Subaru IMPREZA 2002 Service Manual page 557

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE lDl AG
NOSTICS)
Step
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 terminal and
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(S0HC)-32, Subaru Select
Monitor.>
Connector & terminal
(6134) No. 3 (+)
-
Chassis ground (-):
CHECK GROUND SHORT CIRCUIT IN RADI-
ATOR MAIN FAN RELAY CONTROL CIR-
CUIT.
1)Turn the ignition switch to OFF.
2)Disconnect the connectors from ECM.
3)Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(6134) No. 3
-
Chassis ground:
CHECK POWER SUPPLY FOR RELAY.
1)Remove the main fan relay from N C relay
holder.
2)Turn the ignition switch to ON.
3)Measure the voltage between fuse and relay
box (F/B) connector and chassis ground.
Connector & terminal
(F66) No. 28 (+)
-
Chassis ground (-):
CHECK MAIN FAN RELAY.
1)Turn the ignition switch to OFF.
2)Measure the resistance between main fan
relay terminals.
Terminal
NO. 28
-
NO.
27:
CHECK OPEN CIRCUIT IN MAIN FAN RE-
LAY CONTROL CIRCUIT.
Measure the resistance of harness between
ECM and main fan relay connector.
Connector & terminal
(6134) NO. 3
-
(F66) NO. 27:
CHECK POOR CONTACT.
Check poor contact in ECM or main fan relay
Connector.
Check
Ioes the voltage change
letween 0 and 10 V?
s the resistance less than
10
2?
s the voltage more than 10 V?
s the resistance between 87
md 107 R?
s the resistance less than
1
2?
s
there poor contact in ECM or
nain fan relay connector?
Yes
lepair poor con-
3ct in ECM con-
lector.
3epair ground
,hart
circuit in
adiator main fan
elay control cir-
uit.
30 to step 4.
; o to step 5.
20 to step
6 .
qepair poor con-
act in ECM or
nain fan relay con
lector.
~~ ~
No
20 to step 2.
i o
to step 3.
3epair open circui
n harness
)etween ignition
;witch and fuse
md relay box (F/B:
:onnector.
3eplace the main
an relay.
3epair harness
and connector.
VOTE:
n this case, repai
he following:
1
Open circuit in
iarness between
ICM and main far
'elay connector
1
Poor contact in
:oupling connect0
:F45)
:ontact with SOA
:distributor) ser-
dice.
EN(S0HC)-233