LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2000 >> Taurus LX, 3.0 2, AX4N >> Repair and Diagnosis >> External Pages >> Different car >> Section 204 (Engine Controls - Pinpoint Tests - 6.0L Diesel (99P F450/550)) >> Pinpoint Test AH: Visctronic Drive Fan (VDF) >> Test Procedure

Test Procedure

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2005 Ford RV Cutaway, 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
  1. AH1 PRELIMINARY DIAGNOSIS 
    • Key OFF.
    • Record the freeze frame data.
    • Carry out the PCM self-test.

    Are any DTCs present? 

    Yes No
    For DTC P0480, GO to  AH4.
    For DTC P0528, GO to  AH3.
    For all other DTCs, REFER to DIAGNOSTIC TROUBLE CODE (DTC) DESCRIPTIONS .    		 GO to  AH2.
  2. AH2 CHECK THE COOLING FAN FOR MECHANICAL BINDING 
    NOTE: The VDF is a viscous coupling. The viscous drag should be smooth during fan rotation. The amount of resistance is dependent upon the final VDF operational state before engine shutdown.
    • Key OFF.
    • Manually rotate the cooling fan.

    Does the fan clutch rotation feel rough or binding? 

    Yes No
    INSTALL a new VDF. REFER to ENGINE COOLING . GO to  AH3.
  3. AH3 CHECK THE VDF OPERATION 
    NOTE: Check and verify the most current PCM calibration level.
    NOTE: Inherent to viscous clutches is a delay in transitioning from a low to a high speed or from a high to a low speed. This delay can vary between 10 seconds and 3 minutes and is dependent upon engine speed and clutch temperature. With the engine at operating temperature and at 2,500 RPM, the delay should be less than 30 seconds.
    • Key ON, engine running.
    • Access Output State Control.
    • Access the FANSS and RPM PIDs.
    • Increase the engine speed to 2,500 RPM.
    • Monitor the FANSS PID and the VDF duty cycle.
    • Command the VDF to LOW.
    • Allow the fan speed to stabilize below 600 RPM.
    • Command the VDF duty cycle to HIGH.

    Does the fan speed change and does the FANSS PID indicate an RPM change? 

    Yes No
    If the FANSS PID stabilizes at less than 2,800 RPM with the engine speed at 2,500 RPM, INSTALL a new VDF. REFER to ENGINE COOLING . CLEAR the DTCs. REPEAT the self-test.
    If the FANSS PID stabilizes at greater than 2,800 RPM with the engine speed at 2,500 RPM, the system is operating correctly. CLEAR the DTCs. REPEAT the self-test.
    For cooling system concerns, REFER to ENGINE COOLING for diagnosis and testing. CLEAR the DTCs. REPEAT the self-test.    		 If the fan speed did not change, GO to  AH4.
    If the fan speed did change and the FANSS PID did not indicate an RPM change, GO to  AH12.
  4. AH4 CHECK THE VDF SOLENOID RESISTANCE 
    • Key OFF.
    • Disconnect the VDF.
    • Measure the resistance between the VDF solenoid VPWR circuit pin 5, component side and the VDF solenoid control circuit pin 4, component side.

    Is the resistance between 6.0 and 10.0 ohms? 

    Yes No
    GO to  AH5. INSTALL a new VDF. CLEAR the DTCs.
    REPEAT the self-test.
  5. AH5 CHECK THE VDF SOLENOID FOR A SHORT TO GROUND 
    • Measure the resistance between the VDF solenoid control circuit pin 4, component side and ground.

    Is the resistance greater than 10,000 ohms? 

    Yes No
    GO to  AH6. INSTALL a new VDF. REFER to ENGINE COOLING . CLEAR the DTCs. REPEAT the self-test.
  6. AH6 CHECK THE VDF SOLENOID VPWR CIRCUIT FOR VOLTAGE 
    • Key ON, engine OFF.
    • Measure the voltage between the VDF solenoid VPWR circuit pin 5, harness side and ground.

    Is the voltage greater than 10.5 volts? 

