Cooling Fan Circuit

2ZR-FXE COOLING: COOLING FAN SYSTEM: Cooling Fan Circuit
- Cooling Fan Circuit

DESCRIPTION

The ECM turns the fan relays on or off 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 the fan relays on or off in order to control the speed of the cooling fan motors in two steps.

WIRING DIAGRAM

Refer to System Diagram Description and Operation.

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 ENGINE ROOM RELAY BLOCK (FAN NO. 1, FAN NO. 2 OR FAN NO. 3 RELAY VOLTAGE)

C -- INSPECT FAN NO. 1 RELAY

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

2. INSPECT ENGINE ROOM RELAY BLOCK (FAN NO. 1, FAN NO. 2 OR FAN NO. 3 RELAY VOLTAGE)

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





(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





(d) Reinstall the FAN No. 1 relay, FAN No. 2 relay and FAN No. 3 relay.

NG -- CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - NO. 2 INTEGRATION RELAY)
OK -- Continue to next step.

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

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





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

Standard Voltage:





Text in Illustration





(c) Reinstall the FAN No. 1 relay and FAN No. 3 relay.

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

4. INSPECT FAN NO. 1 RELAY

(a) Inspect the FAN No. 1 relay Testing and Inspection.

NG -- REPLACE FAN NO. 1 RELAY
OK -- Continue to next step.

5. INSPECT FAN NO. 2 RELAY

(a) Inspect the FAN No. 2 relay Testing and Inspection.

NG -- REPLACE FAN NO. 2 RELAY
OK -- Continue to next step.

6. INSPECT FAN NO. 3 RELAY

(a) Inspect the FAN No. 3 relay Testing and Inspection.

NG -- REPLACE FAN NO. 3 RELAY
OK -- Continue to next step.

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

(a) Remove the FAN No. 2 relay from the engine room relay block.

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

Standard Resistance (Check for Open):





(c) Reinstall the FAN No. 2 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)
OK -- Continue to next step.

8. INSPECT COOLING FAN MOTOR

(a) Inspect the cooling fan motor Testing and Inspection.

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

9. 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 (Check for Open):





(c) Reconnect the cooling fan motor connector.

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

10. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

(a) Disconnect the cooling fan motor connector.

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

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the cooling fan motor connector.

(e) Reinstall the FAN No. 1 relay and FAN No. 2 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)
OK -- Continue to next step.

11. INSPECT NO. 2 COOLING FAN MOTOR

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

NG -- REPLACE NO. 2 COOLING FAN MOTOR Removal
OK -- Continue to next step.

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

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

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

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the No. 2 cooling fan motor connector.

(e) 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 -- Continue to next step.

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

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





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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





Text in Illustration





(c) Reinstall the FAN No. 1 relay and FAN No. 2 relay.

NG -- REPLACE ENGINE ROOM RELAY BLOCK
OK -- Continue to next step.

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

(a) Remove the FAN No. 2 relay and FAN No. 3 relay from the engine room relay block.

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):





(d) Reconnect the ECM connector.

(e) Reinstall the FAN No. 2 relay and FAN No. 3 relay.

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

OK -- REPLACE ECM Removal

15. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - NO. 2 INTEGRATION RELAY)

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

(b) Disconnect the No. 2 integration relay connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reinstall the FAN No. 1 relay, FAN No. 2 relay and FAN No. 3 relay.

(e) Reconnect the No. 2 integration relay connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - NO. 2 INTEGRATION RELAY)

OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit

16. INSPECT FAN NO. 1 RELAY

(a) Inspect the FAN No. 1 relay Testing and Inspection.

NG -- REPLACE FAN NO. 1 RELAY
OK -- Continue to next step.

17. INSPECT FAN NO. 3 RELAY

(a) Inspect the FAN No. 3 relay Testing and Inspection.

NG -- REPLACE FAN NO. 3 RELAY
OK -- Continue to next step.

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

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

(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Short):





(d) Reinstall the FAN No. 1 relay, FAN No. 2 relay and FAN No. 3 relay.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - ECM)
OK -- Continue to next step.

19. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)

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

(b) Disconnect the cooling fan motor connector.

(c) Turn the power switch on (IG).

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

Standard Voltage:





(e) Reinstall the FAN No. 1 relay and FAN No. 2 relay.

(f) Reconnect the cooling fan motor connector.

NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK)
OK -- Continue to next step.

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

(a) Remove the FAN No. 3 relay from the engine room relay block.

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

(c) Turn the power switch on (IG).

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

Standard Voltage:





(e) Reinstall the FAN No. 3 relay.

(f) Reconnect the No. 2 cooling fan motor connector.

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

OK -- REPLACE ECM Removal