Subaru Legacy IV (2008 year). Manual - part 363

EN(H4DOTC)(diag)-273

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CW:DTC P1560 BACK-UP VOLTAGE CIRCUIT MALFUNCTION

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-183, 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(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-05666

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:

SBF-6

MAIN SBF

SBF-7

B72

A7

B2

C23

D2

A5

D3

B5

B19

No.12

B47

E2

B21

1

2

4

6

5

3

E

E

B134

B135

A:

C: B136

D: B137

B:

35

34

40

3

4

1

2

5

6

B47

No.13

D7

36

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:

SBF-5

D1

37

3

1

MAIN RELAY

TO OXYGEN SENSOR

IGNITION
SWITCH

BATTERY

ECM

EN(H4DOTC)(diag)-274

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(H4DOTC)(diag)-275

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CX:DTC P1602 CONTROL MODULE PROGRAMMING ERROR

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-185, DTC P1602 CONTROL MODULE PROGRAM-
MING 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(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-05668

E

#4

1

2

SBF-7

#3

1

2

#2

1

2

B21

#1

1

2

48

54

53

52

51

8

9

10

11

1 2

5
3

6
4

2
1

B21

B137

E5

E5

E2

E6

E6

E16

E16

E17

B47

E17

B47

3

4

1

2

5

6

B137

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

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

MAIN RELAY

ECM

BATTERY

FUEL INJECTOR

EN(H4DOTC)(diag)-276

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EN-05673

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

1 2

7 8

3
4

5
6

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

34 35

36 37 38 39 40 41

48 49

50 51 52 53 54

42 43

44 45

46 47

26 27 28 29 30 31 32 33

1 2 3 4
5 6 7 8

1

2

7

8 9

5

6

3

4

10 11 12

19 20 21

29

30 31

13 14 15 16 17

27

28

18

22 23

24 25

26

1

2

8 9

5

6

3

4

10 11 12

19 20 21

29 30

31

13 14 15 16

17

27

28

18

22 23 24 25 26

7

32 33 34 35

1 2 3 4 5 6

E57

B47

B137

D:

B21

B122

B136

C:

B362

B134

A:

36

40

34

35

37

E2

B21

C21

C1

A29

6

A18

C6

A28

6

4

25

*

*

B122

24

E

38

39

28

D5

D4

A19

A5

D7

D1

D2

D3

3

E57

2

1

5

B134

B362

B47

5

7

6

A:

B137

B136

D:

C:

*

E

SBF-7

8

6

4

E

3

4

1

2

5

6

ELECTRONIC
THROTTLE 
CONTROL RELAY

MAIN RELAY

BATTERY

ECM

ELECTRONIC THROTTLE 
CONTROL

: TERMINAL No. OPTIONAL 
  ARRANGEMENT