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Service bulletin 43-089

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11036293
Published by NHTSA2026-08-20
Manufacturer's number43-089
Manufacturer's date2026-08-13
NHTSA componentENGINE

NHTSA's summary

This optional software update is expected to be available in late August 2026 for chassis equipped with EPA 2024 EMY 2024-2026 PACCAR MX-11 and MX-13 engines. This bulletin will be updated when the software is ready. This update provides customers with additional time to service their trucks before a DEF-related derate occurs. The software is being offered to customers in alignment with recently updated regulatory agency guidance. The procedure document has also been updated for clarity.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Vehicles listed
KENWORTH L7702024, 2025, 2026
KENWORTH T6802024, 2025, 2026
KENWORTH T8802024, 2025, 2026
KENWORTH W9002024 to 2025
KENWORTH W900B2024 to 2025
PETERBILT 5202024, 2025, 2026
PETERBILT 5672024, 2025, 2026
PETERBILT 5792024, 2025, 2026
PETERBILT 5892024, 2025, 2026

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
23V7490002023-11-07. ENGINE

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
P0012026-09-29. Service bulletin. "Kenworth: Dealers should check the chassis list and SIR weekly for VIN changes. 2 chassis added to the chassis list. Peterbilt: Dealers should check the chassis list and SIR weekly for VIN changes. 10 chassis added to the chassis list."
41-0282026-09-29. Service campaign. The campaign expiration date has been extended from 10/01/2026 to 04/01/2027.
E3432026-09-23. Service bulletin. An exhaust manifold slip joint seal kit is now available for EPA 2017-2024 PACCAR MX-13 engines.
P0032026-09-23. Service bulletin. "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 1 chassis. The total chassis count is now 10. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
P0012026-09-23. Service bulletin. "KW: The chassis list has been updated to include 1 chassis. The total chassis count is now 53. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 8 chassis. The total chassis count is now 130. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
P0022026-09-23. Service bulletin. "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 2 chassis. The total chassis count is now 4. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
P0032026-08-27. Service bulletin. "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 1 chassis. The total chassis count is now 10. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
P0022026-08-27. Service bulletin. "KW: A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 2 chassis. The total chassis count is now 4. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
P0012026-08-27. Service bulletin. "KW: The chassis list has been updated to include 1 chassis. The total chassis count is now 53. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section. PB: The chassis list has been updated to include 8 chassis. The total chassis count is now 130. A link to the PACCAR Powertrain Prognostics Webcast has been added in the Links section."
43-0892026-08-25. Service bulletin. This optional software update is expected to be available after 08/28/2026.