Subaru 2002 IMPREZA Service Manual page 465

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DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
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(D0HC TURBO)-38, Subaru
Select Monitor.>
Connector & terminal
(8137) No. 17 (+)
-
Chassis ground (-):
(8137) No. 28 (+)
-
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
(8137) No. 17
-
Chassis ground:
(8137) No. 28
-
Chassis ground:
CHECK POWER SUPPLY FOR RELAY.
1)Remove the main fan relay 1 and 2 from A/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. 27 (+)
-
Chassis ground ( - ) :
(F30) No. 22 (+)
-
Chassis ground (-):
3
CHECK MAIN FAN RELAY.
1)Turn the ignition switch to OFF.
2)Measure the resistance between main fan
relay terminals.
Terminal
No. 27
-
No. 28:(Main fan relay 1)
No. 22
-
No. 21 :(Main fan relay 2)
5
CHECK OPEN CIRCUIT IN MAIN FAN RE-
LAY CONTROL CIRCUIT.
Measure the resistance of harness between
ECM and main fan relay connector.
Connector & terminal
(8137) NO. 17
-
(F66) NO. 28:
(8137) NO. 28
-
(F30) NO. 21:
5 CHECK POOR CONTACT.
Check poor contact in ECM
or
main fan relay
connector.
Check
Ioes the voltage change
tetween 0 and 10 V?
s the resistance less than 10
2?
s
the voltage more than 10 V?
s the resistance between 87
and 107 Q?
s the resistance less than 1
n?
s there poor contact in ECM of
nain fan relay connector?
Yes
lepair poor con-
3ct in ECM con-
lector.
lepair ground
ihort circuit in
adiator main fan
elay control cir-
uit.
; o to step
4.
; o to step 5.
20 to step
6 .
3epair poor con-
act in ECM
or
nain fan relay con
lector.
No
; o to step 2.
20 to step
3.
qepair open circui
n harness
ietween 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
ECM and main far
'elay connector
1
Poor contact in
:oupling connectc
2ontact with SOA
[distributor) ser-
ice.
EN(D0HC TURBO)-241