Subaru Legacy (2005 year). Manual - part 227

EN(H4SO 2.5)(diag)-193

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BD:DTC P1153 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (HIGH) (BANK1 

SENSOR1)

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(H4SO 2.5)(diag)-
40, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.5)(diag)-33, Inspection Mode.>.
WIRING DIAGRAM:

EN-03457

3

4

1

2

5

6

B327

SBF-5

E

E

B327

E24

6
4

5
3

2
1

25

33

26

3

2

6

7

52

B134

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

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

ECM

BATTERY

FRONT OXYGEN

(A/F) SENSOR

OXYGEN (A/F) 
SENSOR RELAY

1

3

4 5 6

2

3

4

1

6

EN(H4SO 2.5)(diag)-194

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 connector and chassis ground.

Connector & terminal

(B134) No. 26 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 2.

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

2

CHECK HARNESS BETWEEN ECM AND 
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
Measure the resistance of harness between 
ECM connector and chassis ground.

Connector & terminal

(B134) No. 33 — Chassis ground:

Is the resistance more than 1 
M

Ω?

Go to step 3.

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

3

CHECK OUTPUT SIGNAL FOR ECM.
1) Connect the connectors to ECM and front 
oxygen (A/F) sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector and chassis ground.

Connector & terminal

(B134) No. 26 (+) — Chassis ground (

−

):

Is the voltage more than 4.5 V? Go to step 4.

Go to step 5.

4

CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector 
and chassis ground.

Connector & terminal

(B134) No. 26 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Repair the battery 

short circuit of har-
ness between 
ECM and front 
oxygen (A/F) sen-
sor connector. 
After repair, 
replace the ECM. 
<Ref. to FU(H4SO 
2.5)-37, Engine 
Control Module 
(ECM).>

Repair the poor 
contact in ECM 
connector.

5

CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector 
and chassis ground.

Connector & terminal

(B134) No. 33 (+) — Chassis ground (

−

):

Is the voltage more than 4.95 
V?

Go to step 6.

Replace the front 
oxygen (A/F) sen-
sor. <Ref. to 
FU(H4SO 2.5)-35, 
Front Oxygen (A/
F) Sensor.>

6

CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector 
and chassis ground.

Connector & terminal

(B134) No. 33 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Repair the battery 

short circuit of har-
ness between 
ECM and front 
oxygen (A/F) sen-
sor connector. 
After repair, 
replace the ECM. 
<Ref. to FU(H4SO 
2.5)-37, Engine 
Control Module 
(ECM).>

Repair the poor 
contact in ECM 
connector.

EN(H4SO 2.5)(diag)-195

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BE:DTC P1160 RETURN SPRING FAILURE

NOTE:
For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H4SO 2.5)(diag)-224, DTC P2101 THROT-
TLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Di-
agnostic Trouble Code (DTC).>

BF:DTC P1492 EGR SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION 

(LOW INPUT)

NOTE:
For the diagnostic procedure, refer to DTC P1498. <Ref. to EN(H4SO 2.5)(diag)-196, DTC P1498 EGR SO-
LENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

BG:DTC P1493 EGR SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION 

(HIGH INPUT)

NOTE:
For the diagnostic procedure, refer to DTC P1499. <Ref. to EN(H4SO 2.5)(diag)-198, DTC P1499 EGR SO-
LENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

BH:DTC P1494 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION 

(LOW INPUT)

NOTE:
For the diagnostic procedure, refer to DTC P1498. <Ref. to EN(H4SO 2.5)(diag)-196, DTC P1498 EGR SO-
LENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

BI: DTC P1495 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION 

(HIGH INPUT)

NOTE:
For the diagnostic procedure, refer to DTC P1499. <Ref. to EN(H4SO 2.5)(diag)-198, DTC P1499 EGR SO-
LENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

BJ:DTC P1496 EGR SOLENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION 

(LOW INPUT)

NOTE:
For the diagnostic procedure, refer to DTC P1498. <Ref. to EN(H4SO 2.5)(diag)-196, DTC P1498 EGR SO-
LENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

BK:DTC P1497 EGR SOLENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION 

(HIGH INPUT)

NOTE:
For the diagnostic procedure, refer to DTC P1499. <Ref. to EN(H4SO 2.5)(diag)-198, DTC P1499 EGR SO-
LENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

EN(H4SO 2.5)(diag)-196

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BL:DTC P1498 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION 

(LOW INPUT)

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Erroneous idling
• Poor driving performance
• Engine breathing

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO 2.5)(diag)-
40, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.5)(diag)-33, Inspection Mode.>.
WIRING DIAGRAM:

EN-03464

E

E

B47

E18

2

5

1

4

3

6

B21

E2

B21

E2

B21

E2

5
3

6

2
1

48

26

A10

A9

A11

A8

D2

D1

B4

25

29

30

35

36

SBF-7

BATTERY

MAIN RELAY

EGR

VALVE

A: B134

B: B135

D: B137

ECM

B47

E18

3

4

1

2

5

6

1

3

4 5 6

2

B1

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

B137

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

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

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

A:

B:

D:

4