Restraints and Safety Systems: Description and Operation
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The electrical system that supports the air bag supplemental restraint system (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 restraints indicator lamp.
- provides the electrical path from the RCM to the data link connector (DLC).
- provides the electrical path from the RCM to the instrument cluster module.
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
- Occupant classification sensor (OCS) system
- Powertrain control module (PCM)
- Transmission control module (TCM)
- Restraints control module (RCM)
- 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) for additional information.