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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.

Warranty extensions
N242450640-012025-10-20. 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.
N2424506402024-11-06. 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.
22-NA-2442024-05-30. ELECTRICAL SYSTEM; EXTERIOR LIGHTING; STRUCTURE:BODY; UNKNOWN OR OTHER; SERVICE BRAKES. This service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.

A warranty extension may pay for a repair after the basic warranty has ended. Read the document for which vehicles and which repair it covers.

By type

By component

By trouble code

By topic

Bulletins, newest first
PIT5698F2026-09-30. Service bulletin. UNKNOWN OR OTHER. This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.
PIP4902W2026-09-10. Service bulletin. UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIT5995B2026-09-10. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information provides the dealer information of the location of the rear seat child anchors.
PIT6196A2026-09-02. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information provides a diagnostic tip for diagnosing an issue with Cruise Control, Adaptive Cruise and Lane Keep Assist Turns Off or Inoperative.
PIC6551C2026-08-27. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
PIC6589B2026-08-04. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the techicians a diagnostic tip if a customer has a complaint of a whistle/wind noise at highway speeds.
PIC6548B2026-07-30. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the technician the direction needed when encountering an issue with switching between adaptive cruise control and regular cruise control or an issue with automatic high beam feature after the front camera was replaced.
PIT5099J2026-07-29. Service bulletin. UNKNOWN OR OTHER. PI to help diagnose A/C concern
PIT5966F2026-07-07. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
PIP6032C2026-06-08. Service bulletin. UNKNOWN OR OTHER. PIP6032B provides diagnostic direction for dealers when encountering transmission leaks
PIC6423A2026-05-19. Service bulletin. UNKNOWN OR OTHER. Pi created to provide GM dealers with information on gathering information for projection issue
PIC6551B2026-05-19. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
PIP6029A2026-04-29. Service bulletin. UNKNOWN OR OTHER. This PI instructs dealers to install foam around the shifter cable to stop rattling
PIT3271Q2026-04-07. Service bulletin. UNKNOWN OR OTHER. This preliminary information communicates information about how to determine if a wheel and tires size change is available.
PIC6553B2026-04-07. Service bulletin. UNKNOWN OR OTHER. This bulletin communicates to a dealer the repair direction that should be taken if they encounter a vibration from the engine when the vehicle is parked facing downhill.
N25-2505522026-04-02. Over-the-air update. UNKNOWN OR OTHER. Improvements to OnStar functionality.
PIP61042026-03-17. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.
PIP4902V2026-03-17. Service bulletin. UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIT6425D2026-03-11. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC'ss
N25-2505522026-02-24. Over-the-air update. UNKNOWN OR OTHER. Improvements to OnStar functionality. During the update process, your radio may stay on up to 5 minutes after you exit the vehicle. This is expected behavior when an update package is onboard the vehicle. Do not service your vehicle during installation.
PIP5929G2026-01-29. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the dealers diagnostic tips related to MIL on with P219A.
PIP60982026-01-19. Service bulletin. UNKNOWN OR OTHER. This PI advised dealer technicians of possible causes of diesel fuel contamination in gasoline powered vehicles and advises of warranty direction.
PIT6425C2026-01-19. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's
PIP4902U2026-01-13. Service bulletin. UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIC66322025-12-29. Service bulletin. UNKNOWN OR OTHER. This bulletin communicates to the dealer actions to take when a customer has no or reduced air flow from HVAC vents.

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