COOLING FAN SYSTEM Cooling Fan Circuit

DESCRIPTION

The ECM calculates an appropriate cooling fan speed based on the engine coolant temperature, air conditioning switch condition, refrigerant pressure, engine speed, and vehicle speed and sends the signals to the cooling fan ECUs to regulate the cooling fans. The cooling fan ECUs control each cooling fan speed based on the duty ratio signal sent from the ECM. By basing its control on the operating conditions, the ECM can control the fan speed optimally using the cooling fan ECUs, achieving both high cooling performance and quietness. The cooling fan speed is determined based on engine coolant temperature, air conditioner operating conditions, engine speed, and vehicle speed.

WIRING DIAGRAM

A015YQJE03

INSPECTION PROCEDURE

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE COOLING FAN)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Enter the following menus: Powertrain / Engine / Active Test / Control the Cooling Fan.

    4. Check the operation of the cooling fan while operating it using the intelligent tester.

      OK
      Tester Operation Fan Operation
      ON Cooling fan rotates
      OFF Cooling fan stopped
      Result
      Result Proceed to
      OK A
      NG (Main fan) B
      NG (Sub fan) C
      NG (Main and sub fans) D

    B

    INSPECT COOLING FAN SYSTEM (FOR MAIN FAN) Click here

    C

    INSPECT COOLING FAN SYSTEM (FOR SUB FAN) Click here

    D

    INSPECT COOLING FAN SYSTEM Click here

    A

    REPLACE ECM Click here

  2. INSPECT COOLING FAN SYSTEM (FOR MAIN FAN)


    1. Disconnect the ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the cooling fan.

      OK
      The cooling fan rotates.

    NG

    CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU (FOR MAIN FAN)) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU (FOR MAIN FAN))


    1. A0162SDE01

      Disconnect the cooling fan ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-19 (RFC) - B14-2 (SI) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COOLING FAN ECU (FOR MAIN FAN)

  4. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU (FOR MAIN FAN))


    1. A0162SDE01

      Disconnect the cooling fan ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-19 (RFC) or B14-2 (SI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT COOLING FAN MOTOR (FOR MAIN FAN)


    1. Inspect the cooling fan motor Click here.


    NG

    REPLACE COOLING FAN MOTOR (FOR MAIN FAN) Click here

    OK

  6. CHECK ECU POWER SOURCE CIRCUIT (FOR MAIN FAN)


    1. A0161TVE01

      Disconnect the cooling fan ECU connector.

    2. Turn the engine switch on (IG).

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B14-1 (+B1) - B14-3 (E1) Engine switch on (IG) 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - BODY GROUND) Click here

    OK

    REPLACE COOLING FAN ECU (FOR MAIN FAN)

  7. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - BODY GROUND)


    1. A0161TVE02

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      B14-3 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT FAN NO. 1 RELAY


    1. A01637T

      Remove the FAN No. 1 relay from the engine room No. 1 relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Normal 10 kΩ or higher
      3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω

    NG

    REPLACE FAN NO. 1 RELAY

    OK

  9. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - BATTERY)


    1. A015ZHYE01

      Remove the FAN No. 1 relay from the engine room No. 1 relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (FAN No.1 relay) - Body ground Always 11 to 14 V

    NG

    INSPECT FUSIBLE LINK BLOCK (FAN NO. 1 FUSE) Click here

    OK

  10. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - LH-IG FUSE)


    1. A015ZHYE01

      Remove the FAN No. 1 relay from the engine room No. 1 relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (FAN No.1 relay) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - BODY GROUND)


    1. A015ZHYE01

      Remove the FAN No. 1 relay from the engine room No. 1 relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (FAN No.1 relay) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - BODY GROUND)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - FAN NO. 1 RELAY)

  12. INSPECT FUSIBLE LINK BLOCK (FAN NO. 1 FUSE)


    1. A015ZLLE03

      Remove the fusible link block from the engine room No. 1 relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      1F-1 - 1F-2 Always Below 1 Ω

    NG

    REPLACE FUSIBLE LINK BLOCK

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - BATTERY)

  13. INSPECT COOLING FAN SYSTEM (FOR SUB FAN)


    1. Disconnect the ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the cooling fan.

      OK
      The cooling fan rotates.

    NG

    CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - ECM) Click here

    OK

  14. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - ECM)


    1. A0162SDE04

      Disconnect the cooling fan ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-19 (RFC) - z1-2 (SI2) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  15. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - ECM)


    1. A0162SDE05

      Disconnect the cooling fan ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-19 (RFC) or z1-2 (SI2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  16. INSPECT COOLING FAN MOTOR (FOR SUB FAN)


    1. Inspect the cooling fan motor Click here.


    NG

    REPLACE COOLING FAN MOTOR (FOR SUB FAN) Click here

    OK

  17. CHECK ECU POWER SOURCE CIRCUIT (FOR SUB FAN)


    1. A0161TVE05

      Disconnect the cooling fan ECU connector.

