Subaru Legacy (2005 year). Manual - part 116

EN(H4SO 2.0)(diag)-53

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

8

CHECK STARTER RELAY.
1) Connect the battery to starter relay termi-
nals No. 15 and No. 16.
2) Measure the resistance between starter 
relay terminals.

Terminals

No. 13 — No. 14:

Is the resistance less than 1 
Ω?

Go to step 9.

Replace the 
starter relay.

9

CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Connect the connector to starter relay.
3) Disconnect the connector from ECM.
4) Turn the ignition switch to START.
5) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B135) No. 23 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Replace the ECM. 

<Ref. to FU(H4SO 
2.0)-34, Engine 
Control Module 
(ECM).>

Repair the open or 
ground short cir-
cuit of harness 
between ECM and 
starter relay.
For AT model, 
check the inhibitor 
switch. <Ref. to 
4AT-51, INSPEC-
TION, Inhibitor 
Switch.>

Step

Check

Yes

No

EN(H4SO 2.0)(diag)-54

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

C: CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MOD-

ULE (ECM)

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-03507

BATTERY

IGNITION
SWITCH

MAIN RELAY

SBF-6

MAIN SBF

SBF-7

B72

C4

C3

B14

B5

C6

B6

C1

C2

A7

C5

C7

B13

No.12

B47

E2

B21

2

1

4

6

5

3

ECM

E

E

3

6

B134

B135

A:

D: B137

B:

D1

52

37

36

34

3

4

1

2

5

6

B47

No.13

A2

35

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

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

B137

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

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

B72

1

3

4 5 6

2

A:

B:

D:

B136

C:

B136

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

C:

SBF-5

TO OXYGEN SENSOR

EN(H4SO 2.0)(diag)-55

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

Step

Check

Yes

No

1

CHECK MAIN RELAY.
1) Turn the ignition switch to OFF.
2) Remove the main relay.
3) Connect the battery to main relay terminals 
No. 1 and No. 2.
4) Measure the resistance between main relay 
terminals.

Terminals

No. 3 — No. 5:
No. 4 — No. 6:

Is the resistance less than 10 
Ω?

Go to step 2.

Replace the main 
relay.

2

CHECK GROUND CIRCUIT FOR ECM.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness 
between ECM and chassis ground.

Connector & terminal

(B134) No. 2 — Chassis ground:
(B134) No. 7 — Chassis ground:
(B135) No. 5 — Chassis ground:
(B135) No. 6 — Chassis ground:
(B136) No. 1 — Chassis ground:
(B136) No. 2 — Chassis ground:
(B136) No. 5 — Chassis ground:
(B136) No. 6 — Chassis ground:
(B137) No. 1 — Chassis ground:

Is the resistance less than 5 
Ω?

Go to step 3.

Repair the open 
circuit of harness 
between ECM 
connector and 
engine grounding 
terminal.

3

CHECK INPUT VOLTAGE OF ECM.
Measure the voltage between ECM connector 
and chassis ground.

Connector & terminal

(B136) No. 7 (+) — Chassis ground (

−

):

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

Repair the open or 
ground short cir-
cuit of power sup-
ply circuit.

4

CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.

Connector & terminal

(B135) No. 13 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 5.

Repair the open or 
ground short cir-
cuit of power sup-
ply circuit.

5

CHECK INPUT VOLTAGE OF MAIN RELAY.
Measure the voltage between main relay con-
nector and chassis ground.

Connector & terminal

(B47) No. 1 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 6.

Repair the open 
circuit of harness 
between ECM 
connector and 
main relay connec-
tor.

6

CHECK INPUT VOLTAGE OF ECM.
1) Connect the connectors to ECM and main 
relay.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector and chassis ground.

Connector & terminal

(B135) No. 14 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 7.

Repair the open or 
ground short cir-
cuit of harness 
between ECM 
connector and 
main relay connec-
tor.

7

CHECK INPUT VOLTAGE OF MAIN RELAY.
Measure the voltage between main relay con-
nector and chassis ground.

Connector & terminal

(B47) No. 5 (+) — Chassis ground (

−

):

(B47) No. 6 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 8.

Repair the open or 
ground short cir-
cuit of harness of 
power supply cir-
cuit.

EN(H4SO 2.0)(diag)-56

ENGINE (DIAGNOSTICS)

Diagnostics for Engine Starting Failure

D: IGNITION CONTROL SYSTEM

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:

8

CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.

Connector & terminal

(B136) No. 3 (+) — Chassis ground (

−

):

(B136) No. 4 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Check ignition 

control system. 
<Ref. to EN(H4SO 
2.0)(diag)-56, 
IGNITION CON-
TROL SYSTEM, 
Diagnostics for 
Engine Starting 
Failure.>

Repair the open or 
ground short cir-
cuit of harness 
between ECM 
connector and 
main relay connec-
tor.

Step

Check

Yes

No

EN-03472

BATTERY

3

IGNITION
SWITCH

6

24

B21

E2

E12

MAIN SBF

13

49

15

B134

ECM

23

3

4

1

2

IGNITION COIL

&

IGNITOR ASSY

B72

E

E

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

B72

E12

9

10

1

2

3

4

5

6

7

8

11 12

14

15 16

13

18

19 20

17

22

23 24

21

38

39 40

37

34

35 36

33

30

31 32

29

26

27 28

25

B225

SBF-6

No.12

1 2 3 4

1

3

4 5 6

2

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

  2.0 L : 1

2.5 L LHD : 2

2.5 L RHD : 4

2.0 L : 4

2.5 L LHD : 1

2.5 L RHD : 1

2.0 L : 2

2.5 L LHD : 4

2.5 L RHD : 3

2.0 L : 3

2.5 L LHD : 3

2.5 L RHD : 2

*

1

*

*

2

3

*

4

3

4

2

*

1

*

*

*