Pinpoint Test F: The AUTOLAMPS Are Inoperative

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

F1 RETRIEVE THE VEHICLE SECURITY MODULE DIAGNOSTIC TROUBLE CODES (DTCs)
NOTE: Make sure the headlamp switch is in the OFF position.
- Key in OFF position.
- Connect the diagnostic tool.
- Key in ON position.
- Carry out the vehicle security module on-demand self-test.
- Are any DTCs present?
- Yes : If DTC B1793, GO to F2.
  All others, REFER to the VEHICLE SECURITY MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX for correct diagnostics.
- No : GO to F4.
F2 VERIFY DTC B1793
- Key in OFF position.
- Disconnect: Vehicle Security Module C3008b.
- Measure the resistance between vehicle security module C3008b-10, circuit 218 (WH/VT), harness side and ground.
  
  Fig 1: Measuring Resistance Between Vehicle Security Module C3008b-10, Circuit 218 (WH/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to F3.
- No : GO to F7.
F3 CHECK CIRCUIT 218 (WH/VT) FOR A SHORT TO GROUND
- Disconnect: Light Sensor C286.
- Measure the resistance between vehicle security module C3008b-10, circuit 218 (WH/VT), harness side and ground.
  
  Fig 2: Measuring Resistance Between Vehicle Security Module C3008b-10, Circuit 218 (WH/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : REPAIR the circuit. TEST the system for normal operation.
- No : INSTALL a new light sensor. REFER to LIGHT SENSOR . TEST the system for normal operation.
F4 CHECK THE INPUT FROM THE HEADLAMP SWITCH
- Key in OFF position.
- Disconnect: Vehicle Security Module C3008b.
- Turn the headlamp switch in the AUTO position.
- Measure the voltage between vehicle security module C3008b-7, circuit 220 (VT/OG), harness side and ground.
  
  Fig 3: Measuring Voltage Between Vehicle Security Module C3008b-7, Circuit 220 (VT/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : TURN the headlamp switch off. GO to F5.
- No : GO to F6.
F5 CHECK CIRCUIT 220 (VT/OG) FOR AN OPEN
- Disconnect: Headlamp Switch.
- Carry out the headlamp switch component test. Refer to COMPONENT TESTING -- F150 PICKUP article.
- Is the headlamp switch OK?
- 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.
F6 MONITOR THE VEHICLE SECURITY MODULE LIGHT SENSOR PID
- Connect: Headlamp Switch.
- Connect: Vehicle Security Module C3008b.
- Key in ON position.
- 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 F7.
- No : INSTALL a new light sensor. REFER to LIGHT SENSOR . TEST the system for normal operation.
F7 CHECK FOR CORRECT 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 MODULE COMMUNICATIONS NETWORK . 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.