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Service bulletins for the 2021 Western Star 4700

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.

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

By type

By component

Only bulletins with component: Software are shown. Show all

Bulletins, newest first
20TS-072020-10-21. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE AND ENGINE COOLING. Technical Service Letter for Cold Weather Faults on GHG17/21 DD13 with MCM Software Version 14. Due to colder weather, there may be an increase in the frequency of faults, noted below, on GHG17/21 DD13 trucks built after June 5th 2019. This is due to a calibration issue in the current MCM software (14.1.1.5 or 14.2.1.3). New software is scheduled for release in the first quarter of 2021 that will address these faults.
17TS-05REV22020-10-21. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE. Revised Technical Service Letter for Detroit DT12 TCM GHG17 Only; Bootloader Update. On Detroit DT12 equipped vehicles, it may be necessary to complete an additional step in the programming process when updating the TCM software.
D20R1REV12020-09-01. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM:SOFTWARE. Revised Detroit Emissions Recall for Daimler Trucks North America LLC, on behalf of its Detroit Powertrain Division, has determined that some Model Year 2020 GHG21 DD13 engines require reprogramming of the MCM to meet certification. NOTE: Reference 20TS-04 Detroit CPC501T GHG21 Only; Bootloader Update if New Cascadia CPC501T is not at the software level shown in this table. The Corrective Procedure also has been updated.
D20R12020-09-01. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Detroit Emissions Recall for GHG21 Detroit DD13 Model Year 2020 Software Reprogramming. Daimler Trucks North America LLC, on behalf of its Detroit Powertrain Division, has determined that some Model Year 2020 GHG21 DD13 engines require reprogramming of the MCM to meet certification.

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