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Test Procedure

  1. AH1 PRELIMINARY DIAGNOSIS 

    Are DTCs P0480, P0483, P0494, P0495, P0528, P0529, P0691, P0692, P0693, or P0694 present? 

    Yes No
    F-150, F-650/F-750 and F-Series Super Duty with DTCs P0483, P0494, P0495, P0528 or P0529, GO to  AH2.
    For all others, GO to  AH11.    		 For F-150, F-650/F-750 and F-Series Super Duty symptoms without DTCs, GO to  AH2.
    For all others, RETURN to SYMPTOM CHARTS for further direction.
  2. AH2 CHECK THE FAN SPEED SENSOR FOR VOLTAGE 
    • Ignition OFF.
    • Cooling Fan connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Cooling Fan Connector, Harness Side (-) Cooling Fan Connector, Harness Side
    VBPWR - Pin 3 SIGRTN - Pin 5

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  AH7. GO to  AH3.
  3. AH3 CHECK THE VBPWR CIRCUIT FOR VOLTAGE 
    • Measure the voltage between:
    (+) Cooling Fan Connector, Harness Side (-)
    VBPWR - Pin 3 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  AH6. GO to  AH4.
  4. AH4 CHECK THE VBPWR CIRCUIT FOR AN OPEN 
    • Ignition OFF.
    • PCM-B connector disconnected.
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-) PCM-B Connector, Harness Side
    VBPWR - Pin 3 VBPWR - Pin 38

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  AH5. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  5. AH5 CHECK THE VBPWR CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-)
    VBPWR - Pin 3 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    For DTC P0494 or cooling fan always on, GO to  AH17.
    For DTC P0495 or cooling fan does not run, GO to  AH18.
    For all others, GO to PINPOINT TEST ZZ .    		 REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  6. AH6 CHECK THE GND AND SIGRTN CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-)
    SIGRTN - Pin 5 Ground

    Is the resistance less than 5 ohms? 

    Yes No
    For DTC P0494 or cooling fan always on, GO to  AH17.
    For DTC P0495 or cooling fan does not run, GO to  AH18.
    For all others, GO to PINPOINT TEST ZZ .    		 REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  7. AH7 CHECK THE FAN SPEED SENSOR SIGNAL AND SIGRTN CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • PCM-B connector disconnected.
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-) PCM-B Connector, Harness Side
    FSS - Pin 4 FSS - Pin 37
    SIGRTN - Pin 5 SIGRTN - Pin 70

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  AH8. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  8. AH8 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-)
    FSS - Pin 4 Ground
    SIGRTN - Pin 5 Ground

    Are the resistances greater than 10 ohms? 

    Yes No
    GO to  AH9. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  9. AH9 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Cooling Fan Connector, Harness Side (-)
    FSS - Pin 4 Ground
    SIGRTN - Pin 5 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  AH10.
  10. AH10 CHECK THE SIGNAL CIRCUIT FOR VOLTAGE 
    • Ignition OFF.
    • PCM-B connector connected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Cooling Fan Connector, Harness Side (-)
    FSS - Pin 4 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    For DTC P0494 or cooling fan always on, GO to  AH17.
    For DTC P0495 or cooling fan does not run. GO to  AH18.
    For all others, GO to PINPOINT TEST ZZ .    		 GO to  AH19.
  11. AH11 CHECK THE VPWR CIRCUIT FOR VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Cooling Fan Connector, Harness Side (-)
    VPWR - Pin 1 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  AH12. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  12. AH12 CHECK THE FCV CIRCUIT FOR AN OPEN CIRCUIT 
    • Ignition OFF.
    • PCM-B connector disconnected.
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-) PCM-B Connector, Harness Side
    FCV - Pin 6 FCV - Pin 80

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  AH13. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  13. AH13 CHECK THE FCV CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Cooling Fan Connector, Harness Side (-)
    FCV - Pin 6 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  AH14. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  14. AH14 CHECK THE FCV CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Cooling Fan Connector, Harness Side (-)
    FCV - Pin 6 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  AH15.
  15. AH15 CHECK THE COOLING FAN RESISTANCE 
    • Ignition OFF.
    • Cooling Fan connector disconnected.
    • Measure the resistance between:
    (+) Cooling Fan Connector, Component Side (-) Cooling Fan Connector, Component Side
    VPWR - Pin 1 FCV - Pin 6

    Is the resistance between 9 - 14 ohms? 

    Yes No
    GO to  AH16. INSTALL a new Cooling Fan. REFER to the appropriate Engine Cooling, Cooling Fan article.
    Clear the PCM DTCs. REPEAT the self-test.
  16. AH16 CHECK THE FCV CIRCUIT FOR AN INTERNAL SHORT TO GROUND 
    • Measure the resistance between:
    (+) Cooling Fan Connector, Component Side (-)
    FCV - Pin 6 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to PINPOINT TEST ZZ . INSTALL a new Cooling Fan. REFER to the appropriate Engine Cooling, Cooling Fan article.
    Clear the PCM DTCs. REPEAT the self-test.
  17. AH17 CHECK THE COOLING FAN OPERATION 
    • Ignition ON, engine running.
    • Access the PCM and monitor the FANSS (RPM) and RPM (RPM) PIDs.
    • Engine at normal operating temperature.
    • Access the PCM and control the (RPM) PID.
    • Increase and maintain the engine speed to 2, 500 RPM.
    • Access the PCM and control the FANDC (PER) PID.
    • Command the cooling fan duty cycle to 0%.
    • Allow the fan speed to stabilize below 600 RPM.

    Does the fan speed stabilize less than 600 RPMs before two minutes? 

    Yes No
    The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.
    Clear the PCM DTCs. REPEAT the self-test.    		 INSTALL a new Cooling Fan Clutch. REFER to the appropriate Engine Cooling, Cooling Fan article.
    Clear the PCM DTCs. REPEAT the self-test.
  18. AH18 CHECK COOLING FAN OPERATION 
    • Ignition ON, engine running.
    • Access the PCM and monitor the FANSS (RPM) and RPM (RPM) PIDs.
    • Engine at normal operating temperature.
    • Access the PCM and control the (RPM) PID.
    • Increase and maintain the engine speed to 2, 500 RPM.
    • Access the PCM and control the FANDC (PER) PID.
    • Command the cooling fan duty cycle to 70%.
    • Allow the fan speed to stabilize above 2, 800 RPM.

    Is the fan speed greater than 2, 800 RPMs and less than 3, 600 RPMs within 30 seconds? 

    Yes No
    The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.
    Clear the PCM DTCs. REPEAT the self-test.    		 INSTALL a new Cooling Fan Clutch. REFER to the appropriate Engine Cooling, Cooling Fan article.
    Clear the PCM DTCs. REPEAT the self-test.
  19. AH19 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM.
    REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .    		 The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.
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