Interior Lamps

The interior Lamps consist of two groups. The first group are those lamps which may not be dimmed. The second group includes lamps that may be dimmed.

Courtesy/Illuminated Entry Lamps

Courtesy/illuminated entry lamps are lamps that may be illuminated by opening a door, manually operating a switch, or through a remote control door lock receiver (RCDLR) command. This group consists of the following lamps:

The INT LP fuse in the rear fuse block supplies battery positive voltage to the normally open switch contacts of the INT LP relay. The rear fuse block supplies battery positive voltage to the interior lamp relay coil. When a door is opened, the switch contacts of the door jamb close. When a door open input is grounded, that door module sends a class 2 message to the rear integration module (RIM) in order to indicate which door is open. When the sunload sensor indicates low light conditions, the RIM activates the interior lamp relay in order to provide battery positive voltage to the interior courtesy lamps. The RIM provides a pulse width modulated (PWM) ground to the interior courtesy lamps on the front and rear interior lamp control circuits for theater dimming. The RIM pulses the on time of the ground circuit between 0-100% at a frequency of approximately 100 hertz. By decreasing the on time percentage of the controlled ground circuit the intensity of the lamps will decrease. The RIM will illuminate these lamps under various conditions which will be described in the following information.

Courtesy/Illuminated Entry: When any door is opened, all of the courtesy lamps will illuminate. The lamps will remain illuminated as long as either door remains open or the inadvertent power/battery run down protection causes the outputs to be turned off. When a front door is opened, the driver door module will also illuminate all backlit components in the driver's door at full brightness. The lamps will remain illuminated as long as either door remains open or the inadvertent power/battery run down protection causes the outputs to be turned off. The courtesy lamps will remain illuminated approximately 25 seconds after the all of the doors have been closed. At this time the RIM will fade the lamps from full intensity to off in 3-5 seconds. The courtesy lamps will turn off using the theater dimming feature if the ignition switch is placed in the RUN position. The courtesy lamps will turn off immediately if an all door lock command is received with all the doors closed.

Courtesy/Illuminated Entry, Limo/Hearse Vehicles: When a front door is opened, the front door, and the overhead console courtesy lamps will illuminate. The driver door module will also illuminate all backlit components in the driver's door at full brightness. The lamps will remain illuminated as long as either door remains open or the inadvertent power/battery run down protection causes the outputs to be turned off. When a rear door is opened, the rear courtesy/reading lamps and rear door courtesy lamps will illuminate. The lamps will remain illuminated as long as either door remains open or the inadvertent power/battery run down protection causes the outputs to be turned off. The courtesy lamps will remain illuminated approximately 25 seconds after all of the doors have been closed. At this time the RIM will fade the lamps from full intensity to off in 3-5 seconds. The courtesy lamps will turn off using the theater dimming feature if the ignition switch is placed in the RUN position. The courtesy lamps will turn off immediately if an all door lock command is received with all the doors closed. When the hearse cargo/rear door is opened the reverse lamps will also illuminate.

Exit Lighting: The RIM will activate all courtesy lamps when it receives a class 2 message from the instrument panel cluster (IPC) indicating that the ignition key has been removed from the lock cylinder. The ambient light status must be NIGHT, and all of the doors must be closed. The RIM will theater dim the interior lamps after 20-25 seconds. During exit lighting feature the RIM will also request that the drivers door module illuminate the driver door switch backlighting at full intensity for 20-25 seconds. If the key is placed back into the lock cylinder before the lamps have dimmed, the RIM will immediately activate the theater dim feature. For limo/hearse vehicles the RIM only requires that the front doors are closed for exit lighting. The RIM will activate only the front courtesy lamps for the limo/hearse.

IP Compartment Lamp: The RIM energizes the interior lamp relay which provides battery positive voltage to the instrument panel compartment lamp. When the IP compartment is opened, its switch closes to provide a ground circuit and the IP compartment lamp illuminates.

Keyless Entry Illumination: When the remote control door lock receiver (RCDLR) receives a door unlock command from the keyless entry transmitter, the RCDLR will send a class 2 message to the rear integration module (RIM) indicating that an UNLOCK command was received. The RIM must have inputs that indicate that the ignition switch is OFF, all the doors are closed, and the sunload sensor is indicating low light conditions. The RIM will then activate the interior lamp relay, providing battery positive voltage and also a PWM ground to the interior lamps. The RIM will keep the courtesy lamps on for approximately 40 seconds and then turn them off through the theater dimming feature. If the door locks are activated to the LOCK position the courtesy lamps will deactivate immediately. The courtesy lamps will turn off using the theater dimming feature if the ignition switch is placed in the RUN position.

