1997 SUBARU LEGACY fuel pump

8. Diagnostics for Engine Starting
Failure
A: BASIC DIAGNOSTICS CHART
Inspection of starter motor circuit.
Inspection of ECM power supply and ground line.
Inspection of ignition control system.
Inspection of fuel pump circuit.
Inspection of fuel injector circuit.
Inspection of crankshaft position sensor circuit.
Inspection of camshaft position sensor circuit.
Inspection using Subaru select monitor or OBD-II
general scan tool or inspection using“9. General
Diagnostics Table.







96
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

D: IGNITION CONTROL SYSTEM
WIRING DIAGRAM:
B2M0522
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

OBD0727B
B2M0644B
8D1
CHECK IGNITION SYSTEM FOR SPARKS.
1) Remove plug cord cap from each spark plug.
2) Install new spark plug on plug cord cap.
CAUTION:
Do not remove spark plug from engine.
3) Contact spark plug’s thread portion on engine.
4) While opening throttle valve fully, crank engine to check
that spark occurs at each cylinder.
: Does spark occur at each cylinder?
: Check fuel pump system. [T8F0].>
: Go to step8D2.
107
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M0523A
8D7CHECK HARNESS BETWEEN ECM AND
IGNITOR CONNECTOR.
1) Disconnect connector from ECM.
2) Measure resistance of harness connector between
ECM and ignitor.
: Connector & terminal
(B84) No. 41—(B13) No. 1:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
ignitor connector.
: Connector & terminal
(B84) No. 40—(B13) No. 2:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
ignitor connector.
: Connector & terminal
(B84) No. 94—(B13) No. 3:
Is the resistance less than 1Ω?
: Repair open circuit in harness between ECM and
ignitor connector.
: Go to next step 3).
B2M0524A
3) Measure resistance of harness connector between
ECM and chassis ground.
: Connector & terminal
(B84) No. 41—Chassis ground:
Is the resistance more than 1 MΩ?
: Go to next.
: Repair ground short circuit in harness between
ECM and ignitor connector.
: Connector & terminal
(B84) No. 40—Chassis ground:
Is the resistance more than 1 MΩ?
: Go to next.
: Repair ground short circuit in harness between
ECM and ignitor connector.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Check fuel pump circuit. [T8F0].>
111
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

E: FUEL PUMP CIRCUIT (2200 cc FWD, 2500
cc AWD TAIWAN SPEC. VEHICLES)
WIRING DIAGRAM:
B2M1052
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

11 2
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

8E1CHECK 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 check can also be executed using
Subaru Select Monitor (Function mode: FD01).
For the procedure, refer to“COMPULSORY VALVE
OPERATION CHECK MODE”.
: Check fuel injector circuit.
: Go to step8E2.
OBD0132A
8E2CHECK GROUND CIRCUIT OF FUEL
PUMP.
1) Turn ignition switch to OFF.
2) Disconnect connector from fuel pump.
3) Measure resistance of harness connector between fuel
pump and chassis ground.
: Connector & terminal
(R58) No. 4—Chassis ground:
Is the resistance less than 5Ω?
: Go to step8E3.
: Repair open circuit in fuel pump ground circuit.
OBD0133A
8E3
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. 1 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Replace fuel pump.
: Go to step8E4.
11 3
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M0526A
8E4CHECK HARNESS BETWEEN FUEL
PUMP AND FUEL PUMP RELAY CON-
NECTOR.
1) Turn ignition switch to OFF.
2) Measure resistance of harness connector between fuel
pump and fuel pump relay.
: Connector & terminal
(R58) No. 1—(B46) No. 4:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between fuel pump
and fuel pump relay connector.
: Connector & terminal
(R58) No. 1—Chassis ground:
Is the resistance more than 1 MΩ?
: Go to step8E5.
: Repair short circuit in harness between fuel pump
and fuel pump relay connector.
G2M0461
8E5
CHECK FUEL PUMP RELAY.
1) Disconnect connectors from fuel pump relay and main
relay.
2) Remove fuel pump relay and main relay with bracket.
3) Connect battery to fuel pump relay connector terminals
No. 1 and No. 3.
4) Measure resistance between connector terminals of
fuel pump relay.
: Terminals
No. 2—No. 4:
Is the resistance less than 10Ω?
: Go to step8E6.
: Replace fuel pump relay.
11 4
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

B2M0527A
8E6CHECK HARNESS BETWEEN ECM AND
FUEL PUMP RELAY CONNECTOR.
1) Disconnect connectors from ECM.
2) Measure resistance of harness between ECM and fuel
pump relay connector.
: Connector & terminal
(B84) No. 32—(B46) No. 3:
Is the resistance less than 1Ω?
: Go to next.
: Repair open circuit in harness between ECM and
fuel pump relay connector.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Check fuel injector circuit.
11 5
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

F: FUEL PUMP CIRCUIT (2200 cc AWD
EXCEPT TAIWAN SPEC. VEHICLES)
WIRING DIAGRAM:
B2M1053
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

11 6
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure