Service bulletins for the 2021 Chevrolet Blazer
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.
814 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
By topic
| 21NA279 | 2021-12-27. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides a procedure to replace the starter if found the cause of the rattle noise. |
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| 21NA278 | 2021-12-27. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides diagnostic strategy information to aid in diagnosing a Ticking, Tap or Rattle Noise from Engine with Possible Misfire, Malfunction Indicator Lamp (MIL) Illuminated. |
| 21NA276 | 2021-12-27. Service bulletin. ELECTRICAL SYSTEM; ENGINE; EQUIPMENT. This service bulletin provides a procedure to correct a customer concern of Starter Not Cranking Engine, Grinding Noise When Starting?. |
| 21NA257 | 2021-12-27. Service bulletin. ENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This service bulletin provides a service procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3075 Set. |
| 21NA256 | 2021-12-27. Service bulletin. EXTERIOR LIGHTING; EQUIPMENT; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:ENGINE COOLANT HOSES AND FITTINGS. This service bulletin provides repair information for dealers/technicians to correct a customer concern of a Malfunction Indicator Lamp Illuminated with DTC P26BB Set. |
| 21NA252 | 2021-12-27. Service bulletin. EQUIPMENT; PARKING BRAKE:ELECTRICAL; ELECTRICAL SYSTEM:SOFTWARE. This technical bulletin provides repair information to correct a customer concern of Electronic Park Brake Applying Intermittently After Vehicle Shutdown without DTC?s. |
| 21NA169 | 2021-12-27. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. This service bulletin provides diagnostic information/procedures to aid the service technician in diagnosing 9T45/50/60 automatic transmissions with low mileage and DTCs current or history related to the control solenoids and valves. |
| 21NA054 | 2021-12-27. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. This service bulletin provides repair information to correct a customer concern of Instrument Cluster Resets, Center Display Goes Blank, or Gauges Inoperative. |
| 20NA136 | 2021-12-27. Service bulletin. EQUIPMENT; POWER TRAIN. This informational bulletin describes/outlines the process for the 9T65 Automatic Transmission Replacement Pilot Program (U.S. Only). |
| 19NA104 | 2021-12-27. 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. |
| 20NA136 | 2021-12-20. Service bulletin. POWER TRAIN. This informational bulletin describes/outlines the process for the 9T65 Automatic Transmission Replacement Pilot Program (U.S. Only). |
| 20NA132 | 2021-12-20. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements. |
| 19NA256 | 2021-12-20. Service bulletin. ENGINE. This service bulletin provides diagnostic aid information/procedures to perform inspections to determine if the engine needs to be replaced as opposed to just internal parts for knocking, rattle, squeak and/or squeal type noises from engine. |
| 18NA073 | 2021-12-20. Service bulletin. ENGINE. This service bulletin provides graphics, information and guidelines for engine component wear to assist service personnel as a guideline to perform necessary engine repairs and prevent unnecessary engine replacement. |
| PIT5863 | 2021-12-13. Service bulletin. ENGINE; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This Preliminary information communicates that a vehicle may be encountered with a buzz or rattle type noise emanating from the exhaust. The dealer technician is directed to replace the exhaust system. |
| PIP5824 | 2021-10-25. Service bulletin. FUEL SYSTEM, GASOLINE. This Preliminary information communicates a possible issue with the active fuel management rockers causing a misfire and the correction for this concern. |
| PIT5847B | 2021-10-25. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates that a vehicle may come into the dealer with various concerns which may include a service engine light or various warning messages on the DIC. The technician is instructed to inspect a wiring harness for chaffing on a bracket which is located beneath the battery tray. If damage to the harness is found the technician is instructed to repair the damaged wiring and secure the harness away from the bracket so that future damage to the harness will be eliminated. |
| PIT5834F | 2021-10-25. Service bulletin. EQUIPMENT:APPLIANCE:AIR CONDITIONER. This preliminary information addresses the possibility for the air conditioning to be slow to cool the cabin due to contamination in the refrigerant. |
| PIP5608H | 2021-10-25. Service bulletin. POWER TRAIN. This Preliminary information communicates to perform a transmission fluid drain and fill to correct a TCC shudder concern. |
| PIP5608G | 2021-09-13. Service bulletin. POWER TRAIN. This Preliminary information communicates to perform a transmission fluid drain and fill to correct a TCC shudder concern. |
| PIT5662F | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:WARNING; PARKING BRAKE. This Preliminary information communicates information to diagnose DTC C056D or C056E. |
| PIT5834E | 2021-09-13. Service bulletin. EQUIPMENT:APPLIANCE:AIR CONDITIONER. This preliminary information addresses the possibility for the air conditioning to be slow to cool the cabin due to contamination in the refrigerant. |
| PIC6438B | 2021-09-13. 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. |
| PIC6444 | 2021-09-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates a possible SIM issue with vehicles in the middle east. |
| PIT5847A | 2021-09-13. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This Preliminary information communicates that a vehicle may come into the dealer with various concerns which may include a service engine light or various warning messages on the DIC. The technician is instructed to inspect a wiring harness for chaffing on a bracket which is located beneath the battery tray. If damage to the harness is found the technician is instructed to repair the damaged wiring and secure the harness away from the bracket so that future damage to the harness will be eliminated. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.