.
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.
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.
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.
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.
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.
21-NA-1492023-12-19. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN; ENGINE AND ENGINE COOLING. This service bulletin provides repair information for Engine Wire Harness Chafing to correct customer concerns of IPC Gauges Sweep, IPC Warning Message, SES/Check Engine/MIL, No Start/ No Crank, Runs Rough, Stalls, Reduced Engine Power, Various DTCs.
PIT60882023-12-18. Service bulletin. POWER TRAIN; STEERING. This Preliminary information communicates a diagnostic tip to inspect the main ground connection when diagnosing any lack of power steering assist issues with DTCs C1597 and/or C1599.
PIP59492023-12-18. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer, a potential rough running condition following an autostop event that is caused by the incorrect crankshaft position sensor.
PIP59432023-12-04. Service bulletin. EQUIPMENT:MECHANICAL:POWER TAKE-OFF (PTO); POWER TRAIN. This Preliminary Information communication advises the technician on diagnostic aids to help with the diagnosis and repair of 8 Speed Transmissions

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