Interior Lighting System: Overview Ford Expedition II

The interior lighting system consists of the following

1. Front map lamp assembly
2. Front door courtesy lamp
3. Glove box lamp assembly
4. Instrument cluster
5. Vehicle security module
6. Interior lamp switch
7. Interior lamp relay
8. Illuminated vanity mirrors
9. Reading lamp assembly
10. Rear courtesy lamp
11. Puddle lamps
12. Underhood lamp assembly

Refer to SYSTEM WIRING DIAGRAMS (Navigator) or SYSTEM WIRING DIAGRAMS (Expedition) for schematic and connector information.

Scheme 1

Principles of Operation

VEHICLE SECURITY MODULE

The vehicle security module receives inputs from the following

1. Door ajar switches
2. Keyless entry keypad
3. Ignition switch
4. Remote keyless entry transmitter

The vehicle security module uses these inputs to control an output signal to the instrument cluster which controls the battery saver relay and courtesy lamp output.

INTERIOR LIGHTING SYSTEMS

The instrument cluster grounds the battery saver relay and supplies the power for courtesy lamps when any door ajar switch is opened, or the interior lamp (headlamp) switch is closed. The instrument cluster then supplies voltage to the interior lamp circuit. Vehicle speed must be less than 24 kph (15 mph) for the instrument cluster module to keep courtesy lamps on. The interior lamps will remain illuminated for up to 25 seconds after all doors are closed unless the instrument cluster module receives an input from any of the following

1. Voltage from the ignition switch
2. A vehicle speed signal
3. Input from the keyless entry keypad through the vehicle security module
4. Input from the remote keyless entry transmitter lock or panic switch through the vehicle security module

ILLUMINATED ENTRY

Illuminated entry is activated when a vehicle is unlocked using the keyless entry keypad or the remote keyless entry transmitter. The vehicle security module then requests that the instrument cluster module supply voltage to the interior lamps. Illuminated entry is deactivated when the vehicle security module receives a lock signal from the remote keyless entry transmitter. Illuminated entry will also be deactivated when the instrument cluster module receives a change in ignition switch pid status.

BATTERY SAVER

The battery saver is activated when the instrument cluster module is not receiving voltage input from the ignition switch (OFF position). The instrument cluster module will then provide ground to the battery saver relay coil. This activates for a period of 10 minutes with the interior lamp (headlamp) switch in the OFF position, or a maximum period of 30 minutes with the interior lamp (headlamp) switch in the ON position, or a door is ajar, provided that the instrument cluster module does not receive any other input signals within the time-out period. The activated battery saver relay switches voltage to the demand lamp circuit. After time-out, the instrument cluster module disconnects ground from the battery saver relay coil, disabling the demand lamp circuit.

Scheme 2

1. Verify the customer concern.
2. Visually inspect the following for obvious signs of electrical damage
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the cause is not visually evident, connect the diagnostic tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle: Check that the diagnostic card is correctly installed. Check the connections to the vehicle. Check the ignition switch position.
5. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
6. Carry out the DATA LINK DIAGNOSTICS test. If the diagnostic tool responds with: CKT 70, CKT 914, CKT 915 or CKT 693 = ALL ECUS NO RESP/NO EQUIP, refer to «MODULE COMMUNICATIONS NETWORK»(ref-209944) . NO RESPONSE/NOT EQUIPPED for Instrument cluster, refer to «INSTRUMENT CLUSTER»(ref-209929) or Vehicle Security Module, refer to «MULTIFUNCTION ELECTRONIC MODULE»(ref-209949) . SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs, and carry out self-test diagnostics.
7. If the DTCs retrieved are related to the concern, go to the «INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE INDEX»(ref-209942-S24359181472005121200000) .
8. If no DTCs related to the concern are retrieved, proceed to the «SYMPTOM CHART»(ref-209942-S14962417972005121200000) .

INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE INDEX

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

1. Remove the map lamp assembly. Carefully release the lamp lens. NOTE: Identify the location of each screw to aid in the installation of the map lamp assembly. Remove interior lamp screws. Remove the map lamp assembly.