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 INTELLIGENT TESTER (CONTROL THE ELECTRIC COOLING FAN)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

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

    5. Check the operation of the cooling fans while operating them using the intelligent tester.

      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 (LH-IG RELAY 2 - 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 (LH-IG RELAY 2 - FAN NO. 1, NO. 2 OR NO. 3 RELAY)


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

    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
      1 (FAN NO. 1 relay) - Body ground Engine switch on (IG) 11 to 14 V
      1 (FAN NO. 2 relay) - Body ground Engine switch on (IG) 11 to 14 V
      1 (FAN NO. 3 relay) - Body ground Engine switch on (IG) 11 to 14 V

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


    NG

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

    OK

  3. INSPECT ENGINE ROOM RELAY BLOCK NO. 2 (FAN NO. 1 OR NO. 3 RELAY VOLTAGE)


    1. A01CC84E01
      Text in Illustration
      *1 Engine Room Relay Block NO. 2

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      5 (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 (ENGINE ROOM RELAY BLOCK NO. 2 - BODY GROUND)


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

    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 (ENGINE ROOM RELAY BLOCK NO. 2 - BODY GROUND)

    OK

  8. INSPECT COOLING FAN MOTOR


    1. Inspect the cooling fan motor Click here.


    NG

    REPLACE COOLING FAN MOTOR Click here

    OK

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


    1. Disconnect the 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
      B16-1 - Body ground Always Below 1 Ω

    3. Reconnect the cooling fan motor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - BODY GROUND)

    OK

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


    1. Disconnect the cooling fan motor connector.

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

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B16-2 - 3 (FAN NO. 1 relay) Always Below 1 Ω
      B16-2 - 4 (FAN NO. 2 relay) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B16-2 or 3 (FAN NO. 1 relay) or 4 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher

    4. Reconnect the cooling fan motor connector.

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


    NG

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

    OK

  11. 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

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


    1. Disconnect the NO. 2 cooling fan motor connector.

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

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B17-1 - 3 (FAN NO. 2 relay) Always Below 1 Ω
      B17-2 - 3 (FAN NO. 3 relay) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B17-1 or 3 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher
      B17-2 or 3 (FAN NO. 3 relay) - Body ground Always 10 kΩ or higher

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

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


    NG

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

    OK

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


    1. A01CEYXE01
      Text in Illustration
      *1 Engine Room Relay Block NO. 2

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

    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 NO. 2

    OK

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


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

    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) - A8-22 (FANH) Always Below 1 Ω
      2 (FAN NO. 3 relay) - A8-21 (FANL) Always Below 1 Ω

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


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

    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 A8-22 (FANH) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 3 relay) or A8-21 (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