Subaru Legacy (2005 year). Service manual - part 148

EN(H4SO 2.0)(diag)-181

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BK: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, 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-03483

E

E

B47

E18

2

5

1

4

3

6

B21

E2

B21

E2

B21

E2

5
3

6
4

2
1

48

26

A12

A3

A13

A4

C6

C5

D1

25

29

30

35

36

SBF-7

BATTERY

MAIN RELAY

EGR

VALVE

A: B134

C: B136

D: B137

ECM

B47

3

4

1

2

5

6

A2

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

A:

D:

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:

1

3

4 5 6

2

E18

EN(H4SO 2.0)(diag)-182

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK POWER SUPPLY TO EGR SOLE-
NOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from EGR sole-
noid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between EGR sole-
noid valve connector and engine ground.

Connector & terminal

(E18) No. 2 (+) — Engine ground (

−

):

(E18) No. 5 (+) — Engine ground (

−

):

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

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
EGR solenoid 
valve and main 
relay connector
• Poor contact in 
coupling connector

2

CHECK HARNESS BETWEEN ECM AND 
EGR SOLENOID VALVE CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ECM and 
EGR solenoid valve connector.

Connector & terminal

DTC P1492; (B134) No. 13 — (E18) No. 3:
DTC P1494; (B134) No. 12 — (E18) No. 1:
DTC P1496; (B134) No. 3 — (E18) No. 4:
DTC P1498; (B134) No. 4 — (E18) No. 6:

Is the resistance less than 1 
Ω?

Go to step 3.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following item:
• Open circuit of 
harness between 
ECM and EGR 
solenoid valve 
connector
• Poor contact in 
coupling connector

3

CHECK HARNESS BETWEEN ECM AND 
EGR SOLENOID VALVE CONNECTOR.
1) Disconnect the connector from ECM.
2) Measure the resistance between ECM con-
nector and chassis ground.

Connector & terminal

DTC P1492; (B134) No. 13 — Chassis 
ground:
DTC P1494; (B134) No. 12 — Chassis 
ground:
DTC P1496; (B134) No. 3 — Chassis 
ground:
DTC P1498; (B134) No. 4 — Chassis 
ground:

Is the resistance more than 1 
M

Ω?

Go to step 4.

Repair the ground 
short circuit in har-
ness between 
ECM and EGR 
solenoid valve 
connector.

4

CHECK POOR CONTACT.
Check poor contact in ECM connector and 
EGR solenoid valve connector.

Is there poor contact in ECM 
connector or EGR solenoid 
valve connector?

Repair the poor 
contact in ECM 
connector or EGR 
solenoid valve 
connector.

Replace the EGR 
solenoid valve. 
<Ref. to FU(H4SO 
2.0)-28, EGR 
Valve.>

EN(H4SO 2.0)(diag)-183

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BL:DTC P1499 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION 

(HIGH 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, 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-03483

E

E

B47

E18

2

5

1

4

3

6

B21

E2

B21

E2

B21

E2

5
3

6
4

2
1

48

26

A12

A3

A13

A4

C6

C5

D1

25

29

30

35

36

SBF-7

BATTERY

MAIN RELAY

EGR

VALVE

A: B134

C: B136

D: B137

ECM

B47

3

4

1

2

5

6

A2

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

A:

D:

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:

1

3

4 5 6

2

E18

EN(H4SO 2.0)(diag)-184

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

BM:DTC P1518 STARTER SWITCH CIRCUIT LOW INPUT

DTC DETECTING CONDITION:
Detects when malfunction occurs in 2 continuous driving cycles.
TROUBLE SYMPTOM:
Failure of engine to start

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.>.

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).>

Go to step 2.

2

CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ECM con-
nector and chassis ground.

Connector & terminal

(B134) No. 2 — Chassis ground:
(B136) No. 5 — Chassis ground:
(B136) No. 6 — Chassis ground:
(B137) No. 1 — Chassis ground:

Is the resistance less than 5 
Ω?

Go to step 3.

Repair the har-
ness and connec-
tor.

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

3

CHECK HARNESS BETWEEN ECM AND 
EGR SOLENOID VALVE CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from EGR sole-
noid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM con-
nector and chassis ground.

Connector & terminal

DTC P1493; (B134) No. 13 (+) — Chassis 
ground (

−

):

DTC P1495; (B134) No. 12 (+) — Chassis 
ground (

−

):

DTC P1497; (B134) No. 3 (+) — Chassis 
ground (

−

):

DTC P1499; (B134) No. 4 (+) — Chassis 
ground (

−

):

Is the voltage more than 10 V? Repair the battery 

short circuit in har-
ness between 
ECM and EGR 
solenoid valve 
connector. After 
repair, replace the 
ECM. <Ref. to 
FU(H4SO 2.0)-34, 
Engine Control 
Module (ECM).>

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