Subaru Legacy IV (2008 year). Manual - part 580

EN(H6DO)(diag)-293

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

DR:DTC P1560 BACK-UP VOLTAGE CIRCUIT MALFUNCTION

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-180, DTC P1560 BACK-UP VOLTAGE CIRCUIT MAL-
FUNCTION, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

SBF-6

MAIN SBF

SBF-7

B72

A7

B2

C23

A3

D2

D1

D7

B5

B19

No. 12

B47

E2

B21

1

2

4

6

5

3

ECM

E

E

3

1

B134

B135

A:

C: B136

D: B137

B:

35

34

52

3

4

1

2

5

6

B47

TO OXYGEN SENSOR

No. 13

A5

36

B72

1

3

4 5 6

2

E

SBF-5

D3

37

MAIN RELAY

BATTERY

IGNITION
SWITCH

EN-06864

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

16

10 11 12 13

14 15
25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

6

5

27

26

33 34 35

B136

C:

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

B134

A:

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

B135

B:

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

B137

D:

EN(H6DO)(diag)-294

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK INPUT SIGNAL OF ECM.
1) Turn the ignition switch to OFF.
2) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B135) No. 5 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Repair the poor 
contact of ECM 
connector.

Go to step 2.

2

CHECK HARNESS BETWEEN ECM AND 
MAIN FUSE BOX CONNECTOR.
1) Disconnect the connectors from ECM.
2) Measure the resistance between ECM and 
chassis ground.

Connector & terminal

(B135) No. 5 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 3.

Repair the ground 
short circuit of har-
ness between 
ECM and battery 
terminal.

3

CHECK FUSE NO. 13.

Is the fuse blown out?

Replace the fuse.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and battery
• Poor contact in
ECM connector
• Poor contact of
battery terminal

EN(H6DO)(diag)-295

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

DS:DTC P1602 CONTROL MODULE PROGRAMMING ERROR

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-182, DTC P1602 CONTROL MODULE PROGRAMMING
ERROR, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Engine keeps running at higher speed than specified idle speed.
• Engine keeps running at a lower speed than the specified idle speed.
• Engine stalls.

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

3

4

1

2

5

6

1 2

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

B47

B137

E6

E17

E5

E16

E43

E44

1

2

E5

8

42

B47

MAIN RELAY

1

2

3

5

4

6

48

1

2

E16

1

2

E6

10

ECM

BATTERY

SBF-7

B137

9

43

44

FUEL

INJECTOR 

No. 1

1

2

E17

1

2

E43

11

45

12

46

1

2

E44

E

B21

E2

13

47

EN-06776

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

FUEL

INJECTOR 

No. 2

FUEL

INJECTOR 

No. 3

FUEL

INJECTOR 

No. 4

FUEL

INJECTOR 

No. 5

FUEL

INJECTOR 

No. 6

EN(H6DO)(diag)-296

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check the appro-
priate DTC using 
the “List of Diag-
nostic Trouble 
Code (DTC)”. 
<Ref. to 
EN(H6DO)(diag)-
81, List of Diagnos-
tic Trouble Code 
(DTC).>

Go to step 2.

2

CHECK ENGINE OIL.

Is there a proper amount of 
engine oil?

Go to step 3.

Replace engine oil. 
<Ref. to 
LU(H6DO)-8,
REPLACEMENT, 
Engine Oil.>

3

CHECK EXHAUST SYSTEM.

Are there holes or loose bolts 
on exhaust system?

Repair the exhaust 
system.

Go to step 4.

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

B20

1 2 3 4 5 6

E57

1 2 3 4
5 6 7 8

B122

1 2

7 8

3
4

5
6

B362

36

52

34

35

37

E

E2

B21

E

A5

C21

C1

A29

19

E1

B20

A18

C6

A28

6

4

15

*

*

B122

16

E

38

39

20

D5

D4

A19

D7

D1

A3

D2

D3

3

E57

ELECTRONIC THROTTLE 

CONTROL

2

1

5

B134

B362

5

7

6

A:

B137

B136

D:

C:

ECM

*

: TERMINAL No. OPTIONAL ARRANGEMENT

E

SBF-7

BATTERY

ELECTRONIC 
THROTTLE
CONTROL RELAY

MAIN RELAY

8

6

4

B47

B47

3

4

1

2

5

6

EN-06873

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

B136

C:

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

B137

D:

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

B134

A:

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47