Subaru 2009 IMPREZA Service Manual page 1477

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK INPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Place the shift lever in neutral.
3) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 31 (+) — Chassis ground (–):
2 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
neutral position switch.
3) Measure the resistance of harness between
ECM and neutral position switch connector.
Connector & terminal
(B136) No. 31 — (T12) No. 1:
(B136) No. 6 — (T12) No. 2:
3 CHECK NEUTRAL POSITION SWITCH.
1) Place the shift lever in neutral.
2) Measure the resistance between neutral
position switch terminals.
Terminals
No. 1 — No. 2:
Check
Is the voltage less than 1 V?
Is the resistance less than 1 ? Go to step 3.
Is the resistance less than 1 ? Repair the poor
EN(H4DOTC)(diag)-256
Yes No
Repair the poor Go to step 2.
contact of ECM
connector.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and neutral
position
connector
• Poor contact of
coupling connector
Replace the neu-
contact of ECM tral position switch.
connector. <Ref. to 5MT-33,
Switches and Har-
ness.>
switch