Pinpoint Test J: The AUTOLAMPS Are On Continuously

WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

J1 RETRIEVE THE VEHICLE SECURITY MODULE DIAGNOSTIC TROUBLE CODES (DTCs)
NOTE: Make sure the headlamp switch is in the OFF position.
- Key in ON position.
- Carry out the vehicle security module on-demand self-test.
- Are any DTCs present?
- Yes : For DTC B1695, GO to J2.
  For DTC B1792, GO to J4.
  
  All other DTCs, refer to the VEHICLE SECURITY MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
- No : GO to J4.
J2 CHECK THE HEADLAMP SWITCH INPUT
- Key in OFF position.
- Disconnect: Vehicle Security Module C3203e.
- Key in ON position.
- Measure the voltage between the vehicle security module C3203e-5, circuit 1399 (DB/WH), harness side and ground.
  
  Fig 1: Measuring Voltage Between Vehicle Security Module C3203e-5 And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : GO to J3.
- No : GO to J8.
J3 CHECK CIRCUIT 1399 (DB/WH) FOR SHORT TO POWER
- Disconnect: Headlamp Switch C205a.
- Measure the voltage between the vehicle security module C3203e-5, circuit 1399 (DB/WH), harness side and ground.
  
  Fig 2: Measuring Voltage Between Vehicle Security Module C3203e-5 And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR the circuit. TEST the system for normal operation.
- No : INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH . TEST the system for normal operation.
J4 MONITOR THE LIGHT SENSOR INPUT
- Connect: Vehicle Security Module C3203e.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Vehicle Security Module Light Sensor PID.
- Monitor the vehicle security module light sensor PID while illuminating, then removing the light source from the light sensor.
- Does the PID percentage change with the sensor covered and then illuminated?
- Yes : GO to J8.
- No : GO to J5.
J5 CHECK CIRCUIT 1205 (BK) FOR OPEN
- Key in OFF position.
- Disconnect: Light Sensor C286.
- Measure the resistance between the light sensor C286-5, circuit 1205 (BK), harness side and ground.
  
  Fig 3: Measuring Resistance Between Light Sensor C286-5 And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to J6.
- No : REPAIR the circuit. TEST the system for normal operation.
J6 CHECK CIRCUIT 218 (WH/VT) FOR SHORT TO POWER
- Disconnect: Vehicle Security Module C3203e.
- Key in ON position.
- Measure the voltage between the light sensor C286-2, circuit 218 (WH/VT), harness side and ground.
  
  Fig 4: Measuring Voltage Between Light Sensor C286-2 And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR the circuit. TEST the system for normal operation.
- No : GO to J7.
J7 CHECK CIRCUIT 218 (WH/VT) FOR OPEN OR SHORT TO GROUND
- Measure the resistance between the light sensor C286-2, circuit 218 (WH/VT), harness side and the vehicle security module C3203e-4, circuit 218 (WH/VT), harness side; and between the light sensor C286-2, circuit 218 (WH/VT), harness side and ground.
  
  Fig 5: Measuring Resistance Between Light Sensor C286-2 And Vehicle Security Module C3203e-4
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the light sensor and the vehicle security module; and greater than 10,000 ohms between the light sensor and ground?
- Yes : INSTALL a new light sensor. REFER to LIGHT SENSOR . TEST the system for normal operation.
- No : REPAIR the circuit. TEST the system for normal operation.
J8 CHECK FOR VEHICLE SECURITY MODULE OPERATION
- Disconnect all vehicle security module connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all vehicle security module 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 vehicle security module. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
- No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.