Subaru Forester 2004 Service Manual page 145

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
Step
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector at the lower
portion of instrument panel (on the driver's side).
3) Turn the ignition switch to ON.
4) While operating the purge control solenoid
valve, measure voltage between ECM and
chassis ground.
NOTE:
Purge control solenoid valve operation can be
executed using Subaru Select Monitor. For the
procedure, refer to "Compulsory Valve Opera-
tion Check Mode". <Ref. to EN(H4DOTC 2.5)-
43, Compulsory
Mode.>
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
2 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 (
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
4 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from purge con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
5 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between purge
control solenoid valve terminals.
Terminals
No. 1 — No. 2:
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Valve Operation Check
−
):
−
):
−
):
EN(H4DOTC 2.5)-144
Check
Is the voltage 0 — 13 V?
Is the voltage more than 10 V? Go to step 4.
Is there poor contact in ECM
connector?
Is the voltage more than 10 V? Repair battery
Is the resistance less than 1
Ω?
Is there poor contact in ECM
connector?
Yes
Go to step 2. Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. In this
case, repair poor
contact in ECM
connector.
Go to step 3.
Repair the poor Replace the ECM.
contact in ECM <Ref. to
connector. FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
Go to step 5.
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
After repair,
replace the ECM.
<Ref. to
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
Replace the purge Go to step 6.
control solenoid
valve and ECM.
<Ref. to
EC(H4DOTC)-7,
Purge Control
Solenoid Valve.>
<Ref. to
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
Repair the poor Replace the ECM.
contact in ECM <Ref. to
connector. FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
No