Principles of Operation

The smart junction box (SJB) monitors the input from the instrument panel dimmer switch when the parking lamps are on. The SJB sends a pulse-width modulated (PWM) voltage to the dimmable components based on input received from the instrument panel dimmer switch. The SJB also sends a message over the medium speed controller area network (CAN) to the electronic automatic temperature control (EATC) (if equipped), the audio unit, and the instrument cluster to indicate the backlighting intensity level.