Circuit Operation - Interior Lights Dimming

PANEL LAMPS
When the Park Lamps or Headlamps are turned "ON," voltage is applied to terminals "D" and "B" of the Incandescent Power Driven The Incandescent Power Driver is a solid state device. When these two voltages are present, the Incandescent Power Driver allows voltage to be applied through the RH ILLUM Fuse for Panel Lamps on the RH side of the vehicle, and through the LH ILLUM Fuse for Panel Lamps on the LH side of the vehicle.

The Panel Lamps are dimmed by using the Dimmer Rheostat at the Headlamp Switch. The Dimmer Rheostat controls the voltage applied to terminal "B" of the Incandescent Power Driver (the lower the voltage # the dimmer the Panel Lamps). This voltage at terminal "B" is "transferred" through the Incandescent Power Driver to the Panel Lamps.

Ground for the Panel Lamps is provided by G201 and G202.

LED LIGHTING
The LED dimming and LCD dimming is controlled by the Central Control Module (CCM).

When the Park Lamps or Headlamps are turned "ON," voltage is applied to the CCM by the Park Lamps Circuit (CKT 9) and the Dimmer Rheostat Circuit (CKT 44). When the CCM receives these voltages, a digital signal is sent to the various LED and LCD devices. The digital signal is variable, depending upon the position of the Dimmer Rheostat at the Headlamp Switch.

The Central Control Module will set Diagnostic Trouble Codes (DTCs) 71, 72, 73 or 74 if a problem exists in the LED and LCD dimming circuits.