Subaru 2009 IMPREZA, Service Manual

Page: 1477 / 3619

EN(H4DOTC)(diag)-256
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
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 (–):
Is the voltage less than 1 V? Repair the poor
contact of ECM
connector. Go to step 2 .
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:
Is the resistance less than 1
:
? Go to step 3 . Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and neutral
position switch
connector
• Poor contact of
coupling connector
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:
Is the resistance less than 1
:
? Repair the poor
contact of ECM
connector.
Replace the neu-
tral position switch.
<Ref. to 5MT-33,
Switches and Har-
ness.>