2026 Kenworth T380 TSBs

transmission, featuring a more durable design for enhanced long-term performance.

W990 chassis with PACCAR TX-12 and TX-18 transmissions, TCM software version R5.5 or later and an AT5 controller, where the TASPS fails. PB: A Transmission Control Module (TCM) software update is now available for certain Model 537, 548, 567, 579, and 589 chassis with PACCAR TX-12 and TX-18 transmissions, TCM software version R5.5 or later and an AT5 controller, where the TASPS fails.

T380 / T480 chassis equipped with a PACCAR TX-8 transmission received transmission software with an incorrect software variable. This software issue may cause Wheel Speed Sensor DTC 521215-2 to set, the Transmission Dash Light to Illuminate, and restricted shifting . A software update is now available to fix the issue.

The DAVIE4 cache must be cleared before attempting to reprogram a chassis that is experiencing problems to ensure the latest version of software is installed. Follow all steps in the attached procedures before submitting a TCS case."

one headlamp to deactivate.

The Exterior Lighting Switch (ELS) in certain T180/T280/T380/T480 chassis may not function and can be reset only by a key cycle. This issue may result in non-compliance with FMVSS/CMVSS 101 and 108. Affected chassis must have the Vehicle Software updated.

function and can be reset only by a key cycle. This issue may result in non-compliance with FMVSS/CMVSS 101 and 108. This bulletin will be updated when software and programming procedures are available."

certain Engine Model Year (EMY) 2024-2026 PX-7 and PX-9 Operators Manuals.

Loss of communication between the right-hand shift stalk and the vehicle may result in the vehicle being disabled after it comes to a stop, thereby increasing the risk of crash or injury. A warning will appear on the dash display when communication is lost, including transmission or engine warnings, ! next to DNR/DNRP indicator, - in the DNR/DNRP indicator, and/or chimes, depending upon whether you are operating a diesel/gas or battery electric vehicle.

Control Unit (VECU) part number Q21-1157-013-011 / Q21-1157-013-013. Parts and procedures for Phase 2 chassis will be available at a later date. This bulletin will be updated at that time. Please refer to the condition section for more details. Certain Ethernet Multiplexed Architecture (EMUX) chassis fail to conform to Federal and Canada Motor Vehicle Safety Standards (FMVSS/CMVSS) No. 108. Delayed or unsteady illumination of the vehicles stop lamps, reverse lamps, turn signal lamps and inadvertent change in headlamp illumination or lift axle position may"

The update must be completed before performing a DAVIE4 Learn dash switches procedure to fix intermittent dash switch functionality.

installation.

part number Q21-1157-013-011 / Q21-1157-013-013 / Q21-1157-002-002 / Q21-1157-004-004 / Q21-1157-006-006 / Q21-1157-009-009. See attached Parts Matrix for required parts per chassis.

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."

is no longer compatible.

It must be used if safety recall 25PACF is performed prior to or at the same time as this repair since the 25PACF remedy also satisfies this safety recall.