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.
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
PERFORM ACTIVE TEST USING GTS (Control the Electric Cooling Fan)
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.
Tester Display |
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Control the Electric Cooling Fan |
Check the operation of the cooling fans while operating them using the GTS.
OK | ||||||
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Result | |||
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OK |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
NG |
CHECK HARNESS AND CONNECTOR (FANH AND FANL VOLTAGE)
Disconnect the A142 ECM connector.
Turn the power switch on (IG).
*a | Front view of wire harness connector (to ECM) |
Measure the voltage according to the value(s) in the table below.
Standard Voltage | |||||||||
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Reconnect the A142 ECM connector.
Result | |||
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|
NG |
INSPECT FAN NO. 1 RELAY Click here |
OK |
INSPECT NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY (FAN NO. 1 RELAY AND FAN NO. 3 RELAY)
*1 | No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly |
*2 | FAN NO. 1 Relay |
*3 | FAN NO. 3 Relay |
Remove the FAN NO. 1 relay and FAN NO. 3 relay from the No. 1 engine room relay block and No. 1 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 and FAN NO. 3 relay.
Result | |||
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NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
INSPECT FAN NO. 1 RELAY
Inspect the FAN NO. 1 relay.
Result | |||
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|
NG |
REPLACE FAN NO. 1 RELAY |
OK |
INSPECT FAN NO. 2 RELAY
Inspect the FAN NO. 2 relay.
Result | |||
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|
NG |
REPLACE FAN NO. 2 RELAY |
OK |
INSPECT FAN NO. 3 RELAY
Inspect the FAN NO. 3 relay.
Result | |||
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|
NG |
REPLACE FAN NO. 3 RELAY |
OK |
CHECK HARNESS AND CONNECTOR (FAN NO. 2 RELAY - BODY GROUND)
Remove the FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 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. 2 relay.
Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
INSPECT COOLING FAN MOTOR
Inspect the cooling fan motor.
Result | |||
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|
NG |
REPLACE COOLING FAN MOTOR |
OK |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - BODY GROUND)
Disconnect the A112 cooling fan motor connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
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|
Reconnect the A112 cooling fan motor connector.
Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)
Disconnect the A112 cooling fan motor connector.
Remove the FAN NO. 1 relay and FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open) | |||||||||
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Standard Resistance (Check for Short) | |||||||||
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Tech Tips
Make sure that there are no short circuits to the auxiliary battery.
Reinstall the FAN NO. 1 relay and FAN NO. 2 relay.
Reconnect the A112 cooling fan motor connector.
Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
INSPECT NO. 2 COOLING FAN MOTOR
Inspect the No. 2 cooling fan motor.
Result | |||
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|
NG |
REPLACE NO. 2 COOLING FAN MOTOR |
OK |
CHECK HARNESS AND CONNECTOR (NO. 2 COOLING FAN MOTOR - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)
Disconnect the A113 No. 2 cooling fan motor connector.
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.
Measure the resistance according to the value(s) in the table below.
Tech Tips
Make sure that there are no short circuits to the auxiliary battery.
Standard Resistance (Check for Open) | |||||||||
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Standard Resistance (Check for Short) | |||||||||
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Reinstall the FAN NO. 2 relay and FAN NO. 3 relay.
Reconnect the A113 No. 2 cooling fan motor connector.
Result | |||
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|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (FAN NO. 1 RELAY - FAN NO. 2 RELAY)
Remove the FAN NO. 1 relay and FAN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open) | |||||||||
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|
Standard Resistance (Check for Short) | |||||||||
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|
Tech Tips
Make sure that there are no short circuits to the auxiliary battery.
Reinstall the FAN NO. 1 relay and FAN NO. 2 relay.
Result | |||
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|
OK |
REPLACE ECM |
NG |
REPLACE NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY |
INSPECT FAN NO. 1 RELAY
Inspect the FAN NO. 1 relay.
Result | |||
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|
NG |
REPLACE FAN NO. 1 RELAY |
OK |
INSPECT FAN NO. 2 RELAY
Inspect the FAN NO. 2 relay.
Result | |||
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|
NG |
REPLACE FAN NO. 2 RELAY |
OK |
INSPECT FAN NO. 3 RELAY
Inspect the FAN NO. 3 relay.
Result | |||
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|
NG |
REPLACE FAN NO. 3 RELAY |
OK |
CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - ECM)
Remove the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
Disconnect the A142 ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open) | ||||||||||||
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|
Standard Resistance (Check for Short) | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
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Tech Tips
Make sure that there are no short circuits to the auxiliary battery.
Reconnect the A142 ECM connector.
Reinstall the FAN NO. 1 relay, FAN NO. 2 relay and FAN NO. 3 relay.
Result | |||
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|
OK |
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - ECM) |