This SAE Recommended Practice defines the Physical Layer and portions of the Data Link Layer of the OSI model for data communications. In particular, this document specifies the physical layer requirements for any Carrier Sense Multiple Access/Collision Resolution (CSMA/CR) data link which operates on a single wire medium to communicate among Electronic Control Units (ECU) on road vehicles.

Requirements state in this document will provide a minimum standard level of performance to which all compatible ECUs and media shall be designed. This will assure full serial data communication among all connected devices regardless of supplier.

This document is to be referenced by the particular vehicle OEM Component Technical Specification which describes any given ECU in which the single wire data link controller and physical layer interface is located. Primarily, the performance of the physical layer is specified in this document. ECU environmental and other requirements when provided in the Component Technical Specification, shall superceded the requirements of this document.

The intended audience includes, but is not limited to, ECU suppliers, CAN controller suppliers, CAN transceiver suppliers, component release engineers, and vehicle system engineers.