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Service bulletins for the 2021 Chevrolet Trailblazer

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.

753 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

Bulletins, newest first
23-NA-1192025-10-16. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. This service bulletin provides service procedure information to correct a customer concern of Shift to Park Displayed on DIC When Vehicle is in- Park, No Start - DTC B000A Set.
PI0281L2025-06-12. Service bulletin. STEERING; POWER TRAIN; SUSPENSION. This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
19-NA-2002025-04-10. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. This service bulletin provides a repair procedure to correct a customer concern of start/stop inoperative, MIL illuminated w/DTC P2797.
PIP5975A2025-03-02. Service bulletin. POWER TRAIN. This Preliminary information communicates information on what dealer technicians should due if they encounter a broken chain on a CVT transmission
PIP6032A2025-02-03. Service bulletin. POWER TRAIN. This Preliminary Information communication advises the technician on possible sources of transmission fluid leaks from the transmission oil filter or cooler line seals .
21-NA-2932025-01-30. Service bulletin. ENGINE; POWER TRAIN; ELECTRICAL SYSTEM. This technical bulletin provides repair information to correct a customer concern of Poor Engine Performance in Extremely Cold Weather Conditions, Charge Air Cooler Icing - Malfunction Indicator Lamp (MIL) Illuminated, DTC P0299, P0234, P0236, P00C7 Set.
09-06-04-026Z2025-01-23. Service bulletin. ENGINE; POWER TRAIN; ELECTRICAL SYSTEM. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
08-07-30-035I2024-12-19. Service bulletin. POWER TRAIN. This service bulletin provides information on the harmful effects of ethylene glycol in transmission fluid.
21-NA-1812024-12-18. Service bulletin. POWER TRAIN. This service bulletin provides 9th gear operation information to respond to customers that may comment on transmission shift operation.
PIP60322024-12-16. Service bulletin. POWER TRAIN. This Preliminary Information communication advises the technician on possible sources of transmission fluid leaks from the transmission oil filter or cooler line seals .
PIP60292024-12-16. Service bulletin. UNKNOWN OR OTHER; POWER TRAIN. This Preliminary information communicates to Technicians how to repair a rattle noise coming from the shift cable assembly.
23-NA-0212024-12-04. Service bulletin. ENGINE; POWER TRAIN. This service bulletin advises the tech that the rotational Clicking Noise Heard After Engine Shut Down may be normal characteristics of the vehicle.
04-06-01-029K2024-12-04. Service bulletin. POWER TRAIN; STEERING; ENGINE. This informational bulletin explains Unscheduled Supplemental Services and the importance of GM Simplified Maintenance Schedules.
20-NA-1382024-11-05. Service bulletin. POWER TRAIN; ENGINE. This bulletin provides information on Policies Applicable to All U.S. Dealers for Engine and Transmission Assembly Replacement Under Warranty, Policy or Customer Enthusiasm and information on Submission of Warranty Transaction in Global Warranty Management.
23-NA-1192024-10-24. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. This service bulletin provides service procedure information to correct a customer concern of Shift to Park Displayed on DIC When Vehicle is in- Park, No Start - DTC B000A Set.
08-07-30-026I2024-10-24. Service bulletin. POWER TRAIN. This service bulletin provides information on some vehicles that may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.
PIC6553A2024-08-16. Service bulletin. POWER TRAIN. This Preliminary information communicates the direction to take when a customer complains about a vibration when parking on a steep slope with engine running.
24-NA-1412024-08-15. Service bulletin. POWER TRAIN. GM is receiving damaged (cracked or broken) transmission cores returned to the reman facilities. The damage is being caused either in the removal process by the technician, or inadequate packaging or shipping. This bulletin advises the dealers to be more careful not to damage the transmissions during removal and to package the core properly for return.
PIP59782024-08-12. Service bulletin. POWER TRAIN. This Preliminary information communicates the possibility of dtc p0299 setting as a result of the vacuum supply line from the vacuum pump to the wastegate solenoid being restricted with adhesive bonding material.
99-04-20-002O2024-07-30. Service bulletin. POWER TRAIN. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
24-NA-0092024-06-18. Service bulletin. POWER TRAIN. This service bulletin advises the technician to replace valve body first to determine if that is the issue for and if not, to inspect internal parts of transmission for any signs of abnormal wear to correct customer concerns of Loss of Forward gear, slipping, MIL.
08-07-30-035H2024-06-07. Service bulletin. POWER TRAIN. This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
21-NA-1692024-05-24. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. 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.
15-00-89-004G2024-05-15. Service bulletin. ENGINE; SUSPENSION; POWER TRAIN. This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
23-NA-1192024-04-23. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. This service bulletin provides service procedure information to correct a customer concern of Shift to Park Displayed on DIC When Vehicle is in- Park, No Start - DTC B000A Set.

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