Manual Interior Lighting: The interior lamps may also be illuminated manually in any ambient light status. When the IP dimmer switch/interior lamp switch is rotated clockwise into the interior lamp ON position the contacts in the switch close, grounding the interior lamp switch on signal circuit of the Instrument panel integration module (IPM). The IPM then sends a class 2 message to the RIM to activate all courtesy lamps. When the IP Dimmer switch is placed out of the interior lamp ON position, the RIM will immediately turn OFF the interior lamps.

Panic Interior Illumination: The RIM will activate all courtesy lamps when the RCDLR receives a panic signal from the keyless entry transmitter, the power mode is OFF, and the ambient light status is NIGHT. The RIM will activate all courtesy lamps and request that the driver door module illuminate the driver door switch backlighting at full intensity. The interior lamps will remain illuminated for 30 seconds or until the RIM received a door unlock message.

Reading Lamps: The RIM energizes the interior lamp relay which provides battery positive voltage to the reading lamps. By placing a reading lamp switch in the ON position the switch closes and provides a path to ground and the reading lamp illuminates.

Rear Compartment Lamp: The RIM energizes the interior lamp relay which provides battery positive voltage to the rear compartment lamp. When the rear deck lid opens, the rear compartment lamp switch in the latch assembly closes to provide a ground for the rear compartment lamp.

Supplemental Inflatable Restraint (SIR) Interior Illumination: Approximately 0.5 seconds after activation of the supplemental inflatable restraint (SIR) system, all courtesy lamps will illuminate. When the SIR system is activated the inflatable restraint sensor and diagnostic module (SDM) sends a class 2 message to the RIM. If the ambient light sensor status is night the RIM will activate the interior lamps approximately 15 seconds after airbag deployment. The interior lamps will remain illuminated until there is a change in power mode.

Vanity Mirror Lamps: The RIM energizes the interior lamp relay which provides battery positive voltage to the vanity mirror lamps. When the vanity mirror cover on the sunshade is opened, its switch closes to provide a ground circuit and the vanity lamp illuminates. The vanity mirror lamp may be dimmed by the sliding switch next to the mirror. The switch is a potentiometer in which the resistance varies as the switch is moved. As the resistance of the potentiometer increases, the vanity lamp receives less voltage. The vanity lamp then becomes dimmer.

Interior Lamp Dimming

Interior lamp dimming are lamps that may be dimmed by operating the IP Dimmer switch. This group consist of the following lamps:

When the ignition switch is turned to the ON position, the vacuum fluorescent (VF) displays turn on at maximum brightness. When the park lamps are on and the sunload sensor indicates low light conditions, all incandescent back lighting and vacuum fluorescent (VF) displays turn on at the dimming level indicated by the IP dimmer switch. The rear fuse block supplies battery positive voltage to the normally open switch of the PRK LP relay. The dash integration module (DIM) supplies battery positive voltage to the PRK LP relay coil controlled positive voltage circuit. The DIM also provides ground to the control circuit of the PRK LP relay coil. When the DIM energizes the park lamp relay, current flows through the PRK LP relay switch to the DIMR fuse to the instrument panel lamp fuse supply voltage-1 circuit of the DIM. With the park lamps on, the DIM sends proportional voltage to the circuit in response to an input from the instrument panel integration module (IPM). The potentiometer of the IP dimmer switch receives a reference voltage and ground from the IPM. The potentiometer is an input to the IPM. When the driver selects a dimming setting, the IPM responds with a message to the DIM indicating this setting. All vacuum fluorescent (VF) lamps and all incandescent back lighting lamps have ground at G200, G201, and G302 for limo/hearse vehicles. When the IP dimmer switch is moved from MIN to MAX, all vacuum fluorescent (VF) displays, as well as all incandescent back lighting respond from Minimum intensity to maximum brightness in response to the IP dimmer switch. The instrument cluster provides a 54 volt supply to the instrument panel integration module (IPM). The supply circuit is used to power the HVAC vacuum fluorescent (VF) display. The incandescent back lighting for the doors also operates in response to a class 2 message regarding dimming intensity. The IPM sends the message to the appropriate door module regarding dimming intensity. The driver may select parade mode by manually turning on the park lamps during daylight conditions. The front park lamp circuit supplies voltage to the instrument panel cluster, radio and HVAC assembly for a park lamp on input, and the displays will become full bright.

Battery Run Down Protection/Inadvertent Power

To provide battery run down protection, the interior lamps will be deactivated automatically under certain conditions. The rear integration module (RIM) initiates a 10 minute timer if the interior lamp relay control output is still active, and the ignition switch is in the OFF position. The RIM timer is set to 3 minutes until the vehicle mileage is above 22.5 KM (14 miles). At the end of the designated time, the RIM will deactivate the interior lamp relay, disabling the interior lamps. This feature will be cancelled if any power mode other than OFF becomes active. The RIM will reset the timer if any interior lamp switch is turned on, a door is opened, or the RCDLR is activated.