Principles of Operation

PRINCIPLES OF OPERATION

Dimmable Backlighting
When the parking lamps or the headlamps are ON, 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 switches and control 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.

Non-Dimmable Backlighting
When the ignition switch is in the START or RUN positions, the delayed accessory relay provides voltage from the smart junction box (SJB) to the non-dimmable components.