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Home >> Infiniti >> 2024 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (2 Of 2) >> Component /Circuit Diagnosis >> Electrically-Controlled Cooling Fan Coupling >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK DRIVE BELT 
    1. Turn ignition switch OFF.
    2. Check that the drive belt is not broken.

    Is inspection result normal?

    YES>>

    GO TO 2.

    NO>>

    Replace drive belt.

  2. CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING POWER SUPPLY 
    1. Disconnect electrically-controlled cooling fan coupling harness connector.
    2. Turn ignition switch ON.
    3. Check the voltage between electrically-controlled cooling fan coupling harness connector and ground.
      + - Voltage
      (Approx.)
      Electrically-controlled cooling fan coupling
      Connector Terminal
      F39 1 Ground Battery voltage

    Is inspection result normal?

    YES>>

    GO TO 3.

    NO>>

    Perform trouble diagnosis for power supply circuit.

  3. CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Check the continuity between electrically-controlled cooling fan coupling harness connector and ground.
      + - Continuity
      Electrically-controlled cooling fan coupling
      Connector Terminal
      F39 6 Ground Existed

    Is inspection result normal?

    YES>>

    GO TO 4.

    NO>>

    Repair or replace error-detected parts.

  4. CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING CONTROL SIGNAL 

    SYMBOL WITH CONSULT

    1. Start the engine.
    2. Perform "FAN DUTY CONTROL" in "ACTIVE TEST" mode of "ECM" with CONSULT.
    3. Set the Duty value to 100%.
    4. Check the voltage between electrically-controlled cooling fan coupling harness connector and ground.
      CAUTION:

      Wait for 1 minute or more to measure.

      + - Voltage
      (Approx.)
      Electrically-controlled cooling fan coupling
      Connector Terminal
      F39 3 Ground 5 V

    SYMBOL WITHOUT CONSULT

    1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98°C (209°F).
    2. Check the voltage between electrically-controlled cooling fan coupling harness connector and ground.
      CAUTION:

      Wait for 1 minute or more to measure.

      + - Voltage
      (Approx.)
      Electrically-controlled cooling fan coupling
      Connector Terminal
      F39 3 Ground 5 V

    Is the inspection result normal?

    YES>>

    GO TO 7.

    NO>>

    GO TO 5.

  5. CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING CONTROL CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector.
    3. Check the continuity between electrically-controlled cooling fan coupling harness connector and IPDM E/R harness connector.
      + - Continuity
      Electrically-controlled cooling fan coupling IPDM E/R
      Connector Terminal Connector Terminal
      F39 3 E17 72 Existed
    4. Also check harness for short to power.

    Is the inspection result normal?

    YES>>

    GO TO 6.

    NO>>

    Repair or replace error-detected parts.

  6. CHECK CAN COMMUNICATION 

    Refer to Trouble Diagnosis Flow Chart .Is inspection result normal?

    YES>>

    Check intermittent incident. Refer to Inspection .

    NO>>

    Repair or Replace error-detected parts.

  7. CHECK COOLING FAN SPEED SENSOR 

    Refer to DTC Diagnosis Procedure .Is inspection result normal?

    YES>>

    Replace electrically-controlled cooling fan coupling. Refer to ENGINE COOLING FAN : Exploded View .

    NO>>

    Repair or replace error-detected parts.

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