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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: Engine are shown. Show all

Bulletins, newest first
00-06-01-026R2025-12-03. Service bulletin. ENGINE. This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
23-NA-1532025-10-25. Service bulletin. ENGINE. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
N242450640-012025-10-20. Warranty extension. ENGINE. Special Coverage. Certain 2021 model year Buick Encore GX and Chevrolet Trailblazer vehicles, equipped with a 1.2L engine, may have a condition that could cause the turbocharger to fail. If this condition occurs, the Malfunction Indicator Lamp (Check Engine Light) will illuminate, and a diagnostic trouble code will set. Additionally, a message may be displayed indicating the vehicle’s available engine power is reduced. This special coverage covers the condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after November 6, 2024, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to November 6, 2024, must be submitted to the Service Contract provider. Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are eligible for reimbursement of their reasonable and customary expenses in accordance with the procedures specified below. The conditional right to reimbursement is provided by GM solely in the interest of customer satisfaction and is personal to Customers. Customers may not assign and GM does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special Coverage to any third party, including but not limited to service contract providers, and this Special Coverage is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties. Dealers are to replace the turbocharger as necessary. The repairs will be made at no charge to the customer.
23-NA-1222025-10-01. Service bulletin. ENGINE. This service bulletin provides a procedure to fix an oil leak from a porous area at the cylinder head and how to fix it so that the engine does not have to be replaced.
15-NA-0102025-07-07. Service bulletin. ENGINE. This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
25-NA-1002025-06-12. Service bulletin. ENGINE. This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California Emission State may be entitled to the 7 year, 70,000-mile Emission Select State Component Limited Warranty.
20-NA-0842025-05-01. Service bulletin. ENGINE. This service bulletin provides information on normal engine characteristics/noise produced by the LIH or LBP engine.
25-NA-0522025-04-28. Service bulletin. ENGINE. This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to oil in system.
25-NA-0522025-04-10. Service bulletin. ENGINE. This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to oil in system.
22-NA-0742025-02-12. Service bulletin. ENGINE. This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large amounts of debris has flowed throughout the oiling system.
21-NA-0432025-02-12. Service bulletin. VISIBILITY/WIPER; SERVICE BRAKES; ENGINE; ELECTRICAL SYSTEM; WHEELS. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
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.
19-NA-2192024-12-17. Service bulletin. ENGINE. This diagnostic tip bulletin provides additional information on how to diagnose a possible valve, lifter or camshaft issue.
21-NA-0432024-12-10. Service bulletin. STRUCTURE:BODY; WHEELS; ENGINE; SERVICE BRAKES; UNKNOWN OR OTHER. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
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.
01-06-01-011Q2024-11-13. Service bulletin. ENGINE. This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
N2424506402024-11-06. Warranty extension. ENGINE. Special Coverage. Certain vehicles, equipped with a 1.2L engine, may have a condition that could cause the turbocharger to fail. If this condition occurs, the Malfunction Indicator Lamp (Check Engine Light) will illuminate, and a diagnostic trouble code will set. Additionally, a message may be displayed indicating the vehicle’s available engine power is reduced. Dealers are to replace the turbocharger as necessary. The repairs will be made at no charge to the customer.
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.
04-06-04-051J2024-10-31. Service bulletin. ENGINE. This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
04-06-04-051J2024-10-31. Service bulletin. ENGINE. This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
18-NA-0732024-10-11. 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.
23-NA-0442024-09-11. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on AGM batteries that require less frequent charging in storage.
23-NA-1412024-09-06. Service bulletin. ENGINE. This informational bulletin advises the technician that the engine and related parts will be debited if found that the tech did not properly prepare the engine block from dirt and debris in bolt holes or if found that the block was damaged by the tech.

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