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Home >> Infiniti >> 2008 >> G35 Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Component Testing >> Cooling Fan >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK COOLING FAN CONTROL MODULE POWER SUPPLY CIRCUIT-I
    1. Turn ignition switch OFF.
    2. Disconnect cooling fan control module harness connector E37.
    3. Turn ignition switch ON.
    4. Check the voltage between cooling fan control module harness connector and ground.
      TERMINALS VOLTAGE REFERENCE

      Cooling fan control module Ground Voltage
      Connector Terminal
      E37 3 Ground Battery voltage

    Is the inspection result normal? 

    YES: GO TO 2.

    NO: GO TO  7.

  2. CHECK COOLING FAN CONTROL MODULE GROUND CIRCUIT
    1. Turn ignition switch OFF.
    2. Check the continuity between cooling fan control module harness connector and ground.
      TERMINALS CONTINUITY REFERENCE

      Cooling fan control module Ground Continuity
      Connector Terminal
      E37 1 Ground Existed
    3. Also check harness for short to power.

    Is the inspection result normal? 

    YES: GO TO 3.

    NO: Repair open circuit or short to power in harness or connectors.

  3. CHECK IPDM E/R GROUND CIRCUIT
    1. Disconnect IPDM E/R harness connectors E5, E6.
    2. Check the continuity between IPDM E/R harness connector and ground.
      TERMINALS CONTINUITY REFERENCE

      IPDM E/R Ground Continuity
      Connector Terminal
      E5 12 Ground Existed
      E6 41
    3. Also check harness for short to power.

    Is the inspection result normal? 

    YES: GO TO 4.

    NO: Repair open circuit or short to power in harness or connectors.

  4. CHECK COOLING FAN CONTROL SIGNAL CIRCUIT
    1. Disconnect IPDM E/R harness connector E9.
    2. Check the continuity between IPDM E/R harness connector and cooling fan control module harness connector.
      TERMINALS CONTINUITY REFERENCE

      IPDM E/R Cooling fan control module Continuity
      Connector Terminal Connector Terminal
      E9 97 E37 2 Existed
    3. Also check harness for short to ground and short to power.

    Is the inspection result normal? 

    YES: GO TO 5.

    NO: Repair open circuit or short to ground or short to power in harness or connectors.

  5. CHECK COOLING FAN CONTROL MODULE OUTPUT SIGNAL CIRCUIT
    1. Reconnect all harness connectors disconnected.
    2. Disconnect cooling fan control module harness connectors E301, E302.
    3. Turn ignition switch ON.
    4. Check the voltage between cooling fan control module harness connector and ground.
      TERMINALS VOLTAGE REFERENCE

      Cooling fan control module Ground Voltage
      Connector Terminal
      E301 4 Ground Battery voltage
      E302 6

    Is the inspection result normal? 

    YES: GO TO 6.

    NO: Replace cooling fan control module.

  6. CHECK COOLING FAN MOTORS -1 AND -2

    Refer to "COMPONENT INSPECTION (COOLING FAN MOTOR) ".

    Is the inspection result normal? 

    YES: GO TO  11.

    NO: Replace cooling fan motor.

  7. CHECK COOLING FAN CONTROL MODULE POWER SUPPLY CIRCUIT-II
    1. Turn ignition switch OFF.
    2. Disconnect cooling fan relay harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between cooling fan relay harness connector and ground.
      TERMINALS VOLTAGE REFERENCE

      Cooling fan relay Ground Voltage
      Connector Terminal
      E17 1 Ground Battery voltage
      3

    Is the inspection result normal? 

    YES: GO TO  9.

    NO: GO TO 8.

  8. DETECT MALFUNCTIONING PART

    Check the following.

    • 10A fuse (No. 42)
    • IPDM E/R harness connector E7
    • 50A fusible link (letter F)
    • Harness for open or short between cooling fan relay and fuse
    • Harness for open or short between cooling fan relay and battery

      Repair open circuit or short to ground or short to power in harness or connectors.

  9. CHECK COOLING FAN CONTROL MODULE POWER SUPPLY CIRCUIT-III
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector E6.
    3. Check the continuity between cooling fan relay harness connector and IPDM E/R harness connector.
      TERMINALS CONTINUITY REFERENCE

      Cooling fan relay IPDM E/R Continuity
      Connector Terminal Connector Terminal
      E17 2 E6 42 Existed
    4. Check the continuity between cooling fan relay harness connector and cooling fan control module harness connector.
      TERMINALS CONTINUITY REFERENCE

      Cooling fan relay Cooling fan control module Continuity
      Connector Terminal Connector Terminal
      E17 5 E37 3 Existed
    5. Also check harness for short to ground and short to power.

    Is the inspection result normal? 

    YES: GO TO 10.

    NO: Repair open circuit or short to ground or short to power in harness or connectors.

  10. CHECK COOLING FAN RELAY

    Refer to "COMPONENT INSPECTION (COOLING FAN RELAY) ".

    Is the inspection result normal? 

    YES: GO TO 11.

    NO: Replace cooling fan relay.

  11. CHECK INTERMITTENT INCIDENT

    Perform "INTERMITTENT INCIDENT ".

    Is the inspection result normal? 

    YES: Replace IPDM E/R.

    NO: Repair or replace harness connectors.

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