Principles of Operation: Notes
The instrument cluster and the smart junction box (SJB) use a combination of hardwired circuitry and the controller area network (CAN) to transmit and receive information. It is very important to understand:
- where the input (command) originates from.
- all the information (messages) necessary in order for a feature to operate.
- which module(s) receive(s) the input or command message.
- if the module which received the input controls the output of the feature, or if it sends a message over the CAN to another module.
- which module controls the output of the feature.
Each time the ignition switch is turned from OFF to ON, the charging system indicator, the low oil pressure indicator, and the malfunction indicator lamp (MIL) prove out and remain on until the engine is started. The safety belt indicator proves out for 60 seconds or until the safety belt is fastened. The air bag indicator proves out for approximately 6-8 seconds while the following instrument cluster indicators and warning indicators prove out for approximately 3 seconds:
- ABS warning indicator
- THEFT warning indicator
- brake warning indicator
- check fuel cap warning indicator (Escape, Mariner)
- 4x4 indicator (Escape, Mariner)
- low fuel level warning indicator (Escape, Mariner)
- Escape Hybrid hazard warning indicator
- service soon warning indicator
- overtemp warning indicator