Pinpoint Test F: The AUTOLAMPS Are Inoperative

WARNING: This page is about a different car, the 2007 Lincoln MKX and 2007 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

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

F1 CHECK THE MANUAL HEADLAMP OPERATION
- Place the headlamp switch in the HEADLAMPS ON position.
- Do the headlamps operate correctly?
1. YES : Go to F2.
2. NO : REFER to Headlamps in this.
F2 CHECK FOR VOLTAGE TO THE LIGHT SENSOR
- Key in OFF position.
- Disconnect: Light Sensor C286 or C287
- Key in ON position.
- Place the headlamp switch in the AUTOLAMPS ON position.
- For vehicles with EATC, measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- For vehicles with manual temperature control, measure the voltage between the light sensor C287a-A, circuit VLF14 (BU/BN), harness side and ground.
- Is the voltage approximately 5 volts?
1. YES : INSTALL a new light sensor. REFER to Light Sensor in this. CLEAR the DTCs. REPEAT the self-test.
2. NO : Go to F3.
F3 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?
1. YES : INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.