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Home >> Ford >> 2000 >> Taurus LX, 3.0 2, AX4N >> Repair and Diagnosis >> External Pages >> Different car >> Section 1376 (Exterior Lighting System) >> Diagnosis And Testing >> Headlamps >> Pinpoint Tests >> Pinpoint Test D: The Low Beam(s) Are Always On >> Pinpoint Test D: The Low Beam(S) Are Always On

Pinpoint Test D: The Low Beam(S) Are Always On

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
  1. D1 CHECK FOR AUTOLAMP DTCs 
    • Review the DTCs retrieved from the SJB self-test.
    • Is DTC B1696, B1791, B1793 or B2008 present? 
    • Yes:  REFER to AUTOLAMPS .
    • No:  If equipped with autolamps, GO to  D2.

      If not equipped with autolamps, GO to  D3.

  2. D2 CHECK THE SJB AUTOLAMP ON REQUEST PID 
    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: SJB DataLogger.
    • While placing the headlamp switch in the AUTOLAMPS ON and then OFF position, monitor the SJB headlamp switch PID (HDLMP_AUT_CKT).
    • Does the PID indicate ON with the headlamp switch in the AUTOLAMPS ON position and OFF when the headlamp switch is in the OFF position? 
  3. D3 CHECK THE SJB HEADLAMP SWITCH PIDs 
    NOTE: Make sure the headlamp switch is lined up in the correct position when monitoring the PIDs.
    • Enter the following diagnostic mode on the scan tool: SJB DataLogger.
      NOTE: Only one PID should indicate ON at each headlamp switch position.
    • While moving the headlamp switch through all positions, monitor the SJB headlamp switch input PIDs (HDLMP_OFF_CKT, HDLMP_PRK_CKT, HDLMP_ON_CKT).
    • Do the headlamp switch positions agree with the PIDs (with only one PID indicating ON in each position)? 
    • Yes:  GO to  D8.
    • No:  GO to  D4.
  4. D4 CHECK FOR VOLTAGE SIGNALS TO THE HEADLAMP SWITCH 
    • Ignition OFF.
    • Disconnect: Headlamp Switch C205.
    • Measure the voltage between the headlamp switch, harness side and ground as follows:
      TERMINAL VOLTAGE REFERENCE TABLE

      Headlamp Switch Connector-Pin Circuit
      C205-6 CLF23 (WH/VT)
      C205-2 CLS34 (GY)
      C205-7 CLF18 (BU/WH)
      Fig 1: Measuring Voltage Between Headlamp Switch & Ground
      G06141776Courtesy of FORD MOTOR CO.
    • Are the voltages greater than 10 volts? 
    • Yes:  GO to  D5.
    • No:  GO to  D6.
  5. D5 CHECK FOR VOLTAGE TO THE HEADLAMP SWITCH USING THE CONNECTOR GROUND 
    • Measure the voltage between the headlamp switch C205-6, circuit CLF23 (WH/VT), harness side and the headlamp switch C205-3, circuit GD116 (BK/VT), harness side.
      Fig 2: Measuring Voltage Between Headlamp Switch C205-6 & C205-3
      G06141777Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    • Yes:  INSTALL a new headlamp switch. REFER to Removal and Installation . TEST the system for normal operation.
    • No:  REPAIR circuit GD116 (BK/VT) for an open. TEST the system for normal operation.
  6. D6 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR A SHORT TO GROUND 
    • Disconnect: SJB C2280b.
    • Measure the resistance between the headlamp switch, harness side and ground as follows:
      TERMINAL RESISTANCE REFERENCE TABLE

      Headlamp Switch Connector-Pin Circuit
      C205-6 CLF23 (WH/VT)
      C205-2 CLS34 (GY)
      C205-7 CLF18 (BU/WH)
      Fig 3: Measuring Resistance Between Headlamp Switch & Ground
      G06065222Courtesy of FORD MOTOR CO.
    • Are the resistances greater than 10,000 ohms? 
    • Yes:  GO to  D7.
    • No:  REPAIR the circuit in question for a short to ground. TEST the system for normal operation.
  7. D7 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR AN OPEN 
    • Measure the resistance between the headlamp switch, harness side and the SJB, harness side as follows:
      TERMINAL RESISTANCE REFERENCE TABLE

      Headlamp Switch Connector-Pin SJB Connector-Pin Circuit
      C205-6 C2280b-47 CLF23 (WH/VT)
      C205-2 C2280b-31 CLF34 (YE/OG)
      C205-7 C2280b-30 CLF18 (BU/WH)
      Fig 4: Measuring Resistance Between Headlamp Switch & SJB Terminals
      G06065223Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    • Yes:  GO to  D11.
    • No:  REPAIR the circuit in question for an open. TEST the system for normal operation.
  8. D8 CHECK THE SJB OUTPUT 
    • Disconnect: SJB C2280e.
    • Does the LH or RH headlamp continue to illuminate? 
    • Yes:  For MKZ with halogen headlamps or Fusion, REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BU/GN) (RH headlamp) for a short to voltage. TEST the system for normal operation.

      For MKZ with HID headlamps or Milan, GO to  D9.

    • No:  GO to  D11.
  9. D9 CHECK THE HEADLAMP RELAY OUTPUT CIRCUIT 
    • Disconnect: Suspect Headlamp Relay.
    • Does the LH or RH headlamp continue to illuminate? 
    • Yes:  REPAIR circuit CLF30 (VT/BN) (LH headlamp) or circuit CLF31 (YE/GY) (RH headlamp) for a short to voltage. TEST the system for normal operation.
    • No:  GO to  D10.
  10. D10 CHECK HEADLAMP RELAY 
    • Substitute a known good relay.
    • Does the LH or RH headlamp continue to illuminate? 
    • Yes:  REMOVE the known good relay. TEST the system for normal operation.
    • No:  REMOVE the known good relay. GO to  D11.
  11. D11 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 INSTALLATION . 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.
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