Subaru Legacy 2003 Service Manual page 915

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
1 CHECK INPUT SIGNAL FOR ECM.
1) Select MT shift lever to neutral position.
2) Turn ignition switch to ON.
3) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 26 (+) — Chassis ground ( − − − − ):
Is the measured value within the specified
value?
2 CHECK INPUT SIGNAL FOR ECM.
1) Select MT shift lever in any position other
than neutral.
2) Measure voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 26 (+) — Chassis ground ( − − − − ):
Is the measured value less than the speci-
fied value?
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) Select MT shift lever to neutral position.
3) Disconnect connector from transmission
harness.
4) Measure resistance between transmission
harness and connector terminals.
Connector & terminal
(T2) No. 1 — No. 2:
Does the measured value exceed the spec-
ified value?
5 CHECK NEUTRAL POSITION SWITCH.
1) Move MT shift lever to any position other
than neutral.
2) Measure resistance between transmission
harness connector terminals.
Connector & terminal
(T2) No. 1 — No. 2:
Is the measured value less than the speci-
fied value?
6 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1) Disconnect connector from ECM.
2) Measure resistance of harness between
ECM and transmission harness connector.
Connector & terminal
(B135) No. 26 — (B25) No. 1:
Is the measured value less than the speci-
fied value?
Step
EN(H4SOw/oOBD)-96
Value
4.5 — 5.5 V
1 V
There is poor contact.
1 MΩ
10 Ω
1 Ω
Yes
Go to step 3. Go to step 2.
Go to step 3. Go to step 4.
Repair poor con- Replace ECM.
tact in ECM con- <Ref. to
nector. FU(H4SOw/
oOBD)-42, Engine
Control Module.>
Go to step 5. Repair short circuit
in transmission
harness or replace
neutral position
switch.
Go to step 6. Repair open circuit
in transmission
harness or replace
neutral position
switch.
Go to step 7. Repair open circuit
in harness
between ECM and
transmission har-
ness connector.
No