Subaru Legacy 2003 Service Manual page 478

DIAGNOSTICS FOR ENGINE STARTING FAILURE
Step
1 CHECK OPERATION OF EACH FUEL INJEC-
TOR.
While cranking the engine, check that each
fuel injector emits "operating" sound. Use a
sound scope or attach a screwdriver to injector
for this check.
Does the fuel injector produce "operating"
sound?
2 CHECK POWER SUPPLY TO EACH FUEL
INJECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from fuel injector.
3) Turn ignition switch to ON.
4) Measure 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 (–):
Does the measured value exceed the spec-
ified value?
3 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
1) Disconnect connector from ECM and fuel
injector.
2) Measure resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B134) No. 34 — (E5) No. 1:
(B134) No. 23 — (E16) No. 1:
(B134) No. 22 — (E6) No. 1:
(B134) No. 8 — (E17) No. 1:
Is the measured value less than the speci-
fied value?
4 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
Measure resistance of harness between ECM
and fuel injector connector.
Connector & terminal
(B134) No. 34 — Chassis ground:
(B134) No. 23 — Chassis ground:
(B134) No. 22 — Chassis ground:
(B134) No. 8 — Chassis ground:
Does the measured value exceed the specified
value?
5 CHECK EACH FUEL INJECTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between each fuel
injector terminals.
Terminals
No. 1 — No. 2:
Is the measured value within the specified
range?
Value
Operating sound produced.
10 V
1 Ω
1 MΩ
5 - 20 Ω
EN(H4SO)-81
ENGINE (DIAGNOSTICS)
Yes
Check fuel pres- Go to step 2.
sure. <Ref. to
ME(H4SO)-28,
INSPECTION,
Fuel Pressure.>
Go to step 3. Repair harness
and connector.
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 harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and fuel
injector connector
• Poor contact in
coupling connector
Go to step 5. Repair ground
short circuit in har-
ness between
ECM and fuel
injector connector.
Go to step 6. Replace faulty fuel
injector.
No