Circuit/System Description
The BCM supplies a voltage reference through the instrument panel (I/P) dimming voltage reference circuit to the interior lamp dimmer switch, which is part of the headlamp switch. When the dimmer switch is placed in a desired brightness position, reference voltage is applied through the dimmer switch rheostat and the I/P lamps dimmer switch signal circuit to the BCM. The BCM interprets this voltage signal, then applies a pulse width modulated (PWM) voltage through the instrument panel lamp supply voltage circuit, the backlight lamp control circuit, and the LED dimming supply circuit illuminating the LED and I/P panel lamps. For more detailed information concerning interior lamp operation refer to Interior Lighting Systems Description and Operation .