Principles of Operation
WARNING: This page is about a different car, the 2005 Mercury Sable and 2005 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
The smart junction box (SJB) constantly monitors its subsystems for concerns. If a concern is found in one of the subsystems, the SJB will record the concern in the form of a diagnostic trouble code (DTC).
The ignition switch position is very important to the SJB functionality. Erratic or unexpected SJB functions can often be traced to problems with these ignition SJB inputs.
The SJB controls a variety of systems:
- battery saver relay
- heated backlight
- windshield wipers
- interior lamps
- remote keyless entry (RKE)
- power lock system
- exterior lamps
- power windows
- parking brake actuator warning chime