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Service bulletins for the 2021 GMC Sierra

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.

1649 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Brakes are shown. Show all

Bulletins, newest first
23-NA-2012025-10-21. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM; STEERING. This service bulletin advises the technician of a possible loose ground that may be causing customer concerns of Loss of Steering Assist and/or Loss of Brake Assist and Malfunction Indicator Lamp (MIL) Illuminated.
25-NA-0652025-04-24. Service bulletin. STEERING; SERVICE BRAKES; FUEL/PROPULSION SYSTEM. This informational bulletin instructs the tech when fuel/fluid is needed to be tested and where it can be sent for analysis.
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-1552025-01-30. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM. This informational bulletin advises the technician to check for faults that may be caused by the trailer otherwise found by a possible faulty trailer connector.
PIT5828D2025-01-20. Service bulletin. SERVICE BRAKES. This Preliminary Information communication provides information to the technician about customers that may request the factory Integrated Trailer Brake Controller Regular Production Option Code (JL1) be installed on their Full-Size Pickup or SUV when the vehicle was not ordered with the option. Dealer should advise the customer it cannot be added to the vehicle.
PIT6134G2025-01-20. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
PIT6134F2025-01-03. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
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.
PIT6134E2024-12-05. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
21-NA-0892024-12-04. Service bulletin. SERVICE BRAKES. This technical bulletin provides a procedure to replace the rear calipers if found packed for of mud and debris.
22-NA-0922024-12-03. Service bulletin. SERVICE BRAKES. This informational bulletin provides an optional repair using a different set of brakes that may correct the customers concern of Early Brake Wear in Harsh Environments.
21-NA-2752024-10-30. Service bulletin. WHEELS; SERVICE BRAKES; POWER TRAIN. This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing “D” on Driver Information Center (DIC) when Lightly or Moderately Accelerating Forcing an 8-7 or 8-6 Downshift.
PIT6134D2024-10-25. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
23-NA-2012024-10-24. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM; STEERING. This service bulletin advises the technician of a possible loose ground that may be causing customer concerns of Loss of Steering Assist and/or Loss of Brake Assist and Malfunction Indicator Lamp (MIL) Illuminated.
PIT6134C2024-10-22. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
PIT5509L2024-09-11. Service bulletin. SERVICE BRAKES. This Preliminary Information communication provides information to the technician on how to diagnose and repair vehicle that may have a "Check Trailer Wiring" or "Service Trailer Brake System” message on the Driver Information Center when a trailer is connected to the vehicle. Diagnostic Trouble Code C1114 set in the Chassis Control Module. Chassis Control Module has to determine the type of trailer brake system that is being used. The Chassis Control Module can be sensitive to a variety of trailer wiring issues. The technician will need to make a trailer tester using Electric Trailer Brake Magnets and 7-way trailer connector to determine if it is a vehicle or trailer issue. If the concern is not duplicated with the tester installed, the vehicle is operating correctly and the focus should be on the trailer wiring or 7 way connector.
PIT62122024-09-11. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with the Hydrastar Electric Over Hydraulic trailer brake system causing a voltage spike into the trucks electrical system which is causing DTC C1114 to set.
PIT6134B2024-09-06. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
21-NA-0892024-07-22. Service bulletin. SERVICE BRAKES. This technical bulletin provides a procedure to replace the rear calipers if found packed for of mud and debris.
22-NA-2442024-05-30. Warranty extension. 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.
21-NA-1552024-04-23. Service bulletin. ELECTRICAL SYSTEM; SERVICE BRAKES, HYDRAULIC; EQUIPMENT. This informational bulletin advises the technician to check for faults that may be caused by the trailer otherwise found by a possible faulty trailer connector.
PIT61372024-04-15. Service bulletin. SERVICE BRAKES. This Preliminary information communicates an issue with clearing DTC: C15DD and how to rest the average release time to clear DTC.
PIT61342024-04-15. Service bulletin. SERVICE BRAKES, AIR:DISC:PADS. This Preliminary information communicates an issue with premature brake pad life and engineering is working on release new pad lining material.
PIP5596A2024-04-15. Service bulletin. SERVICE BRAKES; FUEL SYSTEM, GASOLINE. This Preliminary information communicates that when removing the fuel line jumper hose care should be taken to be sure the line is reinstalled correctly to avoid a no/low fuel pressure situation.
PIT5479F2024-03-18. Service bulletin. SERVICE BRAKES. This Preliminary Information communication provides information to the technician about fluid leaking from the brake caliper piston area found during a service of the vehicle. The substance is actually excess assembly grease from the caliper boot and piston installation. This grease can be cleaned off and the rest of the service completed.

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