Up to 08/2009

2GR-FXE COOLING: COOLING FAN SYSTEM: Cooling Fan Circuit
- 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





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE ELECTRIC COOLING FAN)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG) and turn the Techstream on.

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

(d) Check operation of the cooling fans while operating them using the Techstream.

OK:





Result:





D -- INSPECT COOLING FAN SYSTEM (FOR MAIN AND SUB FANS)

C -- INSPECT COOLING FAN SYSTEM (FOR SUB FAN)

B -- INSPECT COOLING FAN SYSTEM (FOR MAIN FAN)

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2. INSPECT COOLING FAN SYSTEM (FOR MAIN FAN)

(a) Disconnect the A76 ECM connector.

(b) Turn the power switch on (IG).

(c) Check the operation of the cooling fan (for main fan).

OK:

The cooling fan (for main fan) operates.

(d) Reconnect the A76 ECM connector.

NG -- CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - ECM)
OK -- Continue to next step.

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

(a) Disconnect the cooling fan ECU connector.





(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the cooling fan ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COOLING FAN ECU (FOR MAIN FAN)

4. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - ECM)

(a) Disconnect the cooling fan ECU connector.





(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the cooling fan ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. INSPECT COOLING FAN MOTOR (FOR MAIN FAN)

(a) Inspect the cooling fan motor (for main fan) Testing and Inspection.

NG -- REPLACE COOLING FAN MOTOR (FOR MAIN FAN)
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) POWER SOURCE)

(a) Disconnect the cooling fan ECU connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the cooling fan ECU connector.

NG -- CHECK HARNESS OR CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - BODY GROUND)

OK -- REPLACE COOLING FAN ECU (FOR MAIN FAN)

7. CHECK HARNESS OR CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - BODY GROUND)

(a) Disconnect the cooling fan ECU connector.

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





Standard Resistance:





Text in Illustration





(c) Reconnect the cooling fan ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

8. INSPECT RELAY (RDI FAN NO. 1)

(a) Remove the RDI FAN NO. 1 relay from the engine room relay block.





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

Standard Resistance:





(c) Reinstall the RDI FAN NO. 1 relay.

NG -- REPLACE RELAY (RDI FAN NO. 1)
OK -- Continue to next step.

9. CHECK HARNESS AND CONNECTOR (RDI FAN NO. 1 RELAY POWER SOURCE)

(a) Remove the RDI FAN NO. 1 relay from the engine room relay block.





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

Standard Voltage:





Text in Illustration





(c) Reinstall the RDI FAN NO. 1 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (RDI FAN NO. 1 RELAY - BATTERY)
OK -- Continue to next step.

10. CHECK HARNESS AND CONNECTOR (RDI FAN NO. 1 RELAY POWER SOURCE)

(a) Remove the RDI FAN NO. 1 relay from the engine room relay block.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reinstall the RDI FAN NO. 1 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (RDI FAN NO. 1 RELAY - IG1 RELAY)
OK -- Continue to next step.

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

(a) Remove the RDI FAN NO. 1 relay from the engine room relay block.





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

Standard Resistance:





Text in Illustration





(c) Reinstall the RDI FAN NO. 1 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU (FOR MAIN FAN) - RDI FAN NO. 1 RELAY)

12. INSPECT COOLING FAN SYSTEM (FOR SUB FAN)

(a) Disconnect the A76 ECM connector.

(b) Turn the power switch on (IG).

(c) Check operation of the cooling fan (for sub fan).

OK:

The cooling fan (for sub fan) operates.

(d) Reconnect the A76 ECM connector.

NG -- CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - ECM)
OK -- Continue to next step.

13. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - ECM)

(a) Disconnect the cooling fan ECU connector.





(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the cooling fan ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COOLING FAN ECU (FOR SUB FAN)

14. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - ECM)

(a) Disconnect the cooling fan ECU connector.





(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the cooling fan ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

15. INSPECT NO. 2 COOLING FAN MOTOR (FOR SUB FAN)

(a) Inspect the No. 2 cooling fan motor (for sub fan) Testing and Inspection.

NG -- REPLACE NO. 2 COOLING FAN MOTOR (FOR SUB FAN)
OK -- Continue to next step.

16. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) POWER SOURCE)

(a) Disconnect the cooling fan ECU connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the cooling fan ECU connector.

NG -- CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - BODY GROUND)

OK -- REPLACE COOLING FAN ECU (FOR SUB FAN)

17. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - BODY GROUND)

(a) Disconnect the cooling fan ECU connector.

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





Standard Resistance:





Text in Illustration





(c) Reconnect the cooling fan ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

18. INSPECT RELAY (RDI FAN NO. 2)

(a) Remove the RDI FAN NO. 2 relay from the engine room No. 3 relay block.





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

Standard Resistance:





(c) Reinstall the RDI FAN NO. 2 relay.

NG -- REPLACE RELAY (RDI FAN NO. 2)
OK -- Continue to next step.

19. CHECK HARNESS AND CONNECTOR (RDI FAN NO. 2 RELAY POWER SOURCE)

(a) Remove the RDI FAN NO. 2 relay from the engine room No. 3 relay block.





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

Standard Voltage:





Text in Illustration





(c) Reinstall the RDI FAN NO. 2 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (RDI FAN NO. 2 - BATTERY)
OK -- Continue to next step.

20. INSPECT RELAY VOLTAGE (RDI FAN NO. 2 RELAY)

(a) Remove the RDI FAN NO. 2 relay from the engine room No. 3 relay block.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reinstall the RDI FAN NO. 2 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (RDI FAN NO. 2 RELAY - IG1 RELAY)
OK -- Continue to next step.

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

(a) Remove the RDI FAN NO. 2 relay from the engine room No. 3 relay block.





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

Standard Resistance:





Text in Illustration





(c) Reinstall the RDI FAN NO. 2 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU (FOR SUB FAN) - RDI FAN NO. 2 RELAY)

22. INSPECT COOLING FAN SYSTEM (FOR MAIN AND SUB FANS)

(a) Disconnect the A76 ECM connector.

(b) Turn the power switch on (IG).

(c) Check operation of the cooling fans (for main and sub fans).

OK:

The cooling fans (for main and sub fans) operate.

(d) Reconnect the A76 ECM connector.

NG -- CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN AND SUB FANS) - ECM)
OK -- Continue to next step.

23. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN AND SUB FANS) - ECM)

(a) Disconnect the cooling fan ECU connectors.





(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the cooling fan ECU connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal

24. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU (FOR MAIN FAN AND SUB FANS) - ECM)

(a) Disconnect the cooling fan ECU connectors.





(b) Disconnect the ECM connector.

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

Standard Resistance:





Text in Illustration





(d) Reconnect the ECM connector.

(e) Reconnect the cooling fan ECU connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

25. CHECK HARNESS AND CONNECTOR (RDI FAN NO. 1 RELAY POWER SOURCE)

(a) Remove the RDI FAN NO. 1 relay from the engine room relay block.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reinstall the RDI FAN NO. 1 relay.

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

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