Principles of Operation: Notes
WARNING: This page is about a different car, the 2010 Ford Pickup, 2010 Ford F550 Super Duty, 2010 Ford F450 Super Duty, and 2010 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
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) bus, Medium Speed Controller Area Network (MS-CAN) bus 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.