2021 Chevrolet Trailblazer TSBs

749 manufacturer communications for the 2021 Chevrolet Trailblazer sit in NHTSA's public file. A TSB is factory repair guidance, not a recall — the repair is not automatically free. The 2021 Trailblazer problem report covers complaints, recalls, and investigations.

749Communications
9Campaigns & extensions

What the bulletins cover

Engine200 bulletins
Electrical182 bulletins
Transmission & drivetrain94 bulletins
Wheels & tires42 bulletins
Brakes & stability34 bulletins
Body & structure31 bulletins

Warranty extensions, campaigns & software updates

Worth checking your VIN against — these can mean free or reimbursed work if your vehicle qualifies.

Software update N25-250552 March 21, 2026 Software update

Improvements to OnStar functionality.

Software update N25-250552 February 5, 2026 Software update

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.

Software update N25-250552 December 3, 2025 Software update

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.

Engine N242450640-01 October 20, 2025 Warranty extension

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…

Service campaign N252494770-01 June 20, 2025 Service campaign

Amendments to the Song-Beverly Act (SBA) California warranty law provides vehicle owners with an opportunity to submit a written notice to GM before filing a lawsuit seeking a vehicle repurchase. If such a notice is not provided to GM, then the vehicle owner is prevented from…

Service campaign N252494770 June 17, 2025 Service campaign

Amendments to the Song-Beverly Act (SBA) California warranty law provides vehicle owners with an opportunity to submit a written notice to GM before filing a lawsuit seeking a vehicle repurchase. If such a notice is not provided to GM, then the vehicle owner is prevented from…

Engine N242450640 November 6, 2024 Warranty extension

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…

Electrical General Communication August 26, 2024 Service campaign

Vehicle Wide Programming (VWP) is a new process to update software on GM Vehicles. It provides the ability via a single selection within Techline Connect to first identify which modules need updating and then proceed to updating affected modules (with some exceptions). The…

Electrical · Body & structure · Brakes & stability 22-NA-244 May 3, 2024 Warranty extension

This service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.

Most recent service bulletins

The 20 most recent of 749 communications on file. The complete set is searchable on NHTSA's page for this vehicle.

Service bulletin PIC6589B July 31, 2026

This Preliminary information communicates to the techicians a diagnostic tip if a customer has a complaint of a whistle/wind noise at highway speeds.

Service bulletin PIC6548B July 23, 2026

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.

Service bulletin PIT5099J July 21, 2026

PI to help diagnose A/C concern

Service bulletin PIT5966F June 23, 2026

This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.

Service bulletin PIP6032C June 3, 2026

PIP6032B provides diagnostic direction for dealers when encountering transmission leaks

Service bulletin PIC6551B May 11, 2026

This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues

Service bulletin PIC6423A May 11, 2026

Pi created to provide GM dealers with information on gathering information for projection issue

Service bulletin PIP6029A April 21, 2026

This PI instructs dealers to install foam around the shifter cable to stop rattling

Service bulletin PIT3271Q April 1, 2026

This preliminary information communicates information about how to determine if a wheel and tires size change is available.

Service bulletin PIC6553B March 30, 2026

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.

Service bulletin PIP4902V March 9, 2026

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

Service bulletin PIP6104 March 9, 2026

This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.

Service bulletin PIT6425D March 2, 2026

This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC'ss

Service bulletin PIP5929G January 22, 2026

This Preliminary information communicates to the dealers diagnostic tips related to MIL on with P219A.

Service bulletin PIT6425C January 16, 2026

This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's

Service bulletin PIP6098 January 14, 2026

This PI advised dealer technicians of possible causes of diesel fuel contamination in gasoline powered vehicles and advises of warranty direction.

Service bulletin PIP4902U January 8, 2026

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

Service bulletin PIC6632 December 23, 2025

This bulletin communicates to the dealer actions to take when a customer has no or reduced air flow from HVAC vents.

Service bulletin PIT5214G November 20, 2025

This Preliminary Information communication provides information to the technician about vehicles that have had multiple repair attempts that are being performed on customer’s vehicles that exhibit vibration conditions without utilizing the support of General Motors Technical…

Service bulletin PIP5975B October 27, 2025

This PI advises to get a session log for transmissions with broken chains

← 2021 Trailblazer problems All Trailblazer TSB years
Data updated 2026-08-20 from NHTSA's public records

Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.