Subaru 2002 IMPREZA Service Manual page 707

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
2 CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 26 (+) — Chassis ground ( − − − − ):
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
4 CHECK NEUTRAL POSITION SWITCH.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from transmission
harness.
3)Measure the resistance between transmis-
sion harness and connector terminals.
Connector & terminal
(T2) No. 1 — No. 2:
5 CHECK NEUTRAL POSITION SWITCH.
Measure the resistance between transmission
harness connector terminals.
6 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B135) No. 26 — Chassis ground:
7 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1)Disconnect the connector from ECM.
2)Measure the resistance of harness between
ECM and transmission harness connector.
Connector & terminal
(B135) No. 26 — (B25) No. 1:
8 CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
Measure the resistance of harness between
transmission harness connector and engine
ground.
Connector & terminal
(B25) No. 2 — Engine ground:
9 CHECK POOR CONTACT.
Check poor contact in transmission harness
connector.
Check
Is the voltage less than 1V in
other position?
Is the poor contact in ECM
connector?
Is the resistance more than
1MΩ in neutral position?
Is the resistance less than 1Ω
in other positions?
Is the resistance less than 10
Ω?
Is the resistance less than 1
Ω?
Is the resistance less than 5
Ω?
Is there poor contact in trans-
mission harness connector?
EN-275
ENGINE (DIAGNOSTICS)
Yes
Go to step 3. Go to step 4.
Repair the poor Contact with your
contact in ECM Subaru distributor
connector. service.
Go to step 5. Repair the short
circuit in transmis-
sion harness or
replace neutral
position switch.
Go to step 6. Repair the short
circuit in transmis-
sion harness or
replace neutral
position switch.
Repair the ground Go to step 7.
short circuit in har-
ness between
ECM and trans-
mission harness
connector.
Go to step 8. Repair the open
circuit in harness
between ECM and
transmission har-
ness connector.
Go to step 9. Repair the open
circuit between
transmission har-
ness connector
and engine ground
terminal.
Repair the poor Contact with your
contact in trans- Subaru distributor
mission harness service.
connector.
No