Subaru Legacy 2003 Service Manual page 1964

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INPUT SIGNAL TO ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 11 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN EXHAUST
VALVE CONTROL DUTY SOLENOID VALVE
AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from exhaust
valve control duty solenoid valve and ECM.
3) Measure the resistance of harness
between exhaust valve control duty sole-
noid valve connector and engine ground.
Connector & terminal
(B220) No. 12 — Engine ground:
Does the measured value exceed the spec-
ified value?
3 CHECK HARNESS BETWEEN EXHAUST
VALVE CONTROL DUTY SOLENOID VALVE
AND ECM CONNECTOR.
Measure the resistance of harness between
ECM and exhaust valve control duty solenoid
valve of harness connector.
Connector & terminal
(B137) No. 11 — (B220) No. 12:
Is the measured value less than the specified
value?
4 CHECK EXHAUST VALVE CONTROL DUTY
SOLENOID VALVE.
Measure the resistance between purge control
solenoid valve terminals.
Terminals
No. 11 — No. 12:
Is the measured value within the specified
value?
5 CHECK POWER SUPPLY TO EXHAUST
VALVE CONTROL DUTY SOLENOID VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between exhaust
valve control duty solenoid valve and
engine ground.
Connector & terminal
(B220) No. 11 (+) — Engine ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
Value
10 V
1 MΩ
1 Ω
17 — 21 Ω
10 V
EN(H4DOSTC)-125
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 the ground
short circuit in har-
ness between
ECM and exhaust
valve control duty
solenoid valve
connector.
Go to step 4. Repair the open
circuit in harness
between ECM and
exhaust valve con-
trol duty solenoid
valve connector.
Go to step 5. Replace the
exhaust valve con-
trol duty solenoid
valve. <Ref. to
IN(H4DOSTC)-19,
Solenoid Box
Assembly.>
Go to step 6. Repair the open
circuit in harness
between main
relay and exhaust
valve control duty
solenoid valve
connector.
No