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
| PIP5653L | 2022-02-14. Service bulletin. POWER TRAIN:AXLE ASSEMBLY. This Preliminary information communicates that engineering is investigating a repair for a chirp noise associated with the front axle assembly. |
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| PIT5702C | 2022-02-14. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:FILTER/SCREEN; EQUIPMENT. This Preliminary information communication provides information to the technician on installing Regular Production Option Code 9L7 Up-fitter Auxiliary Switches. Technician will need to reference the latest version of General Motors Up-fitter Integration Bulletin 153. The information can be found at http://www.gmupfitter.com/ under the "Technical Bulletin" Tab and then "Show all bulletins." |
| 21NA199 | 2022-02-14. Service bulletin. POWER TRAIN; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY. This informational bulletin advises the technician to replace the TBV if the transmission has any type of repair even if no problem was found, to replace the tbv. |
| 21NA238 | 2021-12-27. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak. |
| PIP5806D | 2021-10-25. Service bulletin. POWER TRAIN. This preliminary information bulletin instructs to technicians to check the trigger wheel for interfering with the timing chain, and adding a shim to the camshaft position sensor. |
| PIP5810 | 2021-09-13. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION:SEALS/GASKETS. 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. |
| PIP5792B | 2021-09-13. Service bulletin. FUEL SYSTEM, GASOLINE; POWER TRAIN. This Preliminary information communicates to the dealer technician that if a customer comments that their vehicle equipped with a 6L80, 6L90, 8L90, 10L80, or 10L1000 transmission has a harsh shift, shudder, stall or high transmission fluid temperature concern they should inspect for a twisted transmission cooler line. Technicians are instructed to disconnect the cooler line and untwist it then reconnect the cooler line and inspect the cooler line for being misshaped. Technicians are instructed to replace the cooler line if it is misshaped. |
| PIC5650J | 2021-09-13. Service bulletin. POWER TRAIN; AIR BAGS. This Preliminary Information communication provides information to the technician about vehicles that have an intermittent no crank, no start, or start stall concern with the security light coming on. Technician may find Diagnostic Trouble Codes B3055, B3060, and/or B3935. Technician should not replace any parts for this concern. If unable to duplicate the concern ask if the customer uses any Radio Frequency Identification Devices when the concern is present. Dealer should also direct their customers to the appropriate section in the Owner manuals that references that the device complies. |
| N212336800 | 2021-08-09. 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. |
| PIE0645 | 2021-08-09. 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. |
| PIE0602C | 2021-08-09. 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. |
| 990420002L | 2021-08-09. 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. |
| 080730035E | 2021-08-09. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid. |
| 21NA120 | 2021-07-19. Service bulletin. POWER TRAIN. This technical bulletin provides the tech with a procedure to check if the transmission is the cause of the concern by checking the data. |
| 21NA113 | 2021-07-19. Service bulletin. POWER TRAIN. This technical bulletin provides a procedure to perform a learn procedure for the turbo actuator. |
| 21NA120 | 2021-07-06. Service bulletin. POWER TRAIN. This technical bulletin provides the tech with a procedure to check if the transmission is the cause of the concern by checking the data. |
| PIP5807 | 2021-06-14. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that it is a normal characteristic for vehicles equipped with the 10L1000 transmission to start off in second gear in normal driving mode. It also communicates that the vehicle will start off in first gear if tow haul is selected. |
| PIP5792A | 2021-06-14. Service bulletin. POWER TRAIN; FUEL SYSTEM, GASOLINE. This Preliminary information communicates to the dealer technician that if a customer comments that their vehicle equipped with a 6L80, 6L90, 8L90, 10L80, or 10L1000 transmission has a harsh shift, shudder or stall concern they should inspect for a twisted transmission cooler line. Technicians are instructed to disconnect the cooler line and untwist it then reconnect the cooler line and inspect the cooler line for being misshaped. Technicians are instructed to replace the cooler line if it is misshaped. |
| PIE0615A | 2021-06-07. Service bulletin. POWER TRAIN; SERVICE BRAKES. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards on a tick and/or ping type noise heard from the Propeller Shaft during acceleration and/or braking. |
| 21NA106 | 2021-05-24. Service bulletin. POWER TRAIN. This informational bulletin advises the technician to verify the TCM is asleep before trying to repair the transmission in order for all the codes to be re-set. |
| 20NA218 | 2021-05-24. Service bulletin. POWER TRAIN. This service bulletin provides repair information to correct a customer concern of Possible Crank No Start or Extended Crank with DTC P12A6. |
| 16NA338 | 2021-05-24. Service bulletin. POWER TRAIN. 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. |
| PIP5794A | 2021-05-17. Service bulletin. POWER TRAIN. This Preliminary information communicates diagnostics to the dealer involving a vehicle shudder concern caused by the camshaft actuator system that can be mistaken for a transmission issue. |
| PIP5799 | 2021-05-17. Service bulletin. STRUCTURE; POWER TRAIN. This Preliminary information communicates to the dealer technician to replace the transmission valve body on 2019-2021 10 speed transmissions to correct DTCs P2812 and P2814 setting if Service Information does not lead to root case of these DTCs. |
| PIE0615 | 2021-05-03. Service bulletin. POWER TRAIN. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards on a tick and/or ping type noise heard from the Propeller Shaft during acceleration and/or braking. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.