When the interior lamp switch is placed in the ON position, the instrument panel integration module (IPM) Interior Lamps On Input is grounded via CKT 1597 (PNK/BLK) through the interior lamp switch and CKT 851 (FW) or (BLK/WHT). When the interior lamp switch is placed in the OFF position, the IPM Interior Lamps Off Input is grounded via CKT 1598 (GRY/BLK) through the interior lamp switch and CKT 851 (FW) or (BLK/WHT). When the interior lamp switch is placed in the AUTO position, IPM Interior Lamps On Input and Interior Lamps Off Input are both 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 the LH rear door is opened, the LH rear door jamb switch contacts close. The LH rear door module (LRDM) LH Rear Door Open Input is grounded via CKT 49 (DK BLU). In response to this input, the LRDM sends a simple bus interface (SBI) message to the LH front door module (LFDM) indicating that the LH rear door is open. When the RH rear door is opened, the RH rear door jamb switch contacts close. The RH rear door module (RRDM) RH Rear Door Open Input is grounded via CKT 49 (DK BLU). In response to this input, the RRDM sends a SBI message to the LFDM indicating that the RH rear door is open. When a rear door is open, the LFDM sends a class 2 message to the rear integration module (RIM) indicating the a rear door is open. If the ambient light sensor indicates nighttime conditions, the RIM will activate the INT LP relay, FRT CTSY relay, and RR CTSY relay.

When the RH front door is opened, the RH front door jamb switch contacts close. The RH front door module (RFDM) RH Front Door Open Input is grounded via CKT 49 (DK BLU). In response to this input, the RFDM sends a SBI message to the LFDM indicating that the RH front door is open. When the LH front door is opened, the LH front door jamb switch contacts close. The LFDM LH Front Door Open Input is grounded via CKT 126 (TAN). When a front door is open, the LFDM sends a class 2 message to the RIM indicating the a front door is open. If the ambient light sensor indicates nighttime conditions, the RIM will activate the INT LP relay and FRT CTSY relay.

The RIM will continue to keep the active 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, FRT CTSY relay, and RR CTSY 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. Refer to Keyless Entry System Circuit Description in Keyless Entry.

The INT LP relay supplies battery positive voltage (B+) to the courtesy lamps, reading lamps, 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 junction block. Battery positive voltage (B+) is supplied at all times from the rear junction block INT LP Fuse to the INT LP relay. When conditions are right to activate any interior lamps, the RIM grounds the INT LP Relay 54 coil via CKT 1599 (GRY). The coil is energized, closing the switch contacts. Battery Positive Voltage (B+) is then supplied to all interior lamps via CKT 149 (DK BLU/WHT).

The FRT CTSY relay supplies ground to the front courtesy lamps (foot well courtesy lamps, all door courtesy lamps, and overhead console courtesy lamps). Battery positive voltage (B+) is supplied at all times to the FRT CTSY relay coil through the rear junction block. The FRT CTSY relay is permanently grounded via CKT 750 (BLK) to G301. When conditions are right to activate the front courtesy lamps, the RIM grounds the FRT CTSY relay coil via CKT 1393 (DK BLU). The coil is energized, closing the switch contacts, supplying ground to the front courtesy lamps via CKT 157 (GRY).

The RR CTSY relay supplies ground to the rear courtesy lamps (rear reading lamps). Battery positive voltage (B+) is supplied at all times to the RR CTSY relay coil through the rear junction block. The RR CTSY relay is permanently grounded via CKT 750 (BLK) to G301. When conditions are right to activate the rear courtesy lamps, the RIM grounds the RR CTSY relay coil via CKT 690 (GRY/BLK). The coil is energized, closing the switch contacts, supplying ground to the rear courtesy lamps via CKT 1495 (DK BLU/WHT).

When any reading lamp switch is turned to the ON position, the rear integration module (RIM) Inadvertent Power Input is grounded via CKT 149 (DK BLU/WHT) through the reading lamp bulb, the wiring between the lamp and the switch, the reading lamp switch, and CKT 850 (BLK). CKT 522 (LT GRN) is between the LH reading lamp and switch. CKT 523 (DK GRN) is between the RH reading lamp and switch. CKT 9175 (FW), CKT 660 (FW), and CKT 661 (FW) are the circuits between the reading lamps and switches in the overhead console. In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+) via CKT 149 (DK BLU/WHT). 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 via CKT 149 (DK BLU/WHT) through the rear compartment lamp bulb, CKT 737 (ORN/BLK), the rear compartment lid release solenoid, and CKT 850 (BLK). In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+) via CKT 149 (DK BLU/WHT). 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 via CKT 149 (DK BLU/WHT) through the vanity lamp bulbs and CKT 850 (BLK). 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+) via CKT 149 (DK BLU/WHT). 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 via CKT 149 (DK BLU/WHT) through the IP compartment lamp bulb, CKT 148 (DK BLU), the IP compartment lamp switch, and CKT 450 (BLK). In response to this input, the RIM energizes the INT LP relay to supply battery positive voltage (B+) via CKT 149 (DK BLU/WHT). The IP compartment lamp will light because it is receiving power and ground.

If any courtesy lamps, reading 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 from CKT 149 (DK BLU/WHT). The counter will not reset if any other courtesy lamps, reading lamps, rear compartment lamp, vanity lamps, or IP compartment lamp are activated.