Subaru 2002 IMPREZA Service Manual page 1234

DIAGNOSTICS FOR ENGINE STARTING FAILURE
ENGINE (DIAGNOSTICS)
Step
2 CHECK POWER SUPPLY TO EACH FUEL
INJECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from #1 cylinder
fuel injector.
3)Turn the ignition switch to ON.
4)Measure the power supply voltage between
the fuel injector terminal and engine ground.
Connector & terminal
#1 (E5) No. 2 (+) — Engine ground (–):
#2 (E16) No. 2 (+) — Engine ground ( − − − − ):
#3 (E6) No. 2 (+) — Engine ground (–):
#4 (E17) No. 2 (+) — Engine ground (–):
3 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
1)Disconnect the connector from ECM.
2)Measure the resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B137) No. 1 — (E5) No. 1:
(B136) No. 6 — (E16) No. 1:
(B136) No. 5 — (E6) No. 1:
(B136) No. 4 — (E6) No. 1:
4 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
Measure the resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B137) No. 1 — Chassis ground:
(B136) No. 6 — Chassis ground:
(B136) No. 5 — Chassis ground:
(B136) No. 4 — Chassis ground:
5 CHECK EACH FUEL INJECTOR.
1)Turn the ignition switch to OFF.
2)Measure the resistance between each fuel
injector terminals.
Terminals
No. 1 — No. 2:
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the voltage more than 10 V? Go to step 3.
Is the resistance less than 1
Ω?
Is the resistance less than 1
Ω?
Is the resistance between 5
and 20 Ω?
Is there poor contact in ECM
connector?
EN(TURBO)-74
Yes
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
main relay and fuel
injector connector
• Poor contact in
main relay con-
nector
• Poor contact in
coupling connector
• Poor contact in
fuel injector con-
nector
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 fuel
injector connector
• Poor contact in
coupling connector
Repair the ground Go to step 5.
short circuit in har-
ness between
ECM and fuel
injector connector.
Go to step 6. Replace the faulty
fuel injector.
Repair the poor Inspection using
contact in ECM "General Diagnos-
connector. tic Table". <Ref. to
EN(TURBO)-350,
INSPECTION,
General Diagnos-
tic Table.>
No