# 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 bulletins from NHTSA, as of 2026-10-19.

- [PIT5698F](/bulletins/11037555.md), 2026-09-30, Service bulletin: UNKNOWN OR OTHER. This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.
- [PIP4902W](/bulletins/11037253.md), 2026-09-10, Service bulletin: UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
- [PIT5995B](/bulletins/11037252.md), 2026-09-10, Service bulletin: UNKNOWN OR OTHER. This Preliminary Information provides the dealer information of the location of the rear seat child anchors.
- [PIT6196A](/bulletins/11036693.md), 2026-09-02, 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.
- [PIC6551C](/bulletins/11036392.md), 2026-08-27, Service bulletin: UNKNOWN OR OTHER. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
- [PIC6589B](/bulletins/11035696.md), 2026-08-04, 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.
- [PIC6548B](/bulletins/11035349.md), 2026-07-30, 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.
- [PIT5099J](/bulletins/11035340.md), 2026-07-29, Service bulletin: UNKNOWN OR OTHER. PI to help diagnose A/C concern
- [PIT5966F](/bulletins/11034769.md), 2026-07-07, 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.
- [PIP6032C](/bulletins/11033723.md), 2026-06-08, Service bulletin: UNKNOWN OR OTHER. PIP6032B provides diagnostic direction for dealers when encountering transmission leaks
- [PIC6423A](/bulletins/11032764.md), 2026-05-19, Service bulletin: UNKNOWN OR OTHER. Pi created to provide GM dealers with information on gathering information for projection issue
- [PIC6551B](/bulletins/11032763.md), 2026-05-19, Service bulletin: UNKNOWN OR OTHER. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
- [PIP6029A](/bulletins/11031713.md), 2026-04-29, Service bulletin: UNKNOWN OR OTHER. This PI instructs dealers to install foam around the shifter cable to stop rattling
- [PIT3271Q](/bulletins/11030974.md), 2026-04-07, Service bulletin: UNKNOWN OR OTHER. This preliminary information communicates information about how to determine if a wheel and tires size change is available.
- [PIC6553B](/bulletins/11030970.md), 2026-04-07, 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\-250552](/bulletins/11030532.md), 2026-04-02, Over\-the\-air update: UNKNOWN OR OTHER. Improvements to OnStar functionality.
- [PIP6104](/bulletins/11030092.md), 2026-03-17, 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.
- [PIP4902V](/bulletins/11030091.md), 2026-03-17, Service bulletin: UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
- [PIT6425D](/bulletins/11029950.md), 2026-03-11, 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\-250552](/bulletins/11028977.md), 2026-02-24, 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.
- [PIP5929G](/bulletins/11027867.md), 2026-01-29, Service bulletin: UNKNOWN OR OTHER. This Preliminary information communicates to the dealers diagnostic tips related to MIL on with P219A.
- [PIP6098](/bulletins/11027701.md), 2026-01-19, 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.
- [PIT6425C](/bulletins/11027697.md), 2026-01-19, 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
- [PIP4902U](/bulletins/11027601.md), 2026-01-13, Service bulletin: UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
- [PIC6632](/bulletins/11026862.md), 2025-12-29, 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.

More: [the next page](/v1/vehicles/2021_chevrolet_trailblazer/bulletins?cursor=2025-12-29_11026862) (JSON)

JSON: [/v1/vehicles/2021_chevrolet_trailblazer/bulletins](/v1/vehicles/2021_chevrolet_trailblazer/bulletins)

[Report an error on this page](https://github.com/wenmar-pro/wenmar-open/issues/new?template=data_correction.yml&title=Data%20correction%3A%202021%20Chevrolet%20Trailblazer&page=https%3A%2F%2Fopen.wenmarpro.com%2Fmakes%2Fchevrolet%2Ftrailblazer%2F2021%2Fbulletins&vehicle=2021%20Chevrolet%20Trailblazer)