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Test Procedure

  1. AF1 PRELIMINARY DIAGNOSIS 
    • For F-150, F-650/F-750 and F-Series Super Duty,
    • Clear the PCM DTCs.
    • Carry out the PCM self-test.
    • For all others,
    • Clear the PCM DTCs.
    • Carry out the KOER Glow Plug Monitor self-test.

    Are DTCs P0384, P052F, P064C, P066A, P066B, P066C, P066D, P066E, P066F, P0671, P0672, P0673, P0674, P0675, P0676, P0677, P0678, P067A, P067B, P067C, P067D, P067E, P067F, P068C, P068D, P068E, P068F, P06B9, P06BA, P06BB, P06BC, P06BD, P06BE, P06BF, P06C0, P06E5, P138B, P263C, P263E, U0074 or U0106 present? 

    Yes No
    For DTCs U0074 or U0106, GO to  AF10.
    For DTCs P06DF or P06E5, GO to  AF13.
    For all others, GO to  AF2.    		 For symptoms without DTCs, GO to  AF2.
    For all others, RETURN to SYMPTOM CHARTS for further direction.
  2. AF2 REPROGRAM THE GPCM OR UPDATE THE GPCM CALIBRATION 
    NOTE: Wait for 2 minutes before disconnecting the GPCM connectors.
    • Ignition OFF.
    • For F-150, F-650/F-750 and F-Series Super Duty,
    • Disconnect all the GPCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
      • damaged seals
    • Connect all the GPCM connectors.
    • Make sure the GPCM connectors are seated correctly.
    • Ignition ON, engine OFF.
    • Clear the PCM DTCs.
    • Carry out the PCM 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. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .
    • Clear the PCM DTCs.
    • Carry out the PCM self-test.
    • For all others,
    • GPCM-A connector disconnected.
    • GPCM-B connector disconnected.
    • GPCM-C connector disconnected.
    • Visually inspect for:
      • pushed out pins
      • corrosion
      • damaged seals
    • GPCM-A connector connected.
    • GPCM-B connector connected.
    • GPCM-C connector connected.
    • Make sure the GPCM connectors are seated correctly.
    • Ignition ON, engine OFF.
    • 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. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .
    • Clear the PCM DTCs.
    • Carry out the KOER Glow Plug Monitor self-test.

    Are any glow plug DTCs retrieved again? 

    Yes No
    For DTCs P064C and P263E, GO to  AF13.
    For DTCs P138B and P263C, GO to  AF4.
    For all others, 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. For F-150, F-650/F-750 and F-Series Super Duty, INSTALL a new Glow Plug.
      REFER to the appropriate Glow Plug System article.
      Clear the PCM DTCs. REPEAT the self-test.
      For all others, INSTALL a new Glow Plug.
      REFER to the appropriate Glow Plug System article. Carry out the KOER Glow Plug Monitor self-test.
      Clear the PCM DTCs. REPEAT the self-test.
    • AF4 CHECK THE VBATT CIRCUIT FOR VOLTAGE 
      NOTE: Wait for 2 minutes before disconnecting the GPCM connectors.
      • Ignition OFF.
      • For Transit Connect,
      • GPCM-B connector disconnected.
      • Ignition ON, engine OFF.
      • Measure the voltage between:
        (+) GPCM-B Connector, Harness Side (-)
        VBATT - Pin 2, 4 Ground
      • For all others,
      • GPCM-A connector disconnected.
      • Ignition ON, engine OFF.
      • Measure the voltage between:
        (+) GPCM-A Connector, Harness Side (-)
        VBATT Ground

      Is the voltage greater than 10.5 V? 

