COOLING FAN SYSTEM Cooling Fan Circuit

DTC Code DTC Name
Cooling Fan Circuit

DESCRIPTION

The ECM calculates an appropriate cooling fan speed based on the engine coolant temperature, air conditioning switch condition, refrigerant pressure, engine speed and vehicle speed, and sends signals to the cooling fan ECU to regulate the cooling fan. The cooling fan ECU controls the cooling fan speed based on the duty ratio signal sent from the ECM.

WIRING DIAGRAM

A206924E05

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 INTELLIGENT TESTER (CONTROL THE ELECTRIC COOLING FAN)

    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

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

    4. Check the operation of the cooling fan while operating it using the intelligent tester.

      OK

      Tester Operation

      Fan Operation

      ON

      Cooling fan operates

      OFF

      Cooling fan stops
      Table 1. Result

      Result

      Proceed to

      OK

      A

      Cooling fan does not operate

      B

      Cooling fan does not stop

      C

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

    CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)Click here

  2. CHECK COOLING FAN SYSTEM

    1. U123365E02

      Disconnect the A76 ECM connector.

    2. Turn the ignition switch to ON.

    3. Check the operation of the cooling fan.

      OK

      The cooling fan operates.

      Table 2. Text in Illustration

      *a

      Front view of wire harness connector

      (to ECM)

    4. Reconnect the ECM connector.

    REPLACE ECM

    (Click here)

  3. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)

    U122292E02

    1. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)

      Tester Connection

      Condition

      Specified Condition

      A76-60 (RFC) - A40-2 (SI)

      Always

      Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection

      Condition

      Specified Condition

      A76-60 (RFC) or A40-2 (SI) - Body ground

      Always

      10 kΩ or higher
      Table 3. Text in Illustration

      *a

      Front view of wire harness connector

      (to Cooling Fan ECU)

      *b

      Front view of wire harness connector

      (to ECM)

    3. Reconnect the cooling fan ECU connector.

    4. Reconnect the ECM connector.

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU)

  4. INSPECT COOLING FAN MOTOR

    1. U121611E02

      Disconnect the cooling fan motor connector.

    2. Apply 12 V battery voltage to the cooling fan motor and check that the cooling fan operates.

      OK

      Measurement Condition

      Specified Condition

      • Battery positive (+) → Terminal 2

      • Battery negative (-) → Terminal 1

      Cooling fan operates
      Table 4. Text in Illustration

      *a

      Component without harness connected

      (Cooling Fan Motor)

    3. Reconnect the cooling fan motor connector.

    REPLACE COOLING FAN MOTOR

    (Click here)

  5. CHECK COOLING FAN ECU (POWER SOURCE)

    1. U121668E02

      Disconnect the cooling fan ECU connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      A40-1 (+B1) - A40-3 (E1)

      Ignition switch ON

      11 to 14 V
      Table 5. Text in Illustration

      *a

      Front view of wire harness connector

      (to Cooling Fan ECU)

    4. Reconnect the cooling fan ECU connector.

    REPLACE COOLING FAN ECU

  6. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - BODY GROUND)

    1. Disconnect the cooling fan ECU connector.

    2. U121669E02

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A40-3 (E1) - Body ground

      Always

      Below 1 Ω
      Table 6. Text in Illustration

      *a

      Front view of wire harness connector

      (to Cooling Fan ECU)

    3. Reconnect the cooling fan ECU connector.

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

  7. INSPECT FAN NO. 1 RELAY

    1. B016200

      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

      No battery voltage applied to terminals 1 and 2

      10 kΩ or higher

      3 - 5

      Battery voltage applied to terminals 1 and 2

      Below 1 Ω

    3. Reinstall the FAN NO. 1 relay.

    REPLACE FAN NO. 1 RELAY

  8. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - FAN NO. 1 RELAY)

    1. Disconnect the cooling fan ECU connector.

      A390322E01

    2. Remove the FAN NO. 1 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

      A40-1 (+B1) - Relay block FAN NO. 1 relay terminal (5)

      Always

      Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection

      Condition

      Specified Condition

      A40-1 (+B1) or Relay block FAN NO. 1 relay terminal (5) - Body ground

      Always

      10 kΩ or higher
      Table 7. Text in Illustration

      *1

      Engine Room No. 1 Relay Block

      *a

      Front view of wire harness connector

      (to Cooling Fan ECU)

      *b

      Relay Block FAN NO. 1 Relay Terminals

    4. Reinstall the FAN NO. 1 relay.

    5. Reconnect the cooling fan ECU connector.

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

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

    1. A206928E02

      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

      Relay block FAN NO. 1 relay terminal (2) - Body ground

      Always

      Below 1 Ω
      Table 8. Text in Illustration

      *1

      Engine Room No. 1 Relay Block

      *a

      Relay Block FAN NO. 1 Relay Terminals

    3. Reinstall the FAN NO. 1 relay.

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

  10. CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - BATTERY)

    1. A206928E03

      Remove the FAN NO. 1 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

      Relay block FAN NO. 1 relay terminal (3) - Body ground

      Always

      11 to 14 V
      Table 9. Text in Illustration

      *1

      Engine Room No. 1 Relay Block

      *a

      Relay Block FAN NO. 1 Relay Terminals

    3. Reinstall the FAN NO. 1 relay.

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - IG1 RELAY)

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

  11. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)

    1. U122292E02

      Disconnect the ECM connector.

    2. Disconnect the cooling fan ECU connector.

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

      Standard Resistance (Check for Open)

      Tester Connection

      Condition

      Specified Condition

      A76-60 (RFC) - A40-2 (SI)

      Always

      Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection

      Condition

      Specified Condition

      A76-60 (RFC) or A40-2 (SI) - Body ground

      Always

      10 kΩ or higher
      Table 10. Text in Illustration

      *a

      Front view of wire harness connector

      (to Cooling Fan ECU)

      *b

      Front view of wire harness connector

      (to ECM)

    4. Reconnect the cooling fan ECU connector.

    5. Reconnect the ECM connector.

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU)

  12. REPLACE COOLING FAN ECU

    1. Replace the cooling fan ECU.

  13. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Check the cooling fan operation.

      OK

      Malfunction has been repaired successfully.

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

    REPLACE ECM

    (Click here)