Cooling Fan System Cooling Fan Circuit

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE ELECTRIC COOLING FAN)

INSPECT ECM (FANL AND FANH VOLTAGE)

INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY AND FAN NO. 3 RELAY VOLTAGE)

INSPECT FAN NO. 1 RELAY

INSPECT FAN NO. 2 RELAY

INSPECT FAN NO. 3 RELAY

CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - BODY GROUND)

INSPECT NO. 1 COOLING FAN MOTOR (RADIATOR FAN MOTOR)

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

CHECK HARNESS AND CONNECTOR (NO. 1 COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

INSPECT NO. 2 COOLING FAN MOTOR (AIR CONDITIONER CONDENSER FAN MOTOR)

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

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

CHECK FUSE (ECU-IG NO. 1 FUSE)

INSPECT FAN NO. 1 RELAY

INSPECT FAN NO. 2 RELAY

INSPECT FAN NO. 3 RELAY

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

CHECK HARNESS AND CONNECTOR (ECU-IG NO. 1 FUSE - ENGINE ROOM RELAY BLOCK)

INSPECT FAN NO. 1 RELAY

INSPECT FAN NO. 3 RELAY

CHECK HARNESS AND CONNECTOR

COOLING FAN SYSTEM - Cooling Fan Circuit


DESCRIPTION

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.

WIRING DIAGRAM


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


INSPECTION PROCEDURE

NOTICE:
After replacing the ECM, the new ECM needs registration (COROLLA_ZRE142 RM000000PDT0ANX.html).
1.PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE ELECTRIC COOLING FAN)

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

    OK:

    Techstream Operation
    		Specified Condition
    ON
    		Fans operate
    OFF
    		Fans do not operate

    Result:

    Result
    		Proceed to
    OK
    		A
    NG (Cooling fans do not operate)
    		B
    NG (Cooling fans do not stop)
    		C


B
Go to step 2

C
Go to step 20
A

PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE (COROLLA_ZRE142 RM000003E0003FX.html)

2.INSPECT ECM (FANL AND FANH VOLTAGE)


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

  1. Disconnect the ECM 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
    A50-21 (FANL) - Body ground
    		Ignition switch ON
    		11 to 14 V
    A50-22 (FANH) - Body ground
    		Ignition switch ON
    		11 to 14 V

  1. Reconnect the ECM connector.



NG
Go to step 14
OK


3.INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1 RELAY AND FAN NO. 3 RELAY VOLTAGE)


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

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

  1. 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
    5 (FAN No. 3 relay) - Body ground
    		Always
    		11 to 14 V

  1. Reinstall the FAN No. 1 relay and FAN No. 3 relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ENGINE ROOM RELAY BLOCK)
OK


4.INSPECT FAN NO. 1 RELAY

  1. Inspect the FAN No. 1 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 1 RELAY
OK


5.INSPECT FAN NO. 2 RELAY

  1. Inspect the FAN No. 2 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 2 RELAY
OK


6.INSPECT FAN NO. 3 RELAY

  1. Inspect the FAN No. 3 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 3 RELAY
OK


7.CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - BODY GROUND)

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

  1. Reinstall the FAN No. 2 relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - BODY GROUND)
OK


8.INSPECT NO. 1 COOLING FAN MOTOR (RADIATOR FAN MOTOR)

  1. Inspect the No. 1 cooling fan motor (COROLLA_ZRE142 RM000000YFJ0A9X.html).



NG
REPLACE NO. 1 COOLING FAN MOTOR (RADIATOR FAN MOTOR) (COROLLA_ZRE142 RM000002GF700WX.html)
OK


9.CHECK HARNESS AND CONNECTOR (NO. 1 COOLING FAN MOTOR - BODY GROUND)

  1. Disconnect the No. 1 cooling fan motor (radiator fan motor) connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    A58-1 - Body ground
    		Always
    		Below 1 Ω

  1. Reconnect the No. 1 cooling fan motor connector.



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


10.CHECK HARNESS AND CONNECTOR (NO. 1 COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

  1. Disconnect the No. 1 cooling fan motor (radiator fan motor) connector.

  1. Remove the FAN No. 1 relay and FAN No. 2 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
    A58-2 - 5 (FAN No. 1 relay)
    		Always
    		Below 1 Ω
    A58-2 - 4 (FAN No. 2 relay)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    A58-2 or 5 (FAN No. 1 relay) - Body ground
    		Always
    		10 kΩ or higher
    A58-2 or 4 (FAN No. 2 relay) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the radiator fan motor connector.

