Subaru Legacy (2005 year). Manual - part 135

EN(H4SO 2.0)(diag)-129

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

WIRING DIAGRAM:

EN-03508

SBF-7

B134

A:

B137

B136

D:

B362

E1

B20

C:

E

E

E

D6

D9

38

39

20

19

16

15

E2

B21

E78

2

5

D4

D5

D2

C17

C6

A2

C2

C5

C1

C30

36

35

37

D24

D23

ECM

5

7

8

6

B362

B20

B21

E78

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

B136

C:

B137

D:

BATTERY

MAIN RELAY

ELECTRONIC
THROTTLE 
CONTROL RELAY

ELECTRONIC
THROTTLE CONTROL

D7

D1

D3

C18

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

A:

1

3

4 5 6

2

B83

:LHD

B138 :RHD

B83

:LHD

B138 :RHD

B83

B138

*

1

: TERMINAL No.
  RANDOM ARRANGEMENT
  AMONG 3,4,7, AND 8

*

2

: TERMINAL No.
  RANDOM ARRANGEMENT
  AMONG 1,2,5, AND 6

*

3

LHD : 4
RHD : 6

*

4

LHD : 6
RHD : 4

*

5

LHD : 3
RHD : 1

*

6

LHD : 1
RHD : 3

*

1

*

1

*

3

*

4

*

5

*

6

*

2

*

2

1 2 3 4
5 6 7 8
9 10 11 12

14

13

15 16

EN(H4SO 2.0)(diag)-130

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK SENSOR OUTPUT.
1) Turn the ignition switch to ON.
2) Read the data of sub throttle sensor signal 
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.0)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage less than 4.73 
V?

Go to step 2.

Go to step 3.

2

CHECK POOR CONTACT.
Check poor contact in connector between 
ECM and electronic throttle control.

Is there poor contact in con-
nector between ECM and elec-
tronic throttle control?

Repair the poor 
contact.

Temporary poor 
contact occurred, 
but it is normal at 
present.

3

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

Connector & terminal

(B137) No. 24 — (E78) No. 2:
LHD model

(B136) No. 18 — (E78) No. 1:

RHD model

(B136) No. 18 — (E78) No. 3:

Is the resistance less than 1 
Ω?

Go to step 4.

Repair the open 
circuit of harness 
connector.

4

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Connect the ECM connector.
2) Measure the resistance between electronic 
throttle control connector and engine ground.

Connector & terminal

LHD model

(E78) No. 1 — Engine ground:

RHD model

(E78) No. 3 — Engine ground:

Is the resistance less than 5 
Ω?

Go to step 5.

Repair the poor 
contact in ECM 
connector. 
Replace the ECM 
if defective. <Ref. 
to FU(H4SO 2.0)-
34, Engine Con-
trol Module 
(ECM).>

5

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
Measure the voltage between electronic throt-
tle control connector and engine ground.

Connector & terminal

(E78) No. 2 (+) — Engine ground (

−

):

Is the voltage less than 10 V?

Go to step 6.

Repair the battery 
short circuit of har-
ness between 
ECM connector 
and electronic 
throttle control 
connector.

6

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between connector 
terminals.

Connector & terminal

(B137) No. 24 — (B136) No. 17:

Is the resistance more than 1 
M

Ω?

Repair the poor 
contact. Replace 
the electronic 
throttle control.

Sensor power sup-
ply circuit may be 
shorted.

EN(H4SO 2.0)(diag)-131

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AA:DTC P0301 CYLINDER 1 MISFIRE DETECTED

NOTE:
For the diagnostic procedure, refer to DTC P0304. <Ref. to EN(H4SO 2.0)(diag)-132, DTC P0304 CYLIN-
DER 4 MISFIRE DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AB:DTC P0302 CYLINDER 2 MISFIRE DETECTED

NOTE:
For the diagnostic procedure, refer to DTC P0304. <Ref. to EN(H4SO 2.0)(diag)-132, DTC P0304 CYLIN-
DER 4 MISFIRE DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AC:DTC P0303 CYLINDER 3 MISFIRE DETECTED

NOTE:
For the diagnostic procedure, refer to DTC P0304. <Ref. to EN(H4SO 2.0)(diag)-132, DTC P0304 CYLIN-
DER 4 MISFIRE DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

EN(H4SO 2.0)(diag)-132

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AD:DTC P0304 CYLINDER 4 MISFIRE DETECTED

DTC DETECTING CONDITION:
• Detects when malfunction occurs in 2 continuous driving cycles.
• Immediately at fault recognition(A misfire which could damage catalyst occurs.)
TROUBLE SYMPTOM:
• Engine stalls.
• Erroneous idling
• Rough driving

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-03474

E6

E17

E5

E16

1 2

1

2

1

2

1

2

1

2

34

27

17

33

42

48

43

44

45

ECM

B134

E5

E16

E6

E17

B21

E2

FUEL INJECTOR

No. 1

FUEL INJECTOR

No. 2

FUEL INJECTOR

No. 3

FUEL INJECTOR

No. 4

BATTERY

SBF-7

B47

MAIN RELAY

1

2

4

6

3

5

B47

3

4

1

2

5

6

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

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