Subaru Legacy 2003 Service Manual page 474

DIAGNOSTICS FOR ENGINE STARTING FAILURE
Step
1 CHECK OPERATING SOUND OF FUEL
PUMP.
Make sure that fuel pump is in operation for
two seconds when turning ignition switch to
ON.
Does fuel pump produce operating sound?
NOTE:
Fuel pump operation can also be executed us-
ing Subaru Select Monitor (Function mode:
FD01).
For the procedure, refer to "Compulsory Valve
Operation Check Mode". <Ref. to EN(H4SO)-
48, Compulsory Valve Operation Check
Mode.>
2 CHECK GROUND CIRCUIT OF FUEL PUMP.
1) Turn ignition switch to OFF.
2) Remove fuel pump access hole lid located
on the right rear of trunk compartment floor
(Sedan) or luggage compartment floor
(Wagon).
3) Disconnect connector from fuel pump.
4) Measure resistance of harness connector
between fuel pump and chassis ground.
Connector & terminal
(R58) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied value?
3 CHECK POWER SUPPLY TO FUEL PUMP.
1) Turn ignition switch to ON.
2) Measure voltage of power supply circuit
between fuel pump connector and chassis
ground.
Connector & terminal
(R58) No. 2 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
4 CHECK HARNESS BETWEEN FUEL PUMP
AND FUEL PUMP RELAY CONNECTOR.
1) Turn ignition switch to OFF.
2) Measure resistance of harness connector
between fuel pump and fuel pump relay.
Connector & terminal
(R58) No. 2 — (B46) No. 4:
Is the measured value less than the speci-
fied value?
5 CHECK HARNESS BETWEEN FUEL PUMP
AND FUEL PUMP RELAY CONNECTOR.
Measure resistance of harness between fuel
pump and fuel pump relay connector.
Connector & terminal
(R58) No. 2 — Chassis ground:
Is the measured value less than the specified
value?
Value
Operating sound produced.
5 Ω
10 V
1 Ω
1 MΩ
EN(H4SO)-77
ENGINE (DIAGNOSTICS)
Yes
Check fuel injec- Go to step 2.
tor circuit. <Ref. to
EN(H4SO)-80,
FUEL INJECTOR
CIRCUIT, Diag-
nostics for Engine
Starting Failure.>
Go to step 3. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
fuel pump connec-
tor and chassis
grounding terminal
• Poor contact in
coupling connector
Replace fuel Go to step 4.
pump. <Ref. to
FU(H4SO)-62,
Fuel Pump.>
Go to step 5. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
fuel pump connec-
tor and chassis
grounding terminal
• Poor contact in
coupling connec-
tors
Go to step 6. Repair short circuit
in harness
between fuel
pump and fuel
pump relay con-
nector.
No