The interior lamps consists of two groups, lamps that can not be dimmed and lamps that can be dimmed. This first group consists of lamps that may not be dimmed. This Includes those lamps that may be manually turned on by placing the interior lamp switch to the DOME position, or by opening a door or a compartment:

Battery positive voltage is applied at all times to the DIC/RKE fuse and to the switched side of the BATT RUNDOWN PROTECTION relay in the right I/P junction block. The DIC/RKE fuse supplies battery positive voltage to the coil side of the BATT RUNDOWN PROTECTION relay. When the ignition is turned to the ON position, the body control module (BCM) provides a ground to the courtesy lamp relay control circuit. This energizes the BATT RUNDOWN PROTECTION relay and applies battery positive voltage to I/P BRP fuse and to the TRK/ROOF/BRP fuse. Battery positive voltage is applied from the I/P BRP fuse to the I/P courtesy lamps, I/P compartment lamp and to the courtesy lamp supply voltage circuit to the BCM. Battery positive voltage is also applied from the TRK/ROOF/BRP fuse to the:

If the BCM receives a door lock or unlock input signal, the BCM will activate the BATT RUNDOWN PROTECTION relay, which provides battery positive voltage to all interior courtesy lamps. When any door is opened, the door jam switch contacts close and the BCM receives a door-open input signal. The BCM then applies a ground to the interior lamp control circuit and to the courtesy lamp low control circuit illuminating the courtesy and dome lamps.

After all the doors are closed, the courtesy lamps remain illuminated for approximately 40 seconds. The courtesy lamps will also turn on and remain illuminated for approximately 15 seconds after the ignition key is removed, prior to any door being opened.

When the headlamp switch is placed in the DOME position, the BCM receives a ground signal. The BCM then applies a ground to the interior lamps control circuit. This illuminates the dome and roof rail lamps.

The courtesy lamps will normally turn off using the theater dimming feature. The BCM provides a pulse width modulated ground to all courtesy/reading, dome, and inside rear view mirror lamps for the theater dimming feature. The BCM will immediately turn off the courtesy lamps if a door lock command is received with all the doors closed, or if the ignition switch is turned to either the ON or RUN position.

The BCM activates the interior lighting output 15 seconds after receiving the class 2 message "Airbags Deployed" from the sensing and diagnostic module (SDM). The interior lamps remain activated for 25 minutes.

Auxiliary Dome Lamp (SEO, RPO 6C7)

An auxiliary dome lamp on special equipment option (SEO) vehicles is mounted to the headliner near the windshield. The auxiliary dome lamp is turned ON using a switch at its base.

Interior Lamps (SEO)

When the emergency vehicle interior lamp switch is turn to the OFF position, the interior lamps are deactivated immediately.

I/P Compartment Lamp

The I/P BRP provides battery positive voltage to the instrument panel compartment lamp. When the I/P compartment is opened, a switch closes, providing a ground circuit to G201, and the I/P compartment lamp illuminates.

Keyless Entry Interior Illumination

When the door key is used to unlock the doors, the BCM receives a door unlock signal. The BCM activates the interior lamps, provided the BCM has input signals indicating the following conditions:

If the door locks are activated to the LOCK position, or if the ignition switch is turned to either the RUN or CRANK position the courtesy lamps turn off immediately, otherwise the courtesy lamps will remain on for approximately 40 seconds after the door is closed. The BCM turns the courtesy lights off through the theater dimming feature.

If the remote function actuator transmitter is used to unlock the doors or the trunk, or if the panic button is pressed, the BCM will keep the courtesy lamps on for approximately 15 seconds. If the door locks are activated to the UNLOCK or LOCK position, or if the ignition switch is turned to either the RUN or CRANK position, the courtesy lamps will turn off immediately.

The BCM keeps the courtesy lamps on for approximately 40 seconds after an alarm event is completed.

The courtesy lamps in special equipment option (SEO) vehicles may be disabled by using the emergency vehicle interior lamp switch, called surveillance mode.

Rear Compartment Lamp

The TRK/ROOF fuse provides battery positive voltage to the rear compartment lamp. When the rear compartment is opened, the rear compartment lid ajar switch closes, providing a ground circuit to G302 and the rear compartment lamp illuminates.

Sunshade Vanity Lamps

The TRK/ROOF fuse provides battery positive voltage to each vanity mirror lamp. When the vanity mirror cover on the sunshade is opened, a switch closes, providing a ground circuit to G302, and the vanity lamps illuminates.

Surveillance Mode Switch (SEO)

The surveillance mode switch turns off the daytime running lamps, or low beam headlamps and tail lamps during low light conditions, instrument cluster, Park, Reverse, Neutral, Drive, Low (PRNDL) and radio indicators. Interior courtesy lights are also disabled when the switch is activated.

The second group of interior lighting includes lamps which may be dimmed. This group uses a combination of class 2 controlled illumination and incandescent lamps:

The RH instrument panel (I/P) fuse block supplies battery positive voltage to both the coil and normally open switch contacts of the park lamp relay. When the body control module (BCM) energizes the park lamp relay, current flows from the park lamp relay switched contacts through the REAR PARK LP fuse to the I/P dimming switch. When dimming is selected, by moving the I/P dimming switch, all incandescent back lighting lamps (see schematics) and the BCM are provided with a variable voltage through the instrument panel lamp supply voltage #1 circuit. The incandescent back lighting lamps are then grounded at G201, G203 and G302. The BCM then applies a message signal to the class 2 circuit to the IPC and radio. The class 2 displays then dim to the level set by the I/P dimmer switch. When the I/P dimmer switch is moved from MIN to MAX, all class 2 displays and all incandescent back lighting respond from minimum intensity to maximum brightness.

Parade mode may be selected by manually turning on the park lamps during daylight conditions. The front park lamp circuit supplies voltage the HVAC assembly for a park lamp on input, and the display will become full bright. The BCM applies a message signal to the class 2 circuit to the IPC and radio commanding the displays to become full bright. The surveillance mode switch (SEO) overrides this feature.

The body control module (BCM) controls the lighting system through circuits that enable the park lamps, head lamps and fog lamps as well as the interior lamps. The BCM opens these enabling circuits 20 minutes after the ignition switch is turned OFF with no subsequent lamp switch activity. If the ignition switch is turned to any position other than OFF, or if a lamp switch is activated, during this 20-minute period, the timer will reset for another 20 minutes.