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Home >> Toyota >> 2012 >> Camry L4-2.5L (2AR-FXE) Hybrid >> Repair and Diagnosis >> Engine, Cooling and Exhaust >> Cooling System >> Radiator Cooling Fan >> Testing and Inspection >> Component Tests and General Diagnostics >> Cooling Fan Circuit

Cooling Fan Circuit





2AR-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 ECU to regulate the cooling fans. The cooling fan ECU controls the 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 ECU, 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).

(c) Turn the Techstream on.

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

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

OK:





Result:





B -- INSPECT COOLING FAN MOTOR (COOLING FAN MOTOR AND NO. 2 COOLING FAN MOTOR)

C -- CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

2. INSPECT COOLING FAN MOTOR (COOLING FAN MOTOR AND NO. 2 COOLING FAN MOTOR)

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

Result:





B -- REPLACE COOLING FAN MOTOR Removal

C -- REPLACE NO.2 COOLING FAN MOTOR Removal
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU 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





NG -- CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - BODY GROUND)
OK -- Continue to next step.

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

(a) Disconnect the ECM connector.

(b) Disconnect the cooling fan ECU connector.

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

Standard Resistance:





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

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

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

(a) Disconnect the cooling fan ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - BODY GROUND)
OK -- Continue to next step.

6. INSPECT FAN RELAY

(a) Inspect the FAN relay Testing and Inspection.

NG -- REPLACE FAN RELAY
OK -- Continue to next step.

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

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





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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - AUXILIARY BATTERY)
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - FAN RELAY)

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

(b) Disconnect the cooling fan ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - FAN RELAY)
OK -- Continue to next step.

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

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

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - BODY GROUND)
OK -- Continue to next step.

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

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

(b) Disconnect the instrument panel junction block assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
OK -- Continue to next step.

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

(a) Disconnect the instrument panel junction block assembly connector.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (IG1 NO. 2 RELAY)
OK -- Continue to next step.

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

(a) Disconnect the instrument panel junction block assembly connector.





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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - AUXILIARY BATTERY)
OK -- Continue to next step.

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

(a) Disconnect the instrument panel junction block assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)
OK -- Continue to next step.

14. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the instrument panel junction block assembly connector.

(b) Disconnect the power management control ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - POWER MANAGEMENT CONTROL ECU)

OK -- CHECK SMART KEY SYSTEM How To Proceed With Troubleshooting

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

(a) Disconnect the ECM connector.

(b) Disconnect the cooling fan ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU)
OK -- Continue to next step.

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

(a) Disconnect the cooling fan motor connector.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE COOLING FAN MOTOR Removal
OK -- Continue to next step.

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

(a) Disconnect the No. 2 cooling fan motor connector.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE NO.2 COOLING FAN MOTOR Removal

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
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