When the interior lamp switch is placed in the ON position, the instrument panel integration module (IPM) Interior Lamps On Input is grounded through the interior lamp switch. When the interior lamp switch is placed in the AUTO position, IPM Interior Lamps On Input is left open.

The IPM sends a class 2 message to the rear integration module (RIM) indicating the state of the interior lamp switch. The RIM then controls the activation and deactivation of the courtesy lamps based on other inputs.

The interior lamp switch must be in the AUTO position.

When a door is opened, the respective door lock actuator contacts close. The door module Door Open Input is grounded. In response to this input, the door module sends a class 2 message to the rear integration module (RIM) indicating that a door is open. If the ambient light sensor indicates nighttime conditions, the RIM will activate the INT LP relay.

The RIM will continue to keep the courtesy lamps on for 25 seconds after all doors are closed. The courtesy lamps will turn off immediately if the ignition switch is turned to the ON position, the interior lamp switch is placed in the OFF position, or an all doors lock command is issued with all doors closed.

When the remote keyless entry (RKE) module receives a door unlock command from the keyless entry transmitter, the RKE will send a class 2 message to the rear integration module (RIM) indicating that a keyless entry command was received. In response to the message and if the ambient light sensor indicates nighttime conditions, the RIM will activate the INT LP relay. The RIM will keep the courtesy lamps on for 40 seconds. The courtesy lamps will turn off immediately if the ignition switch is turned to the ON position, the interior lamp switch is placed in the OFF position, or an all doors lock command is issued with all doors closed.

The INT LP relay supplies battery positive voltage (B+) to the courtesy lamps, underhood lamp, rear compartment lamp, vanity lamps, and IP compartment lamp. Battery positive voltage (B+) is supplied at all times to the INT LP relay coil through the rear fuse block. Battery positive voltage (B+) is supplied at all times from the rear fuse block INT LP Fuse to the INT LP relay switch. When conditions are right to activate any interior lamps, the RIM grounds the INT LP Relay coil. The coil is energized, closing the switch contacts. Battery Positive Voltage (B+) is then supplied to all interior lamp.

The RIM CTSY LP 1 input supplies ground to the front door courtesy lamps and overhead console courtesy lamps.

The RIM CTSY LP 2 supplies ground to the rear door courtesy lamps and LH and RH courtesy lamps.

When any courtesy lamp switch is turned to the ON position, the rear integration module (RIM) Inadvertent Power Input is grounded through the courtesy lamp bulb, the wiring between the lamp and the switch, and the courtesy lamp switch. In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+). Only lamps that have active switches will light because they will be the only ones that are grounded.

When the rear compartment lid is opened, the rear integration module (RIM) Inadvertent Power Input is grounded through the rear compartment lamp bulb and the rear compartment lid release solenoid. In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+). The rear compartment lamp will light because it is receiving power and ground.

When the vanity mirror cover is opened, the rear integration module (RIM) Inadvertent Power Input is grounded through the vanity lamp bulbs. The vanity lamp switch is internal to the vanity lamp. In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+). The vanity lamp will light because it is receiving power and ground. The vanity lamp is dimmed by sliding the vanity mirror dimming switch. The switch is a potentiometer that varies in resistance as the switch moves. As the resistance of the potentiometer increases, the less voltage the vanity lamps receives. The vanity lamp then becomes dimmer.

When the IP compartment is opened, the rear integration module (RIM) Inadvertent Power Input is grounded through the IP compartment lamp bulb and the IP compartment lamp switch. In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+). The IP compartment lamp will light because it is receiving power and ground.

If any courtesy lamps, rear compartment lamp, vanity lamps, or IP compartment lamp is on for 10 minutes and the rear integration module (RIM) does not receive any new input that would keep the courtesy lamps on, the RIM will turn off the INT LP relay, removing power. The counter will not reset if any other courtesy lamps, rear compartment lamp, vanity lamps, or IP compartment lamp are activated.