Subaru Legacy 2003 Service Manual page 2066

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INTPUT SIGNAL TO ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 11 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 CHECK HARNESS BETWEEN RELIEF
VALVE CONTROL SOLENOID VALVE 2 AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from relief valve
control solenoid valve 2 and ECM.
3) Measure the resistance of harness
between relief valve control solenoid valve
2 connector and engine ground.
Connector & terminal
(B220) No. 2 — Engine ground:
Does the measured value exceed the spec-
ified value?
3 CHECK HARNESS BETWEEN RELIEF
VALVE CONTROL SOLENOID VALVE 2 AND
ECM CONNECTOR.
Measure the resistance of harness between
ECM and relief valve control solenoid valve 2
of harness connector.
Connector & terminal
(B136) No. 11 — (B220) No. 2:
Is the measured value less than the specified
value?
4 CHECK RELIEF VALVE CONTROL SOLE-
NOID VALVE 2.
Measure the resistance between relief valve
control solenoid valve 2 terminals.
Terminals
No. 1 — No. 2:
Is the measured value within the specified
value?
5 CHECK POWER SUPPLY TO RELIEF VALVE
CONTROL SOLENOID VALVE 2.
1) Turn the ignition switch to ON.
2) Measure the voltage between wastegate
control solenoid valve and engine ground.
Connector & terminal
(B220) No. 1 (+) — Engine ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
Value
10 V
1 MΩ
1 Ω
37 — 44 Ω
10 V
EN(H4DOSTC)-227
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 relief
valve control sole-
noid valve 2 con-
nector.
Go to step 4. Repair the open
circuit in harness
between ECM and
relief valve control
solenoid valve 2
connector.
Go to step 5. Replace the relief
valve control sole-
noid valve 2.
<Ref. to
IN(H4DOSTC)-19,
Solenoid Box
Assembly.>
Go to step 6. Repair the open
circuit in harness
between main
relay and relief
valve control sole-
noid valve 2 con-
nector.
No