Subaru Legacy 2005 Service Manual page 1386

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 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. 14 (+) — Chassis ground (
2 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from purge con-
trol solenoid valve and ECM.
3) Measure the resistance of harness
between purge control solenoid valve connec-
tor and engine ground.
Connector & terminal
(E4) No. 2 — Engine ground:
3 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
Measure the resistance of harness between
ECM and purge control solenoid valve.
Connector & terminal
(B134) No. 14 — (E4) No. 2:
4 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Remove the purge control solenoid valve.
2) Measure the resistance between purge
control solenoid valve terminals.
Terminals
No. 1 — No. 2:
5 CHECK POWER SUPPLY TO PURGE CON-
TROL SOLENOID VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between purge control
solenoid valve and engine ground.
Connector & terminal
(E4) No. 1 (+) — Engine ground (
6 CHECK POOR CONTACT.
Check poor contact in purge control solenoid
valve connector.
Check
Is the voltage more than 10 V? Even if the mal-
−
):
Is the resistance more than 1
MΩ?
Is the resistance less than 1
Ω?
Is the resistance 29 — 35 Ω?
Is the voltage more than 10 V? Go to step 6.
−
):
Is there poor contact in purge
control solenoid valve connec-
tor?
EN(H4DOTC)(diag)-146
Yes
Go to step 2.
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.
Go to step 3. Repair the ground
short circuit of har-
ness between
ECM and purge
control solenoid
valve connector.
Go to step 4. Repair the open
circuit of harness
between ECM and
purge control sole-
noid valve connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ECM and purge
control solenoid
valve connector
• Poor contact in
coupling connector
Go to step 5. Replace the purge
control solenoid
valve. <Ref. to
EC(H4DOTC)-6,
Purge Control
Solenoid Valve.>
Repair the open
circuit of harness
between main
relay and purge
control solenoid
valve connector.
Repair the poor Replace the ECM.
contact in purge <Ref. to
control solenoid FU(H4DOTC)-34,
valve connector. Engine Control
Module (ECM).>
No