Subaru Legacy IV (2008 year). Manual - part 574

EN(H6DO)(diag)-269

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CW:DTC P0604 INTERNAL CONTROL MODULE RANDOM ACCESS MEMORY 

(RAM) ERROR

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-154, DTC P0604 INTERNAL CONTROL MODULE RAN-
DOM ACCESS MEMORY (RAM) ERROR, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Engine does not start.
• 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:

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)-270

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CX:DTC P0605 INTERNAL CONTROL MODULE READ ONLY MEMORY (ROM) 

ERROR

NOTE:
For the diagnostic procedure, refer to DTC P0607. <Ref. to EN(H6DO)(diag)-271, DTC P0607 THROTTLE
CONTROL SYSTEM CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>

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).>

Even if DTC is 
detected, the cir-
cuit has returned to 
a normal condition 
at this time. Repro-
duce the failure, 
and then perform 
the diagnosis 
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

EN(H6DO)(diag)-271

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CY:DTC P0607 THROTTLE CONTROL SYSTEM CIRCUIT RANGE/PERFORMANCE

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-156, DTC P0607 THROTTLE CONTROL SYSTEM CIR-
CUIT RANGE/PERFORMANCE, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance

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:

B135

B:

B134

A:

B137

B136

D:

E1

B20

C:

E

E

38

39

20

19

16

15

*
*

E2

B21

E57

4

6

1

2

3

5

D4

D5

A29

A19

D1

D7

A5

D2

A3

D3

35

34

37

52

36

A28

C6

A18

ECM

B122

1 2 3 4
5 6 7 8

1

2

3

4

5

6

B47

ELECTRONIC THROTTLE 

CONTROL

B20

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

E57

1 2 3 4 5 6

B122

*

: TERMINAL No. OPTIONAL ARRANGEMENT

E

SBF-6

MAIN SBF

SBF-7

B72

A7

B2

C23

B5

B19

No. 12

B47

1

2

4

6

5

3

E

3

1

No. 13

SBF-5

MAIN RELAY

BATTERY

IGNITION
SWITCH

EN-06880

B72

1

3

4 5 6

2

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

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

29 30 31

32 33

34 35

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

33 34

29

32

30 31

B134

A:

TO OXYGEN SENSOR

EN(H6DO)(diag)-272

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CZ:DTC P0638 THROTTLE ACTUATOR CONTROL RANGE/PERFORMANCE 

(BANK 1)

NOTE:
For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H6DO)(diag)-324, DTC P2101 THROTTLE
ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

DA:DTC P0700 TRANSMISSION CONTROL SYSTEM (MIL REQUEST)

NOTE:
For the diagnostic procedure, refer to AT section. <Ref. to 5AT(diag)-2, Basic Diagnostic Procedure.>

Step

Check

Yes

No

1

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

Connector & terminal

(B134) No. 7 (+) — Chassis ground (–):
(B135) No. 2 (+) — Chassis ground (–):

Is the voltage 10 — 13 V?

Go to step 2.

Repair the open or 
ground short circuit 
of power supply 
circuit.

2

CHECK INPUT VOLTAGE OF ECM.
1) Start the engine.
2) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B134) No. 7 (+) — Chassis ground (–):
(B135) No. 2 (+) — Chassis ground (–):

Is the voltage 13 — 15 V?

Go to step 3.

Repair the open or 
ground short circuit 
of power supply 
circuit.

3

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and 
electronic throttle control.
3) Measure the resistance of harness between 
ECM and electronic throttle control connector.

Connector & terminal

(B134) No. 19 — (E57) No. 5:
(B134) No. 29 — (E57) No. 3:

Is the resistance less than 1 

:? Go to step 4.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and electron-
ic throttle control
connector
• Poor contact of
coupling connector

4

CHECK ECM GROUND HARNESS.
Measure the voltage between ECM and chassis 
ground.

Connector & terminal

(B134) No. 3 (+) — Chassis ground (–):
(B134) No. 5 (+) — Chassis ground (–):
(B137) No. 1 (+) — Chassis ground (–):
(B137) No. 2 (+) — Chassis ground (–):
(B137) No. 3 (+) — Chassis ground (–):
(B137) No. 7 (+) — Chassis ground (–):

Is the voltage less than 1 V?

Repair the poor 
contact of ECM 
connector.

Repair the follow-
ing item.
• Open circuit of 
ground circuit
• Retightening of 
engine ground ter-
minals
• Poor contact of 
coupling connector