Subaru Legacy (2005 year). Service manual — part 437

EN(H6DO)(diag)-61

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

2

CHECK IGNITION SYSTEM FOR SPARKS.
1) Connect the spark plug to ignition coil.
2) Release the fuel pressure.
3) Contact the spark plug’s thread portion on
engine.
4) While opening the throttle valve fully, start
the engine to check if spark occurs at each cyl-
inder.

Does spark occur at each cyl-
inder?

Check fuel pump
system. <Ref. to
EN(H6DO)(diag)-
62, FUEL PUMP
CIRCUIT, Diag-
nostics for Engine
Starting Failure.>

Go to step 3.

3

CHECK POWER SUPPLY CIRCUIT OF IGNI-
TION COIL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
ignition coil connector and engine ground.

Connector & terminal

(E31) No. 3 (+) — Engine ground (

−

):

(E32) No. 3 (+) — Engine ground (

−

):

(E33) No. 3 (+) — Engine ground (

−

):

(E34) No. 3 (+) — Engine ground (

−

):

(E45) No. 3 (+) — Engine ground (

−

):

(E46) No. 3 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Go to step 4.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ignition coil and
ignition switch con-
nector
• Poor contact in
coupling connector

4

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

Connector & terminal

(E31) No. 2 — Engine ground:
(E32) No. 2 — Engine ground:
(E33) No. 2 — Engine ground:
(E34) No. 2 — Engine ground:
(E45) No. 2 — Engine ground:
(E46) No. 2 — Engine ground:

Is the resistance less than 5
Ω?

Go to step 5.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ignition coil con-
nector and engine
ground terminal

5

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

Connector & terminal

(B135) No. 18 — (E31) No. 1:
(B135) No. 17 — (E32) No. 1:
(B135) No. 16 — (E33) No. 1:
(B135) No. 15 — (E34) No. 1:
(B135) No. 14 — (E45) No. 1:
(B135) No. 13 — (E46) No. 1:

Is the resistance less than 1
Ω?

Go to step 6.

Repair the har-
ness and connec-
tor.

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

6

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

Connector & terminal:

(B135) No. 18 — Engine ground:
(B135) No. 17 — Engine ground:
(B135) No. 16 — Engine ground:
(B135) No. 15 — Engine ground:
(B135) No. 14 — Engine ground:
(B135) No. 13 — Engine ground:

Is the resistance more than 1
M

Ω?

Go to step 7.

Repair the ground
short circuit of har-
ness between
ECM and ignition
coil connector.

Step

Check

Yes

No

EN(H6DO)(diag)-62

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

E: FUEL PUMP CIRCUIT

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)(diag)-41,
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)(diag)-34, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

7

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(H6DO)(diag)-
62, FUEL PUMP
CIRCUIT, Diag-
nostics for Engine
Starting Failure.>

Step

Check

Yes

No

EN-03492

E

E

M

10

7

6

5

6

No.11

B362

R122

B135

B:

B137

D:

R58

7

D28

B27

1

2

9

8

5

FUEL PUMP
CONTROL UNIT

FUEL
PUMP

ECM

BATTERY

FUEL PUMP
RELAY

R58

2

5

4
6

1
3

B135

B:

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

B137

D:

5

6

7

8

2

1

9

4

3

10

22 23

11 12 13 14 15

24 25

26

16 17

18 19 20 21

27

28 29

30 31

R122

3 4

1 2
5

8 9 10

6 7

B98

1

2 3

4 5 6 7 8

B362

5
6

7 8

3
4

1 2

B97

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16

*

LHD: 16
RHD: 4

1

*

LHD: B97
RHD: B98

2

*

3

*

2

*

5

*

4

*

1

*

2

*

3

*

LHD: R1
RHD: R2

3

*

LHD: 6
RHD: 5

4

*

LHD: 15
RHD: 6

5

EN(H6DO)(diag)-63

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

Step

Check

Yes

No

1

CHECK OPERATING SOUND OF FUEL
PUMP.
Make sure that the fuel pump operates for two
seconds 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(H6DO)(diag)-42, Compulsory Valve Oper-
ation Check Mode.>

Does the fuel pump emit oper-
ating sound?

Check the fuel
injector circuit.
<Ref. to
EN(H6DO)(diag)-
64, FUEL INJEC-
TOR CIRCUIT,
Diagnostics for
Engine Starting
Failure.>

Display DTC.
<Ref. to
EN(H6DO)(diag)-
33, OPERATION,
Read Diagnostic
Trouble Code
(DTC).>

EN(H6DO)(diag)-64

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

F: FUEL INJECTOR CIRCUIT

CAUTION:
• Check or repair only faulty parts.
• After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)(diag)-
41, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)(diag)-34, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

Step

Check

Yes

No

1

CHECK OPERATION OF EACH FUEL INJEC-
TOR.
While cranking the engine, check each fuel
injector emits operating sound. Use a sound
scope or attach a screwdriver to the injector for
this check.

Does the fuel pump emit oper-
ating sound?

Check the fuel
pressure. <Ref. to
ME(H6DO)-27,
INSPECTION,
Fuel Pressure.>

Go to step 2.

E6

E17

E5

E16

E43

E44

1

2

1

2

1

2

1

2

4

5

6

3

42

48

43

44

45

ECM

B136

E5

E16

E6

E17

B21

E2

FUEL INJECTOR

No. 1

FUEL INJECTOR

No. 2

FUEL INJECTOR

No. 3

FUEL INJECTOR

No. 4

BATTERY

1

2

1

2

2

1

46

47

E43

E44

FUEL INJECTOR

No. 5

FUEL INJECTOR

No. 6

SBF-7

B47

MAIN RELAY

B47

3

4

1

2

5

6

B136

1 2

EN-03493

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

35

B21

1 2 3 4

12 13 14 15

5 6 7 8

16 17 18 19

9 10 11

20 21 22

23 24 25 26 27 28 29 30 31 32 33

35

34

37

36

39

38

41

40

43

42

44

45

47

46

49

48

51

50

53

52

54

E

6
4