Electronic Control Modules (Service Information): Communication: Operation

The Controller Area Network (CAN) data bus allows all electronic modules or nodes connected to the bus to share information with each other. Regardless of whether a message originates from a module on the lower speed CAN-B bus or on the higher speed CAN-C bus, the message structure and layout is similar, which allows the Body Control Module (BCM) to process and transfer messages between the CAN buses. The BCM also stores a Diagnostic Trouble Code (DTC) for certain bus network faults.

These networks and their subnetworks are protected by a Security Gateway Module (SGM).

All modules transmit and receive messages over one of these buses. Data exchange between nodes is achieved by serial transmission of encoded data messages. Each node can both send and receive serial data simultaneously. Each digital bit of a CAN bus message is carried over the bus as a voltage differential between the two bus circuits which, when strung together, form a message. Each node uses arbitration to sort the message priority if two competing messages are attempting to be broadcast at the same time.

Refer to the wiring diagrams COMMUNICATION Service Information to view the bus topologies and module top bus assignments.