Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: Cooling Fan Circuit

DESCRIPTION

The ECM turns on or off the fan relays using signals calculated from the engine coolant temperature, air conditioning switch (on/off), air conditioning 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

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Before replacing the ECM, refer to Service Bulletin.

PROCEDURE

1.

PERFORM ACTIVE TEST USING GTS (CONTROL THE ENGINE COOLING FAN)

(a) Connect the GTS to the DLC3.

(b) Turn the ignition switch to ON (IG)

(c) Turn the GTS on.

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

Powertrain > Engine > Active Test

Tester Display

Control the Engine Cooling Fan

(e) Perform the Active Test according to the display on the GTS.

OK:

Active Tester Operation

Fan Operation

HIGH

Cooling fans high speed operate

LOW

Cooling fans low speed operate

OFF

Cooling fans stop

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

CHECK HARNESS AND CONNECTOR (FANL - FANH POWER SOURCE)

(a) Disconnect the A47 ECM connector.

(b) Turn the ignition switch to ON (IG)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A47-32 (FANH) - Body ground

Ignition switch ON

11 to 14 V

A47-33 (FANL) - Body ground

Ignition switch ON

11 to 14 V

*a

ECM connector

NG

GO TO STEP 12

OK

3.

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

(a) Remove the FAN NO. 1 relay from the No. 2 relay block.

(b) Remove the FAN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 1 Relay

*3

FAN NO. 3 Relay

-

-

Standard Voltage:

Tester Connection

Condition

Specified Condition

3 (FAN NO. 1 relay) - Body ground

Always

11 to 14 V

3 (FAN NO. 3 relay) - Body ground

Always

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY AND FAN NO. 3 RELAY POWER SOURCE CIRCUIT)

OK

4.

INSPECT COOLING FAN RELAY (FAN NO. 1, FAN NO. 2 AND FAN NO. 3)

(a) Inspect the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 relay.

Click here

Result

Proceed to

OK

A

NG (FAN NO. 1 relay)

B

NG (FAN NO. 2 relay)

C

NG (FAN NO. 3 relay)

D

B

REPLACE FAN NO. 1 RELAY

C

REPLACE FAN NO. 2 RELAY

D

REPLACE FAN NO. 3 RELAY

A

5.

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

(a) Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 2 Relay

(b) 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) - Body ground

Always

Below 1 Ω

NG

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

OK

6.

INSPECT NO. 2 COOLING FAN MOTOR

(a) Inspect the No. 2 cooling fan motor.

Click here

NG

REPLACE NO. 2 COOLING FAN MOTOR

OK

7.

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

(a) Disconnect the A182 cooling fan motor RH connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A182-1 - Body ground

Always

Below 1 Ω

NG

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

OK

8.

CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY AND FAN NO. 2 RELAY - COOLING FAN MOTOR RH)

(a) Disconnect the A182 cooling fan motor RH connector.

(b) Remove the FAN NO. 1 relay from the No. 2 relay block.

(c) Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 1 Relay

*3

FAN NO. 2 Relay

-

-

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A182-2 - 5 (FAN NO. 1 relay)

Always

Below 1 Ω

A182-2 - 4 (FAN NO. 2 relay)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A182-2 or 5 (FAN NO. 1 relay) - Body ground

Always

10 kΩ or higher

A182-2 or 4 (FAN NO. 2 relay) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY AND FAN NO. 2 RELAY - COOLING FAN MOTOR RH)

OK

9.

INSPECT COOLING FAN MOTOR

(a) Inspect the cooling fan motor.

Click here

NG

REPLACE COOLING FAN MOTOR

OK

10.

CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY AND FAN NO. 3 RELAY - COOLING FAN MOTOR LH)

(a) Disconnect the A183 cooling fan motor LH connector.

(b) Remove the FAN NO. 2 relay and FAN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 1 Relay

*3

FAN NO. 3 Relay

-

-

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A183 - 3 (FAN NO. 2 relay)

Always

Below 1 Ω

A183-2 - 5 (FAN NO. 3 relay)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A183-1 or 3 (FAN NO. 2 relay) - Body ground

Always

10 kΩ or higher

A183-2 or 5 (FAN NO. 3 relay) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 2 RELAY AND FAN NO. 3 RELAY - COOLING FAN MOTOR LH)

OK

11.

CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - FAN NO. 2 RELAY)

(a) Remove the FAN NO. 1 relay from the No. 2 relay block.

(b) Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 1 Relay

*3

FAN NO. 2 Relay

-

-

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) - 1 (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

OK

REPLACE ECM

NG

REPAIR OR REPLACE NO. 2 RELAY BLOCK

12.

INSPECT COOLING FAN RELAY (FAN NO. 1, FAN NO. 2 AND FAN NO. 3)

(a) Inspect the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 relay.

Click here

Result

Proceed to

OK

A

NG (FAN NO. 1 relay)

B

NG (FAN NO. 2 relay)

C

NG (FAN NO. 3 relay)

D

B

REPLACE FAN NO. 1 RELAY

C

REPLACE FAN NO. 2 RELAY

D

REPLACE FAN NO. 3 RELAY

A

13.

CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY, FAN NO. 2 RELAY AND FAN NO. 3 RELAY POWER SOURCE CIRCUIT)

(a) Remove the FAN NO. 1 relay from the No. 2 relay block.

(b) Remove the FAN NO. 2 relay and FAN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 1 Relay

*3

FAN NO. 2 Relay

*4

FAN NO. 3 Relay

Standard Voltage:

Tester Connection

Condition

Specified Condition

1 (FAN NO. 1 relay) - Body ground

Always

11 to 14 V

1 (FAN NO. 2 relay) - Body ground

Always

11 to 14 V

1 (FAN NO. 3 relay) - Body ground

Always

11 to 14 V

OK

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

NG

14.

CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY, FAN NO. 2 RELAY AND FAN NO. 3 RELAY - NO. 1 INTEGRATION RELAY)

(a) Remove the FAN NO. 1 relay from the No. 2 relay block.

(b) Remove the FAN NO. 2 relay and FAN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(c) Remove the No. 1 integration relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(d) Disconnect the 2B No. 1 integration relay connector.

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

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

FAN NO. 1 Relay

*3

FAN NO. 2 Relay

*4

FAN NO. 3 Relay

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

1 (FAN NO. 1 relay) - 5 (EFI-MAIN NO. 1 relay)

Always

Below 1 Ω

1 (FAN NO. 2 relay) - 5 (EFI-MAIN NO. 1 relay)

Always

Below 1 Ω

1 (FAN NO. 3 relay) - 5 (EFI-MAIN NO. 1 relay)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

1 (FAN NO. 1 relay) or 5 (EFI-MAIN NO. 1 relay) - Body ground

Always

10 kΩ or higher

1 (FAN NO. 2 relay) or 5 (EFI-MAIN NO. 1 relay) - Body ground

Always

10 kΩ or higher

1 (FAN NO. 3 relay) or 5 (EFI-MAIN NO. 1 relay) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY, FAN NO. 2 RELAY AND FAN NO. 3 RELAY - EFI-MAIN NO. 1 RELAY)

OK

15.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY POWER SOURCE CIRCUIT)

(a) Remove the EFI-MAIN NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(b) Disconnect the EFI-MAIN NO. 1 relay connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

3 (EFI-MAIN NO. 1 relay) - Body ground

Always

11 to 14 V

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

EFI-MAIN NO. 1 Relay

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY POWER SOURCE CIRCUIT)

OK

16.

CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 - BODY GROUND)

(a) Remove the EFI-MAIN NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(b) Disconnect the EFI-MAIN NO. 1 relay connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

EFI-MAIN NO. 1 - Body ground

Always

Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - BODY GROUND)

OK

17.

CHECK HARNESS AND CONNECTOR (ECM - EFI-MAIN NO. 1 RELAY)

(a) Disconnect the A47 ECM connector.

(b) Disconnect the EFI-MAIN NO. 1 relay connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A47-15 (MREL) - 1(EFI-MAIN NO. 1 relay)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A47-15 (MREL) or 1(EFI-MAIN NO. 1 relay) - Body ground

Always

10 kΩ or higher

OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - EFI MAIN NO. 1 RELAY)

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