Subaru Legacy (2005 year). Manual - part 117

EN(H4SO 2.0)(diag)-57

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

Step

Check

Yes

No

1

CHECK IGNITION SYSTEM FOR SPARKS.
1) Remove the plug cord cap from each spark 
plug.
2) Install a new spark plug on plug cord cap.

CAUTION:

Do not remove the spark plug from engine.

3) Contact the spark plug thread portion on 
engine.
4) While opening the throttle valve fully, crank 
the engine to check that spark occurs at each 
cylinder.

Does spark occur at each cyl-
inder?

Check the fuel 
pump system. 
<Ref. to EN(H4SO 
2.0)(diag)-59, 
FUEL PUMP CIR-
CUIT, Diagnostics 
for Engine Start-
ing Failure.>

Go to step 2.

2

CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL AND IGNITOR ASSEMBLY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil 
and ignitor assembly.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between 
ignition coil and ignitor assembly connector 
and engine ground.

Connector & terminal

2.0 L model

(E12) No. 1 (+) — Engine ground (

−

):

2.5 L LHD model

(E12) No. 2 (+) — Engine ground (

−

):

2.5 L RHD model

(E12) No. 4 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Go to step 3.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
ignition coil and 
ignitor assembly, 
and main relay 
connector
• Poor contact in 
coupling connector
• Blown out fuse

3

CHECK HARNESS OF IGNITION COIL AND 
IGNITOR ASSEMBLY GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ignition 
coil and ignitor assembly connector and engine 
ground.

Connector & terminal

2.0 L model and 2.5 L LHD model

(E12) No. 3 — Engine ground:

2.5 L RHD model

(E12) No. 2 — Engine ground:

Is the resistance less than 5 
Ω?

Go to step 4.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
ignition coil and 
ignitor assembly 
connector and 
engine grounding 
terminal

4

CHECK IGNITION COIL AND IGNITOR AS-
SEMBLY.
1) Remove the spark plug cords.
2) Measure the resistance between spark 
plug cord contact portions to check secondary 
coil.

Terminals

No. 1 — No. 2:
No. 3 — No. 4:

Is the resistance 10 — 15 k

Ω? Go to step 5.

Replace the igni-
tion coil and ignitor 
assembly. <Ref. to 
IG(H4SO 2.0)-8, 
Ignition Coil and 
Ignitor Assembly.>

EN(H4SO 2.0)(diag)-58

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

5

CHECK INPUT SIGNAL OF IGNITION COIL 
AND IGNITOR ASSEMBLY.
1) Connect the connector to ignition coil and 
ignitor assembly.
2) Check if the voltage varies synchronously 
with engine speed when cranking, while moni-
toring voltage between ignition coil and ignitor 
assembly connector and engine ground.

Connector & terminal
2.0 L model

(E12) No. 4 (+) — Engine ground (

−

):

(E12) No. 2 (+) — Engine ground (

−

):

2.5 L LHD model

(E12) No. 1 (+) — Engine ground (

−

):

(E12) No. 4 (+) — Engine ground (

−

):

2.5 L RHD model

(E12) No. 1 (+) — Engine ground (

−

):

(E12) No. 3 (+) — Engine ground (

−

):

Does the voltage vary more 
than 10 V?

Go to step 6.

Replace the igni-
tion coil and ignitor 
assembly. <Ref. to 
IG(H4SO 2.0)-8, 
Ignition Coil and 
Ignitor Assembly.>

6

CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL AND IGNITOR ASSEMBLY 
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connector from ignition coil 
and ignitor assembly.
4) Measure the resistance of harness 
between ECM and ignition coil and ignitor 
assembly connector.

Connector & terminal
2.0 L model

(B134) No. 23 — (E12) No. 4:
(B134) No. 24 — (E12) No. 2:

2.5 L LHD model

(B134) No. 23 — (E12) No. 1:
(B134) No. 24 — (E12) No. 4:

2.5 L RHD model

(B134) No. 23 — (E12) No. 1:
(B134) No. 24 — (E12) No. 3:

Is the resistance less than 1 
Ω?

Go to step 7.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
ECM and ignition 
coil and ignitor 
assembly connec-
tor
• Poor contact in 
coupling connector

7

CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL AND IGNITOR ASSEMBLY 
CONNECTOR.
Measure the resistance of harness between 
ECM and engine ground.

Connector & terminal:

(B134) No. 23 — Engine ground:
(B134) No. 24 — Engine ground:

Is the resistance more than 1 
M

Ω?

Go to step 8.

