Interior lighting consists of three groups. This first group includes the following lamps that may not be dimmed.

The second group includes the following lamps that may be manually turned on by placing the interior lamp switch in the ON position, or by opening a door.

When the ambient light sensor indicates darkness, the illuminated entry activates the courtesy lamps when the keyless entry transmitter is used to unlock the vehicle, when a door is unlocked with the key, or a door is opened. After unlocking the vehicle with the keyless entry transmitter or unlocking a front door using a key, the BCM will turn on the courtesy lamps for 20 seconds with no other inputs. The courtesy lamps will remain ON for 20 seconds after all of the doors are closed. The BCM controls the time delay. If the ignition switch is turned to the RUN position before 20 seconds has elapsed, the BCM will immediately turn OFF the courtesy lamps.

Battery positive voltage is applied during inadvertent power through the INT LPS Fuse to the courtesy lamps and the coil side of the courtesy relay. When the BCM receives a signal to activate the courtesy lamps, ground is provided for the coil of the courtesy relay. The coil is energized, closing the switch contacts. Ground is then provided for the courtesy lamps. The lamps will then illuminate.

The body control module (BCM) controls the following:

The door position is monitored through the door lock actuators by the BCM. When a door is opened, the respective door lock actuator closes and grounds the door open input to the BCM. When a door is closed, the door lock actuator opens and removes ground from the BCM. When a front door is manually unlocked, the respective door lock cylinder switch closes and grounds the door unlock input to the BCM.

The courtesy lamps can be turned on by the interior lamp switch regardless of ambient light conditions, door position, or ignition state. When the interior lamps switch is enabled, the instrument cluster interior lamps switch input is grounded through the headlamp switch. In response to this input, the instrument cluster sends a Class 2 message to the BCM to activate the courtesy lamps.

The courtesy/reading lamps may be turned on by pressing the lamp. When this is done, the courtesy/reading lamp switch grounds the lamp to G401. The lamps will only illuminate when battery positive voltage is being supplied during inadvertent power through the INT LP Fuse.

The BCM will activate the courtesy lamps 15 seconds after receiving a message that the airbags have been deployed. The courtesy lamps will deactivate when the ignition switch is removed from the RUN position or after any action that would activate or deactivate the courtesy lamps, such as the interior lamp switch or opening a door.

When the keyless entry transmitter is used to unlock the vehicle, The remote function actuator (RFA) sends a Class 2 message to the BCM in order to activate the COURTESY relay. The BCM will turn on the courtesy lamps for 20 seconds.

When the vanity mirror cover on the sunshade is opened, the vanity lamp illuminates. The vanity lamp can be dimmed through sliding switch next to the mirror. The BCM energizes the Inadvertent Power relay which provides battery positive voltage to the vanity mirror lamps. When the vanity mirror cover on the sunshade is opened, its switch closes to provide a ground to G401. The vanity mirror lamp may be dimmed by the sliding switch next to the mirror. The switch is a potentiometer in which the resistance varies as the switch is moved. As the resistance of the potentiometer increases, the vanity lamp receives less voltage. The vanity lamp then becomes dimmer.

When the IP compartment is opened, the IP compartment lamp illuminates. The IP compartment lamp will remain on until the IP compartment door is closed or until the battery rundown protection feature activates. The BCM energizes the Inadvertent Power relay which provides battery positive voltage to the IP compartment lamp through the INT LPS fuse. When the IP compartment (glove box) is in the OPEN position ground is provided at G201.

When the rear compartment lid is opened, the rear compartment lamp illuminates. The rear compartment lamp will remain on until the rear compartment lid is closed or until the battery rundown protection feature activates. The BCM energizes the Inadvertent Power relay which provides battery positive voltage to the rear compartment lamp through the INT LPS fuse. When the rear compartment lid release switch is in the UNLATCHED position ground is provided for the rear compartment lamp at G402.

The third group includes the following lamps which may be dimmed. This group may use a combination of vacuum fluorescent (VF) illumination and of incandescent lamps.

Dimming of the interior lighting systems is as follows:

When the ignition switch is in the RUN position, the instrument cluster activates its VF display. The instrument cluster (IPC) also coordinates the display illumination for the radio (IRC), the cellular telephone (PHN), and the HVAC control module anytime the ignition switch is in the RUN position.

The INC DIM 1 consists of lamps powered by the instrument panel lamp supply voltage-1 circuit. These are referred to as the park lamp backlighting because they are only active if the park lamps are on and the ambient light sensor indicates darkness.

The INC DIM 2 output is used as a general interior light source and an illuminated entry feature that provides interior lighting. The INC DIM 2 consists of lamps powered by the instrument panel lamp supply voltage-2 circuit . When one or more of the following conditions occur, the INC DIM 2 lamps will be active:

The instrument cluster controls all of the interior dimming functions. The instrument cluster receives an ambient light level input from the ambient light sensor and determines whether it is light or dark. If the ambient light sensor is inoperative, the instrument cluster will assume a condition of darkness. Dimming of the VF displays is only allowed when the ignition switch is in the RUN position, the park lamps are on, and the ambient light sensor indicates darkness. If all conditions for the VF dimming are met, the instrument cluster uses the input from the potentiometer in the headlamp switch to determine the level of dimming. The dimming level is sent to the radio (IRC), the cellular telephone (PHN), and the HVAC control module by a Class 2 message. The IRC and the PHN then adjust the dimming level of their VF display. The instrument cluster provides a 54 volt supply to the HVAC control module for its VF display. The instrument cluster provides dimming control of the incandescent lighting through the INC DIM 1 and INC DIM 2 outputs. The instrument cluster provides dimming control of the electronic PRNDL LED through the LED dimming signal circuit. The dimming level will vary based on the potentiometer in the headlamp switch when the park lamps are on and the ambient light sensor indicates darkness, regardless of the position of the ignition switch.