  1. Reinstall the FAN No. 1 relay and FAN No. 2 relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)
OK


11.INSPECT NO. 2 COOLING FAN MOTOR (AIR CONDITIONER CONDENSER FAN MOTOR)

  1. Inspect the No. 2 cooling fan motor (COROLLA_ZRE142 RM000000YFJ0A9X.html).



NG
REPLACE NO. 2 COOLING FAN MOTOR (AIR CONDITIONER CONDENSER FAN MOTOR) (COROLLA_ZRE142 RM000002GF700WX.html)
OK


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

  1. Disconnect the No. 2 cooling fan motor (air conditioner condenser fan motor) connector.

  1. Remove the FAN No. 2 relay and FAN No. 3 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
    A59-1 - 3 (FAN No. 2 relay)
    		Always
    		Below 1 Ω
    A59-2 - 3 (FAN No. 3 relay)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    A59-1 or 3 (FAN No. 2 relay) - Body ground
    		Always
    		10 kΩ or higher
    A59-2 or 3 (FAN No. 3 relay) - Body ground
    		Always
    		10 kΩ or higher

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

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



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


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


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

  1. Remove the FAN No. 1 relay and FAN No. 2 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
    1 (FAN No. 1 relay) - 1 (FAN No. 2 relay)
    		Always
    		Below 1 Ω
    2 (FAN No. 1 relay) - 2 (FAN No. 2 relay)
    		Always
    		Below 1 Ω
    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1 (FAN No. 1 relay) or 1 (FAN No. 2 relay) - Body ground
    		Always
    		10 kΩ or higher
    2 (FAN No. 1 relay) or 2 (FAN No. 2 relay) - Body ground
    		Always
    		10 kΩ or higher

  1. Reinstall the FAN No. 1 relay and FAN No. 2 relay.



NG
REPLACE ENGINE ROOM RELAY BLOCK
OK

REPLACE ECM (COROLLA_ZRE142 RM000002WT402ZX.html)

14.CHECK FUSE (ECU-IG NO. 1 FUSE)


    Corolla. Zre142 Aze141.2Az-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


15.INSPECT FAN NO. 1 RELAY

  1. Inspect the FAN No. 1 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 1 RELAY
OK


16.INSPECT FAN NO. 2 RELAY

  1. Inspect the FAN No. 2 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 2 RELAY
OK


17.INSPECT FAN NO. 3 RELAY

  1. Inspect the FAN No. 3 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 3 RELAY
OK


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

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

  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
    2 (FAN No. 1 relay) - A50-22 (FANH)
    		Always
    		Below 1 Ω
    2 (FAN No. 2 relay) - A50-22 (FANH)
    		Always
    		Below 1 Ω
    2 (FAN No. 3 relay) - A50-21 (FANL)
    		Always
    		Below 1 Ω

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

  1. Reconnect the ECM connector.



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


19.CHECK HARNESS AND CONNECTOR (ECU-IG NO. 1 FUSE - ENGINE ROOM RELAY BLOCK)

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

  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 (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    1 (FAN No. 1 relay) - 2 (ECU-IG No. 1 fuse)
    		Always
    		Below 1 Ω
    1 (FAN No. 2 relay) - 2 (ECU-IG No. 1 fuse)
    		Always
    		Below 1 Ω
    1 (FAN No. 3 relay) - 2 (ECU-IG No. 1 fuse)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    1 (FAN No. 1 relay) or 2 (ECU-IG No. 1 fuse) - Body ground
    		Always
    		10 kΩ or higher
    1 (FAN No. 2 relay) or 2 (ECU-IG No. 1 fuse) - Body ground
    		Always
    		10 kΩ or higher
    1 (FAN No. 3 relay) or 2 (ECU-IG No. 1 fuse) - Body ground
    		Always
    		10 kΩ or higher

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

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



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

CHECK FOR INTERMITTENT PROBLEMS (COROLLA_ZRE142 RM000000PDQ0VNX.html)

20.INSPECT FAN NO. 1 RELAY

  1. Inspect the FAN No. 1 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 1 RELAY
OK


21.INSPECT FAN NO. 3 RELAY

  1. Inspect the FAN No. 3 relay (COROLLA_ZRE142 RM000000XX00AMX.html).



NG
REPLACE FAN NO. 3 RELAY
OK


22.CHECK HARNESS AND CONNECTOR

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

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    2 (FAN No. 1 relay) or A50-22 (FANH) - Body ground
    		Always
    		10 kΩ or higher
    2 (FAN No. 2 relay) or A50-22 (FANH) - Body ground
    		Always
    		10 kΩ or higher
    2 (FAN No. 3 relay) or A50-21 (FANL) - Body ground
    		Always
    		10 kΩ or higher

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

  1. Reconnect the ECM connector.



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

REPLACE ECM (COROLLA_ZRE142 RM000002WT402ZX.html)