Principles of Operation: HS-Can

The HS-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 HS-CAN is a high speed communication network used for the instrument cluster, the powertrain control module (PCM), the transmission control module (TCM), the differential electronic module (DEM), the restraints control module (RCM), and the anti-lock brake system (ABS) module communications, and designed for real time information transfer and control. The HS-CAN network will not communicate while certain faults are present, but will operate with diminished performance with other faults present. The HS-CAN bus may remain operational when 1 of the 2 termination resistors are not present.

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

The following chart describes the specific CAN network messages broadcast by each module, and the module(s) that receive the message: