Principles of Operation: Notes
NOTE:
The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM). Refer to SMART JUNCTION BOX (SJB) in OEM FUSE AND RELAY INFORMATION.
The Instrument Cluster (IC) utilizes a microprocessor to control the gauge, indicator, message center and warning chime functions. Data is sent to the IC over the High Speed Controller Area Network (HS-CAN) and Medium Speed Controller Area Network (MS-CAN) bus lines and through hardwired circuitry from individual components. The IC uses each input to output an action to the gauges or indicators.
It is very important to understand:
- where the input originates.
- all the information necessary in order for a feature to operate.
- which module(s) receive(s) the input or command message.
- does the module which received the input control the output of the feature, or does it output a message over the communication network to another module.
- which module controls the output of the feature.