Exterior Lighting
Exterior Lighting
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
Battery Saver
NOTE: Time-out is 1 minute if the vehicle has less than 80 km (50 miles).
The battery saver is integrated into the SJB and provides automatic shut-off of the headlamps and parking lamps after 10 minutes in order to save battery voltage. A timer is started when the ignition switch is turned to the OFF position with the headlamp switch in the HEADLAMPS ON position, or the headlamp switch is placed in the HEADLAMPS ON position with the ignition switch off. When the time-out period has elapsed, the voltage is automatically shut off to the lamps by the battery saver.
The battery saver does not control the parking lamps if the headlamp switch is in the PARKING LAMPS ON position.
Lamp Assembly Condensation
Exterior lamps are vented to accommodate normal changes in pressure. Condensation can be a natural by-product of this design. When moist air enters the lamp assembly through the vents, there is a possibility that condensation can occur if the temperature is cold. When normal condensation occurs, a thin film of mist can form on the interior of the lens. The thin mist eventually clears and exits through the vents during normal operation. Time to clear the lens of acceptable mist varies with ambient humidity and lamp types. Normal condensation clears from any lamp in 48 hours under dry conditions.
Do not replace a lamp assembly with acceptable levels of condensation such as:
- presence of thin mist (no streaks, drip marks or droplets are present)
- fine mist covers less than 50% of the lens
Examples of unacceptable moisture (usually caused by a lamp housing leak):
- water puddling inside the lamp
- large water droplets, drip marks or streaks present on the interior of the lens
Headlamps
Expedition
The headlamp system is a dual-beam pattern system. It consists of replaceable low/high beam bulbs. The headlamp assembly has the park/turn indicator lamp integrated into the headlamp assembly. The SJB supplies voltage to the headlamps when demanded.
If the headlamps are on when the ignition switch is turned off, the battery saver feature turns off the headlamps after 10 minutes have elapsed.
Navigator
The headlamp system is a single-beam pattern system with a shutter used to expose more light at a higher angle when the high beams are activated. It consists of High Intensity Discharge (HID) headlamps (with replaceable bulbs) and shutters that are integral to the headlamp assembly. There are 2 HID relays located within the Battery Junction Box (BJB) that are used to provide voltage to the ballast located within each headlamp assembly. The headlamp assembly has the park/turn indicator lamp integrated into the headlamp assembly. The SJB supplies voltage to the HID relay coils when demanded.
The flash-to-pass feature is unique for Navigator. If the low beams are off when the flash-to-pass is requested, flash-to-pass lamps, the HID ballasts and the shutters within the headlamps are activated for less then 0.5 second. If the low beams are on when the flash-to-pass is requested, the flash-to-pass lamps and shutters within the headlamps are activated as long as the multifunction switch is held in the FLASH-TO-PASS position. The flash-to-pass lamps also share functionality as a parking lamp when the parking lamps are on.
If the headlamps are on when the ignition switch is turned off, the battery saver feature turns off the headlamps after 10 minutes have elapsed.
Autolamps
The autolamp system provides light sensitive automatic on/off control of the exterior lamps. The autolamp system keeps the exterior lamps on for a pre-selected period of time after the ignition switch is turned to the OFF position (20 seconds is the factory default setting). The pre-selected time lapse is adjustable up to approximately 3 minutes. For additional information, refer to Autolamps Time Delay Adjustment Autolamps Time Delay Adjustment.
Headlamps On With Wipers On Feature
If the headlamp switch is in the AUTOLAMPS ON position and the front wipers are on for more than 3 seconds (except during a mist wipe or while the wipers are on to clear washer fluid during a wash condition), the exterior lamps are turned on. When the ignition switch is changed to the OFF or ACC position, the headlamp switch is placed in the OFF position, or the front wipers are off for more than 30 seconds, the exterior lamps are turned off.
For additional information on the headlamps on with wipers on feature, refer to Wipers and Washers Description and Operation.
Stoplamps
The stoplamps are supplied voltage when the brake pedal is applied.
Turn Signal/Hazard Lamps
The front turn signal lamps are located within the headlamp assemblies. The rear lamps share functionality with the stoplamps. When the multifunction switch is placed in the LH or RH TURN position, the SJB routes voltage to the LH or RH turn signal lamps. The SJB then cycles the voltage on and off approximately 80 times per minute. If a front or rear turn bulb is inoperative, the SJB cycles the voltage on and off approximately 160 times per minute.
The hazard switch is located on the center instrument panel finish panel. When the hazard switch is pressed, the SJB supplies voltage to all the turn lamps. The SJB cycles the voltage on and off approximately 80 times per minute.
Parking Lamps
The SJB supplies voltage to the parking lamps when demanded. The front parking lamps are located in the headlamp assemblies. The rear parking lamps are located in the rear lamp assemblies.
Fog Lamps
The fog lamp switch is integral to the headlamp switch. When the fog lamp switch is engaged, the SJB provides ground for the fog lamp relay coil (integral to the SJB), which then energizes and routes voltage to the fog lamps. The fog lamps can be turned on when the ignition switch is in the RUN or ACC position, the parking lamps are on, and the high beam headlamps are off.
Reversing Lamps
When the transmission is placed in REVERSE (R), the Transmission Control Module (TCM) provides power and ground for the reversing lamp relay coil. The reversing lamps receive voltage when the reversing lamp relay is energized. The reversing lamps are located within the rear lamp assemblies.
Trailer Tow
The BJB supplies voltage to the trailer tow stop/turn, parking and reversing lamps. When the vehicle's rear stop/turn or parking lamps are illuminated, voltage is also supplied to a corresponding trailer tow relay (coil side) located in the BJB. When the reversing lamps are illuminated, voltage from the reversing lamp relay is also supplied to the trailer tow connector.
The trailer tow battery charge relay provides voltage to the trailer tow connector when the ignition switch is in the RUN position.
The vehicle comes equipped with circuitry to support trailer tow electric brakes.
Vehicles equipped with the trailer tow package are also equipped with a trailer sway control feature. For diagnostics and other information regarding this feature, refer to Vehicle Dynamic Systems Testing and Inspection.
Daytime Running Lamps (DRL)
Expedition
The SJB can be configured to turn the Daytime Running Lamps (DRL) on for this vehicle. Refer to Module Configuration [1][2]Initial Inspection and Diagnostic Overview for additional information on this programmable parameter.
The DRL system operates the low beam headlamps at a reduced intensity.
The SJB supplies pulse width modulated voltage to illuminate the low beam headlamps at a reduced intensity when the following conditions are met:
- The ignition switch is in the RUN position.
- The headlamps have not been turned on by the autolamp system or the headlamp switch.
- The transmission is not in PARK (P).
Navigator
The SJB can be configured to turn the DRL on for this vehicle. Refer to Module Configuration [1][2]Initial Inspection and Diagnostic Overview for additional information on this programmable parameter.
The DRL system illuminates the fog lamps at full intensity.
The SJB energizes the fog lamp relay when the following conditions are met:
- The ignition switch is in the RUN position.
- The headlamps have not been turned on by the autolamp system or the headlamp switch.
- The transmission is not in PARK (P).