Subaru Legacy 2003 Service Manual page 594

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B134) No. 29 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from purge control
solenoid valve and ECM.
3) Measure resistance of harness between
purge control solenoid valve connector and
engine ground.
Connector & terminal
(E4) No. 2 — Engine ground:
Does the measured value exceed the spec-
ified value?
3 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
Measure resistance of harness between ECM
and purge control solenoid valve of harness
connector.
Connector & terminal
(B134) No. 29 — (E4) No. 2:
Is the measured value less than the specified
value?
4 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Remove purge control solenoid valve.
2) Measure resistance between purge control
solenoid valve terminals.
Terminals
No. 1 — No. 2:
Is the measured value within the specified
range?
Value
10 V
1 MΩ
1 Ω
10 - 100 Ω
EN(H4SO)-197
ENGINE (DIAGNOSTICS)
Yes
Even if MI lights Go to step 2.
up, the circuit has
returned to a nor-
mal condition at
this time. Contact
SUBARU distribu-
tor service.
NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.
Go to step 3. Repair ground
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
Go to step 4. Repair open circuit
in harness
between ECM and
purge control sole-
noid valve connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and purge
control solenoid
valve connector
• Poor contact in
coupling connector
Go to step 5. Replace purge
control solenoid
valve. <Ref. to
EC(H4SO)-7,
Purge Control
Solenoid Valve.>
No