      Yes No
      For DTCs P138B and P263C, GO to  AF8.
      For all others, GO to  AF5.      		 REPAIR the open circuit. Clear the PCM DTCs.
      REPEAT the self-test.
    • AF5 CHECK THE GLOW PLUG CIRCUIT FOR AN OPEN 
      NOTE: Wait for 2 minutes before disconnecting the GPCM connectors.
      NOTE: The F-150 only has 6 glow plugs. The Transit Connect only has 4 glow plugs. Only the suspect glow plug needs to be diagnosed.
      • Ignition OFF.
      • For Transit Connect,
      • GPCM-A connector disconnected.
      • Measure the resistance between:
        (+) GPCM-A Connector, Harness Side (-) Glow Plug Connector, Harness Side
        Glow Plug Number 1 Suspect Glow Plug
        Glow Plug Number 2 Suspect Glow Plug
        Glow Plug Number 3 Suspect Glow Plug
        Glow Plug Number 4 Suspect Glow Plug
      • For all others,
      • GPCM-B connector disconnected.
      • Measure the resistance between:
        (+) GPCM-B Connector, Harness Side (-) Glow Plug Connector, Harness Side
        Glow Plug Number 1 Suspect Glow Plug
        Glow Plug Number 2 Suspect Glow Plug
        Glow Plug Number 3 Suspect Glow Plug
        Glow Plug Number 4 Suspect Glow Plug
        Glow Plug Number 5 Suspect Glow Plug
        Glow Plug Number 6 Suspect Glow Plug
        Glow Plug Number 7 Suspect Glow Plug
        Glow Plug Number 8 Suspect Glow Plug

      Are the resistances less than 5 ohms? 

      Yes No
      GO to  AF6. For F-150, F-650/F-750 and F-Series Super
      Duty, REPAIR the open circuit.
      Clear the PCM DTCs. REPEAT the self-test.
      For all others, REPAIR the open circuit.
      Carry out the KOER Glow Plug Monitor self-test.
      Clear the PCM DTCs. REPEAT the self-test.
    • AF6 CHECK THE GLOW PLUG CIRCUIT FOR A SHORT TO GROUND 
      NOTE: The F-150 only has 6 glow plugs. The Transit Connect only has 4 glow plugs. Only the suspect glow plug needs to be diagnosed.
      • For Transit Connect,
      • Measure the resistance between:
        (+) GPCM-A Connector, Harness Side (-)
        Glow Plug Number 1 Ground
        Glow Plug Number 2 Ground
        Glow Plug Number 3 Ground
        Glow Plug Number 4 Ground
      • For all others,
      • Measure the resistance between:
        (+) GPCM-B Connector, Harness Side (-)
        Glow Plug Number 1 Ground
        Glow Plug Number 2 Ground
        Glow Plug Number 3 Ground
        Glow Plug Number 4 Ground
        Glow Plug Number 5 Ground
        Glow Plug Number 6 Ground
        Glow Plug Number 7 Ground
        Glow Plug Number 8 Ground

      Are the resistances greater than 10K ohms? 

      Yes No
      GO to  AF7. For F-150, F-650/F-750 and F-Series Super Duty, REPAIR the short circuit.
      Clear the PCM DTCs. REPEAT the self-test.
      For all others, REPAIR the short circuit.
      Carry out the KOER Glow Plug Monitor self-test.
      Clear the PCM DTCs. REPEAT the self-test.
    • AF7 CHECK THE GLOW PLUG CIRCUIT FOR A SHORT TO VOLTAGE 
      NOTE: The F-150 only has 6 glow plugs. The Transit Connect only has 4 glow plugs. Only the suspect glow plug needs to be diagnosed.
      • Ignition ON, engine OFF.
      • For Transit Connect,
      • Measure the voltage between:
        (+) GPCM-A Connector, Harness Side (-)
        Glow Plug Number 1 Ground
        Glow Plug Number 2 Ground
        Glow Plug Number 3 Ground
        Glow Plug Number 4 Ground
      • For all others,
      • Measure the voltage between:
        (+) GPCM-B Connector, Harness Side (-)
        Glow Plug Number 1 Ground
        Glow Plug Number 2 Ground
        Glow Plug Number 3 Ground
        Glow Plug Number 4 Ground
        Glow Plug Number 5 Ground
        Glow Plug Number 6 Ground
        Glow Plug Number 7 Ground
        Glow Plug Number 8 Ground

      Is any voltage present? 

