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Service bulletins for the 2021 Chevrolet Silverado

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.

1747 on file from NHTSA, as of 2026-10-19.

Warranty extensions
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
PIP6127B2026-10-14. Service bulletin. UNKNOWN OR OTHER. This document assists GM dealer technicians with diagnosing torque converter concerns to ensure torque converter replacement is necessary. The torque converter part number will be placed on order restriction, and the technician will be asked to follow 25-NA-148 before requesting a part through PQC.
PIT6477D2026-10-06. Service bulletin. UNKNOWN OR OTHER. This preliminary PI was created to advise techniians in the field that they will not be able to perform a GDS automated bleed with the scan tool dues to a issue with the software in the scan tool
PIP61332026-09-30. Service bulletin. UNKNOWN OR OTHER. This PI was created to help address the correct repair regarding a low coolant message on the DIC
PIT5698F2026-09-30. Service bulletin. UNKNOWN OR OTHER. This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.
PIP5700H2026-09-29. Service bulletin. UNKNOWN OR OTHER. This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering
PIP4902W2026-09-10. Service bulletin. UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIP6127A2026-09-02. Service bulletin. UNKNOWN OR OTHER. This document assists GM dealer technicians with diagnosing torque converter concerns to ensure torque converter replacement is necessary. The torque converter part number will be placed on order restriction, and the technician will be asked to follow 25-NA-148 before requesting a part through PQC.
PIC6551C2026-08-27. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
PIT6031B2026-08-14. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issue where an aftermarket autostop device or rear taillights is causing a dead battery.
PIP61272026-08-04. Service bulletin. UNKNOWN OR OTHER. This document assists GM dealer technicians with diagnosing torque converter concerns to ensure torque converter replacement is necessary. The torque converter part number will be placed on order restriction, and the technician will be asked to follow 25-NA-148 before requesting a part through PQC.
PIT5680B2026-07-30. Service bulletin. UNKNOWN OR OTHER. This PI provides information to repair the door water deflector which is not sealed properly allows water into the door jam/sill area.
PIT5099J2026-07-29. Service bulletin. UNKNOWN OR OTHER. PI to help diagnose A/C concern
PIT5509N2026-07-29. Service bulletin. UNKNOWN OR OTHER. This PI provides diagnostic tips for diagnosing electric trailer brakes issues.
PIT6473F2026-07-21. Service bulletin. UNKNOWN OR OTHER. This PI was created to help avoid unnecessary front camera module replacements
PIT5767B2026-07-21. Service bulletin. UNKNOWN OR OTHER. This PI provides a diagnostic tip on poor a/c performance due to a condenser issue and instructions to replace the ac condenser.
PIT65322026-07-13. Service bulletin. UNKNOWN OR OTHER. The purpose of this PI is to inform dealer technicians of a normal cab pressure relief valve noise to avoid unnecessary part replacement
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.
PIT5544J2026-07-07. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates information on a hydraulic rush type noise from the power steering gear. This noise is a characteristic of the new Active Hydraulic Assist System RPO NV8 and no repairs should be made. The noise is most noticeable in the cab at idle, in park, with all accessories turned off.
PIT65232026-06-18. Service bulletin. UNKNOWN OR OTHER. This PI provides diagnostic steps for dealer technicians to verify the condition and ensure that part replacement is necessary
PIT6132E2026-06-18. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issues with the HVAC making a hum buzz noise when the blower is set to a higher speed. Engineering is working on a new HVAC door seal material to correct the noise.
PIP61152026-05-28. Service bulletin. UNKNOWN OR OTHER. The document advise technicians after an engine repair involving removal of the camshaft actuators, the vehicle may set p1101 P0172 and or stalls when taken off idle. The technician is instructed to verify the intake and exhaust camshaft actuators are installed onto the correct camshafts.
PIP5810D2026-05-28. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates that the tool for the HD transfer cases to install the input seal during a repair is incorrect and a new tool is in development
N25-2505522026-05-26. Over-the-air update. UNKNOWN OR OTHER. • Improvements to OnStar functionality.
PIT5509M2026-05-19. Service bulletin. UNKNOWN OR OTHER. This PI provides diagnostic tips for diagnosing electric trailer brakes issues.
PIC6423A2026-05-19. Service bulletin. UNKNOWN OR OTHER. Pi created to provide GM dealers with information on gathering information for projection issue

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