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.

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 (OPERATE ELECTRIC COOLING FAN)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

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

    NG

    CHECK HARNESS AND CONNECTOR (FANL AND FANH VOLTAGE) Click here

    OK

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

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


    1. A01IOG0E05
      Text in Illustration
      *1

      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
      A51-21 (FANH) - Body ground Ignition switch ON 11 to 14 V
      A51-22 (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. A01IOK6E01
      Text in Illustration
      *1 FAN NO. 3 Relay
      *2 FAN NO. 1 Relay
      *3 Engine Room No. 1 Relay Block

      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.


    NG

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

    OK

  4. INSPECT FAN NO. 1 RELAY


    1. A01INA8E50

      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 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the FAN NO. 1 relay.


    NG

    REPLACE FAN NO. 1 RELAY

    OK

  5. INSPECT FAN NO. 2 RELAY


    1. A01IQOYE01

      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 - 4 Battery voltage not applied between terminals 1 and 2 Below 1 Ω
      Battery voltage applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the FAN NO. 2 relay.


    NG

    REPLACE FAN NO. 2 RELAY

    OK

  6. INSPECT FAN NO. 3 RELAY


    1. A01INA8E50

      Remove the FAN NO. 3 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 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the FAN NO. 3 relay.


    NG

    REPLACE FAN NO. 3 RELAY

    OK

  7. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - BODY GROUND)


    1. A01IPWSE01
      Text in Illustration
      *1 FAN NO. 2 Relay
      *2 Engine Room No. 1 Relay Block

      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 NO. 1 COOLING FAN MOTOR


    1. Inspect the No. 1 cooling fan motor Click here.


    NG

    REPLACE NO. 1 COOLING FAN MOTOR Click here

    OK

  9. CHECK HARNESS AND CONNECTOR (NO. 1 COOLING FAN MOTOR - BODY GROUND)


    1. A01INR4E03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to No. 1 Cooling Fan Motor)

      Disconnect the No. 1 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-1 - Body ground Always Below 1 Ω

    3. Reconnect the No. 1 cooling fan motor connector.


    NG

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

    OK

  10. CHECK HARNESS AND CONNECTOR (NO. 1 COOLING FAN MOTOR - ENGINE ROOM NO. 1 RELAY BLOCK)


    1. A01ISPIE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to No. 1 Cooling Fan Motor)
      *2 FAN NO. 2 Relay
      *3 FAN NO. 1 Relay
      *4 Engine Room No. 1 Relay Block

      Disconnect the No. 1 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 (Check for Open)
      Tester Connection Condition Specified Condition
      A28-2 - 5 (FAN NO. 1 relay) Always Below 1 Ω
      A28-2 - 4 (FAN NO. 2 relay) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A28-2 or 5 (FAN NO. 1 relay) - Body ground Always 10 kΩ or higher
      A28-2 or 4 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher

    4. Reconnect the No. 1 cooling fan motor connector.

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


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 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. A01IQEXE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to No. 2 Cooling Fan Motor)
      *2 FAN NO. 2 Relay
      *3 FAN NO. 3 Relay
      *4 Engine Room No. 1 Relay Block

      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 (Check for Open)
      Tester Connection Condition Specified Condition
      A29-1 - 3 (FAN NO. 2 relay) Always Below 1 Ω
      A29-2 - 3 (FAN NO. 3 relay) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A29-1 or 3 (FAN NO. 2 relay) - Body ground Always 10 kΩ or higher
      A29-2 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.


    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. A01INR5E01
      Text in Illustration
      *1 FAN NO. 2 Relay
      *2 FAN NO. 1 Relay
      *3 Engine Room No. 1 Relay Block

      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 (Check for Open)
      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
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      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.


    NG

    REPLACE ENGINE ROOM NO. 1 RELAY BLOCK

    OK

    REPLACE ECM Click here

  14. INSPECT FAN NO. 1 RELAY


    1. A01INA8E50

      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 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the FAN NO. 1 relay.


    NG

    REPLACE FAN NO. 1 RELAY

    OK

  15. INSPECT FAN NO. 2 RELAY


    1. A01IQOYE01

      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 - 4 Battery voltage not applied between terminals 1 and 2 Below 1 Ω
      Battery voltage applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the FAN NO. 2 relay.


    NG

    REPLACE FAN NO. 2 RELAY

    OK

  16. INSPECT FAN NO. 3 RELAY


    1. A01INA8E50

      Remove the FAN NO. 3 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 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the FAN NO. 3 relay.


    NG

    REPLACE FAN NO. 3 RELAY

    OK

  17. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - ECM)


    1. A01INZ1E03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)
      *2 FAN NO. 2 Relay
      *3 FAN NO. 3 Relay
      *4 FAN NO. 1 Relay
      *5 Engine Room No. 1 Relay Block

      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 (Check for Open)
      Tester Connection Condition Specified Condition
      2 (FAN NO. 1 relay) - A51-21 (FANH) Always Below 1 Ω
      2 (FAN NO. 2 relay) - A51-21 (FANH) Always Below 1 Ω
      2 (FAN NO. 3 relay) - A51-22 (FANL) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      2 (FAN NO. 1 relay) or A51-21 (FANH) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 2 relay) or A51-21 (FANH) - Body ground Always 10 kΩ or higher
      2 (FAN NO. 3 relay) or A51-22 (FANL) - Body ground Always 10 kΩ or higher

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

    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. A01IPZ1E01
      Text in Illustration
      *1 FAN NO. 2 Relay
      *2 FAN NO. 3 Relay
      *3 FAN NO. 1 Relay
      *4 Engine Room No. 1 Relay Block

      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.


    NG

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

    OK

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