Cooling Fan System Cooling Fan Circuit

Engine Hybrid System. Corolla. Zre142 Aze141
2Zr-Fe Cooling. Corolla. Zre142 Aze141

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL COOLING FAN)

INSPECT COOLING FAN ECU

CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)

INSPECT COOLING FAN MOTOR

CHECK COOLING FAN ECU (POWER SOURCE)

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

INSPECT FAN NO. 1 RELAY

INSPECT FUSIBLE LINK BLOCK (RDI FAN FUSE)

INSPECT FUSE (ECU-IG NO. 1 FUSE)

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

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

CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - ECU-IG NO. 1 FUSE)

CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - RDI FAN FUSE)

CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)

COOLING FAN SYSTEM - 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 fan. 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. The cooling fan speed is determined based on the engine coolant temperature, air conditioner operating conditions, engine speed, and vehicle speed.

WIRING DIAGRAM


Corolla. Zre142 Aze141.2Zr-Fe Cooling.Cooling System.Cooling Fan System Cooling Fan Circuit


Corolla. Zre142 Aze141.2Zr-Fe Cooling.Cooling System.Cooling Fan System Cooling Fan Circuit


INSPECTION PROCEDURE

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

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

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

  1. Check the operation of the cooling fan using the Techstream.

    OK:

    Tester Operation
    		Fan Operation
    ON
    		Cooling fan operates
    OFF
    		Cooling fan stopped

Result:

Result
Proceed to
OK
A
NG (Cooling fan does not operate)
B
NG (Cooling fan does not stop)
C


B
Go to step 2

C
Go to step 14
A

PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE (COROLLA_ZRE142 RM000003E0003GX.html)

2.INSPECT COOLING FAN ECU


    Corolla. Zre142 Aze141

  1. Disconnect the ECM connector.

  1. Turn the ignition switch to ON.

  1. Check the operation of the cooling fan.

    OK:
    The cooling fan operates.

  1. Reconnect the ECM connector.



NG
Go to step 3
OK

REPLACE ECM (COROLLA_ZRE142 RM000001CN0030X.html)

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

  1. Disconnect the cooling fan ECU connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    A50-43 (RFC) - A41-2 (SI)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    A50-43 (RFC) or A41-2 (SI) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the ECM connector.

  1. Reconnect the cooling fan ECU connector.



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


4.INSPECT COOLING FAN MOTOR


    Corolla. Zre142 Aze141.2Zr-Fe Cooling.Cooling System.Cooling Fan System Cooling Fan Circuit

  1. Disconnect the cooling fan ECU connector.

  1. Connect a battery positive (+) lead to terminal 2 of the cooling fan motor connector, and connect a battery negative (-) lead to terminal 1 of the cooling fan motor connector.

  1. Check the cooling fan motor.

    OK:
    The cooling fan operates.

  1. Reconnect the cooling fan ECU connector.



NG
REPLACE COOLING FAN MOTOR (COROLLA_ZRE142 RM000002X0S06WX.html)
OK


5.CHECK COOLING FAN ECU (POWER SOURCE)


    Corolla. Zre142 Aze141.2Zr-Fe Cooling.Cooling System.Cooling Fan System Cooling Fan Circuit

  1. Disconnect the cooling fan ECU connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A41-1 (+B1) - A41-3 (E1)
    		Ignition switch ON
    		11 to 14 V

  1. Reconnect the cooling fan ECU connector.



NG
Go to step 6
OK

REPLACE COOLING FAN ECU (COROLLA_ZRE142 RM0000020WP047X.html)

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

  1. Disconnect the cooling fan ECU connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    A41-3 (E1) - Body ground
    		Always
    		Below 1 Ω

  1. Reconnect the cooling fan ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - BODY GROUND)
OK


7.INSPECT FAN NO. 1 RELAY


    Corolla. Zre142 Aze141.2Zr-Fe Cooling.Cooling System.Cooling Fan System Cooling Fan Circuit

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

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3 - 5
    		Normal
    		10 kΩ or higher
    3 - 5
    		Apply battery voltage between terminals 1 and 2
    		Below 1 Ω

  1. Reinstall the FAN No. 1 relay.



NG
REPLACE FAN NO. 1 RELAY
OK


8.INSPECT FUSIBLE LINK BLOCK (RDI FAN FUSE)

  1. Check the RDI FAN fuse.



NG
REPLACE FUSIBLE LINK BLOCK
OK


9.INSPECT FUSE (ECU-IG NO. 1 FUSE)


    Corolla. Zre142 Aze141.2Zr-Fe Cooling.Cooling System.Cooling Fan System Cooling Fan Circuit

  1. Remove the ECU-IG No. 1 fuse from the instrument panel junction block.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    ECU-IG No. 1 fuse
    		Always
    		Below 1 Ω

  1. Reinstall the ECU-IG No. 1 fuse.



NG
REPLACE FUSE (ECU-IG NO. 1 FUSE)
OK


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

  1. Disconnect the cooling fan ECU connector.

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

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    A41-1 (+B1) - 5 (FAN No.1 relay)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    A41-1 (+B1) or 5 (FAN No.1 relay) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the cooling fan ECU connector.



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


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

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

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    2 (FAN No.1 relay) - Body ground
    		Always
    		Below 1 Ω

  1. Reinstall the FAN No. 1 relay.



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


12.CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - ECU-IG NO. 1 FUSE)

  1. Remove the ECU-IG No. 1 fuse from the instrument panel junction block.

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

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    2 (ECU-IG No. 1 fuse) - 1 (FAN No.1 relay)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    2 (ECU-IG No. 1 fuse) or 1 (FAN No.1 relay) - Body ground
    		Always
    		10 kΩ or higher

  1. Reinstall the ECU-IG No. 1 fuse.

  1. Reinstall the FAN No. 1 relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - ECU-IG NO. 1 FUSE)
OK


13.CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - RDI FAN FUSE)

  1. Remove the fusible link block assembly from the engine room relay block.

  1. Disconnect the fusible link block connector.

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    3 (FAN No. 1 relay) - 1C-2 (Fusible link block)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    3 (FAN No. 1 relay) or 1C-2 (Fusible link block) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the fusible link block connector.

  1. Reinstall the fusible link block assembly.



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

REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - RDI FAN FUSE)

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

  1. Disconnect the cooling fan ECU connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    A50-43 (RFC) - A41-2 (SI)
    		Always
    		Below 1 Ω

  1. Reconnect the ECM connector.

  1. Reconnect the cooling fan ECU connector.



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

REPLACE COOLING FAN ECU (COROLLA_ZRE142 RM0000020WP047X.html)