Interior Lights Circuit Description

BATTERY RUNDOWN PROTECTION
Power is supplied to the courtesy lamps, reading lamps, rear compartment lamp, vanity lamps and IP compartment lamp by the interior lamps relay. This relay provides parasitic load protection and is activated by the rear integration module (RIM) when conditions are right to activate any interior lamp. The RIM will keep this relay active for 10 minutes following the key being turned OFF and retained accessory power (RAP) being deactivated or timed out. The 10 minutes is reduced to 3 minutes if mileage is less then 22.5 KM (14 miles).

INTERIOR LAMP SWITCH
When the interior lamp switch is placed in the ON position the instrument panel module (IPM) Interior Lamp Switch Input is grounded through the interior lamp switch. When the interior lamp switch is placed in the OFF position the IPM Interior Lamp Switch Input is left open.

The IPM sends a class 2 message to the 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.

DOOR ACTIVATED COURTESY LIGHTING
The interior lamp switch must be in the OFF position. When LF, RR or LR door is opened the appropriate door ajar switch contacts close. The door module sends a SBI message to the drivers door module (DDM) indicating that the door is open. The drivers door module sends a class 2 message to the RIM indicating that a door is open. If the twilight light sensor indicates night time conditions, the RIM will activate the interior lamps relay and activates a Pulse Width Modulated ground which provides a ground to the lamps. The interior lamps relay supplies power to all interior courtesy lighting.

The RIM will continue to keep the active courtesy lamps on for 25 seconds after the last door is closed. The courtesy lamps will turn off immediately if any of the KEY is turned to the RUN position or the power door locks are activated.

KEYLESS ENTRY INTERIOR ILLUMINATION
When the remote function actuator (RFA) module receives a door unlock command from the RFA transmitter the RFA will send a class 2 message to the RIM indicating that a remote function actuator command was received. In response to the message and if the twilight sensor indicates night time conditions the RIM will activate the interior lamps relay and activates a Pulse Width Modulated ground which provides a ground to the lamps. The interior lamps relay supplies power to all interior courtesy lighting. The RIM will keep the courtesy lamps on for 40 seconds The courtesy lamps will turn off immediately if the Key is turned to the RUN position, or an all doors lock command is issued with all doors closed. Refer to Keyless Entry System Description in Keyless Entry.

INTERIOR LAMPS
Power is supplied to the courtesy lamps, reading lamps, rear compartment lamp, vanity lamps and IP compartment lamp by the interior lamps relay. Battery voltage is supplied at all times from the fuse in the rear fuse block to the interior lamps relay. When conditions are right to activate any interior lamps the RIM grounds the interior lamps relay. The coil is energized closing the switch contacts. Battery Voltage is then supplied to all interior lamps. The RIM activates a Pulse Width Modulated ground which provides a ground to the lamps. The interior lamps relay supplies power to all interior courtesy lighting.

READING LAMPS
The reading lamps can be individually activated by the switch at the lamps if equipped. Power is supplied to the reading lamps by the interior lamps relay. Only lamps that have active switches will light because they will be the only ones that are grounded.

REAR COMPARTMENT LAMP
When the rear compartment lid is opened the rear compartment lamp is grounded through the rear compartment lid release solenoid. Power is supplied to the rear compartment lamp by the interior lamps relay. The rear compartment lamp will light because it is receiving power and ground through the rear compartment lid release solenoid contacts.

VANITY LAMPS
When the vanity mirror cover is opened the vanity lamp contacts close and the vanity lamp is grounded through the vanity lamp contacts and the vanity lamps dimming slide switch. The vanity lamp switch is internal to the vanity lamp. Power is supplied to the vanity lamps by the interior lamps relay. 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 ground the vanity lamp receives. The vanity lamp then becomes dimmer.

IP COMPARTMENT LAMP
When the IP compartment is opened the IP compartment lamp switch contacts close. The RIM activates a Pulse Width Modulated ground which provides a ground to the lamps. Power is supplied to the IP compartment lamp by the interior lamps relay. The IP compartment lamp will light because it is receiving power and ground.