    2. Turn the engine switch on (IG).

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      z1-1 (+B2) - z1-3 (E2) Engine switch on (IG) 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - BODY GROUND) Click here

    OK

    REPLACE COOLING FAN ECU (FOR SUB FAN)

  18. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - BODY GROUND)


    1. A0162OJE17

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      z1-3 (E2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  19. INSPECT FAN NO. 2 RELAY


    1. A01637T

      Remove the FAN No. 2 relay from the engine room No. 1 relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Normal 10 kΩ or higher
      3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω

    NG

    REPLACE FAN NO. 2 RELAY

    OK

  20. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - BATTERY)


    1. A016117E01

      Remove the FAN No. 2 relay from the engine room No. 1 relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (FAN No. 2 relay) - Body ground Always 11 to 14 V

    NG

    INSPECT FUSIBLE LINK BLOCK (FAN NO. 2 FUSE) Click here

    OK

  21. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - LH-IG FUSE)


    1. A016117E01

      Remove the FAN No. 2 relay from the engine room No. 1 relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (FAN No. 2 relay) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  22. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)


    1. A016117E01

      Remove the FAN No. 2 relay from the engine room No. 1 relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (FAN No. 2 relay) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - FAN NO. 2 RELAY)

  23. INSPECT FUSIBLE LINK BLOCK (FAN NO. 2 FUSE)


    1. A015ZLLE03

      Remove the fusible link block from the engine room No. 1 relay block.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      FAN No. 2 fuse Always Below 1 Ω

    NG

    REPLACE FUSIBLE LINK BLOCK

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 2 RELAY - BATTERY)

  24. INSPECT COOLING FAN SYSTEM


    1. Disconnect the ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the cooling fan.

      OK
      The cooling fan rotates.

    NG

    CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU (FOR MAIN AND SUB FAN)) Click here

    OK

  25. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU (FOR MAIN AND SUB FAN))


    1. A0162SDE06

      Disconnect the cooling fan ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-19 (RFC) - B14-2 (SI) Always Below 1 Ω
      A5-19 (RFC) - z1-2 (SI2) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  26. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU (FOR MAIN AND SUB FAN))


    1. A0162SDE07

      Disconnect the cooling fan ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A5-19 (RFC), B14-2 (SI) or z1-2 (SI2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  27. INSPECT FUSE (LH-IG FUSE)


    1. A0161QYE01

      Remove the LH-IG fuse from the cowl side junction block LH.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      LH-IG fuse Always Below 1 Ω

    NG

    REPLACE FUSE (LH-IG FUSE)

    OK

  28. INSPECT MAIN BODY ECU LH (IG1 RELAY)


    1. A016287E01

      Disconnect the main body ECU LH (cowl side junction block LH) connectors.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      LL-6 - LM-1 Normal 10 kΩ or higher
      LL-6 - LM-1 Battery voltage applied between terminals LD-8 and LD-13 Below 1 Ω

    NG

    REPLACE MAIN BODY ECU LH (COWL SIDE JUNCTION BLOCK LH)

    OK

  29. CHECK HARNESS AND CONNECTOR (IG1 RELAY - FAN NO. 1 RELAY)


    1. A015ZHYE01

      Remove the FAN No. 1 relay from the engine room No. 1 relay block.

    2. A0162KQE01

      Disconnect the main body ECU LH (cowl side junction block LH) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      LL-6 - 1 (FAN No. 1 relay) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  30. CHECK HARNESS AND CONNECTOR (IG1 RELAY POWER SOURCE)


    1. A0160M6E02

      Disconnect the main body ECU (cowl side junction block LH) connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      LM-1 - Body ground Engine switch on (IG) 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - POWER SOURCE CONTROL ECU) Click here

    OK

  31. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - BODY GROUND)


    1. A0160POE01

      Disconnect the main body ECU LH (cowl side junction block LH) connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      LD-8 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU LH - BODY GROUND)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - MAIN BODY ECU LH)

  32. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - POWER SOURCE CONTROL ECU)


    1. A015ZXME01

      Disconnect the main body ECU LH (cowl side junction block LH) connector.

    2. Disconnect the power source control ECU connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      J55-34 (IG1D) - LD-13 (Main body ECU LH) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    GO TO ENTRY AND START SYSTEM Click here