Subaru Legacy 2004 Service Manual page 590

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).
3) Turn the ignition switch to ON.
4) While operating the purge control solenoid
valve, measure voltage between ECM and
chassis ground.
NOTE:
Purge control solenoid valve operation can be
executed using Subaru Select Monitor. Refer to
"Compulsory Valve Operation Check Mode" for
procedures. <Ref. to EN(H4SO 2.0)(diag)-39,
Compulsory Valve Operation Check Mode.>
Connector & terminal
(B134) No. 8 (+) — Chassis ground (
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 8 (+) — Chassis ground (
3 CHECK POOR CONTACT.
Check 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
(B134) No. 8 (+) — Chassis ground (
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:
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the voltage 0 — 10 V?
"
):
Is the voltage more than 10 V? Go to step 4.
"
):
Is there poor contact in ECM
connector?
Is the voltage more than 10 V? Repair the battery
"
):
Is the resistance less than 1
&?
Is there poor contact in ECM
connector?
EN(H4SO 2.0)(diag)-158
Yes
Go to step 2. Even if the mal-
function indicator
light illuminates,
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 3.
Repair the poor Replace the ECM.
contact in ECM <Ref. to FU(H4SO
connector. 2.0)-34, Engine
Control Module
(ECM).>
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(H4SO
2.0)-34, Engine
Control Module
(ECM).>
Replace the purge Go to step 6.
control solenoid
valve <Ref. to
EC(H4SO 2.0)-7,
Purge Control
Solenoid Valve.>
and ECM. <Ref. to
FU(H4SO 2.0)-34,
Engine Control
Module (ECM).>
Repair the poor Replace the ECM.
contact in ECM <Ref. to FU(H4SO
connector. 2.0)-34, Engine
Control Module
(ECM).>
No