COOLING FAN SYSTEM Cooling Fan Circuit

DESCRIPTION

The ECM monitors engine coolant temperature, the air conditioning switch, the air conditioning refrigerant pressure and engine speed. It also sends the FANL and FANH signals to the engine room junction block assembly to operate the cooling fan motor and No. 2 cooling fan motor.

The ECM switches the cooling fan motor and No. 2 cooling fan motor circuits from a series (low speed rotation) to parallel (high speed rotation) connection by changing the FANH signal, thereby controlling the 2 levels of fan speed.

Input signal FANL OFF ON ON
FANH OFF OFF ON
Condition Cooling fan motor OFF ON (Series connection (Low speed rotation)) ON (Parallel connection (High speed rotation))
No. 2 cooling fan motor OFF ON (Series connection (Low speed rotation)) ON (Parallel connection (High speed rotation))
A01EZ44E01

WIRING DIAGRAM

A01ETENE02
A01EVNME05

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)

    Tech Tips

    If the cooling fan speed does not change, proceed to the next step.


    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.

    5. Check the operation of the cooling fans using the intelligent tester.

      OK
      Tester Operation Fan Operation
      ON Cooling fan operates
      OFF Cooling fan stops
      Result
      Result Proceed to
      NG A
      OK B

    B

    INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY Click here

    A

  2. CHECK HARNESS AND CONNECTOR (ECM - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the A74 ECM connector.

    2. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

    3. Disconnect the 1F engine room junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A74-21 (FANL) - 1F-17 (FANL) Always Below 1 Ω
      A74-22 (FANH) - 1F-9 (FANH) Always Below 1 Ω
      A74-21 (FANL) or 1F-17 (FANL) - Body ground Always 10 kΩ or higher
      A74-22 (FANH) or 1F-9 (FANH) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

    OK

  3. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY


    1. Using a voltmeter, check the signal reading of the engine room junction block assembly Click here.

      OK
      Output signal reading is normal.

    NG

    INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULTS OF SIGNAL READING CHECK) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE)


    1. A01EUEOE01
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 ALT
      *3 BATT

      Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      (BATT) - Body ground Ignition switch off 11 to 14 V
      (ALT) - Body ground Ignition switch off 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - BATTERY)

    OK

  5. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - BODY GROUND)


    1. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

    2. Disconnect the 1F and 1G engine room junction block assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1F-3 (GND1) - Body ground Always Below 1 Ω
      1G-4 (GND2) - Body ground Always Below 1 Ω

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - BODY GROUND)

    OK

  6. CHECK HARNESS AND CONNECTOR (FAN RELAY POWER SOURCE)


    1. A01EWSHE01
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 FAN Relay

      Remove the FAN relay from the engine room relay block and junction block assembly.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (FAN relay) - Body ground Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (FAN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (FAN RELAY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Remove the FAN relay from the engine room relay block and junction block assembly.

    2. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

    3. Disconnect the 1F engine room junction block assembly connector.

    4. Disconnect the 3D instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (FAN relay) - 1F-15 (IGN) Always Below 1 Ω
      1 (FAN relay) or 1F-15 (IGN) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    OK

  8. INSPECT RELAY (FAN RELAY)


    1. Inspect the FAN relay Click here.


    NG

    REPLACE RELAY (FAN RELAY)

    OK

  9. CHECK HARNESS AND CONNECTOR (FAN RELAY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Remove the FAN relay from the engine room relay block and junction block assembly.

    2. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

    3. Disconnect the 1F engine room junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (FAN relay) - 1F-8 (FN2S) Always Below 1 Ω
      2 (FAN relay) or 1F-8 (FN2S) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

    OK

  10. CHECK HARNESS AND CONNECTOR (FAN RELAY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Remove the FAN relay from the engine room relay block and junction block assembly.

    2. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4 (FAN relay) - 1M-2 (FAN2) Always Below 1 Ω
      4 (FAN relay) or 1M-2 (FAN2) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

    OK

  11. CHECK HARNESS AND CONNECTOR (FAN RELAY - BODY GROUND)


    1. Remove the FAN relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      5 (FAN relay) - Body ground Always Below 1 Ω

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - BODY GROUND)

    OK

  12. 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

  13. CHECK HARNESS AND CONNECTOR (FAN RELAY - NO. 2 COOLING FAN MOTOR)


    1. Remove the FAN relay from the engine room relay block and junction block assembly.

    2. Disconnect the A8 No. 2 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (FAN relay) - A8-1 (L) Always Below 1 Ω
      3 (FAN relay) or A8-1 (L) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

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

    OK

  14. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the A8 No. 2 cooling fan motor connector.

    2. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A8-2 (B) - 1M-3 (CFAN) Always Below 1 Ω
      A8-2 (B) or 1M-3 (CFAN) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

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

    OK

  15. INSPECT COOLING FAN MOTOR


    1. Inspect the cooling fan motor Click here.


    NG

    REPLACE COOLING FAN MOTOR Click here

    OK

  16. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the A7 cooling fan motor connector.

    2. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A7-2 - 1M-1 (RFAN) Always Below 1 Ω
      A7-2 or 1M-1 (RFAN) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

    OK

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


    1. Disconnect the A7 cooling fan motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A7-1 - Body ground Always Below 1 Ω

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

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

    OK

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

  18. CHECK HARNESS AND CONNECTOR (FAN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the FAN relay from the engine room relay block and junction block assembly.

    2. Disconnect the 3D instrument panel junction block assembly connector.

    3. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.

    4. Disconnect the 1F engine room junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (FAN relay) - 3D-36 Always Below 1 Ω
      1 (FAN relay) or 3D-36 - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    OK

  19. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG1 NO. 2 RELAY)


    1. A01EW5FE12
      Text in Illustration
      *1 Instrument Panel Junction Block Assembly

      Disconnect the 3A, 3B, 3D and 3E instrument panel junction block assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3D-36 - 3E-1 Battery voltage is not applied between terminals 3A-27 and 3B-7 10 kΩ or higher
      3D-36 - 3E-1 Battery voltage is applied between terminals 3A-27 and 3B-7 Below 1 Ω

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG1 NO. 2 RELAY)

    OK

  20. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY POWER SOURCE)


    1. A01EW9XE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)

      Disconnect the 3E instrument panel junction block assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3E-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BATTERY)

    OK

  21. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)


    1. Disconnect the 3B instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3B-7 - Body ground Always Below 1 Ω

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)

    OK

  22. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - IGNITION OR STARTER SWITCH ASSEMBLY)


    1. Disconnect the 3A instrument panel junction block assembly connector.

    2. Disconnect the I36 ignition or starter switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3A-27 - I36-1 (IG1) Always Below 1 Ω
      3A-27 or I36-1 (IG1) - Body ground Always 10 kΩ or higher

      Tech Tips

      Make sure that there are no short circuits to the battery.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - IGNITION OR STARTER SWITCH ASSEMBLY)

    OK

  23. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY


    1. Inspect the ignition or starter switch assembly Click here.


    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Click here

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - BATTERY)