COOLING FAN SYSTEM Cooling Fan Circuit

DESCRIPTION

• w/ Air Conditioning System

  The ECM turns on or off the fan relays using signals calculated from the engine coolant temperature, air conditioning (ON/OFF), air conditioner refrigerant pressure, engine speed and vehicle speed signals.

The ECM switches the circuit of the cooling fan motors between series and parallel by turning on or off the fan relays in order to control the speed of the cooling fan motors in two steps.

• w/o Air Conditioning System

  The ECM turns on or off the fan relays using signals calculated from the engine coolant temperature, engine speed and vehicle speed signals.

WIRING DIAGRAM

Refer to System Diagram Click here.

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING GTS (CONTROL THE 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 / Active Test / Control the Electric Cooling Fan.

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

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

      Result
      Result Proceed to OK A NG (w/o Air Conditioning System) B NG (w/ Air Conditioning System) C

   
   

   A

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

   C

   INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY VOLTAGE) Click here

   B

2. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY VOLTAGE)

   
   
   1. 

      Text in Illustration

      *1	Engine Room Relay Block
      *2	FAN No. 1 Relay Terminals

      Remove the FAN No. 1 relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition 5 (FAN No. 1 relay terminal) - Body ground Always 11 to 14 V

   3. Reinstall the FAN No. 1 relay.

   
   

   NG

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

   OK

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

   
   
   1. 

      Text in Illustration

      *1	Engine Room Relay Block
      *2	FAN No. 1 Relay Terminals

      Remove the FAN No. 1 relay from the engine room relay block.

   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 2 (FAN No. 1 relay terminal) - Body ground Ignition switch ON 11 to 14 V

   4. Reinstall the FAN No. 1 relay.

   
   

   NG

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

   OK

4. INSPECT FAN NO. 1 RELAY

   
   

   1. Inspect the FAN No. 1 relay Click here.

   
   

   NG

   REPLACE FAN NO. 1 RELAY

   OK

5. INSPECT COOLING FAN MOTOR

   
   

   1. Inspect the cooling fan motor Click here.

   
   

   NG

   REPLACE COOLING FAN MOTOR Click here

   OK

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

   
   

   1. Disconnect the A45 cooling fan motor connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition A45-1 - Body ground Always Below 1 Ω

   3. Reconnect the A45 cooling fan motor connector.

   
   

   NG

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

   OK

7. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

   
   

   1. Disconnect the A45 cooling fan motor connector.

   2. Remove the FAN No. 1 relay from the engine room 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 A45-2 - 3 (FAN No. 1 relay terminal) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A45-2 or 3 (FAN No. 1 relay terminal) - Body ground Always 10 kΩ or higher

   4. Reconnect the A45 cooling fan motor connector.

   5. Reinstall the FAN No. 1 relay.

   
   

   NG

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

   OK

8. CHECK HARNESS AND CONNECTOR (ECM - ENGINE ROOM RELAY BLOCK)

   
   

   1. Disconnect the A35 ECM connector.

   2. Remove the FAN No. 1 relay from the engine room 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 A35-11 (FAN1) - 1 (FAN No. 1 relay terminal) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A35-11 (FAN1) or 1 (FAN No. 1 relay terminal) - Body ground Always 10 kΩ or higher

   4. Reconnect the A35 ECM connector.

   5. Reinstall the FAN No. 1relay.

   
   

   OK

   REPLACE ECM Click here

   NG

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

9. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY VOLTAGE)

   
   
   1. 

      Text in Illustration

      *1	Engine Room Relay Block
      *2	FAN No. 1 Relay Terminals

      Remove the FAN No. 1 relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition 5 (FAN No. 1 relay terminal) - Body ground Always 11 to 14 V

   3. Reinstall the FAN No. 1 relay.

   
   

   NG

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

   OK

10. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 3 RELAY VOLTAGE)

    
    
    1. 

       Text in Illustration

       *1	Engine Room Relay Block
       *2	FAN No. 3 Relay Terminals

       Remove the FAN No. 3 relay from the engine room relay block.

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

       Standard Voltage
       Tester Connection Switch Condition Specified Condition 5 (FAN No. 3 relay terminal) - Body ground Always 11 to 14 V

    3. Reinstall the FAN No. 3 relay.

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FAN NO. 3 RELAY)

    OK

11. CHECK HARNESS AND CONNECTOR (FAN NO. 1, NO. 2 OR NO. 3 RELAY)

    
    
    1. 

       Text in Illustration

       *1	Engine Room Relay Block
       *2	FAN No. 1 Relay Terminals
       *3	FAN No. 2 Relay Terminals
       *4	FAN No. 3 Relay Terminals

       Remove the FAN No. 1, FAN No. 2 and FAN No. 3 relays from the engine room relay block.

