Circuit Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. In addition to this, Node Alive (State of Health) messages are transmitted by each module on the class 2 serial data circuit about once every two seconds. When the module detects no messages on the class 2 serial data circuit for approximately three seconds, U1305 is set and the setting of all other class 2 serial communication DTCs is inhibited.