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Pinpoint Test A : One Or Both Low Beams Is Inoperative

WARNING: This page is about a different car, the 2015 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

  1. A1 DETERMINE IF ONE OR BOTH LOW BEAMS ARE INOPERATIVE

    • Ignition ON.
    • Place the headlamp switch in the HEADLAMPS position.

    Are both low beams inoperative? 

    Yes  GO to  A8
    No  GO to  A2

  2. A2 CHECK FOR VOLTAGE FROM THE HEADLAMP LOW BEAM CIRCUIT

    • Place the headlamp switch in the OFF position.
    • Ignition OFF.
    • Disconnect: With halogen headlamps, inoperative LH Headlamp C1021 or RH Headlamp C1041 .
    • Disconnect: With LED headlamps, inoperative LH Headlamp C1284 or RH Headlamp C1285 .
    • Ignition ON.
    • Place the headlamp switch in the HEADLAMPS position.
    • For halogen headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1021-1
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1041-1
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground
    • For LED headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1284-5
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1285-5
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the voltage greater than 11 volts? 

    Yes  GO to  A6
    No  GO to  A3

  3. A3 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE HEADLAMP LOW BEAM CIRCUIT

    • Place the headlamp switch in the OFF position.
    • Using a diagnostic scan tool, perform the BCM self-test.
    • Clear the Diagnostic Trouble Codes (DTCs) and repeat the self-test (required to enable the lamp output driver).
    • Ignition OFF.
    • Ignition ON.
    • Place the headlamp switch in the HEADLAMPS position.
    • For halogen headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1021-1
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1041-1
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground
    • For LED headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1284-5
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1285-5
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the voltage greater than 11 volts? 

    Yes  For halogen headlamps, INSTALL a new low beam headlamp bulb. REFER to: Headlamp Bulb . For LED headlamps, GO to  A7
    No  GO to  A4

  4. A4 CHECK THE LOW BEAM CIRCUIT FOR A SHORT TO GROUND

    • Ignition OFF.
    • Place the headlamp switch in the OFF position.
    • For halogen headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1021-1
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 Ground

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1041-1
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 Ground
    • For LED headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1284-5
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 Ground

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1285-5
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance greater than 10, 000 ohms? 

    Yes  GO to  A5
    No  REPAIR the circuit. After the repair: If no Diagnostic Trouble Codes (DTCs) are present, TEST the system for normal operation. If any BCM Diagnostic Trouble Codes (DTCs) other than DTC U3000:49 are present, CLEAR the Diagnostic Trouble Codes (DTCs), REPEAT the self-test (required to enable the lamp output driver) and cycle the ignition OFF and ON. TEST the system for normal operation. If DTC U3000:49 is present, Refer to BCM Hardware Testing .

  5. A5 CHECK THE LOW BEAM CIRCUIT FOR AN OPEN

    • For halogen headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1021-1
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 C2280G-4

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1041-1
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 C2280G-2
    • For LED headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1284-5
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 C2280G-4

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1285-5
      GFD38391Courtesy of FORD MOTOR COMPANY
      		 C2280G-2

    Is the resistance less than 3 ohms? 

    Yes  GO to  A8
    No  REPAIR the circuit.

  6. A6 CHECK THE HEADLAMP GROUND CIRCUIT FOR AN OPEN

    • For halogen headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1021-1
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 C1021-3

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1041-1
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 C1041-3
    • For LED headlamps, measure:

      LH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1284-5
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 C1284-7

      RH Headlamp 

      Positive Lead Measurement / Action Negative Lead
      C1285-5
      GFD38392Courtesy of FORD MOTOR COMPANY
      		 C1285-7

    Is the voltage greater than 11 volts? 

    Yes  For halogen headlamps, INSTALL a new low beam headlamp bulb. REFER to: Headlamp Bulb . For LED headlamps, GO to  A7
    No  REPAIR the circuit in question.

  7. A7 CHECK THE HEADLAMP INTERNAL HARNESS

    • CHECK the internal headlamp harness for open or shorted circuits and damaged or pushed-out pins.

    Is the headlamp internal harness OK? 

    Yes  INSTALL a new ballast. REFER to: Ballast . CLEAR the Diagnostic Trouble Codes (DTCs) and REPEAT the self-test. TEST the system for normal operation. If the condition returns, INSTALL a new LED module. REFER to: Headlamp Bulb .
    No  INSTALL a new headlamp assembly. REFER to: Headlamp Assembly .

  8. A8 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION

    • Disconnect and inspect all BCM connectors.
    • Repair:
      • corrosion (install new connector or terminals - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary
    • Reconnect the BCM connectors. Make sure they seat and latch correctly.
    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, Refer to BCM Hardware Testing .
    No  The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
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