Subaru 2009 IMPREZA Service Manual page 345

Step
17 CHECK MAIN FAN MOTOR ASSEMBLY.
Connect the battery positive (+) terminal to ter-
minal No. 2 of the main fan motor assembly, and
the ground (–) terminal to terminal No. 1.
18 CHECK HARNESS BETWEEN SUB FAN RE-
LAY AND ECM.
1) Disconnect the connectors from ECM.
2) Measure the resistance between the sub
fan relay terminal and ECM connector.
Connector & terminal
(B136) No. 18 — (F27) No. 12:
19 CHECK POOR CONTACT.
Check for poor contact of ECM connector.
20 CHECK MAIN FAN RELAY 1.
1) Turn the ignition switch to OFF.
2) Remove main fan relay 1 from the main fuse
box.
3) Measure the resistance at the main fan relay
1 switch.
21 CHECK MAIN FAN RELAY 1.
1) Connect the main fan relay 1 coil side termi-
nal to the battery.
2) Measure the resistance between terminals
at main fan relay 1 switch side.
22 CHECK HARNESS BETWEEN MAIN FAN
RELAY 1 AND MAIN FAN MOTOR ASSEM-
BLY CONNECTOR.
1) Disconnect the connector from the main fan
motor assembly.
2) Measure the resistance of harness between
the main fan relay 1 terminal and main fan
motor assembly connector.
Connector & terminal
(F17) No. 2 — (F36) No. 6:
23 CHECK HARNESS BETWEEN MAIN FAN
RELAY 1 AND ECM.
1) Disconnect the connectors from ECM.
2) Measure the resistance between the main
fan relay 1 terminal and ECM connector.
Connector & terminal
(B136) No. 29 — (B143) No. 7:
24 CHECK HARNESS BETWEEN MAIN FAN
RELAY 2 AND ECM.
Measure the resistance between the main fan
relay 2 terminal and ECM connector.
Connector & terminal
(B136) No. 29 — (F27) No. 22:
25 CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 2 and 26.
3) Check the condition of fuse.
Radiator Fan System
Check
Does the radiator main fan
rotate?
Is the resistance less than 1 ? Go to step 19.
Is there poor contact of ECM
connector?
Is the resistance 1 M or
more?
Is the resistance less than 1 ? Go to step 22.
Is the resistance less than 1 ? Go to step 23.
Is the resistance less than 1 ? Go to step 24.
Is the resistance less than 1 ? Go to step 25.
Is the fuse blown out?
CO(H4SO)-11
COOLING
Yes No
Go to step 18. Replace the main
fan motor assem-
bly. <Ref. to
CO(H4SO)-23,
Radiator Main Fan
and Fan Motor.>
Repair the open
circuit of harness
between sub fan
relay terminal and
ECM.
Repair the poor Check the DTC.
contact of ECM Repair the trouble
connector. cause. <Ref. to
EN(H4SO)(diag)-
43, Read Diagnos-
tic Trouble Code
(DTC).>
Go to step 21. Replace the main
fan relay 1. <Ref. to
AC-39, Relay and
Fuse.>
Replace the main
fan relay 1. <Ref. to
AC-39, Relay and
Fuse.>
Repair the open
circuit of harness
between the main
fan relay 1 terminal
and main fan motor
assembly connec-
tor.
Repair the open
circuit of the har-
ness between
main fan relay 1
terminal and ECM.
Repair the open
circuit of the har-
ness between
main fan relay 2
terminal and ECM.
Replace the fuse. Go to step 26.