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Emissions M0309 202405

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)
TypeEmissions
NHTSA id11000823
Published by NHTSA2024-06-04
Manufacturer's numberM0309 202405
Manufacturer's date2024-05-28
NHTSA componentENGINE

NHTSA's summary

Emission Recall: Mack Trucks has identified that the Selective Catalyst Reduction (SCR) system in certain vehicles equipped with the MY 2017 or 2018 MP8 (13L VGT) engine are not meeting California and EPA emissions standards, or Mack cannot confirm its compliance. These vehicles have been flagged due to telematics data showing that the NOx conversion efficiency of the SCR system has dropped below 94% for eight weeks. Alternatively, these vehicles may have communication issues with telematics, such as not reporting or ceasing reporting for the same period.

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
MACK CHU2017 to 2018
MACK MRU2017 to 2018

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