Repair the ground 
short circuit of har-
ness between 
ECM and ignition 
coil and ignitor 
assembly connec-
tor.

8

CHECK POOR CONTACT.
Check poor contact in ECM connector.

Is there poor contact in ECM 
connector?

Repair the poor 
contact in ECM 
connector.

Check the fuel 
pump circuit. <Ref. 
to EN(H4SO 
2.0)(diag)-59, 
FUEL PUMP CIR-
CUIT, Diagnostics 
for Engine Start-
ing Failure.>

Step

Check

Yes

No

EN(H4SO 2.0)(diag)-59

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

E: FUEL PUMP CIRCUIT

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4SO 2.0)(diag)-
38, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.0)(diag)-32, PRO-
CEDURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-03473

MAIN SBF

No.12

SBF-6

E

3

6

B72

B362

B97

R1

R58

1
4
3
2

M

6

5

B:  B135

ECM

BATTERY

IGNITION
SWITCH

FUEL PUMP
RELAY

FUEL PUMP

FUEL PUMP
CONDENSER

E

No.11

B:   B135

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17 18 19

20 21

29 30 31

32 33

34 35

5
6

7 8

3
4

1 2

B362

B72

1

3

4 5 6

2

R58

1 2
3 4
5 6

R142

1
2

1
2

R142

2

1

1

2 3

4 5 6 7 8

B98

B97

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16

16

B98

R2

RHD

RHD

LHD

LHD

A:   B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

*

  LHD : WITH IMMOBILIZER : B17

LHD : WITHOUT IMMOBILIZER : A18

RHD : B17

*

4

A:  B134

EN(H4SO 2.0)(diag)-60

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

Step

Check

Yes

No

1

CHECK OPERATING SOUND OF FUEL 
PUMP.
Check if the fuel pump operates for two sec-
onds when turning the ignition switch to ON.

NOTE:

Fuel pump operation can also be executed us-
ing Subaru Select Monitor.
Refer to “Compulsory Valve Operation Check 
Mode” for procedures. <Ref. to EN(H4SO 
2.0)(diag)-39, Compulsory Valve Operation 
Check Mode.>

Does the fuel pump emit oper-
ating sound?

Check the fuel 
injector circuit. 
<Ref. to EN(H4SO 
2.0)(diag)-62, 
FUEL INJECTOR 
CIRCUIT, Diag-
nostics for Engine 
Starting Failure.>

Go to step 2.

2

CHECK GROUND CIRCUIT OF FUEL PUMP.
1) Turn the ignition switch to OFF.
2) Remove the fuel pump access hole lid.
3) Disconnect the connector from fuel pump.
4) Measure the resistance of harness connec-
tor between fuel pump and chassis ground.

Connector & terminal

(R58) No. 6 — Chassis ground:

Is the resistance less than 5 
Ω?

Go to step 3.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
fuel pump connec-
tor and chassis 
grounding terminal

3

CHECK POWER SUPPLY TO FUEL PUMP.
1) Turn the ignition switch to ON.
2) Measure the voltage of power supply circuit 
between fuel pump connector and chassis 
ground.

Connector & terminal

(R58) No. 5 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Replace the fuel 

pump. <Ref. to 
FU(H4SO 2.0)-47, 
Fuel Pump.>

Go to step 4.

4

CHECK HARNESS BETWEEN FUEL PUMP 
AND FUEL PUMP RELAY CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness connec-
tor between fuel pump and fuel pump relay.

Connector & terminal

(R58) No. 5 — (B362) No. 2:

Is the resistance less than 1 
Ω?

Go to step 5.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
fuel pump connec-
tor and chassis 
grounding terminal
• Poor contact in 
coupling connector

5

CHECK HARNESS BETWEEN FUEL PUMP 
AND FUEL PUMP RELAY CONNECTOR.
Measure the resistance of harness between 
fuel pump and fuel pump relay connector.

Connector & terminal

(R58) No. 5 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 6.

Repair the short 
circuit of harness 
between fuel pump 
and fuel pump 
relay connector.

6

CHECK FUEL PUMP RELAY.
1) Disconnect the connectors from fuel pump 
relay and main relay.
2) Remove the fuel pump relay and main relay 
with bracket.
3) Connect the battery to fuel pump relay con-
nector terminals No. 3 and No. 4.
4) Measure the resistance between connector 
terminals of fuel pump relay.

Terminals

No. 2 — No. 1:

Is the resistance less than 10 
Ω?

Go to step 7.

Replace the fuel 
pump relay. <Ref. 
to FU(H4SO 2.0)-
47, Fuel Pump.>