DESCRIPTION
The ECM calculates an appropriate cooling fan speed based on the engine coolant temperature, air conditioning switch condition, refrigerant pressure, engine speed and vehicle speed, and sends signals to the cooling fan ECU to regulate the cooling fan. The cooling fan ECU controls the cooling fan speed based on the duty ratio signal sent from the ECM.
WIRING DIAGRAM
Refer to System Diagram Click here.
INSPECTION PROCEDURE
Note
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
PERFORM ACTIVE TEST USING GTS (CONTROL THE ELECTRIC COOLING FAN)
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.
Check the operation of the cooling fan while operating it using the GTS.
OK | ||||||
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|
Result | Proceed to |
---|---|
OK | A |
Cooling fan does not operate | B |
Cooling fan does not stop | C |
B |
CHECK COOLING FAN SYSTEM Click here |
C |
INSPECT COOLING FAN MOTOR Click here |
A |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here
CHECK COOLING FAN SYSTEM
Disconnect the A20 ECM connector.
Turn the power switch on (IG).
Check the operation of the cooling fan.
OK |
---|
The cooling fan operates. |
Reconnect the ECM connector.
NG |
CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU) Click here |
OK |
REPLACE ECM Click here
CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)
Disconnect the cooling fan ECU connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
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|
Reconnect the cooling fan ECU connector.
Reconnect the ECM connector.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU) |
OK |
INSPECT COOLING FAN MOTOR
Inspect the cooling fan motor and No. 2 cooling fan motor Click here.
Result | Proceed to |
---|---|
OK | A |
NG (Cooling fan motor) | B |
NG (No. 2 cooling fan motor) | C |
B |
REPLACE COOLING FAN MOTOR Click here |
C |
REPLACE NO. 2 COOLING FAN MOTOR Click here |
A |
CHECK COOLING FAN ECU (POWER SOURCE)
*a | Front view of wire harness connector (to Cooling Fan ECU) |
Disconnect the cooling fan ECU connector.
Turn the power switch on (IG).
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||
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|
Reconnect the cooling fan ECU connector.
NG |
CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - BODY GROUND) Click here |
OK |
REPLACE COOLING FAN ECU
CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - BODY GROUND)
Disconnect the cooling fan ECU connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
Reconnect the cooling fan ECU connector.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - BODY GROUND) |
OK |
INSPECT FAN NO. 1 RELAY
Inspect the FAN NO. 1 relay Click here.
NG |
REPLACE FAN NO. 1 RELAY |
OK |
CHECK HARNESS AND CONNECTOR (COOLING FAN ECU - FAN NO. 1 RELAY)
Disconnect the cooling fan ECU connector.
Remove the FAN NO. 1 relay from the No. 1 engine room relay block and junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
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|
Reinstall the FAN NO. 1 relay.
Reconnect the cooling fan ECU connector.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN ECU - FAN NO. 1 RELAY) |
OK |
CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - BODY GROUND)
Remove the FAN NO. 1 relay from the No. 1 engine room relay block and junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
Reinstall the FAN NO. 1 relay.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - BODY GROUND) |
OK |
CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - BATTERY)
*1 | No. 1 Engine Room Relay Block and Junction Block Assembly |
*2 | Relay Block FAN NO. 1 Relay Terminals |
Remove the FAN NO. 1 relay from the No. 1 engine room relay block and junction block assembly.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||
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|
Reinstall the FAN NO. 1 relay.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - BATTERY) |
OK |
REPAIR OR REPLACE HARNESS OR CONNECTOR (FAN NO. 1 RELAY - LH-IG1 RELAY1)
INSPECT COOLING FAN MOTOR
Disconnect the cooling fan motor connector.
Disconnect the No. 2 cooling fan motor connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | Proceed to |
---|---|
OK | A |
NG (Cooling fan motor) | B |
NG (No. 2 cooling fan motor) | C |
Reconnect the cooling fan motor connector.
Reconnect the No. 2 cooling fan motor connector.
B |
REPLACE COOLING FAN MOTOR Click here |
C |
REPLACE NO. 2 COOLING FAN MOTOR Click here |
A |
CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)
Disconnect the ECM connector.
Disconnect the cooling fan ECU connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Reconnect the cooling fan ECU connector.
Reconnect the ECM connector.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - COOLING FAN ECU) |
OK |
REPLACE COOLING FAN ECU
Replace the cooling fan ECU.
NEXT |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Check the cooling fan operation.
OK |
---|
Malfunction has been repaired successfully. |
NG |
REPLACE ECM Click here |
OK |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here