Subaru LEGACY 2003 Service Manual page 101

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chas-
sis ground in selector lever "N" and "P"
positions.
Connector & terminal
(B135) No. 26 (+) — Chassis ground ( − − − − ):
Is the measured value less than the speci-
fied value?
2 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
3 CHECK HARNESS BETWEEN ECM AND IN-
HIBITOR SWITCH CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from ECM and
inhibitor switch.
3) Measure resistance of harness between
ECM and inhibitor switch connector.
Connector & terminal
(B135) No. 26 — (T7) No. 12:
Is the measured value less than the speci-
fied value?
4 CHECK HARNESS BETWEEN ECM AND
TRANSMISSION HARNESS CONNECTOR.
Measure resistance of harness between ECM
connector and chassis ground.
Connector & terminal
(B135) No. 26 — Chassis ground:
Is the measured value less than the specified
value?
5 CHECK INHIBITOR SWITCH GROUND LINE.
Remove re-starter motor connector.
Measure resistance of harness between inhibi-
tor switch connector and engine ground.
Connector & terminal
(T7) No. 12 — (B14) No. 1:
Is the measured value less than the specified
value?
6 CHECK STARTER MOTOR.
Check starter motor. <Ref. to SC(H4SO)-10,
INSPECTION, Starter.>
7 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Value
1 V
There is poor contact.
1 Ω
10 Ω
5 Ω
Starter motor is normal.
There is poor contact.
EN(H4SOw/oOBD)-99
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 3.
Repair poor con- Go to step 3.
tact in ECM con-
nector.
Go to step 4. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and inhibitor
switch connector
• Poor contact in
coupling connector
(B12)
• Poor contact in
inhibitor switch
connector
• Poor contact in
ECM connector
Repair ground Go to step 5.
short circuit in har-
ness between
ECM and trans-
mission harness
connector.
Go to step 6. Repair open circuit
in inhibitor switch
ground line.
Go to step 7. Repair or replace
starter motor.
Repair poor con- Replace ECM.
tact in ECM con- <Ref. to
nector. FU(H4SOw/
oOBD)-42, Engine
Control Module.>
No