Subaru 2002 IMPREZA Service Manual page 941

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK INPUT SIGNAL FOR ECM.
1)Turn the ignition switch to ON.
2)Measure the voltage between ECM and
chassis ground in selector lever "N" and "P"
positions.
Connector & terminal
(B135) No. 26 (+) — Chassis ground ( − − − − ):
2 CHECK POOR CONTACT.
Check poor contact in ECM connector.
3 CHECK HARNESS BETWEEN ECM AND IN-
HIBITOR SWITCH CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connectors from ECM and
inhibitor switch.
3)Measure the resistance of harness between
ECM and inhibitor switch connector.
Connector & terminal
(B135) No. 26 — (T7) No. 12:
4 CHECK INHIBITOR SWITCH GROUND LINE.
Measure the resistance of harness between
inhibitor switch connector and engine ground.
Connector & terminal
(T7) No. 12 — Engine ground:
5 CHECK HARNESS BETWEEN ECM AND
TRANSMISSION HARNESS CONNECTOR.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B135) No. 26 — Chassis ground:
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the voltage less than 1 V?
Is there poor contact in ECM
connector?
Is the resistance less than 1
Ω?
Is the resistance less than 5
Ω?
Is the resistance less than 10
Ω?
Is there poor contact in ECM
connector?
EN(w/oOBD)-107
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 3.
Repair the poor Go to step 3.
contact in ECM
connector.
Go to step 4. Repair the har-
ness and connec-
tor.
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
Go to step 5. Repair the open
circuit in inhibitor
switch ground line.
Repair the ground Go to step 6.
short circuit in har-
ness between
ECM and trans-
mission harness
connector.
Repair the poor Replace the ECM.
contact in ECM <Ref. to FU(w/
connector. oOBD)-48, Engine
Control Module.>
No