Principles of Operation: Ms-Can

The MS-CAN network uses an unshielded twisted pair cable of data (+) and data (-) circuits. The data (+) and the data (-) circuits are each regulated to approximately 2.5 volts during neutral or rested network traffic. As bus messages are sent on the data (+) circuit, voltage is increased by approximately 1.0 volt. Inversely, the data (-) circuit is reduced by approximately 1.0 volt when a bus message is sent. Multiple bus messages can be sent over the network CAN circuits allowing multiple modules to communicate with each other. The MS-CAN is used for the instrument cluster, the smart junction box (SJB), the driver seat module (DSM), the audio unit, the satellite radio receiver, the digital versatile disc (DVD) player, and the electronic automatic temperature control (EATC) module communications, and designed for general information transfer. The MS-CAN network will not communicate while certain faults are present, but will operate with diminished performance with other faults present. The MS-CAN bus may remain operational when 1 of the 2 termination resistors are not present.

The following fault chart describes the specific MS-CAN network failures and their resulting symptom: