Principles of Operation

Instrument Cluster and Panel Lighting - Dimmable
The panel dimmer switch allows the brightness level of backlights and displays to be adjusted dependent upon the headlamp switch position and the dimmer switch position. The panel dimmer switch sends a signal to the instrument panel which then sends a backlighting intensity and dimming curve command over the standard corporate protocol link to the Front Electronic Module (FEM), the audio unit, and the dual automatic temperature control module. The FEM then sends a pulse width modulated dimming signal to the instrument cluster, the dimmable LEDs, and the dimmable incandescents.

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

With the ignition switch in the RUN position and the headlamp switch in the OFF position, the audio unit, DATC module, tripometer, 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 a panel dimmer switch failure occurs.