Subaru 2002 IMPREZA Service Manual page 561

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
1
CHECK OUTPUT SIGNAL FROM ECM.
1)Turn the ignition switch to OFF.
2)Connect the test mode connector at the
lower portion of instrument panel (on the
driver's side), to the side of the center console
box.
3)Turn the ignition switch to ON.
4)While operating the radiator fan relay, mea-
sure voltage between ECM and chassis
ground.
NOTE:
Radiator fan relay operation can be executed
using Subaru Select Monitor. For procedure,
refer to "Compulsory Valve Operation Check
Mode".<Ref. to EN(D0HC TURBO)-50, Com-
pulsory Valve Operation Check Mode.>
Connector & terminal
(8137) No. 17 (+)
-
Chassis ground (-):
(8137) No. 28 (+)
-
Chassis ground ( - ) :
CHECK SHORT CIRCUIT IN RADIATOR FAN
RELAY CONTROL CIRCUIT.
1)Turn the ignition switch to OFF.
2)Remove the main fan relay and sub fan relay.
(with A/C models)
3)Disconnect the test mode connector.
4)Turn the ignition switch to ON.
5)Measure the voltage between ECM and
chassis ground.
2
Connector & terminal
(8137) No. 17 (+)
-
Chassis ground (-):
(8137) No. 28 (+)
-
Chassis ground (-):
3
CHECK MAIN FAN RELAY.
1)Turn the ignition switch to OFF.
2)Remove the main fan relay I and 2.
3)Measure the resistance between main fan
relay terminals.
Terminal
No. 25
-
No. 26 (Main fan relay 1)
No. 23
-
No. 24 (Main fan relay 2)
4
CHECK SUB FAN RELAY.
1)Remove the sub fan relay.
2)Measure the resistance between sub fan
relay terminals.
Terminal
No. 7
-
No. 8 (Sub fan relay 1)
No. 17
-
No. 18 (Sub fan relay 2)
Check poor contact in ECM connector.
5 CHECK POOR CONTACT.
Check
)oes the voltage change
letween 0 and 10 V?
s
the voltage more than 10 V?
s the resistance less than 1
2?
s the resistance less than 1
2?
s there poor contact in ECM
:onnector?
Yes
Iven if MIL lights
ip, the circuit has
eturned to a nor-
nal condition at
his time. In this
:ase, repair poor
:ontact in ECM
:onnector.
3epair battery
;hort circuit in
adiator fan relay
:ontrol circuit.
After repair,
eplace the ECM.
:Ref. to FU(D0HC
ruRBO)-47,
hgine Control
dodule.>
3eplace the main
an relay and
ICM. <Ref. to
W(DOHC
Engine Control
dodule.>
rURBO)-47,
3eplace the sub
an relay and
X M . <Ref. to
-U(DOHC
Engine Control
dodule.>
rURBO)-47,
3epair poor con-
act in ECM con-
lector.
No
io to step 2.
io to step 3.
i o to step 4.
i o to step 5.
leplace the ECM.
:Ref. to FU(D0HC
ingine Control
Aodu1e.i
-U R BO)-47,
EN( DOHC TU RB0)-337