Subaru Legacy (2005 year). Manual - part 146

EN(H4SO 2.0)(diag)-173

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

2. MT MODEL

DTC DETECTING CONDITION:
Detects when malfunction occurs in 2 continuous driving cycles.
TROUBLE SYMPTOM:
Erroneous idling

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:

B12

T3

B14

T7

INHIBITOR SWITCH

NEUTRAL
POSITION
SWITCH

STARTER MOTOR

P

R

N

D

3

2

1

7

12

11

12

B135

ECM

12

B12

T7

1 2 3 4 5 6
7 8 9 10 11 12

1 2 3 4
5 6 7 8
9 10 11 12

E

1

B25

T2

T2

B25

2

MT

AT

EN-03485

M

36

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

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

B25

1 2

1 2 3 4
5 6 7 8

B83    : RHD

B122   : LHD

*

: TERMINAL No. RANDOM ARRANGEMENT

B83

B122 : LHD

: RHD

 E2

B21

*

*

EN(H4SO 2.0)(diag)-174

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK INPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Place the shift lever except in neutral.
3) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B135) No. 12 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 2.

Go to step 4.

2

CHECK INPUT SIGNAL OF ECM.
1) Place the shift lever in neutral.
2) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B135) No. 12 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Go to step 3.

Go to step 4.

3

CHECK POOR CONTACT.
Check poor contact in ECM connector.

Is there poor contact in ECM 
connector?

Repair the poor 
contact in ECM 
connector.

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

4

CHECK NEUTRAL POSITION SWITCH.
1) Place the shift lever except in neutral.
2) Measure the resistance between transmis-
sion harness connector terminals.

Connector & terminal

(T2) No. 1 — No. 2:

Is the resistance less than 1 
Ω?

Go to step 5.

Repair the open 
circuit in transmis-
sion harness or 
replace the neu-
tral position switch.

5

CHECK HARNESS BETWEEN ECM AND 
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness 
between ECM and transmission harness con-
nector.

Connector & terminal

(B135) No. 12 — (B25) No. 2:

Is the resistance less than 1 
Ω?

Go to step 6.

Repair the open 
circuit of harness 
between ECM and 
transmission har-
ness connector.

6

CHECK HARNESS BETWEEN ECM AND 
NEUTRAL POSITION SWITCH CONNEC-
TOR.
Measure the resistance of harness between 
transmission harness connector and engine 
ground.

Connector & terminal

(B25) No. 1 — Engine ground:

Is the resistance less than 5 
Ω?

Go to step 7.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
transmission har-
ness connector 
and engine ground
• Poor contact in 
coupling connector

7

CHECK POOR CONTACT.
Check poor contact in transmission harness 
connector.

Is there poor contact in trans-
mission harness connector.

Repair poor con-
tact in transmis-
sion harness 
connector. 

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

EN(H4SO 2.0)(diag)-175

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BB:DTC P1134 A/F SENSOR MICRO-COMPUTER PROBLEM

DTC DETECTING CONDITION:
Immediately at fault recognition

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-03475

3

4

1

2

5

6

B47

SBF-5

E

B47

E24

5
3

4
6

2
1

C34

C35

C33

B3

B2

B1

B135

E

B5

B6

52

B21

E2

B21

E2

50

51

3

4

E2

B21

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

E24

ECM

BATTERY

FRONT OXYGEN

(A/F) SENSOR

MAIN RELAY

B136

B:

C:

1

2

3

4

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

B:

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:

E24

3

2

*

1

*

*

3

  LHD : 4

RHD : 1

*

1

*

*

2

3

3

1

6 5 4

2

: RHD

: LHD

LHD : 1

RHD : 4

LHD : 2

RHD : 6

EN(H4SO 2.0)(diag)-176

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK ANY OTHER DTC ON DISPLAY.

Is any other DTC displayed?

Check DTC using 
“List of Diagnostic 
Trouble Code 
(DTC)”. <Ref. to 
EN(H4SO 
2.0)(diag)-64, List 
of Diagnostic Trou-
ble Code (DTC).>

NOTE:
It is not necessary
to inspect DTC
P1134.

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