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Service bulletin D20M4

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 id10172528
Published by NHTSA2020-03-19
Manufacturer's numberD20M4
Manufacturer's date2020-03-18
NHTSA componentEQUIPMENT; ENGINE AND ENGINE COOLING

NHTSA's summary

DDC Field service campaign for GHG17 Detroit DD13 engines requiring software reprogramming and new emission label replacement. This field service applies only to MCI (Motor Coach Industries) vehicles.

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, Equipment and accessories

Vehicles listed
MCI J45002000 to 2020
MCI J4500C2006 to 2011

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