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Service bulletin T1379A

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 id10084606
Published by NHTSA2016-11-22
Manufacturer's numberT1379A
Manufacturer's date2014-05-23
NHTSA componentELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:ENGINE:DIESEL; EQUIPMENT

NHTSA's summary

THIS TEMPORARY REPAIR PRACTICE ADDRESSES FAULT CODE 3569 OCCURANCES ON ENGINES IN ALL PETERBILT VEHICLES WITH A PARTICULAR EXHAUST/AFTERTREATMENT CONFIGURATION. THIS ACTION WILL MITIGATE FAILURES CAUSED BY UREA CRYSTALLIZATION INSIDE THE DIESEL EXHAUST FLUID (DEF) DOING VALVE. THIS IS A REVISION TO A PREVIOUS COMMUNICATION.

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Electrical system, Engine, Equipment and accessories

Vehicles listed
CUMMINS ISX12
CUMMINS ISX15

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