ISO 17458-4:2013规定了FlexRay通信系统的电气物理层。 FlexRay的电气物理层设计用于数据速率高达10 Mbit/s的时间触发网络，用于连接汽车电子控制单元（ECU）。使用的介质是双线。总线上的信号发送是通过断言这些导线之间的差分电压来完成的。拓扑变化范围从通过线性无源总线和无源星的点对点连接到有源星拓扑。 ISO 17458-4:2013包括变速器本身电气特性的定义，以及总线驱动器（BD）和有源星形（AS）设备基本功能的文件。

ISO 17458-4:2013 specifies the electrical physical layer for FlexRay communications systems. The electrical physical layer for FlexRay is designed for time-triggered networks with data-rates up to 10 Mbit/s to connect automotive electronic control units (ECUs). The medium that is used is dual wires. Signalling on the bus is accomplished by asserting a differential voltage between those wires. Topology variations range from point-to-point connections via linear passive busses and passive stars up to active star topologies. ISO 17458-4:2013 includes the definition of electrical characteristics of the transmission itself and also documentation of basic functionality for bus driver (BD) and active star (AS) devices.