Pinpoint Test V: The Fog Lamps On Indicator Is Inoperative

Fog Lamps

Pinpoint Test V: The Fog Lamps On Indicator Is Inoperative

Refer to Wiring Diagram Set 86 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Fog Lamps for schematic and connector information. Diagrams By Number

Normal Operation

When the Smart Junction Box (SJB) detects the fog lamps on request, the SJB energizes the fog lamp relay (integrated into the SJB). When the fog lamp relay is energized, voltage is routed through 2 output circuits from the SJB. One output is to the fog lamps and the other output is to the headlamp switch (for the fog lamps on indicator).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Headlamp switch
- SJB


PINPOINT TEST V: THE FOG LAMPS ON INDICATOR IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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V1 CHECK THE HEADLAMP SWITCH

- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Select the SJB fog lamps (FOG_LMP) active command. Command the fog lamps on.
- NOTE: Make sure the fog lamps are illuminated when taking a reading.
- Measure the voltage between the headlamp switch C205-10, circuit CLF12 (BN/YE), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. TEST the system for normal operation.

No
GO to V2.

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V2 CHECK THE SJB FOG LAMPS OUTPUT CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: SJB C2280a.
- Measure the resistance between the headlamp switch C205-10, circuit CLF12 (BN/YE), harness side and the SJB C2280a-6, circuit CLF12 (BN/YE), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to V3.

No
REPAIR circuit CLF12 (BN/YE) for an open. CLEAR the DTCs. REPEAT the self-test.

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V3 CHECK FOR CORRECT SJB OPERATION

- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. REFER to Multifunction Electronic Modules Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR any DTCs. REPEAT the self-test.

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