    Yes No
    GO to  AH7. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  7. AH7 CHECK VDF SOLENOID CONTROL CIRCUIT FOR AN OPEN 
    • Key OFF.
    • Disconnect the PCM.
    • Measure the resistance between the VDF solenoid control circuit pin 4, harness side and the PCM engine connector pin 14, harness side.

      Is the resistance less than 5 ohms? 

      Yes No
      GO to  AH8. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  8. AH8 CHECK THE VDF SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between the VDF solenoid control circuit pin 4, harness side and ground.

    Is the resistance greater than 10,000 ohms? 

    Yes No
    GO to  AH9. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  9. AH9 CHECK THE VDF CONTROL CIRCUIT FOR A SHORT TO POWER 
    • Key ON, engine OFF.
    • Measure the voltage between the VDF solenoid control circuit pin 4, harness side and ground.

    Is any voltage indicated? 

    Yes No
    REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. INSTALL a new PCM. CLEAR the DTCs. REPEAT the self-test.
  10. AH12 CHECK THE FAN SPEED SENSOR FOR VOLTAGE 
    • Key OFF.
    • Disconnect the VDF.
    • Key ON, engine OFF.
    • Measure the voltage between the fan speed sensor VREF circuit pin 6, harness side and the fan speed sensor SIGRTN circuit pin 2, harness side.

    Is the voltage greater than 10.5 volts? 

    Yes No
    GO to  AH17. GO to  AH13.
  11. AH13 CHECK THE VREF CIRCUIT FOR VOLTAGE 
    • Measure the voltage between the fan speed sensor VREF circuit pin 6, harness side and ground.

    Is the voltage greater than 10.5 volts? 

    Yes No
    GO to  AH16. GO to  AH14.
  12. AH14 CHECK THE VREF CIRCUIT FOR AN OPEN 
    • Key OFF
    • Disconnect the PCM.
    • Measure the resistance between the fan speed sensor VREF circuit pin 6, harness side and the PCM engine connector pin 46, harness side.

    Is resistance less than 5 ohms? 

    Yes No
    GO to  AH15. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  13. AH15 CHECK THE VREF CIRCUIT FOR A SHORT TO GROUND 
    • Key OFF
    • Disconnect the PCM.
    • Measure the resistance between the fan speed sensor VREF circuit pin 6, harness side and ground.

    Is the resistance greater than 10,000 ohms? 

    Yes No
    INSTALL a new PCM. CLEAR the DTCs. REPEAT the self-test. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  14. AH16 CHECK THE FAN SPEED SENSOR SIGRTN CIRCUIT FOR AN OPEN 
    • Key OFF.
    • Disconnect the PCM.
    • Measure the resistance between the fan speed sensor SIGRTN circuit pin 2, harness side and the PCM engine connector pin 22, harness side.

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. CLEAR the DTCs. REPEAT the self-test. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  15. AH17 CHECK THE FAN SPEED SENSOR SIGNAL CIRCUIT FOR AN OPEN 
    • Key OFF.
    • Disconnect the PCM.
    • Measure the resistance between the fan speed sensor signal circuit pin 1, harness side and the PCM engine connector pin 6, harness side.

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  AH18. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  16. AH18 CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between the fan speed sensor signal circuit pin 1, harness side and ground.

    Is the resistance greater than 10,000 ohms? 

    Yes No
    GO to  AH19. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
  17. AH19 CHECK THE SIGNAL CIRCUIT FOR A SHORT VOLTAGE 
    • Key ON, engine OFF.
    • Measure the voltage between the fan speed sensor signal circuit pin 1, harness side and ground.

    Is any voltage indicated? 

    Yes No
    REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. GO to  AH20.
  18. AH20 CHECK THE SIGNAL CIRCUIT FOR VOLTAGE 
    • Key OFF.
    • Connect the PCM.
    • Key ON, engine OFF.
    • Measure the voltage between the fan speed sensor signal circuit pin 1, harness side and ground.

    Is the voltage greater than 10 volts? 

    Yes No
    INSTALL a new VDF. REFER to ENGINE COOLING . CLEAR the DTCs. REPEAT the self-test. INSTALL a new PCM. CLEAR the DTCs. REPEAT the self-test.
scientia non olet · About LEMON Manuals