Interior Illumination Control: Notes

WARNING: This page is about a different car, the 2003 Pontiac Montana, 2003 Oldsmobile Silhouette, and 2003 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.

The following interior courtesy lamps can be turned on by the BCM.

Cargo lamp
Courtesy reading lamps
Dome lamps
Footwell lamps

The BCM can activate these interior courtesy lights only when the interior lamps override switch is in the ON position, interior courtesy lights enabled. Then the BCM is able to activate the interior courtesy lights under the following conditions:

When any of the vehicle doors are open.
This includes the left, the right, the sliding door(s) and the rear liftgate door.
When the dimmer switch is in the DOME position.
When the exit illumination feature is active.
When unlocking the doors using the keyless entry transmitter, BCM types 3 and 4 only.
When unlocking a door using the left front, the right front or the liftgate door cylinder lock, BCM type 4 only.

The BCM deactivates the interior courtesy lights when all of the doors are closed and the dimmer switch is in the OFF position.

All of the vehicle doors contain a door lock ajar switch. When the driver door is open, the left front door lock ajar switch closes, sending a ground signal to the BCM through the driver door switch signal circuit. When the right front or the rear liftgate door is open, its corresponding door lock ajar switch closes, sending a ground signal to the BCM through the door open switch signal circuit. When a sliding door is open, its corresponding door jamb switch closes, sending a ground signal to the BCM through the sliding door switch signal circuit.

The BCM grounds the courtesy lamps low control circuit when detecting a ground signal in the following circuits:

Driver door switch signal circuit
Door open switch signal circuit
Sliding door switch signal circuit

When the driver door is closed, the left front door lock ajar switch opens the driver door switch signal circuit. When the right front door and the rear liftgate door are closed, their corresponding door lock ajar switches open the door open switch signal circuit. When the sliding doors are closed, their corresponding door jamb switches open the sliding door switch signal circuit.

The BCM then opens the courtesy lamps low control circuit when the following circuits are open:

Driver door switch signal circuit
Door open switch signal circuit
Sliding door switch signal circuit

The CTSY LAMP fuse supplies voltage to the BCM and the BCM applies the voltage to the interior lights through the courtesy lamps supply voltage circuit. The BCM will remove the voltage in the courtesy lamps supply voltage circuit if the ignition is OFF and there is no BCM activity. The BCM also opens the courtesy lamps low control circuit when the inadvertent load protection is active.