Interior Lamps Dimming

This group includes lamps which may dim. This group may use a combination of vacuum fluorescent (VF) illumination and incandescent lamps.

• HVAC control module, head assembly
• Rear HVAC control module, head assembly
• Radio
• Rear seat Audio
• The instrument panel cluster (IPC)
• The PRNDL lamp, with the exception of the current gear select position
• Power window switches
• Various switches

When the ignition switch is turned to the ON position, the VF display, radio, turns ON at maximum brightness. When the park lamps are ON, all incandescent back lighting turn ON at the dimming level indicated by the instrument panel (I/P) dimmer switch. At the same time all VF displays dim to match the indicated dimming level. When the headlamp switch is placed in the PARK position, the park lamp supply voltage circuit provides an input to the body control module (BCM). The BCM then supplies voltage to the I/P dimmer switch through the I/P dimming lamps control circuit. The setting of the I/P dimmer switch determines the amount of voltage that the I/P dimmer switch supplies to the BCM through the I/P dimming lamps low reference circuit. The BCM then sends a pulse width modulation (PWM) voltage to all the interior lamps. All the VF and incandescent back lighting lamps are provided a specific voltage and are then grounded. When the headlight switch is turned to the park lamp or headlamp position, all incandescent back lighting turn ON at the dimming level indicated by the I/P dimmer switch. When the I/P dimmer switch is moved from MIN to MAX, all VF displays, as well as all incandescent back lighting respond from minimum intensity to maximum brightness in response to the I/P dimmer switch.