2025 Peterbilt 389 technical service bulletins

Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.

• Jul 3, 2025 Warranty extension32 fuel injector part numbers (16 for MX-11 and 16 for MX-13) have been added to this warranty policy.
• Sep 11, 2026 Service bulletinKenworth: Dealers should check the chassis list and SIR weekly for VIN changes
• Sep 5, 2026 Service bulletinAn exhaust manifold slip joint seal kit is now available for EPA 2017-2024 PACCAR MX-13 engines.
• Aug 13, 2026 Service bulletinThe procedure has been updated to include additional steps for verifying the software level on the vehicle...
• Aug 13, 2026 Service bulletinThe verbiage in the Introduction section has been updated.
• Aug 13, 2026 Service bulletinUpdated Sheppard Steering Gear Classification Tool link in Inspection Procedure
• Jul 21, 2026 Service bulletinThis optional software update is now available for chassis equipped with EMY 2021B-2023 PACCAR MX-11 and...
• Jul 10, 2026 Service bulletinThe Condition, Chassis Affected, Service Action, Warranty, and Procedure sections have been updated to...
• Jul 7, 2026 Service bulletinThe software is not yet available
• Jun 29, 2026 Service bulletinAn optional software update will be available on 07/06/2026 for chassis equipped with EMY 2021B-2023PACCAR...
• Jun 3, 2026 Service bulletinKW: A new recommended repair has been added to verify the software level and close the campaign in SIR.The...
• May 5, 2026 Service bulletin(KW) Certain T680 / T800 / T880 / W900 / W990 have updated GHG labels available for order and installation.
• Apr 30, 2026 Service campaignCertain EPA21 PACCAR MX engines are equipped with PHINIA fuel injectors that do not meet PHINIA’s...
• Apr 28, 2026 Service bulletin(KW) Certain T680 / T800 / T880 / W900 / W990 have updated GHG labels available for order and installation
• Apr 4, 2026 EmissionsEMY21-25 ghg
• Apr 1, 2026 EmissionsEPA17-24 mx
• Jan 31, 2026 Service bulletinProcedure pictures updated for clarity
• Jun 7, 2025 Service bulletinNewly designed fuel injectors are available for EPA2021 compliant PACCAR MX-series engines to optimize...
• Mar 26, 2025 Service campaignAs of 03/25/2025, this campaign has resumed
• Feb 27, 2025 EmissionsVehicles equipped with PACCAR MX engines with Engine Software Version NA202 or NA206 may display a dash...
• Jan 10, 2025 Service bulletinSafety Recall Updated software and procedures are now available
• Sep 24, 2024 Service bulletinFix-as-fail
• Sep 19, 2024 Service bulletinFix As Fail Approximately 150 chassis built with an Allison 6th Gen 4500 series 6-speed transmission were...
• Mar 6, 2024 Service bulletinThis Bulletin contains parts ordering and replacement procedures for Steering Gears identified as SUSPECT...