Restraints and Safety Systems: Description and Operation

High Speed Controller Area Network (HS-CAN)
This vehicle utilizes a communication system called a high-speed controller area network (HS-CAN). The HS-CAN consists of a twisted pair of wires connected to the following:
- Anti-lock brake system (ABS) module
- Instrument cluster module
- OCS system
- Powertrain control module (PCM)
- Transmission control module (TCM)
- RCM
- Four wheel drive (4WD) module
- Data link connector (DLC)

The HS-CAN circuits use a bias voltage of approximately 2.5 volts, one is a positive 2.5 volts while the other is a negative 2.5 volts. The HS-CAN also uses 2 terminating resistors, one contained within the PCM, the other in the instrument cluster module. The terminating resistors are not serviced separately. The terminating resistors have a value of 120 ohms each, for a total normal operating system total of 60 ohms. The HS-CAN will operate with only one terminating resistor and has the capability to communicate some messages to some of the control modules with only one circuit functioning, but at a reduced rate of performance. Refer to Information Bus (Module Communications Network).

Electrical System
The electrical system that supports the air bag SRS:
- is powered from the battery through the ignition circuit.
- provides the electrical path from the RCM to the SRS components.
- provides the electrical path from the RCM to the DLC.
- provides the electrical path (via HS-CAN) from the RCM to the instrument cluster module.