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:
NG -- INSPECT ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY (FAN NO. 1 RELAY, FAN NO. 2 RELAY AND FAN NO. 3 RELAY VOLTAGE)
OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
2. INSPECT ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY (FAN NO. 1 RELAY, FAN NO. 2 RELAY AND 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 and junction block assembly.
(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
NG -- CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - NO. 2 INTEGRATION RELAY)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - ECM)
(a) Remove the FAN No. 1 relay, FAN No. 2 relay and FAN No. 3 relay from the engine room relay block and junction block assembly.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - ECM)
OK -- Continue to next step.
4. INSPECT ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY (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 and junction block assembly.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
OK -- Continue to next step.
5. 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.
6. 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.
7. 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.
8. CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)
(a) Remove the FAN No. 2 relay from the engine room relay block and junction block assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)
OK -- Continue to next step.
9. INSPECT COOLING FAN MOTOR
(a) Inspect the cooling fan motor Testing and Inspection.
NG -- REPLACE COOLING FAN MOTOR Removal
OK -- Continue to next step.
10. 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:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - BODY GROUND)
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
(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 and junction block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
Make sure that there are no short circuits to the auxiliary battery.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
OK -- Continue to next step.
12. 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.
13. CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
(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 and junction block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
Make sure that there are no short circuits to the auxiliary battery.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 COOLING FAN MOTOR - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
OK -- REPLACE ECM Removal
14. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - 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 and junction block assembly.
(b) Disconnect the No. 2 integration relay connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - NO. 2 INTEGRATION RELAY)
OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit