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HOMESERVICE MANUALSFORD2014F-450 SUPER DUTY PLATINUM, 4WDREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMENGINE CONTROLS - PINPOINT TESTS (DIESEL)PINPOINT TEST AF: GLOW PLUG SYSTEMTEST PROCEDURE
2014 Ford F-450 Super Duty Platinum, 4WD

Test Procedure

2014 Ford F-450 Super Duty Platinum, 4WDSECTION Test Procedure
  1. AF1 PRELIMINARY DIAGNOSIS 
    • Clear the PCM DTCs.
    • Carry out the KOER Glow Plug Monitor self-test.

    Are any glow plug DTCs present? 

    Yes No
    GO to AF2  . Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary.
    RETURN to ENGINE CONTROLS - SYMPTOM CHARTS (DIESEL) (SECTION 3) , Symptom Charts for further direction.
  2. AF2 REPROGRAM THE GPCM OR UPDATE THE GPCM CALIBRATION 
    NOTE: Wait for 2 minutes before disconnecting any GPCM connectors.
    • Disconnect all the GPCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
      • damaged seals
    • Connect all the GPCM connectors and make sure they seat correctly.
    • Clear the PCM DTCs.
    • Carry out the KOER Glow Plug Monitor self-test.
    • If any glow plug DTCs are retrieved again, turn the ignition OFF and wait for 2 minutes.
    • Reprogram the GPCM or update the GPCM calibration.
    • Clear the PCM DTCs.
    • Carry out the KOER Glow Plug Monitor self-test.

    Are any glow plug DTCs retrieved again? 

    Yes No
    GO to AF3  . The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.
  3. AF3 CHECK THE SUSPECT GLOW PLUG RESISTANCE 
    NOTE: Use the component connector information to match the connector pins with the DTCs.
    • Ignition OFF.
    • Glow Plug connector disconnected.
    • Check for loose, damaged, or backed out terminals.
    • Measure the resistance between:
      (+) Glow Plug Connector, Component Side (-)
      Suspect Glow Plug Ground

    Is the resistance less than 2 ohms? 

    Yes No
    GO to AF4  . INSTALL a new Glow Plug. REFER to the Glow Plug System article.
    Carry out the KOER Glow Plug Monitor self-test.
    Clear the PCM DTCs. REPEAT the self-test.
  4. AF4 CHECK THE VBATT CIRCUIT FOR VOLTAGE 
    NOTE: Wait for 2 minutes before disconnecting any GPCM connectors.
    • GPCM-A connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-A Connector, Harness Side (-)
      VBATT - Pin 1 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to AF5  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  5. AF5 CHECK THE GLOW PLUG CIRCUIT FOR AN OPEN 
    NOTE: Wait for 2 minutes before disconnecting any GPCM connectors.
    • Ignition OFF.
    • GPCM-B connector disconnected.
    • Measure the resistance between:
      (+) GPCM-B Connector, Harness Side (-) Glow Plug Connector, Harness Side
      Suspect Glow Plug Suspect Glow Plug

    Is the resistance less than 5 ohms? 

    Yes No
    GO to AF6  . REPAIR the open circuit.
    Carry out the KOER Glow Plug Monitor self-test.
    Clear the PCM DTCs. REPEAT the self-test.
  6. AF6 CHECK THE GLOW PLUG CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) Glow Plug Connector, Harness Side (-)
      Suspect Glow Plug Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to AF7  . REPAIR the short circuit.
    Carry out the KOER Glow Plug Monitor self-test.
    Clear the PCM DTCs. REPEAT the self-test.
  7. AF7 CHECK THE GLOW PLUG CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Glow Plug Connector, Harness Side (-)
      Suspect Glow Plug Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit.
    Carry out the KOER Glow Plug Monitor self-test.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to AF8  .
  8. AF8 CHECK THE VPWR CIRCUIT FOR VOLTAGE 
    NOTE: Wait for 2 minutes before disconnecting any GPCM connectors.
    • Ignition OFF.
    • GPCM-C connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      VPWR - Pin 6 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to AF9  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  9. AF9 CHECK THE PWRGND CIRCUIT FOR AN OPEN 
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      PWRGND - Pin 5 Ground

    Is the resistance less than 5 ohms? 

    Yes No
    For DTC P138B, GO to  AF13.
    For all others, GO to AF10  .    		 REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  10. AF10 CHECK THE CAN2 CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • PCM-B connector disconnected.
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-) PCM-B Connector, Harness Side
      CAN2+ - Pin 3 CAN2+ - Pin 56
      CAN2- - Pin 4 CAN2- - Pin 39

    Are the resistances less than 5 ohms? 

    Yes No
    GO to AF11  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  11. AF11 CHECK THE CAN2 CIRCUITS FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      CAN2+ - Pin 3 Ground
      CAN2- - Pin 4 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to AF12  . REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  12. AF12 CHECK THE CAN2 CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      CAN2+ - Pin 3 Ground
      CAN2- - Pin 4 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to AF13  .
  13. AF13 CHECK FOR CORRECT GPCM OPERATION 
    NOTE: Wait for 2 minutes before disconnecting any GPCM connectors.
    • Disconnect all the GPCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the GPCM connectors and make sure they seat correctly.
    • Carry out the GPCM self-test and verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new GPCM. REFER to the Glow Plug System article.
    CLEAR the DTCs. REPEAT the self-test.    		 The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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  • • The engine overheats, stalls repeatedly, or misfires under load.
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