COOLING(H4SO) > Radiator Fan System

INSPECTION

DETECTING CONDITION:

• Engine coolant temperature is 95°C (203°F) or more.

• Vehicle speed is 19 km/h (12 MPH) or below.

TROUBLE SYMPTOMS:

Radiator main and sub fans do not rotate under the above conditions.

STEPCHECKYESNO

1.CHECK OPERATION OF RADIATOR FAN.

1) Connect the test mode connector.

2) Turn the ignition switch to ON.

3) Using the Subaru Select Monitor, check the forced operation of the radiator fan relay.

NOTE:

• When performing a forced operation radiator fan relay check using the Subaru Select Monitor, the radiator main fan and sub fan will repeat low speed revolution → high speed revolution → OFF in this order.

• Subaru Select Monitor

Refer to Compulsory Valve Operation Check Mode for detail procedures.

Do the radiator main and sub fans rotate at low speed?

2.CHECK OPERATION OF RADIATOR FAN.

1) Connect the test mode connector.

2) Turn the ignition switch to ON.

3) Using the Subaru Select Monitor, check the forced operation of the radiator fan relay.

NOTE:

• When performing a forced operation radiator fan relay check using the Subaru Select Monitor, the radiator main fan and sub fan will repeat low speed revolution → high speed revolution → OFF in this order.

• Subaru Select Monitor

Refer to Compulsory Valve Operation Check Mode for detail procedures.

Do the radiator main and sub fans rotate at high speed?

Radiator main fan system is normal.

3.CHECK POWER SUPPLY TO MAIN FAN RELAY.

1) Turn the ignition switch to OFF.

2) Remove the main fan relay from the A/C relay holder.

3) Measure the voltage between the main fan relay terminal and chassis ground.

Connector & terminal

(F27) No. 31 (+) — Chassis ground (−):

Is the voltage 10 V or more?

4.CHECK POWER SUPPLY TO MAIN FAN RELAY.

1) Turn the ignition switch to ON.

2) Measure the voltage between the main fan relay terminal and chassis ground.

Connector & terminal

(F27) No. 34 (+) — Chassis ground (−):

Is the voltage 10 V or more?

5.CHECK FUSE.

1) Remove the fuse from the A/C relay holder.

2) Check the condition of fuse.

Is the fuse blown out?

Replace the fuse.

6.FUSE TERMINAL AND MAIN FAN RELAY TERMINAL HARNESS INSPECTION.

1) Turn the ignition switch to OFF.

2) Measure the resistance between the fuse terminal and main fan relay terminal.

Terminals

No. 2 — No. 31:

Is the resistance less than 1 Ω?

Repair the power supply line.

Repair the open circuit of harness.

7.CHECK FUSE.

1) Turn the ignition switch to OFF.

2) Remove the fuse No. 18.

3) Check the condition of fuse.

Is the fuse blown out?

Replace the fuse.

Repair the power supply line.

8.CHECK MAIN FAN RELAY.

1) Turn the ignition switch to OFF.

2) Measure the resistance between main fan relay terminals.

Terminals

No. 30 — No. 31:

Is the resistance 1 MΩ or more?

Replace the main fan relay.

9.CHECK MAIN FAN RELAY.

1) Connect the battery to terminals No. 32 and No. 34 of the main fan relay.

2) Measure the resistance between main fan relay terminals.

Terminals

No. 30 — No. 31:

Is the resistance less than 1 Ω?

Replace the main fan relay.

10.CHECK HARNESS BETWEEN MAIN FAN RELAY TERMINAL AND MAIN FAN MOTOR CONNECTOR.

1) Disconnect the connector from the main fan motor.

2) Measure the resistance of the harness between main fan relay terminal and main fan motor connector.

Connector & terminal

Turbo model

(F17) No. 1 — (F27) No. 30:

Non-turbo model

(F17) No. 2 — (F27) No. 30:

Is the resistance less than 1 Ω?

Repair the open circuit of the harness between main fan relay terminal and main fan motor connector.

11.CHECK THE HARNESS BETWEEN MAIN FAN MOTOR CONNECTOR AND FAN MODE RELAY CONNECTOR.

