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Test Procedure

WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
  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
    For DTC P263C, GO to  AF2.
    For all others, GO to  AF3.    		 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. REFER to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX , if a driveability concern exists.
  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
    • 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 DTC P263C is 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.

    Is DTC P263C present? 

    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 between 0 Ohm - 2 ohms? 

    Yes No
    GO to  AF4. 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.
  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 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 indicated? 

    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 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 indicated? 

    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 appropriate 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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