check engine SUBARU LEGACY 1995 Service Repair Manual

OBD0727
1
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.
: Go to step 2.
OBD0123A
2CHECK POWER SUPPLY CIRCUIT FOR IGNI-
TION COIL.
1) Turn ignition switch to OFF.
2) Disconnect connector from ignition coil.
3) Turn ignition switch to ON.
4) Measure power supply voltage between ignition coil
connector terminal and body.
: Connector & terminal
(E12) No. 2—Body /10 V, or more
: Go to step 3.
: Repair harness between ignition coil and ignition
switch connector.
OBD0124
3
CHECK IGNITION COIL.
1) Measure resistance between ignition coil terminals to
check primary coil.
: Terminals
No. 2—No. 1/0.7±0.3Ω
No. 2—No. 3/0.7±0.3Ω
: Replace ignition coil.
: Go to next step.
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9. Diagnostics for Engine Starting Failure

OBD0125A
2) Measure resistance between spark plug cord contact
portions to check secondary coil.
: Connector & terminal
#1—#2 /21±3 kΩ
#3—#4 /21±3 kΩ
: Go to step 4.
: Replace ignition coil.
OBD0126A
4CHECK HARNESS CONNECTOR BETWEEN
IGNITOR AND IGNITION COIL.
1) Turn ignition switch to OFF.
2) Disconnect connector from ignitor.
3) Measure resistance of harness connector between igni-
tion coil and ignitor.
: Connector & terminal
(B13) No. 5—(E12) No. 1/10Ω, or less
(B13) No. 6—(E12) No. 3/10Ω, or less
: Go to step 5.
: Go to next.
: Is there poor contact in coupling connector
(B22)?
: Repair poor contact in coupling connector.
: Repair harness between ignition coil and ignitor
connector.
OBD0728
5
CHECK INPUT SIGNAL FOR IGNITOR.
Check if voltage varies synchronously with engine speed
when cranking, while monitoring voltage between ignitor
connector and body.
: Connector & terminal:
(B13) No. 1—Body/10 V, or more
(B13) No. 2—Body/10 V, or more
: Go to step 6.
: Replace ignitor.
B2M0224A
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
9. Diagnostics for Engine Starting Failure

OBD0128A
6CHECK HARNESS CONNECTOR OF IGNITOR
GROUND CIRCUIT.
1) Turn ignition switch to OFF.
2) Measure resistance between ignitor and body.
: Connector & terminal
(B13) No. 3—Body /10Ω, or less
: Go to step 7.
: Repair harness between ignitor connector and
body.
OBD0129A
7CHECK HARNESS CONNECTOR BETWEEN
ECM AND IGNITOR.
1) Disconnect connector from ECM.
2) Measure resistance of harness connector between
ECM and ignitor.
: Connector & terminal
(B84) No. 14—(B13) No. 1/10Ω, or less
(B84) No. 13—(B13) No. 2/10Ω, or less
(B84) No. 69—(B13) No. 3/10Ω, or less
: Repair open circuit of harness between ECM and
ignitor connector.
: Go to next step.
OBD0130A
3) Measure resistance of harness connector between
ECM and body.
: Connector & terminal
(B84) No. 13—Body/1 MΩ, or more
(B84) No. 14—Body/1 MΩ, or more
: Repair short circuit of harness between ECM and
ignitor.
: Confirm good connection in ECM connector.
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9. Diagnostics for Engine Starting Failure

E: FUEL PUMP CIRCUIT
1.Check operating sound of fuel pump.
2.Check ground circuit of fuel pump.
3.Check power supply to fuel pump.
4.Check harness connector between fuel pump
and fuel pump relay.
5.Check fuel pump relay.
6.Check harness connector between ECM and
fuel pump relay.
WIRING DIAGRAM:

LHD model
OBD0131





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

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?
: Check fuel injector circuit.
: Go to step 2.
OBD0132A
2
CHECK 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 body.
: Connector & terminal
(R58) No. 4—Body /10Ω, or less
: Go to step 3.
: Repair open circuit of fuel pump ground circuit.
OBD0133A
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 body.
: Connector & terminal
(R58) No. 1—Body /10 V, or more
: Replace fuel pump.
: Go to step 4.
OBD0134A
4CHECK HARNESS CONNECTOR BETWEEN
FUEL PUMP AND FUEL PUMP RELAY.
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. 4/10Ω, or less
: Go to next.
: Repair open circuit of harness between fuel pump
and fuel pump relay connector.
: Connector & terminal
(R58) No. 1—Body/1 MΩ, or more
: Go to step 5.
: Repair short circuit of harness between fuel pump
and fuel pump relay connector.
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9. Diagnostics for Engine Starting Failure

G2M0461
5
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. 4/10Ω, or less
: Go to step 6.
: Replace fuel pump relay.
OBD0136A
6CHECK HARNESS CONNECTOR BETWEEN
ECM AND FUEL PUMP RELAY.
1) Disconnect connectors from ECM.
2) Measure resistance of harness connector between
ECM and fuel pump relay.
: Connector & terminal
(B84) No. 84—(B46) No. 3/10Ω, or less
: Repair harness between ECM and fuel pump
relay connector.
: Confirm good connection in ECM connector.
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9. Diagnostics for Engine Starting Failure

F: FUEL INJECTOR CIRCUIT
1.Check output signal from ECM.

2.Check harness.
3.Check harness.
4.Check fuel injector.
5.Check power supply.
CAUTION:

Check or repair only faulty parts.

After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES. [T3D0] and [T3E0].>
WIRING DIAGRAM:

LHD model
OBD0137



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9. Diagnostics for Engine Starting Failure

G: CRANKSHAFT POSITION SENSOR
CIRCUIT
1.Check harness.
2.Check crankshaft position sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
OBD0109
NOTE:
For the diagnostic procedure on crankshaft position sensor
circuit, refer to“2-7 [T11Z0]”.

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9. Diagnostics for Engine Starting Failure

H: CAMSHAFT POSITION SENSOR CIRCUIT
1.Check harness.
2.Check camshaft position sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
OBD0115
NOTE:
For the diagnostic procedure on crankshaft position sensor
circuit, refer to“2-7 [T11AA]”.

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9. Diagnostics for Engine Starting Failure

10. General Diagnostics Table
1. FOR ENGINE
12345678910111213
Problem parts
Mass air flow sensor
Engine coolant temperature sensor (*1)
Throttle position sensor
Crankshaft position sensor & Camshaft position sensor (*2)
Idle air control solenoid valve
Knock sensor
Purge control solenoid valve
EGR valve
Fuel injection parts (*3)
Ignition parts (*4)
Fuel pump and relay
A/C switch and A/C cut relay
Engine torque control signal circuitSymptom
1 Engine stalls during idling.   
2 Rough idling    
3 Engine does not return to idle.
4 Poor acceleration   
5Engine stalls or engine sags or hesi-
tates at acceleration.    
6 Surge   
7 Spark knock
8 After burning in exhaust system  
*1: The mark,, indicates the symptom occurring only in cold temperatures.
*2: For items with the mark,, ensure the secure installation of crankshaft position sensor and camshaft position sensor. Replacement is
not necessary.
*3: Check fuel injector, fuel pressure regulator and fuel filter.
*4: Check igniter, ignition coil and spark plug.
NOTE:
Malfunction of parts other than the above is also possible. Refer to 1. Engine Trouble in General [K100] in Repair Section 2-3 of the Ser-
vice Manual.
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10. General Diagnostics Table