Subaru Legacy 2003 Service Manual page 1972

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
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 operate?
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 (–):
Does the measured value exceed the spec-
ified value?
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:
Is the measured value less than the speci-
fied value?
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:
Does the measured value exceed the specified
value?
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:
Is the measured value within the specified
value?
Value
Operates.
10 V
1 Ω
1 MΩ
5 — 20 Ω
EN(H4DOSTC)-133
ENGINE (DIAGNOSTICS)
Yes
Check the fuel Go to step 2.
pressure. <Ref. to
ME(H4DOSTC)-
26, FUEL PRES-
SURE, .>
Go to step 3. 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
the harness
between ECM and
fuel injector con-
nector
• Poor contact in
the coupling con-
nector
Go to step 5. Repair the ground
short circuit in har-
ness between
ECM and fuel
injector connector.
Go to step 6. Replace the faulty
fuel injector.
No