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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

Bulletins, newest first
PIT5689N2026-04-23. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates that some customers may comment that after an auto-stop event the engine does not restart and to inspect the engine ground strap. Temporarily on hold while PIE0572 is active. PIE0572 has now ended and reinstating the PI.
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.
N25-2505522026-04-02. Over-the-air update. UNKNOWN OR OTHER. Improvements to OnStar functionality.
PIT6473E2026-03-31. Service bulletin. UNKNOWN OR OTHER. This PI was created to help avoid unnecessary front camera module replacements
PIT6473C2026-03-19. Service bulletin. UNKNOWN OR OTHER. This PI was created to help avoid unnecessary front camera module replacements
PIT6473D2026-03-19. Service bulletin. UNKNOWN OR OTHER. This PI was created to help avoid unnecessary front camera module replacements
PIT6473B2026-03-17. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communicates direction for different audio issues with RPO UQA, UQF, UQS, or NKD
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
PIT64892026-03-03. Service bulletin. UNKNOWN OR OTHER. This preliminary information communicates an issue with the engine running after the ignition is turned off and diagnostic help to isolate a possible Fuel Pump Control Module issue.
PIT5697E2026-03-03. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communication provides information to the technician on installing Regular Production Option Code UVC Rearview Camera. Technician will need to reference the latest version of General Motors Up-fitter Integration Bulletin 152. The information can be found at http://www.gmupfitter.com/ under the "Technical Bulletin" Tab and then "Show all bulletins."
PIT5744F2026-03-03. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates information on how to disable the Side Blind Zone Detection and Park Assist systems when a customer removes the pickup box from the vehicle to install an aftermarket bed or body.
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.
PIT4506J2026-02-23. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communication provides information to the technician that some owners of Heavy Duty Trucks and Utilities may ask if they can lower their tire pressures. Tire pressures being set to the "Tire and Loading Label" will ensure the safe handling and ride characteristics of the truck and should not be lowered.
PIP5865L2026-02-18. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.
PIT64832026-02-11. Service bulletin. UNKNOWN OR OTHER. This preliminary information communicates an issue with aftermarket LED headlights causing IPC warning messages and MIL along with several low speed lan DTCs.
PIP5921B2026-02-01. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates the possibility of DTC p0011 p0016 and potential for a rattle or ticking noise to occur from the Intake Cam Actuator, or cover plate screws backing out and making contact with Cam carrier
PIP5865K2026-02-01. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.
N2525155902026-01-27. Service campaign. ELECTRICAL SYSTEM. Certain vehicles listed above, may have a condition in which the body-to-chassis ground strap may be corroded. Dealers will replace the ground strap.
N252494003-022026-01-21. Service campaign. ENGINE. Certain vehicles listed above, may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have manufacturing defects that can lead to engine damage and engine failure. This special coverage covers if an engine failure occurs in the vehicle as a result of the condition described above for a period of 10 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 May 23, 2025, 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 May 23, 2025, 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 engine. The repairs will be made at no charge to the customer.
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.
PIT6400A2026-01-19. Service bulletin. UNKNOWN OR OTHER. This PI Communications information on an alternative product dealers can use to perform 19-NA-255: Wax Coating on Frame Peeling, Metal Shows Corrosion/Rusting due to issue with getting product from current supplier listed in the bulletin.
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
PIT6344A2026-01-19. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issue with blower motor speed changing when air flow is blocked by snow.

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