COOLING FAN SYSTEM Cooling Fan Circuit

DESCRIPTION

To control the cooling fans, the ECM turns the cooling fan relays on or off based on the engine coolant temperature, air conditioning switch, refrigerant pressure, engine speed and vehicle speed signals.

The ECM turns the fan relays on or off to switch the cooling fan motor circuit between the series circuit and parallel circuit, controlling the cooling fan motor speed in 2 steps.

WIRING DIAGRAM

Refer to System Diagram Click here.

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (OPERATE 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 and ECT / Active Test / Actuator Test of Fan Low Speed.

      OK
      GTS Operation Specified Condition
      ON Cooling fans operate
      OFF Cooling fans stop

    OK

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

    NG

  2. CHECK HARNESS AND CONNECTOR (FANL AND FANH VOLTAGE)


    1. A004N5ME02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A83-45 (FANH) - Body ground Ignition switch ON 11 to 14 V
      A83-20 (FANL) - Body ground Ignition switch ON 11 to 14 V

    3. Reconnect the ECM connector.


    NG

    INSPECT FAN NO. 1 RELAY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY AND FAN NO. 3 RELAY VOLTAGE)


    1. A004TQLE02
      Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *2 FAN NO. 3 Relay
      *3 FAN NO. 1 Relay

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

    3. Reinstall the FAN NO. 1 relay and FAN NO. 3 relay to the engine room No. 1 relay block.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ENGINE ROOM NO. 1 RELAY BLOCK)

    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 NO. 1 RELAY BLOCK - BODY GROUND)


    1. 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
      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 NO. 1 RELAY BLOCK - 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
      Tester Connection Condition Specified Condition
      A47-1 - 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 - ENGINE ROOM NO. 1 RELAY BLOCK)


    1. Disconnect the cooling fan motor connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A47-2 - 5 (FAN NO. 1 relay) Always Below 1 Ω
      A47-2 - 4 (FAN NO. 2 relay) Always Below 1 Ω
      A47-2 or 5 (FAN NO. 1 relay) - Body ground Always 10 kΩ or higher
      A47-2 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 relay and FAN NO. 2 relay to the engine room No. 1 relay block.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM NO. 1 RELAY BLOCK)

    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 - ENGINE ROOM NO. 1 RELAY BLOCK)


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

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A48-1 - 3 (FAN NO. 2 relay) Always Below 1 Ω
      A48-2 - 3 (FAN NO. 3 relay) Always Below 1 Ω
      A48-1 or 3 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher
      A48-2 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 relay and FAN NO. 3 relay to the engine room No. 1 relay block.


    NG

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

    OK

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


    1. Remove the FAN NO. 1 relay and 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
      1 (FAN NO. 1 relay) - 1 (FAN NO. 2 relay) Always Below 1 Ω
      2 (FAN NO. 1 relay) - 2 (FAN NO. 2 relay) Always Below 1 Ω
      1 (FAN NO. 1 relay) or 1 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 1 relay) or 2 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher

    3. Reinstall the FAN NO. 1 relay and FAN NO. 2 relay to the engine room No. 1 relay block.


    OK

    REPLACE ECM Click here

    NG

    REPLACE ENGINE ROOM NO. 1 RELAY BLOCK

  14. INSPECT FAN NO. 1 RELAY


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


    NG

    REPLACE FAN NO. 1 RELAY

    OK

  15. INSPECT FAN NO. 2 RELAY


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


    NG

    REPLACE FAN NO. 2 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 (ENGINE ROOM NO. 1 RELAY BLOCK - ECM)


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

    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
      2 (FAN NO. 1 relay) - A83-45 (FANH) Always Below 1 Ω
      2 (FAN NO. 2 relay) - A83-45 (FANH) Always Below 1 Ω
      2 (FAN NO. 3 relay) - A83-20 (FANL) Always Below 1 Ω
      2 (FAN NO. 1 relay) or A83-45 (FANH) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 2 relay) or A83-45 (FANH) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 3 relay) or A83-20 (FANL) - Body ground Always 10 kΩ or higher

    4. Reinstall the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 relay to the engine room No. 1 relay block.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - ECM)

    OK

  18. CHECK HARNESS AND CONNECTOR (FAN RELAY VOLTAGE)


    1. Remove the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 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 Switch 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

    3. Reinstall the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 relay to the engine room No. 1 relay block.


    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ENGINE ROOM NO. 1 RELAY BLOCK)