Service bulletins for the 2020 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.

854 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Bulletins, newest first
070089037Q	2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
070089037P	2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
21NA124	2021-07-19. Service bulletin. FUEL SYSTEM, GASOLINE:STORAGE:EVAPORATIVE EMISSIONS:CANISTER. 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.
21NA118	2021-07-19. Service bulletin. ENGINE. This technical bulletin provides a procedure to align the exhaust causing a vibration.
21NA108	2021-07-19. Service bulletin. ENGINE; ENGINE AND ENGINE COOLING. This service bulletin provides diagnostic information for the technician regarding a customer concern of engine overheating, cooling system contaminated with engine oil.
21NA088	2021-07-19. Service bulletin. ENGINE. This service bulletin provides repair information to correct a customer concern of a Check Engine Light Displayed on Driver Information Center (DIC), Engine Cooling Fan Windmilling, DTC P0494 Set.
20NA159	2021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
20NA136	2021-07-19. Service bulletin. POWER TRAIN. This informational bulletin describes/outlines the process for the 9T65 Automatic Transmission Replacement Pilot Program (U.S. Only).
19NA256	2021-07-19. Service bulletin. ENGINE. This service bulletin provides diagnostic aid procedure 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.
19NA076	2021-07-19. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides repair information to correct a customer concern of Blue or Black Screen and Service Rear Vision System Message on Radio Display Shifting into Reverse.
19NA044	2021-07-19. 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.
18NA306	2021-07-19. 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	2021-07-19. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking.
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.
21NA118	2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin provides a procedure to align the exhaust causing a vibration.
21NA108	2021-07-06. Service bulletin. UNKNOWN OR OTHER; ENGINE AND ENGINE COOLING. This service bulletin provides diagnostic information for the technician regarding a customer concern of engine overheating, cooling system contaminated with engine oil.
21NA088	2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides repair information to correct a customer concern of a Check Engine Light Displayed on Driver Information Center (DIC), Engine Cooling Fan Windmilling, DTC P0494 Set.
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).
20NA136	2021-07-06. Service bulletin. POWER TRAIN. This informational bulletin describes/outlines the process for the 9T65 Automatic Transmission Replacement Pilot Program (U.S. Only).
19NA256	2021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides diagnostic aid procedure 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.
19NA076	2021-07-06. Service bulletin. BACK OVER PREVENTION. This service bulletin provides repair information to correct a customer concern of Blue or Black Screen and Service Rear Vision System Message on Radio Display Shifting into Reverse.
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.
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.
PIT5843	2021-06-14. 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.

Older bulletins

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