COOLING FAN SYSTEM Cooling Fan Circuit

DTC Code DTC Name
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

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

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

    1. U122182E02

      Disconnect the ECM connector.

      Table 1. Text in Illustration

      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      A76-45 (FANH) - Body ground

      Ignition switch ON

      11 to 14 V

      A76-20 (FANL) - Body ground

      Ignition switch ON

      11 to 14 V

    3. Reconnect the ECM connector.

    INSPECT FAN NO. 1 RELAYClick here

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

    1. A316628E01

      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
      Table 2. Text in Illustration

      *1

      FAN NO. 3 Relay

      *2

      FAN NO. 1 Relay

      *3

      Engine Room No. 1 Relay Block

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

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

  4. INSPECT FAN NO. 1 RELAY

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

    REPLACE FAN NO. 1 RELAY

  5. INSPECT FAN NO. 2 RELAY

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

    REPLACE FAN NO. 2 RELAY

  6. INSPECT FAN NO. 3 RELAY

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

    REPLACE FAN NO. 3 RELAY

  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.

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

  8. INSPECT COOLING FAN MOTOR

    1. Inspect the cooling fan motor (Click here).

    REPLACE COOLING FAN MOTOR

    (Click here)

  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

      A28-1 - Body ground

      Always

      Below 1 Ω

    3. Reconnect the cooling fan motor connector.

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

  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

      A28-2 - 5 (FAN NO. 1 relay)

      Always

      Below 1 Ω

      A28-2 - 4 (FAN NO. 2 relay)

      Always

      Below 1 Ω

      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 cooling fan motor connector.

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

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

  11. INSPECT NO. 2 COOLING FAN MOTOR

    1. Inspect the No. 2 cooling fan motor (Click here).

    REPLACE NO. 2 COOLING FAN MOTOR

    (Click here)

  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

      A29-1 - 3 (FAN NO. 2 relay)

      Always

      Below 1 Ω

      A29-2 - 3 (FAN NO. 3 relay)

      Always

      Below 1 Ω

      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 to the engine room No. 1 relay block.

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

  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.

    REPLACE ECM

    (Click here)

    REPLACE ENGINE ROOM NO. 1 RELAY BLOCK

  14. INSPECT FAN NO. 1 RELAY

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

    REPLACE FAN NO. 1 RELAY

  15. INSPECT FAN NO. 2 RELAY

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

    REPLACE FAN NO. 2 RELAY

  16. INSPECT FAN NO. 3 RELAY

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

    REPLACE FAN NO. 3 RELAY

  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) - A76-45 (FANH)

      Always

      Below 1 Ω

      2 (FAN NO. 2 relay) - A76-45 (FANH)

      Always

      Below 1 Ω

      2 (FAN NO. 3 relay) - A76-20 (FANL)

      Always

      Below 1 Ω

      2 (FAN NO. 1 relay) or A76-45 (FANH) - Body ground

      Always

      10 kΩ or higher

      2 (FAN NO. 2 relay) or A76-45 (FANH) - Body ground

      Always

      10 kΩ or higher

      2 (FAN NO. 3 relay) or A76-20 (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.

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

  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.

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

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