    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 2 (FAN No. 1 relay terminal) - Body ground Ignition switch ON 11 to 14 V 1 (FAN No. 2 relay terminal) - Body ground Ignition switch ON 11 to 14 V 2 (FAN No. 3 relay terminal) - Body ground Ignition switch ON 11 to 14 V

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

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1, NO. 2 OR NO. 3 RELAY)

    OK

12. INSPECT FAN NO. 1 RELAY

    
    

    1. Inspect the FAN No. 1 relay Click here.

    
    

    NG

    REPLACE FAN NO. 1 RELAY

    OK

13. INSPECT FAN NO. 2 RELAY

    
    

    1. Inspect the FAN No. 2 relay Click here.

    
    

    NG

    REPLACE FAN NO. 2 RELAY

    OK

14. INSPECT FAN NO. 3 RELAY

    
    

    1. Inspect the FAN No. 3 relay Click here.

    
    

    NG

    REPLACE FAN NO. 3 RELAY

    OK

15. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)

    
    

    1. Remove the FAN No. 2 relay from the engine room 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 5 (FAN No. 2 relay terminal) - Body ground Always Below 1 Ω

    3. Reinstall the FAN No. 2 relay.

    
    

    NG

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

    OK

16. INSPECT COOLING FAN MOTOR

    
    

    1. Inspect the cooling fan motor Click here.

    
    

    NG

    REPLACE COOLING FAN MOTOR Click here

    OK

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

    
    

    1. Disconnect the A45 cooling fan motor connector.

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

       Standard Resistance (Check for Open)
       Tester Connection Condition Specified Condition A45-1 - Body ground Always Below 1 Ω

    3. Reconnect the A45 cooling fan motor connector.

    
    

    NG

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

    OK

18. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

    
    

    1. Disconnect the A45 cooling fan motor connector.

    2. Remove the FAN No. 1 and FAN No. 2 relays from the engine room 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 A45-2 - 3 (FAN No. 1 relay terminal) Always Below 1 Ω A45-2 - 4 (FAN No. 2 relay terminal) Always Below 1 Ω

       Standard Resistance (Check for Short)
       Tester Connection Condition Specified Condition A45-2 or 3 (FAN No. 1 relay terminal) or 4 (FAN No. 2 relay terminal) - Body ground Always 10 kΩ or higher

    4. Reconnect the A45 cooling fan motor connector.

    5. Reinstall the FAN No. 1 and FAN No. 2 relays.

    
    

    NG

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

    OK

19. 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

20. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

    
    

    1. Disconnect the A46 No. 2 cooling fan motor connector.

    2. Remove the FAN No. 2 and FAN No. 3 relays from the engine room 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 A46-1 - 3 (FAN No. 2 relay terminal) Always Below 1 Ω A46-2 - 3 (FAN No. 3 relay terminal) Always Below 1 Ω

       Standard Resistance (Check for Short)
       Tester Connection Condition Specified Condition A46-1 or 3 (FAN No. 2 relay terminal) - Body ground Always 10 kΩ or higher A46-2 or 3 (FAN No. 3 relay terminal) - Body ground Always 10 kΩ or higher

    4. Reconnect the A46 No. 2 cooling fan motor connector.

    5. Reinstall the FAN No. 2 and FAN No. 3 relays.

    
    

    NG

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

    OK

21. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY - FAN NO. 2 RELAY)

    
    
    1. 

       Text in Illustration

       *1	Engine Room Relay Block
       *2	FAN No. 1 Relay Terminals
       *3	FAN No. 2 Relay Terminals

       Remove the FAN No. 1 and FAN No. 2 relays from the engine room 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 terminal) - 2 (FAN No. 2 relay terminal) Always Below 1 Ω

       Standard Resistance (Check for Short)
       Tester Connection Condition Specified Condition 1 (FAN No. 1 relay terminal) or 2 (FAN No. 2 relay terminal) - Body ground Always 10 kΩ or higher

    3. Reinstall the FAN No. 1 and FAN No. 2 relays.

    
    

    NG

    REPLACE ENGINE ROOM RELAY BLOCK

    OK

22. CHECK HARNESS AND CONNECTOR (ECM - ENGINE ROOM RELAY BLOCK)

    
    

    1. Disconnect the A35 ECM connector.

    2. Remove the FAN No. 2 and FAN No. 3 relays from the engine room 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 A35-11 (FAN1) - 1 (FAN No. 1 relay terminal) Always Below 1 Ω A35-11 (FAN1) - 2 (FAN No. 2 relay terminal) Always Below 1 Ω A35-12 (FAN2) - 1 (FAN No. 3 relay terminal) Always Below 1 Ω

       Standard Resistance (Check for Short)
       Tester Connection Condition Specified Condition A35-11 (FAN1) or 1 (FAN No. 1 relay terminal) or 2 (FAN No. 2 relay terminal) - Body ground Always 10 kΩ or higher A35-12 (FAN2) or 1 (FAN No. 3 relay terminal) - Body ground Always 10 kΩ or higher

    4. Reconnect the A35 ECM connector.

    5. Reinstall the FAN No. 2 and FAN No. 3 relays.

    
    

    OK

    REPLACE ECM Click here

    NG

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