Subaru 2002 IMPREZA Service Manual page 1359

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
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
(B137) No. 16 (+) — 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 connector 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 of har-
ness connector.
Connector & terminal
(B137) No. 16 — (E4) No. 2:
4 CHECK PURGE CONTROL SOLENOID
VALVE.
1)Remove the purge control solenoid valve.
2)Measure the resistance between purge con-
trol 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 ( − − − − ):
Check
Is the voltage more than 10 V? Even if MIL lights
Is the resistance less than 10
Ω?
Is the resistance less than 1
Ω?
Is the resistance between 10
and 100 Ω?
Is the voltage more than 10 V? Go to step 6.
EN(TURBO)-199
ENGINE (DIAGNOSTICS)
Yes
Go to step 2.
up, the circuit has
returned to a nor-
mal condition at
this time. Contact
with your Subaru
distributor service.
NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.
Repair the ground Go to step 3.
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
Go to step 4. Repair the 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 the purge
control solenoid
valve. <Ref. to
EC(TURBO)-7,
Purge Control
Solenoid Valve.>
Repair the open
circuit in harness
between main
relay and purge
control solenoid
valve connector.
No