Subaru Legacy (2005 year). Manual - part 460

EN(H6DO)(diag)-153

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND 
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and 
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness 
between ECM and chassis ground.

Connector & terminal

(B134) No. 27 — Chassis ground:
(B134) No. 34 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Replace the front 
oxygen (A/F) sen-
sor. <Ref. to 
FU(H6DO)-30, 
Front Oxygen (A/
F) Sensor.>

Repair the ground 
short circuit of har-
ness between 
ECM and front 
oxygen (A/F) sen-
sor connector.

EN(H6DO)(diag)-154

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AL:DTC P0152 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 2 SENSOR 1)

DTC DETECTING CONDITION:
Immediately at fault recognition

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)(diag)-41, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)(diag)-34, PROCEDURE, 
Inspection Mode.>.
WIRING DIAGRAM:

BATTERY

SBF-5

B47

MAIN RELAY

A4

A5

A6

A7

2

52

54

B21

E2

ECM

A34

A27

B7

A1

A2

A3

A26

A33

4

1

3

FRONT 

OXYGEN 

(A/F) 

SENSOR LH

E24

2

B135

B:

B134

A:

4

3

1

FRONT 

OXYGEN 

(A/F) 

SENSOR RH

E47

E3

B22

8

5

6

E3

B22

2

1

3

4

B47

3

4

5

6

1

2

A25

B22

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

3 4

1 2

E47

E24

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:

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:

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

E

E

EN-03494

B135

B:

B134

A:

7

5
3

EN(H6DO)(diag)-155

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND 
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Disconnect the connector from front oxygen 
(A/F) sensor.
3) Measure the voltage of harness between 
ECM connector and chassis ground.

Connector & terminal

(B134) No. 27 (+) — Chassis ground (

−

):

(B134) No. 34 (+) — Chassis ground (

−

):

Is the voltage more than 8 V?

Replace the front 
oxygen (A/F) sen-
sor. <Ref. to 
FU(H6DO)-30, 
Front Oxygen (A/
F) Sensor.>

Repair the battery 
short circuit of har-
ness between 
ECM and front 
oxygen (A/F) sen-
sor connector.

EN(H6DO)(diag)-156

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AM:DTC P0153 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 2 SENSOR 1)

DTC DETECTING CONDITION:
Detects when malfunction occurs in 2 continuous driving cycles.

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)(diag)-41, 
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)(diag)-34, PROCEDURE, 
Inspection Mode.>.
WIRING DIAGRAM:

BATTERY

SBF-5

B47

MAIN RELAY

A4

A5

A6

A7

2

52

54

B21

E2

ECM

A34

A27

B7

A1

A2

A3

A26

A33

4

1

3

FRONT 

OXYGEN 

(A/F) 

SENSOR LH

E24

2

B135

B:

B134

A:

4

3

1

FRONT 

OXYGEN 

(A/F) 

SENSOR RH

E47

E3

B22

8

5

6

E3

B22

2

1

3

4

B47

3

4

5

6

1

2

A25

B22

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

3 4

1 2

E47

E24

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:

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:

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

E

E

EN-03494

B135

B:

B134

A:

7

5
3