Subaru IMPREZA 2002 Service Manual page 220

RADIATOR MAIN FAN SYSTEM
COOLING
Yes
Step
3
CHECK POWER SUPPLY TO MAIN FAN
RELAYl.
1)Turn the ignition switch to ON.
2)Measure the voltage between main fan
relayl terminal and chassis ground.
Connector & terminal
(F66) No. 28 (+)
-
Chassis ground (-):
1)Remove the 20 A fuse from N C relay holder
2)Check the condition of fuse.
CHECK POWER SUPPLY TO A/C RELAY
HOLDER 20 A FUSE TERMINAL.
Measure the voltage of harness between N C
relay holder 20 A fuse terminal and chassis
ground.
3 CHECK 20 A FUSE.
I O
Connector & terminal
(F27) No. 1 (+)
-
Chassis ground (-):
I1 CHECK FUSE.
1)Turn the ignition switch to OFF.
2)Remove the fuse No. 18 from joint box.
3)Check the condition of fuse.
12 CHECK MAIN FAN RELAY1.
1)Turn the ignition switch to OFF.
2)Remove the main fan relayl .
3)Measure the resistance of main fan relayl
.
Terminal
NO. 26
-
NO. 25:
13 CHECK MAIN FAN RELAY.
1)Connect the battery to terminals No. 27 and
No. 28 of main fan relayl .
2)Measure the resistance of main fan relayl.
Terminal
NO. 26
-
NO. 25:
14 CHECK HARNESS BETWEEN MAIN FAN
RELAYl TERMINAL AND MAIN FAN MOTOR
CONNECTOR.
Measure the resistance of harness between
main fan motor connector and main fan relayl
terminal.
Connector & terminal
(F17) NO. 3
-
(F66) NO. 25:
15 CHECK HARNESS BETWEEN MAIN FAN
RELAY1 AND ECM.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
main fan relayl connector and ECM connector
Connector & terminal
(F66) NO. 27
-
(8137) NO. 17:
16 CHECK POOR CONTACT.
. Check poor contact in connector between main
fan and ECM.
No Check
Is the voltage more than 10 V?
Is the fuse blown-out? Replace fuse. Go to step 10.
Go to step 12. Go to step 11.
I
Repair the open
circuit in harness
between 20 A fuse
and main fan relay
terminal.
Repair the open
circuit in harness
between main fuse
box connector and
20 A fuse terminal
Is the voltage more than 10 V?
Is the fuse blown-out?
Is the resistance more than 1
MR?
Is the resistance less than 1
Replace the fuse. Repair the open
circuit in harness
between main fan
relay and ignition
switch.
Replace the main
fan relayl
.
Go to step 13.
Go to step 14. Replace the main
I s
the resistance less than 1
R?
Is the resistance less than 1
R?
Is there poor contact in con-
nector between main fan motor
and ECM?
R?
Go to step 15. Repair the open
circuit in harness
between main fan
motor connector
and main fan
relayl terminal.
Go to step 16. Repair the open
circuit in harness
between main fan
relayl and ECM.
Repair the poor
contact connector. service.
Contact with SOA
fan relayl .
CO-14