Interior Lamps: Notes

WARNING: This page is about a different car, the 2004 Chevrolet Monte Carlo and 2004 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

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:

Auxiliary dome lamp (SEO, RPO 6C7)
Dome lamp
Inside rear view mirror lamps
Instrument panel (I/P) courtesy lamps
Reading lamps
Rear compartment courtesy lamp
Sunshade vanity mirror lamps

Battery positive voltage is applied at all times to the driver information center (DIC)/remote keyless entry (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 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:

Rear compartment courtesy lamp
Dome lamp
Inside rear view mirror lamps
Roof rail/reading lamps assembly
Sunshade vanity mirror lamps

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 SDM. The interior lamps remain activated for 25 minutes.