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
| 18NA279 | 2021-07-19. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking. |
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| 21NA128 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin provides repair information to correct a customer concern of MIL Illuminated- ECM Update for P026C, P20EE, or P11D5. |
| 21NA124 | 2021-07-06. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set. |
| 21NA121 | 2021-07-06. Service bulletin. ELECTRICAL SYSTEM. This technical bulletin provides a procedure to inspect fuses F51DR and/or F52DR in the X51R right instrument panel fuse block when they should not be installed. |
| 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. |
| 21NA113 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin provides a procedure to perform a learn procedure for the turbo actuator. |
| 21NA110 | 2021-07-06. Service bulletin. EQUIPMENT. This informational bulletin provides information for dealers/technicians on Information on GM Accessories - Instructions on Claim Submission on Dealer-Replaced Tonneau Covers During Warranty Period. |
| 21NA109 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides diagnostic information for a customer concern of engine vibration. |
| 21NA101 | 2021-07-06. Service bulletin. STRUCTURE. This service bulletin provides a procedure to replace both front door seals to correct a customer concern of Howl, Hoot, or Whistle Type Noise when Driving in Crosswinds. |
| 21NA096 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin provides a procedure to program the ECM to correct the customers concern. |
| 21NA091 | 2021-07-06. Service bulletin. BACK OVER PREVENTION. This service bulletin provides information for customers/dealers/technicians on Normal Rearview Camera Display Operation - Flashing Diamond - Spot - or UFO like image on Rear View Camera Display. |
| 21NA079 | 2021-07-06. Service bulletin. SEATS. This technical bulletin provides a procedure to replace the lower seat frame to correct the condition of Pop Noise Heard During Seat Travel and/or Inadequate Seat Rearward Travel due to a supplier installation error. |
| 20NA218 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides repair information to correct a customer concern of Possible Crank No Start or Extended Crank with DTC P12A6. |
| 20NA159 | 2021-07-06. Service bulletin. TIRES. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only). |
| 19NA129 | 2021-07-06. Service bulletin. BACK OVER PREVENTION. This technical bulletin provides repair information to correct a customer concern of a squeak and/or clunking noise coming from the rear of the vehicle. |
| 19NA044 | 2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy. |
| 18NA361 | 2021-07-06. Service bulletin. FUEL SYSTEM, GASOLINE. This technical bulletin provides a procedure to flush the cooler lines to validate if there is excessive debris in the fuel system caused by a failed part. |
| 18NA306 | 2021-07-06. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA). |
| 18NA279 | 2021-07-06. Service bulletin. LATCHES/LOCKS/LINKAGES. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking. |
| N212330660 | 2021-06-14. Service bulletin. SERVICE BRAKES, HYDRAULIC. Service Update Bulletin. Certain vehicles may have an erratic signal coming from the engine manifold absolute pressure (MAP) sensor. Customers may notice the service engine soon (SES) lamp illuminate or was illuminated and turned off. DTC?s P0106 and P0108 may also be present as active or stored in history. Dealers will replace the MAP sensor. |
| N212335340 | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. Customer Satisfaction Program. Certain vehicles, equipped with a 5.3 L engine, may have a diagnostic calibration in the engine control module (ECM) causing it to stay awake resulting in a parasitic drain on the battery. This could cause diagnostic trouble code (DTC) P0111 and the presence of other low voltage DTC?s. Dealers will update the ECM with the latest calibrations. |
| PIT5681B | 2021-06-14. Service bulletin. SERVICE BRAKES. This Preliminary information communicates the location of the GM Accessory Performance Brake System Rotor Specifications |
| PIT5403H | 2021-06-14. Service bulletin. ELECTRONIC STABILITY CONTROL:AUTOMATIC (ASC); SUSPENSION. This Preliminary Information communication provides information to the technician with the steps to diagnosis and repair vehicles with various handling, vehicle dynamics concerns, noises from the suspension or underbody, or issues related to damaged suspension components. Before any in-depth diagnostics are performed, be aware that various issues could occur if the vehicle has been modified and inform the customer the conditions noted may not be covered under warranty. Technician will inspect for installed aftermarket suspension components. Also inspect for improperly adjusted torsion bars. |
| 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. |
| PIP5806 | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. This preliminary information bulletin instructs to technicians to use the Picoscope or a make physical inspection to check for a suspected bent target wheel on the camshaft. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.