Subaru IMPREZA 2002 Service Manual page 225

RADIATOR SUB FAN SYSTEM
COOLING
~~
6 : INSPECTION
1. NON-TURBO MODEL
NOTE:
System for
A/C
equipped vehicles only.
DETECTING CONDITION:
Condition (1):
Engine coolant temperature is below 95°C
(203" F).
A/C switch is turned ON.
Vehicle speed is below 19 km/h (12 MPH).
Condition (2):
Engine coolant temperature is above 100°C
(212°F).
A/C
switch is turned OFF.
Vehicle speed is below 19 km/h (1 2 MPH).
TROUBLE SYMPTOM:
Radiator sub fan does not rotate under condi-
tions (1) and (2) above.
Step
I
CHECK POWER SUPPLY TO SUB FAN MO-
TOR.
CAUTION:
Be careful not to overheat engine during re-
pair.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from the sub fan
motor and main fan motor.
3)Start the engine, and warm it up until engine
coolant temperature increases over 100°C
(21 2°F).
4)Stop the engine and turn the ignition switch
to ON.
5)Measure the voltage between sub fan motor
connector and chassis ground.
Connector & terminal
(F16) No.
2
(+)
-
Chassis ground (-):
CHECK GROUND CIRCUIT OF SUB FAN
MOTOR.
1)Turn the ignition switch to OFF.
2)Measure the resistance between sub fan
motor connector and chassis ground.
2
Connector & terminal
(F16) No. 1
-
Chassis ground:
3
CHECK POOR CONTACT.
Check poor contact in sub fan motor connec-
tor.
Connect the battery positive (+) terminal toter
minal
No.
2, and negative (-) terminal to termi-
nal No.
1
of sub fan motor connector.
LAY.
1)Turn the ignition switch to OFF.
2)Remove the sub fan relay from A/C relay
holder.
3)Measure the voltage between sub fan relay
terminal and chassis ground.
1 CHECK SUB FAN MOTOR.
5
CHECK POWER SUPPLY TO SUB FAN RE-
Connector & terminal
~
(F28)
No.
18
(+)
-
Chassis ground ( - ) :
6
CHECK POWER SUPPLY TO SUB FAN RE-
LAY.
1)Turn the ignition switch to
ON.
2)Measure the voltage between sub fan relay
terminal and chassis ground.
Connector & terminal
(F28) No. 20 (+)
-
Chassis ground ( - ) :
~~ ~
Check
Is the voltage more than 10 V?
Is the resistance less than 5
R?
Is there poor contact in sub fan
motor connector?
Does the sub fan rotate?
Is the voltage more than 10 V?
Is the voltage more than 10 V?
co-19
Yes
30
to step 2.
30 to step 3 .
3epair the poor
:ontact in sub fan
notor connector.
Fiepair the poor
:ontact in sub fan
notor connector.
So to step 6.
Go to step 10.
No
30 to step 5.
Repair the open
Zircuit in harness
Detween sub fan
motor connector
and chassis
ground.
Go to step 4.
Replace the sub
fan motor with a
new one.
Go to step 7.
Go
to step 9.