Subaru Legacy 2002 Service Manual page 1436

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B137) No. 16 (+) — Chassis ground
(−):
2 CHECK HARNESS BETWEEN PURGE
CONTROL SOLENOID VALVE AND ECM
CONNECTOR.
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:
3 CHECK HARNESS BETWEEN PURGE
CONTROL SOLENOID VALVE AND ECM
CONNECTOR.
Measure resistance of harness between ECM
and purge control solenoid valve of harness
connector.
Connector & terminal
(B137) No. 16 — (E4) No. 2:
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:
5 CHECK POWER SUPPLY TO PURGE CON-
TROL SOLENOID VALVE.
1) Turn ignition switch to ON.
2) Measure voltage between purge control
solenoid valve and engine ground.
Connector & terminal
(E4) No. 1 (+) — Engine ground (−):
Step
Is the voltage more than 10
V?
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?
EN(H6)-229
Check Yes
Even if MIL lights
up, the circuit has
returned to a nor-
mal condition at
this time. Contact
your Subaru dis-
tributor.
NOTE:
Inspection by
DTM is required,
because probable
cause is deterio-
ration of multiple
parts.
Repair ground
short circuit in
harness between
ECM and purge
control solenoid
valve connector.
Go to step 4.
Go to step 5.
Go to step 6.
Engine (DIAGNOSTICS)
No
Go to step 2.
Go to step 3.
Repair open cir-
cuit in harness
between ECM
and purge control
solenoid valve
connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
ECM and purge
control solenoid
valve connector
¼ Poor contact in
coupling connec-
tor
Replace purge
control solenoid
valve. <Ref. to
EC(H6)-8, Purge
Control Solenoid
Valve.>
Repair open cir-
cuit in harness
between main
relay and purge
control solenoid
valve connector.