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 ECU to regulate the cooling fans. The cooling fan ECU controls the 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 ECU, achieving both high cooling performance and quietness.

WIRING DIAGRAM

Refer to the System Diagram.

Click here

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • Make sure to perform the necessary procedures (adjustment, calibration, initialization, or registration) after parts related to the cooling fan system have been removed/installed or replaced.

    Click here

PROCEDURE


  1. CHECK VEHICLE


    1. Check the cooling fan motor type.

      Result
      Result Proceed to
      for Cooling Fan Motor 160 W + 160 W Type or 200 W + 200 W Type A
      for Cooling Fan Motor 240 W + 240 W Type B

    B

    PERFORM ACTIVE TEST USING GTS (CONTROL THE ENGINE COOLING FAN DUTY RATIO) Click here

    A

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE ENGINE COOLING FAN DUTY RATIO)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Active Test / Control the Engine Cooling Fan Duty Ratio.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Engine Cooling Fan Duty Ratio

    5. Check the operation of the cooling fan while operating it using the GTS.

      OK
      GTS Operation Fan Operation
      30 - 100% Cooling fan operates
      0% Cooling fan stops
      Result
      Result Proceed to
      OK A
      Cooling fan does not operate B
      Cooling fan does not stop C

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

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

    B

  3. CHECK COOLING FAN SYSTEM (FAN)


    1. Disconnect the F103 ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the cooling fan.

      OK
      The cooling fan operates.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

  4. INSPECT COOLING FAN MOTOR (COOLING FAN MOTOR AND NO. 2 COOLING FAN MOTOR)


    1. Inspect the cooling fan motor and No. 2 cooling fan motor.

      Click here

      Result
      Result Proceed to
      OK A
      NG (Cooling fan motor) B
      NG (No. 2 cooling fan motor) C

    B

    REPLACE COOLING FAN MOTOR Click here

    C

    REPLACE NO. 2 COOLING FAN MOTOR Click here

    A

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

    B003UCZC06
    *a

    Front view of wire harness connector

    (to Cooling Fan ECU)

    1. Disconnect the A42 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 Condition Specified Condition
      A42-3 (+B1) - A42-1 (E1) Engine switch on (IG) 11 to 14 V
      Result
      Result
      OK
      NG

    NG

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

    OK

  6. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - ECM)


    1. Disconnect the F103 ECM connector.

    2. Disconnect the A42 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A42-2 (SI) or F103-136 (RFC) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    OK

    REPLACE COOLING FAN ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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


    1. Disconnect the A42 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A42-1 (E1) - Body ground Always Below 1 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT FAN RELAY


    1. Inspect the FAN relay.

      Click here

      Result
      Result
      OK
      NG

    NG

    REPLACE FAN RELAY

    OK

  9. CHECK HARNESS AND CONNECTOR (FAN RELAY POWER SOURCE CIRCUIT)

    B003WSHC01
    *1 No. 2 engine room relay block and No. 2 junction block assembly
    *2 FAN Relay

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (FAN relay) - Body ground Always 11 to 14 V
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FAN RELAY)

    OK

  10. CHECK HARNESS AND CONNECTOR (FAN RELAY POWER SOURCE CIRCUIT)

    B003WSHC01
    *1 No. 2 engine room relay block and No. 2 junction block assembly
    *2 FAN Relay

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

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (FAN relay) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 NO. 3 RELAY - FAN RELAY)

    OK

  11. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - FAN RELAY)


    1. Disconnect the A42 cooling fan ECU connector.

    2. Remove the FAN relay from the No. 2 engine room relay block and No. 2 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A42-3 (+B1) - 5 (FAN relay) Always Below 1 Ω
      A42-3 (+B1) or 5 (FAN relay) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - BODY GROUND)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  12. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)


    1. Disconnect the F103 ECM connector.

    2. Disconnect the A42 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F103-136 (RFC) - A42-2 (SI) Always Below 1 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - BODY GROUND)

    B003WG6C13
    *a

    Component without harness connected

    (Cooling fan motor)

    1. Disconnect the z10 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z10-1 (M-) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    NG

    REPLACE COOLING FAN MOTOR Click here

    OK

  14. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - BODY GROUND)

    B003WERC09
    *a

    Component without harness connected

    (No. 2 cooling fan motor)

    1. Disconnect the z9 No. 2 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z9-1 (M-) - Body ground Always 10 kΩ or higher
      Result
      Result
      OK
      NG

    OK

    REPLACE COOLING FAN ECU

    NG

    REPLACE NO. 2 COOLING FAN MOTOR Click here

  15. PERFORM ACTIVE TEST USING GTS (CONTROL THE ENGINE COOLING FAN DUTY RATIO)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Active Test / Control the Engine Cooling Fan Duty Ratio.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Engine Cooling Fan Duty Ratio

    5. Check the operation of the cooling fan while operating it using the GTS.

      OK
      GTS Operation Fan Operation
      30 - 100% Cooling fan operates
      0% Cooling fan stops
      Result
      Result Proceed to
      OK A
      NG (Fan does not operate) B
      NG (No. 2 fan does not operate) C
      NG (Fan does not stop) D
      NG (No. 2 fan does not stop) E

