Principles of Operation

PRINCIPLES OF OPERATION

Instrument Cluster And Panel Lighting - Dimmable
The instrument panel dimmer switch allows the brightness level of backlights and displays to be adjusted dependent upon the headlamp switch position and the instrument panel dimmer switch position. The instrument panel dimmer switch sends a signal to the instrument cluster which then sends a backlighting intensity and dimming curve command over the standard corporate protocol (SCP) link to the front electronic module (FEM). The FEM then sends a pulse width modulated (PWM) dimming signal to the instrument cluster, the dimmable LEDs, and the dimmable incandescent lamps.

When the headlamp switch is in the parking lamps ON, headlamps ON, or the autolamps ON position with the autolamp feature activated, synchronized dimming (of the dimmable components) can be controlled with the instrument panel dimmer switch.

With the ignition switch in the RUN position and the headlamp switch in the OFF position, the audio unit, digital automatic temperature control (DATC) module, trip odometer, odometer, and selector lever indicator bezel will be at 100% brightness.

All backlighting will be disabled when the battery saver function has been activated.

Fault Management
The dimmable backlighting will default to 100% intensity if an instrument panel dimmer switch failure occurs.