1) Remove the fan mode relay from A/C relay holder.

2) Measure the resistance of harness between main fan motor connector and fan mode relay connector.

Connector & terminal

Turbo model

(F17) No. 2 — (F27) No. 9:

Non-turbo model

(F17) No. 1 — (F27) No. 9:

Is the resistance less than 1 Ω?

Repair the open circuit of the harness between the main fan motor connector and fan mode relay connector.

12.CHECK POOR CONTACT.

Check poor contact of main fan motor connector.

Is there poor contact in main fan motor connector?

Repair the poor contact of main fan motor connector.

13.CHECK MAIN FAN MOTOR.

Connect the battery positive (+) terminal to terminal No. 1 (Turbo model), No. 2 (Non-turbo model), and the ground line (−) to No. 2 (Turbo model), No. 1 (Non-turbo model) of the main fan motor.

Does the main fan rotate?

Replace the main fan motor with a new part.

14.CHECK FAN MODE RELAY.

Measure the resistance of fan mode relay.

Terminals

No. 6 — No. 9:

Is the resistance less than 1 Ω?

Replace the fan mode relay.

15.CHECK HARNESS BETWEEN FAN MODE RELAY TERMINAL AND SUB FAN MOTOR CONNECTOR.

1) Disconnect the connector from the sub fan motor.

2) Measure the resistance of harness between fan mode relay terminal and sub fan motor connector.

Connector & terminal

Turbo model

(F16) No. 1 — (F27) No. 6:

Non-turbo model

(F16) No. 2 — (F27) No. 6:

Is the resistance less than 1 Ω?

Repair the open circuit of the harness between fan mode relay terminal and sub fan motor connector.

16.CHECK SUB FAN MOTOR AND GROUND CIRCUIT.

Measure the resistance between the sub fan motor connector and chassis ground.

Connector & terminal

Turbo model

(F16) No. 2 — Chassis ground:

Non-turbo model

(F16) No. 1 — Chassis ground:

Is the resistance less than 5 Ω?

Repair the open circuit of harness between sub fan motor connector and chassis ground.

17.CHECK POOR CONTACT.

Check poor contact of sub fan motor connector.

Is there poor contact in sub fan motor connector?

Repair the poor contact of sub fan motor connector.

18.CHECK SUB FAN MOTOR.

Connect the battery positive (+) terminal to terminal No. 1 (Turbo model), No. 1 (Non-turbo model), and the ground line (−) to No. 2 (Turbo model), No. 1 (Non-turbo model) of the sub fan motor.

Does the sub fan rotate?

Replace the sub fan motor with a new part.

19.CHECK HARNESS BETWEEN MAIN FAN RELAY AND ECM.

1) Disconnect the connectors from the ECM.

2) Measure the resistance between the main fan relay terminal and ECM connector.

Connector & terminal

2.0 L model

(B135) No. 19 — (F27) No. 32:

2.5 L model

(B136) No. 18 — (F27) No. 32:

Is the resistance less than 1 Ω?

Repair the open circuit of the harness between the main fan relay terminal and ECM.

20.CHECK POOR CONTACT.

Check poor contact of ECM connector.

Is there poor contact in ECM connector?

Repair the poor contact of ECM connector.

Contact the SUBARU distributor service.

21.CHECK POWER SUPPLY TO SUB FAN RELAY.

1) Turn the ignition switch to OFF.

2) Remove the sub fan relay from the A/C relay holder.

3) Measure the voltage between the sub fan relay terminal and chassis ground.

Connector & terminal

(F27) No. 28 (+) — Chassis ground (−):

Is the voltage 10 V or more?

22.CHECK POWER SUPPLY TO SUB FAN RELAY.

1) Turn the ignition switch to ON.

2) Measure the voltage between the sub fan relay terminal and chassis ground.

Connector & terminal

(F27) No. 25 (+) — Chassis ground (−):

Is the voltage 10 V or more?

23.CHECK FUSE.

1) Remove the fuse from the A/C relay holder.

2) Check the condition of fuse.

Is the fuse blown out?

Replace the fuse.