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    CHECK COOLING FAN SYSTEM (NO. 2 FAN) Click here

    D

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

    E

    CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - ECM) Click here

    B

  16. CHECK COOLING FAN SYSTEM (FAN)


    1. Disconnect the F103 ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the cooling fan.

      OK
      The cooling fan operates.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

  17. INSPECT COOLING FAN MOTOR


    1. Inspect the cooling fan motor.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE COOLING FAN MOTOR Click here

    OK

  18. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU POWER SOURCE CIRCUIT)

    B003U8VC51
    *a

    Front view of wire harness connector

    (to Cooling Fan ECU )

    1. Disconnect the A87 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 Condition Specified Condition
      A87-1 (+B1) - A87-3 (E1) Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  19. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU AND NO. 2 COOLING FAN ECU - ECM)


    1. Disconnect the F103 ECM connector.

    2. Disconnect the A87 cooling fan ECU connector.

    3. Disconnect the f1 No. 2 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A87-2 (SI), f1-2 (SI) or F103-136 (RFC) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COOLING FAN ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  20. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - BODY GROUND)


    1. Disconnect the A87 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A87-3 (E1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  21. INSPECT FAN RELAY


    1. Inspect the FAN relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FAN RELAY

    OK

  22. CHECK HARNESS AND CONNECTOR (FAN RELAY POWER SOURCE CIRCUIT)

    B003WSHC03
    *1 No. 2 Engine Room Relay Block and No. 2 Junction Block Assembly
    *2 FAN Relay

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (FAN relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FAN RELAY)

    OK

  23. CHECK HARNESS AND CONNECTOR (FAN RELAY POWER SOURCE CIRCUIT)

    B003WSHC03
    *1 No. 2 Engine Room Relay Block and No. 2 Junction Block Assembly
    *2 FAN Relay

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

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (FAN relay) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 NO. 3 RELAY - FAN RELAY)

    OK

  24. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - FAN RELAY)


    1. Disconnect the A87 cooling fan ECU connector.

    2. Remove the FAN relay from the No. 2 engine room relay block and No. 2 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A87-1 (+B1) - 5 (FAN relay) Always Below 1 Ω
      A87-1 (+B1) or 5 (FAN relay) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - BODY GROUND)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  25. CHECK COOLING FAN SYSTEM (NO. 2 FAN)


    1. Disconnect the F103 ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the cooling fan.

      OK
      The cooling fan operates.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

  26. INSPECT NO. 2 COOLING FAN MOTOR


    1. Inspect the No. 2 cooling fan motor.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 2 COOLING FAN MOTOR Click here

    OK

  27. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU POWER SOURCE CIRCUIT)

    B003U8VC39
    *a

    Front view of wire harness connector

    (to No. 2 Cooling Fan ECU)

    1. Disconnect the f1 No. 2 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 Condition Specified Condition
      f1-1 (+B) - f1-3 (GND) Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - BODY GROUND) Click here

    OK

  28. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU AND NO. 2 COOLING FAN ECU - ECM)


    1. Disconnect the F103 ECM connector.

    2. Disconnect the A87 cooling fan ECU connector.

    3. Disconnect the f1 No. 2 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A87-2 (SI), f1-2 (SI) or F103-136 (RFC) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 2 COOLING FAN ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  29. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - BODY GROUND)


    1. Disconnect the f1 No. 2 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      f1-3 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  30. INSPECT FAN NO. 2 RELAY


    1. Inspect the FAN NO. 2 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FAN NO. 2 RELAY

    OK

  31. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY POWER SOURCE CIRCUIT)


    1. Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      B003WWRC01
      *A for LHD *B for RHD
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 FAN NO. 2 Relay
      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (FAN NO. 2 relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FAN RELAY)

    OK

  32. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY POWER SOURCE CIRCUIT)


    1. Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Turn the engine switch on (IG).

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

      B003WWRC01
      *A for LHD *B for RHD
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 FAN NO. 2 Relay
      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (FAN NO. 2 relay) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 NO. 3 RELAY - FAN NO. 2 RELAY)

    OK

  33. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - FAN NO. 2 RELAY)


    1. Disconnect the f1 No. 2 cooling fan ECU connector.

    2. Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      f1-1 (+B) - 5 (FAN NO. 2 relay) Always Below 1 Ω
      f1-1 (+B) or 5 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

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

  34. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - ECM)


    1. Disconnect the F103 ECM connector.

    2. Disconnect the A87 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A87-2 (SI) - F103-136 (RFC) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  35. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - BODY GROUND)

    B003WG6C87
    *a

    Component without harness connected

    (Cooling Fan Motor)

    1. Disconnect the z13 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z13-1 (-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COOLING FAN ECU

    NG

    REPLACE COOLING FAN MOTOR Click here

  36. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - ECM)


    1. Disconnect the F103 ECM connector.

    2. Disconnect the f1 No. 2 cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      f1-2 (SI) - F103-136 (RFC) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  37. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - BODY GROUND)

    B003WG6C88
    *a

    Component without harness connected

    (No. 2 Cooling Fan Motor)

    1. Disconnect the z14 No. 2 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z14-1 (-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 2 COOLING FAN ECU

    NG

    REPLACE NO. 2 COOLING FAN MOTOR Click here