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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

Only bulletins with component: Electrical system are shown. Show all

Bulletins, newest first
21NA2522021-12-27. 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.
21NA0542021-12-27. 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.
20NA1322021-12-20. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements.
PIT5847B2021-10-25. 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.
PIT5662F2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:WARNING; PARKING BRAKE. This Preliminary information communicates information to diagnose DTC C056D or C056E.
PIC6438B2021-09-13. 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.
PIC64442021-09-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates a possible SIM issue with vehicles in the middle east.
PIT5847A2021-09-13. 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.
PIC6438A2021-09-13. Service bulletin. ELECTRICAL SYSTEM. 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.
PIT5700C2021-09-13. Service bulletin. BACK OVER PREVENTION; ELECTRICAL SYSTEM. This Preliminary information communicates that a vehicle may come to the dealer with a "service front camera" message. The technician is instructed to use the data bus tool to determine if the front view camera module and active safety module are both communicating on the low speed bus. If the technician determines that one of the modules is not communicating on low speed the tech is instructed of areas to inspect the low speed communication line, 5060 for possible opens and repair them per SI.
PIT58452021-09-13. Service bulletin. ELECTRICAL SYSTEM; VEHICLE SPEED CONTROL; EQUIPMENT. This Preliminary information communicates information to diagnose adaptive cruse with DTC U0422 in the EBCM.
PIC64382021-09-13. Service bulletin. ELECTRICAL SYSTEM. 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.
PIT5698B2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:BLINDSPOT:SENSORS. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus.
PIP58142021-09-13. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM. This Preliminary information communicates that there some service parts released to dealers missing software.
PIT58472021-09-13. Service bulletin. ELECTRICAL SYSTEM:WIRING. 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.
21NA1472021-08-09. Service bulletin. ELECTRICAL SYSTEM:IGNITION:COIL:SPARK PLUGS; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE AND ENGINE COOLING. This service bulletin provides a repair procedure to correct a customer concern of Coolant and/or Oil Leak, Malfunction Indicator Lamp (MIL) Illuminated?.
21NA1392021-08-09. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). This service bulletin provides a repair procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3055 Set.
19NA0442021-07-19. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy.
18NA2792021-07-19. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking.
21NA1242021-07-06. 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.
PIT58432021-06-14. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates that a vehicle may come to the dealer with concerns of various warning messages, possibly the door locks cycling, passive entry inoperative or other concerns. The technician is instructed to inspect G401 for loose or missing terminals.
PIE06282021-06-07. Service bulletin. EXTERIOR LIGHTING; ELECTRICAL SYSTEM. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Malfunction Indicator Lamp illuminated on Driver Information Center (DIC) with DTCs P3055, P3056 Set.
21NA0682021-05-10. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. This warranty administration bulletin provides policy information requirements applicable to key fob replacement under the New Vehicle Limited Warranty or under a Replacement Parts Warranty on 2021 and newer model year vehicles with RPO ATH (U.S. Only).
21NA0612021-05-10. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. This service bulletin provides information for dealers on Using EL-52545 When Diagnosing PEPs Transmitter Key Fobs (North America ONLY).
21NA0542021-05-03. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Instrument Cluster Resets, Center Display Goes Blank, or Gauges Inoperative.

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