COOLING FAN SYSTEM Cooling Fan Circuit

DESCRIPTION

The ECM turns on or off the fan relays using signals calculated from the engine coolant temperature, air conditioning (ON/OFF), air conditioner refrigerant pressure, engine speed, and vehicle speed signals.

The ECM switches the circuit of the cooling fan motors between series and parallel by turning on or off the fan relays in order to control the speed of the cooling fan motors in two steps.

WIRING DIAGRAM

Refer to System Diagram Click here.

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (CONTROL THE ELECTRIC COOLING FAN)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

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

      OK
      Tester Operation Specified Condition
      ON Cooling fans operate
      OFF Cooling fans stop
      Result
      Result Proceed to
      OK A
      NG (Cooling fans do not operate) B
      NG (Cooling fans do not stop) C

    B

    CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - FAN NO. 1, NO. 2 OR NO. 3 RELAY) Click here

    C

    INSPECT FAN NO. 1 RELAY Click here

    A

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

  2. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - FAN NO. 1, NO. 2 OR NO. 3 RELAY)


    1. A01EMBOE01
      Text in Illustration
      *1 Engine Room Relay Block

      Remove the FAN NO. 1, FAN NO. 2 and FAN NO. 3 relays from the engine room relay block.

    2. Turn the ignition switch to ON.

    3. 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 Ignition switch ON 11 to 14 V
      1 (FAN NO. 2 relay) - Body ground Ignition switch ON 11 to 14 V
      1 (FAN NO. 3 relay) - Body ground Ignition switch ON 11 to 14 V

    4. Reinstall the FAN NO. 1, FAN NO. 2 and FAN NO. 3 relays.


    NG

    REPLACE ENGINE ROOM RELAY BLOCK

    OK

  3. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 OR NO. 3 RELAY VOLTAGE)


    1. A01EL89E01
      Text in Illustration
      *1 Engine Room Relay Block

      Remove the FAN NO. 1 and FAN NO. 3 relays from the engine room 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
      5 (FAN NO. 3 relay) - Body ground Always 11 to 14 V

    3. Reinstall the FAN NO. 1 and FAN NO. 3 relays.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FAN NO. 1 OR NO. 3 RELAY)

    OK

  4. INSPECT FAN NO. 1 RELAY


    1. Inspect the FAN NO. 1 relay Click here.


    NG

    REPLACE FAN NO. 1 RELAY

    OK

  5. INSPECT FAN NO. 2 RELAY


    1. Inspect the FAN NO. 2 relay Click here.


    NG

    REPLACE FAN NO. 2 RELAY

    OK

  6. INSPECT FAN NO. 3 RELAY


    1. Inspect the FAN NO. 3 relay Click here.


    NG

    REPLACE FAN NO. 3 RELAY

    OK

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


    1. A01EIYZE01
      Text in Illustration
      *1 Engine Room Relay Block

      Remove the FAN NO. 2 relay from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      5 (FAN NO. 2 relay) - Body ground Always Below 1 Ω

    3. Reinstall the FAN NO. 2 relay.


    NG

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

    OK

  8. INSPECT NO. 2 COOLING FAN MOTOR


    1. Inspect the NO. 2 cooling fan motor Click here.


    NG

    REPLACE NO. 2 COOLING FAN MOTOR Click here

    OK

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


    1. A01ELQBE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to NO. 2 Cooling Fan Motor)

      Disconnect the NO. 2 cooling fan motor connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A48-2 - Body ground Always Below 1 Ω

    3. Reconnect the NO. 2 cooling fan motor connector.


    NG

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

    OK

  10. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - FAN NO. 1 OR NO. 2 RELAY)


    1. A01EJOZE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to NO. 2 Cooling Fan Motor)
      *2 Engine Room Relay Block

      Disconnect the NO. 2 cooling fan motor connector.

    2. Remove the FAN NO. 1 and FAN NO. 2 relays from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A48-1 - 5 (FAN NO. 1 relay) Always Below 1 Ω
      A48-1 - 4 (FAN NO. 2 relay) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A48-1 or 5 (FAN NO. 1 relay) or 4 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher

    4. Reconnect the NO. 2 cooling fan motor connector.

    5. Reinstall the FAN NO. 1 and FAN NO. 2 relays.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 COOLING FAN MOTOR - FAN NO. 1 OR NO. 2 RELAY)

    OK

  11. INSPECT COOLING FAN MOTOR


    1. Inspect the cooling fan motor Click here.


    NG

    REPLACE COOLING FAN MOTOR Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - FAN NO. 2 OR NO. 3 RELAY)


    1. A01ELRZE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Cooling Fan Motor)
      *2 Engine Room Relay Block

      Disconnect the cooling fan motor connector.

    2. Remove the FAN NO. 2 and FAN NO. 3 relays from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A47-1 - 3 (FAN NO. 2 relay) Always Below 1 Ω
      A47-2 - 3 (FAN NO. 3 relay) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A47-1 or 3 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher
      A47-2 or 3 (FAN NO. 3 relay) - Body ground Always 10 kΩ or higher

    4. Reconnect the cooling fan motor connector.

    5. Reinstall the FAN NO. 2 and FAN NO. 3 relays.


    NG

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

    OK

  13. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY - FAN NO. 2 RELAY)


    1. A01EMHHE01
      Text in Illustration
      *1 Engine Room Relay Block

      Remove the FAN NO. 1 and FAN NO. 2 relays from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      2 (FAN NO. 1 relay) - 2 (FAN NO. 2 relay) Always Below 1 Ω

    3. Reinstall the FAN NO. 1 and FAN NO. 2 relays.


    NG

    REPLACE ENGINE ROOM RELAY BLOCK

    OK

  14. CHECK HARNESS AND CONNECTOR (FAN NO. 2 OR NO. 3 RELAY - ECM)


    1. A01ELHPE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)
      *2 Engine Room Relay Block

      Remove the FAN NO. 2 and FAN NO. 3 relays from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      2 (FAN NO. 2 relay) - A49-22 (FANH) Always Below 1 Ω
      2 (FAN NO. 3 relay) - A49-21 (FANL) Always Below 1 Ω

    4. Reinstall the FAN NO. 2 and FAN NO. 3 relays.

    5. Reconnect the ECM connector.


    NG

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

    OK

    REPLACE ECM Click here

  15. INSPECT FAN NO. 1 RELAY


    1. Inspect the FAN NO. 1 relay Click here.


    NG

    REPLACE FAN NO. 1 RELAY

    OK

  16. INSPECT FAN NO. 3 RELAY


    1. Inspect the FAN NO. 3 relay Click here.


    NG

    REPLACE FAN NO. 3 RELAY

    OK

  17. CHECK HARNESS AND CONNECTOR (FAN NO. 1, NO. 2 OR NO. 3 RELAY - ECM)


    1. A01EJ82E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)
      *2 Engine Room Relay Block

      Remove the FAN NO. 1, FAN NO. 2 and FAN NO. 3 relays from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      2 (FAN NO. 1 relay) or 2 (FAN NO. 2 relay) or A49-22 (FANH) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 3 relay) or A49-21 (FANL) - Body ground Always 10 kΩ or higher

    4. Reinstall the FAN NO. 1, FAN NO. 2 and FAN NO. 3 relays.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1, NO. 2 OR NO. 3 RELAY - ECM)

    OK

    REPLACE ECM Click here