Subaru Legacy (2005 year). Manual - part 333

EN(H4DOTC)(diag)-101

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

P: DTC P0132 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 1)

DTC DETECTING CONDITION:
Immediately at fault recognition

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-03522

SBF-5

B47

1

2

4

6

3

5

E

E

B21

F2

54

A6

A7

A2

A3

A26

A33

A25

ECM

B134

3

1

4

2

B18

3 4

1 2

3

4

1

2

5

6

B21

B47

B18

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

MAIN RELAY

FRONT OXYGEN
(A/F) SENSOR

BATTERY

A:

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

A:

EN(H4DOTC)(diag)-102

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. 26 (+) — Chassis ground (

−

):

(B134) No. 33 (+) — Chassis ground (

−

):

Is the voltage more than 8 V?

Replace the front 
oxygen (A/F) sen-
sor. <Ref. to 
FU(H4DOTC)-32, 
Front Oxygen (A/
F) Sensor.>

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

EN(H4DOTC)(diag)-103

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Q: DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SEN-

SOR 1)

DTC DETECTING CONDITION:
Immediately at fault recognition

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-03522

SBF-5

B47

1

2

4

6

3

5

E

E

B21

F2

54

A6

A7

A2

A3

A26

A33

A25

ECM

B134

3

1

4

2

B18

3 4

1 2

3

4

1

2

5

6

B21

B47

B18

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

MAIN RELAY

FRONT OXYGEN
(A/F) SENSOR

BATTERY

A:

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

A:

EN(H4DOTC)(diag)-104

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 connectors from ECM and 
front oxygen (A/F) sensor.
3) Measure the resistance of harness 
between ECM and front oxygen (A/F) sensor 
connector.

Connector & terminal

(B134) No. 26 — (B18) No. 1:
(B134) No. 33 — (B18) No. 2:

Is the resistance less than 1 
Ω?

Replace the front 
oxygen (A/F) sen-
sor. <Ref. to 
FU(H4DOTC)-32, 
Front Oxygen (A/
F) Sensor.>

Repair the open 
circuit of harness 
between ECM and 
front oxygen (A/F) 
sensor connector.