Subaru Legacy 2003 Service Manual page 654

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.
Connector & terminal
(B136) No. 21 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value in neutral position?
2 CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM and chassis
ground.
Connector & terminal
(B136) No. 21 (+) — Chassis ground ( − − − − ):
Is the measured value less than the specified
value at except neutral position?
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
4 CHECK NEUTRAL POSITION SWITCH.
1) Turn ignition switch to OFF.
2) Disconnect connector from transmission
harness.
3) Measure resistance between transmission
harness and connector terminals.
Connector & terminal
(T2) No. 1 — No. 2:
Does the measured value exceed the spec-
ified value in neutral position?
5 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1) Disconnect connector from ECM.
2) Measure resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 21 — Chassis ground:
Does the measured value exceed the spec-
ified value?
6 CHECK POOR CONTACT.
Check poor contact in transmission harness
connector.
Is there poor contact in transmission harness
connector?
Value
5 V
1 V
There is poor contact.
1 MΩ
1 MΩ
There is poor contact.
EN(H4SO)-257
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 4.
Go to step 3. Go to step 4.
Repair poor con- Contact SUBARU
tact in ECM con- distributor service.
nector.
NOTE:
Inspection by DTM
is required,
cause
cause is deteriora-
tion of
parts.
Go to step 5. Repair short circuit
in transmission
harness or replace
neutral position
switch.
Repair ground Go to step 6.
short circuit in har-
ness between
ECM and trans-
mission harness
connector.
Repair poor con- Contact SUBARU
tact in transmis- distributor service.
sion harness
NOTE:
connector.
Inspection by DTM
is required,
cause
cause is deteriora-
tion of
parts.
No
be-
probable
multiple
be-
probable
multiple