Principles of Operation

PRINCIPLES OF OPERATION

Dimmable Backlighting
When the parking lamps or the headlamps are in the ON position, or the headlamp switch is in the AUTOLAMPS ON position and the ambient light sensor status senses or equals night, the smart junction box (SJB) monitors the input from the instrument panel dimmer switch. The SJB sends a pulse-width modulated (PWM) voltage to the dimmable components and switches based on input received from the instrument panel dimmer switch. The SJB also sends a message over the controller area network (CAN) to the audio unit, and the instrument cluster to indicate the backlighting intensity level.

Fixed Backlighting
When the accessory delay relay is energized, switched voltage is supplied to the non-dimmable components and switches.