COOLING FAN SYSTEM(w/ Towing Package) 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 the signals to the cooling fan ECUs to regulate the cooling fans. The cooling fan ECUs control each cooling fan speed based on the duty ratio signal sent from the ECM. By basing its control on the operating conditions, the ECM can control the fan speed optimally using the cooling fan ECUs, achieving both high cooling performance and quietness.

WIRING DIAGRAM

Refer to the System Diagram.

Click here

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING GTS (CONTROL THE ENGINE COOLING FAN DUTY RATIO)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Engine / Active Test / Control the Engine Cooling Fan Duty Ratio.

      
      Powertrain > Engine > Active Test

      Tester Display
      Control the Engine Cooling Fan Duty Ratio

   5. Check the operation of the cooling fans while operating them using the GTS.

      OK
      Tester Operation Fan Operation 100% Cooling fans operate 0% Cooling fans stop

      Result
      Result Proceed to OK A NG (Fan does not operate) B NG (No. 2 fan does not operate) C NG (Fan does not stop) D NG (No. 2 fan does not stop) E

   
   

   A

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

   C

   CHECK COOLING FAN SYSTEM Click here

   D

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

   E

   CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - ECM) Click here

   B

2. CHECK COOLING FAN SYSTEM

   
   

   1. Disconnect the ECM connector.

   2. Turn the engine switch on (IG).

   3. Check the operation of the cooling fan.

      OK
      The cooling fan operates.

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE ECM Click here ENGINE CONTROL (2AD-FTV) > ECM > REMOVAL

   NG

3. INSPECT COOLING FAN MOTOR

   
   

   1. Inspect the cooling fan motor.

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE COOLING FAN MOTOR Click here

   OK

4. CHECK TERMINAL VOLTAGE (COOLING FAN ECU POWER SOURCE)

   

   *a	Front view of wire harness connector (to Cooling Fan ECU)

   
   

   1. Disconnect the cooling fan ECU connector.

   2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition A93-1 (+B1) - A93-3 (E1) Engine switch on (IG) 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

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

   OK

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

   
   

   1. Disconnect the cooling fan ECU connector.

   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 A93-2 (SI) or A61-49 (RFC) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE COOLING FAN ECU

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

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

   
   

   1. Disconnect the cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A93-3 (E1) - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

7. INSPECT FAN NO. 1 RELAY

   
   

   1. Inspect the FAN NO. 1 relay.

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE FAN NO. 1 RELAY

   OK

8. INSPECT NO. 2 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY (FAN NO. 1 RELAY)

   

   *1	No. 2 engine room relay block and junction block assembly
   *2	FAN NO. 1 Relay

   
   

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

   2. Turn the engine switch on (IG).

   3. 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 1 (FAN NO. 1 relay) - Body ground Engine switch on (IG) 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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

   
   

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

   2. Disconnect the cooling fan ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 5 (FAN NO. 1 relay) - A93-1 (+B1) Always Below 1 Ω 5 (FAN NO. 1 relay) or A93-1 (+B1) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

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

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

10. CHECK COOLING FAN SYSTEM

    
    

    1. Disconnect the ECM connector.

    2. Turn the engine switch on (IG).

    3. Check the operation of the No. 2 cooling fan.

       OK
       The No. 2 cooling fan operates.

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE ECM Click here ENGINE CONTROL (2AD-FTV) > ECM > REMOVAL

    NG

11. INSPECT NO. 2 COOLING FAN MOTOR

    
    

    1. Inspect the No. 2 cooling fan motor.

       Click here

       Result
       Proceed to OK NG

    
    

    NG

    REPLACE NO. 2 COOLING FAN MOTOR Click here

    OK

12. CHECK TERMINAL VOLTAGE (NO. 2 COOLING FAN ECU POWER SOURCE)

    

    *a	Front view of wire harness connector (to No. 2 Cooling Fan ECU)

    
    

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

    2. Turn the engine switch on (IG).

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

       Standard Voltage
       Tester Connection Switch Condition Specified Condition A99-1 (+B2) - A99-3 (E2) Engine switch on (IG) 11 to 14 V

       Result
       Proceed to OK NG

    
    

    NG

    CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - BODY GROUND) Click here

    OK

13. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - ECM)

    
    

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

    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 A99-2 (SI2) or A61-48 (RFC2) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE NO. 2 COOLING FAN ECU

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

14. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - BODY GROUND)

    
    

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

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

       Standard Resistance
       Tester Connection Condition Specified Condition A99-3 (E2) - Body ground Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

15. INSPECT FAN NO. 2 RELAY

    
    

    1. Inspect the FAN NO. 2 relay.

       Click here

       Result
       Proceed to OK NG

    
    

    NG

    REPLACE FAN NO. 2 RELAY

    OK

16. INSPECT NO. 2 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY (NO. 2 RELAY)

    

    *1	No. 2 engine room relay block and junction block assembly
    *2	FAN NO. 2 Relay

    
    

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

    2. Turn the engine switch on (IG).

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

       Standard Voltage
       Tester Connection Condition Specified Condition 3 (FAN NO. 2 relay) - Body ground Always 11 to 14 V 1 (FAN NO. 2 relay) - Body ground Engine switch on (IG) 11 to 14 V

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

17. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - NO. 2 COOLING FAN ECU)

    
    

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

    2. Disconnect the No. 2 cooling fan ECU connector.

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

       Standard Resistance
       Tester Connection Condition Specified Condition 5 (FAN NO. 2 relay) - A99-1 (+B2) Always Below 1 Ω 5 (FAN NO. 2 relay) or A99-1 (+B2) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    
    

    1. Disconnect the cooling fan ECU connector.

    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 A93-2 (SI) - A61-49 (RFC) Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

19. 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 z1-1 (-) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE COOLING FAN ECU

    NG

    REPLACE COOLING FAN MOTOR Click here

20. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN ECU - ECM)

    
    

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

    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 A99-2 (SI2) - A61-48 (RFC2) Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

21. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - BODY GROUND)

    
    

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

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

       Standard Resistance
       Tester Connection Condition Specified Condition z9-1 (-) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE NO. 2 COOLING FAN ECU

    NG

    REPLACE NO. 2 COOLING FAN MOTOR Click here