      Yes No
      For F-150, F-650/F-750 and F-Series Super Duty, REPAIR the short circuit.
      Clear the PCM DTCs. REPEAT the self-test.
      For all others, REPAIR the short circuit.
      Carry out the KOER Glow Plug Monitor self-test.
      Clear the PCM DTCs. REPEAT the self-test.      		 GO to  AF8.
    • AF8 CHECK THE CIRCUIT FOR VOLTAGE 
      NOTE: Wait for 2 minutes before disconnecting the GPCM connectors.
      • Ignition OFF.
      • For F-650/F-750 and F-Series Super Duty,
      • GPCM-B connector disconnected.
      • Ignition ON, engine OFF.
      • Measure the voltage between:
        (+) GPCM-B Connector, Harness Side (-)
        VPWR Ground
        ISP-R Ground
    • For Transit Connect,
    • GPCM-C connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      VPWR - Pin 8 Ground
      ISP-R - Pin 10 Ground
    • For all others,
    • GPCM-C connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      VPWR - Pin 8 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.
  4. AF9 CHECK THE PWRGND CIRCUIT FOR AN OPEN 
    • Ignition OFF.
    • For F-650/F-750 and F-Series Super Duty,
    • Measure the resistance between:
      (+) GPCM-B Connector, Harness Side (-)
      PWRGND Ground
    • For Transit Connect,
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      PWRGND - Pin 9 Ground
    • For all others,
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      PWRGND - Pin 9 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.
  5. AF10 CHECK THE CAN2 CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • For F-650/F-750 and F-Series Super Duty,
    • GPCM-B connector disconnected.
    • PCM-B connector disconnected.
    • Measure the resistance between:
      (+) GPCM-B Connector, Harness Side (-) PCM-B Connector, Harness Side
      CAN2+ CAN2+
      CAN2- CAN2-
    • For all others,
    • GPCM-C connector disconnected.
    • PCM-B connector disconnected.
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-) PCM-B Connector, Harness Side
      CAN2+ - Pin 2 CAN2+
      CAN2- - Pin 3 CAN2-

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  AF11. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  6. AF11 CHECK THE CAN2 CIRCUITS FOR A SHORT TO GROUND 
    • NOx11 Module connector disconnected.
    • NOx12 Module connector disconnected.
    • PM11 Module connector disconnected.
    • Reductant Dosage Control Module connector disconnected.
    • Reductant Quality Module connector disconnected.
    • TCM connector disconnected.
    • For F-650/F-750 and F-Series Super Duty,
    • Measure the resistance between:
      (+) GPCM-B Connector, Harness Side (-)
      CAN2+ Ground
      CAN2- Ground
    • For all others,
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      CAN2+ - Pin 2 Ground
      CAN2- - Pin 3 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.
  7. AF12 CHECK THE CAN2 CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • For F-650/F-750 and F-Series Super Duty,
    • Measure the voltage between:
      (+) GPCM-B Connector, Harness Side (-)
      CAN2+ Ground
      CAN2- Ground
    • For all others,
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      CAN2+ - Pin 2 Ground
      CAN2- - Pin 3 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  AF13.
  8. AF13 CHECK FOR CORRECT GPCM OPERATION 
    NOTE: Wait for 2 minutes before disconnecting the GPCM connectors.
    • Ignition OFF.
    • Disconnect all the GPCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the GPCM connectors and make sure they seat correctly.
    • NOx11 Module connector connected.
    • NOx12 Module connector connected.
    • PM11 Module connector connected.
    • Reductant Dosage Control Module connector connected.
    • Reductant Quality Module connector connected.
    • TCM connector connected.
    • For F-150, F-650/F-750 and F-Series Super Duty,
    • Carry out the PCM self-test and verify the concern is still present.
    • For all others,
    • Carry out the GPCM self-test and verify the concern is still present.

    Is the concern still present? 

    Yes No
    For F-150, INSTALL a new GPCM.
    REFER to the appropriate Glow Plug System article.
    Clear the PCM DTCs. REPEAT the self-test.
    For all others, INSTALL a new GPCM.
    REFER to the appropriate Glow Plug System article. CLEAR the GPCM and PCM 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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