Interior Lighting System: Other — Ford Taurus IV facelift (2004-2006)

Interior Lighting System: Other Ford Taurus IV facelift

Smart Junction Box (SJB)

The SJB receives inputs from the following

Door ajar switches
Liftgate ajar switch (wagon)
Liftgate glass switch (wagon)
Headlamp switch
Remote keyless entry (RKE) transmitter/keyless entry keypad switches
Powertrain control module (PCM) (vehicle speed signal)
Ignition switch

The SJB uses these inputs to control the output to the battery saver relay, interior lamp relay and the approach lamp relay. Both relays are integral to the SJB and cannot be accessed directly.

The SJB grounds the battery saver relay and interior lamp relay coils when any door ajar switch or the headlamp switch is closed. The interior lamp relay then supplies power to the interior lamp circuit. Vehicle speed must be less than 5 km/h (3 mph) for the SJB to ground the interior lamp relay. The interior lamps will remain illuminated for a period of up to 25 seconds after all doors are closed or until the ignition is switched from the OFF position, or the SJB receives a vehicle speed signal. Actuating the interior lights from the headlamp switch will operate at any time.

Illuminated Entry

Illuminated entry is activated when a keyless entry keypad switch provides ground on the SJB input or when the SJB receives an unlock signal from a remote keyless entry (RKE) transmitter. The SJB then provides ground to the battery saver and interior lamp relay coils. Illuminated entry is deactivated when the SJB receives a lock signal from an RKE transmitter or if the SJB receives ground inputs from the keyless entry keypad switch lock code. Illuminated entry will also be deactivated when the SJB receives input voltage from the ignition switch.

Battery Saver

The battery saver is activated when the SJB is not receiving voltage input from the ignition switch (OFF position). The SJB will then provide ground to the battery saver relay coil for a maximum of 30 minutes depending on the state of the interior lamp switch inputs to the SJB. The energized battery saver relay switches voltage to the demand lamp circuit and the interior lamp relay coil. After time-out, the SJB removes ground to the battery saver relay disabling the demand lamp circuit.

Approach Lamps

The approach lamp relay coil receives voltage when the ignition switch is in the START or RUN position, which disables the circuit to the approach lamps.

Scheme 2

Scheme 2: Inspection and Verification

Verify the customer concern.
Visually inspect for obvious signs of mechanical and electrical damage.
If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
If the cause is not visually evident, connect the diagnostic tool to the data link connector 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 program card is correctly installed. Check the connections to the vehicle. Check the ignition switch position.
If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
Carry out the data link diagnostics test. If the diagnostic tool responds with: CAN circuits fault; all electronic control units no response/not equipped, refer to «MODULE COMMUNICATIONS NETWORK»(ref-212136) . No response/not equipped for smart junction box (SJB), refer to «MULTIFUNCTION ELECTRONIC CONTROL MODULES»(ref-212140) . System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the SJB.
If the DTCs retrieved are related to the concern, go to the «SMART JUNCTION BOX (SJB) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(ref-212134-S31193447252005122300000) .
If no DTCs related to the concern are retrieved, GO to «SYMPTOM CHART»(ref-212134-S01044891642005122300000) .
If the DTCs are retrieved that are not found in the following Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index, refer to the master Diagnostic Trouble Code Index in «MULTIFUNCTION ELECTRONIC CONTROL MODULES»(ref-212140) .