Subaru Legacy 2003 Service Manual page 1992

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
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 center console
box.
3) Turn the ignition switch to ON.
4) While operating the purge control solenoid
valve, measure the voltage between ECM
and chassis ground.
NOTE:
Purge control solenoid valve operation can be
executed using the Subaru Select Monitor. For
procedure, refer to "Compulsory Valve Opera-
tion Check Mode". <Ref. to EN(H4DOSTC)-36,
Compulsory Valve Operation Check Mode.>
Connector & terminal
(B137) No. 16 (+) — Chassis ground ( − − − − ):
Is the measured value within the specified
value?
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 16 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
4 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from purge con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 16 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
5 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between purge
control solenoid valve terminals.
Terminals
No. 1 — No. 2:
Is the measured value less than the speci-
fied value?
Value
0 — 13 V
10 V
There is poor contact.
10 V
1 Ω
EN(H4DOSTC)-153
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Even if MI light up,
the circuit has
returned to a nor-
mal condition at
this time. In this
case, repair the
poor contact in
ECM connector.
Go to step 4. Go to step 3.
Repair the poor Replace the ECM.
contact in ECM <Ref. to
connector. FU(H4DOSTC)-
40, Engine Con-
trol Module.>
Repair the battery Go to step 5.
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
After repair,
replace the ECM.
<Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>
Replace the purge Go to step 6.
control solenoid
valve <Ref. to
EC(H4DOSTC)-6,
Purge Control
Solenoid Valve.>
and ECM <Ref. to
FU(H4DOSTC)-
40, Engine Con-
trol Module.>
No