Principles of Operation (How Does It Work?)

Communications Network / Principles of Operation (How Does It Work?)


Multifunction Modules
The vehicle's electronic functions are divided into zones. The FEM controls the front portion of the vehicle and the REM controls the rear portion of the vehicle. These systems rely heavily on the SCP communication network in order to transmit and receive signals. As a technician, it is very important to understand:
- where the input (command) originates from.
- all information (messages) necessary in order for a feature to operate.
- which module(s) receive(s) the input or command message.
- whether the module which received the input (message) controls the output of the feature, or whether it outputs a message over the SCP communication network to another module.
- which module controls the output of the feature.

Communications Network
The CAN communications network is a high speed communication network used for powertrain communication. The CAN communication network will remain operational even with the severing of one of the bus wires. Communications will also continue if one of the bus wires is shorted to ground or voltage, or if some but not all termination resistors are lost.

The SCP communications network will remain operational even with the severing of one of the bus wires. Communication will continue if one of the bus wires is shorted to ground or voltage, or if some but not all termination resistors are lost.

The ISO 9141 communications network will not function if the single bus wire is shorted to ground or voltage.