As described in the SAE J1939 document, there is a minimum of seven documents required to fully define an SAE J1939 network. This document, SAE J1939-15, describes a physical layer utilizing Unshielded Twisted Pair (UTP) cable. The SAE J1939 Recommended Practice documents are intended for light- and heavy-duty vehicles on- or off-road as well as appropriate stationary applications which use vehicle derived components (e.g., generator sets). Vehicles of interest include but are not limited to: on- and off-highway trucks and their trailers; construction equipment; and agricultural equipment and implements.

The purpose of the J1939 documents is to provide an open interconnect system for electronic systems. It is the intention of these documents to allow electronic devices to communicate with each other by providing a standard architecture.