24.FUSE TERMINAL AND SUB FAN RELAY TERMINAL HARNESS INSPECTION.

1) Turn the ignition switch to OFF.

2) Measure the resistance between the fuse terminal and sub fan relay terminal.

Terminals

No. 4 — No. 28:

Is the resistance less than 1 Ω?

Repair the power supply line.

Repair the open circuit of harness.

25.CHECK FUSE.

1) Turn the ignition switch to OFF.

2) Remove the fuse No. 17.

3) Check the condition of fuse.

Is the fuse blown out?

Replace the fuse.

Repair the power supply line.

26.CHECK SUB FAN RELAY.

1) Turn the ignition switch to OFF.

2) Remove the sub fan relay from the A/C relay holder.

3) Measure the resistance of the sub fan relay.

Terminals

No. 28 — No. 29:

Is the resistance 1 MΩ or more?

Replace the sub fan relay.

27.CHECK SUB FAN RELAY.

1) Connect the battery to terminals No. 25 and No. 27 of the sub fan relay.

2) Measure the resistance between sub fan relay terminals.

Terminals

No. 28 — No. 29:

Is the resistance less than 1 Ω?

Replace the sub fan relay.

28.CHECK HARNESS BETWEEN SUB FAN RELAY TERMINAL AND SUB FAN MOTOR CONNECTOR.

1) Disconnect the connector from the sub fan motor.

2) Measure the resistance of harness between the sub fan relay terminal and sub fan motor connector.

Connector & terminal

Turbo model

(F16) No. 1 — (F27) No. 29

Non-turbo model

(F16) No. 2 — (F27) No. 29

Is the resistance less than 1 Ω?

Repair the open circuit of harness between sub fan relay terminal and sub fan motor connector.

29.CHECK HARNESS BETWEEN SUB FAN RELAY AND ECM.

1) Disconnect the connectors from the ECM.

2) Measure the resistance between the sub fan relay terminal and ECM connector.

Connector & terminal

2.0 L model

(B135) No. 27 — (F27) No. 27:

2.5 L model

(B136) No. 29 — (F27) No. 27:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between sub fan relay terminal and ECM.

30.CHECK HARNESS BETWEEN FAN MODE RELAY AND ECM.

Measure the resistance between fan mode relay terminal and ECM connector.

Connector & terminal

2.0 L model

(B135) No. 27 — (F27) No. 7:

2.5 L model

(B136) No. 29 — (F27) No. 7:

Is the resistance less than 1 Ω?

Repair the open circuit of the harness between fan mode relay terminal and ECM.

31.CHECK POOR CONTACT.

Check poor contact of ECM connector.

Is there poor contact in ECM connector?

Repair the poor contact of ECM connector.

Contact the SUBARU distributor service.

NOTE:

Multiple parts may be deteriorated.

32.CHECK OPERATION OF RADIATOR FAN.

Does the radiator main fan rotate when the radiator main and sub fans do not rotate at high speed?

33.CHECK GROUND CIRCUIT OF FAN MODE RELAY.

1) Remove the fan mode relay from A/C relay holder.

2) Measure the resistance between fan mode relay terminal and chassis ground.

Connector & terminal

(F27) No. 8 — Chassis ground:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between fan mode relay and chassis ground.

34.CHECK POWER SUPPLY TO FAN MODE RELAY.

1) Turn the ignition switch to ON.

2) Measure the voltage between fan mode relay terminal and chassis ground.

Connector & terminal

(F27) No. 5 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Repair the power supply line.

35.CHECK FAN MODE RELAY.

1) Turn the ignition switch to OFF.

2) Remove the fan mode relay.

3) Measure the resistance of fan mode relay.

Terminals

(F27) No. 8 — (F27) No. 9:

Is the resistance 1 MΩ or more?

Replace the fan mode relay.

36.CHECK FAN MODE RELAY.

1) Connect the battery to terminals No. 5 and No. 7 of fan mode relay.

2) Measure the resistance of fan mode relay.

Terminals

(F27) No. 8 — (F27) No. 9:

Is the resistance less than 1 Ω?

Replace the fan mode relay.