Subaru Legacy IV (2008 year). Manual - part 579

EN(H6DO)(diag)-289

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

WIRING DIAGRAM:

E

B47

E18

2

5

1

4

3

6

B21

E2

E76

E77

48

3

4

7

6

SBF-7

B134

ECM

B47

3

4

1

2

5

6

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

B134

10

E76

E77

21

32

33

22

B21

E2

E18

1

3

4 5 6

2

1 2

3 4

5

6

7

8

9

10

E77

MAIN RELAY

BATTERY

EGR VALVE

6
4

9

10

8

20

EN-06877

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47

EN(H6DO)(diag)-290

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

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

Connector & terminal

(E18) No. 2 (+) — Engine ground (–):
(E18) No. 5 (+) — Engine ground (–):

Is the voltage 10 V or more?

Go to step 2.

Repair the harness 
and connector.

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

2

CHECK HARNESS BETWEEN ECM AND 
EGR VALVE CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness between 
ECM and EGR valve connector.

Connector & terminal

DTC P1492; (B134) No. 8 — (E18) No. 3:
DTC P1494; (B134) No. 9 — (E18) No. 1:
DTC P1496; (B134) No. 10 — (E18) No. 4:
DTC P1498; (B134) No. 20 — (E18) No. 6:

Is the resistance less than 1 

:? Go to step 3.

Repair the harness 
and connector.

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

3

CHECK HARNESS BETWEEN ECM AND 
EGR VALVE CONNECTOR.
1) Disconnect the connectors from ECM.
2) Measure the resistance between ECM and 
chassis ground.

Connector & terminal

DTC P1492; (B134) No. 8 — Chassis 
ground:
DTC P1494; (B134) No. 9 — Chassis 
ground:
DTC P1496; (B134) No. 10 — Chassis 
ground:
DTC P1498; (B134) No. 20 — Chassis 
ground:

Is the resistance 1 M

: or 

more?

Go to step 4.

Repair the ground 
short in harness 
between ECM and 
EGR valve con-
nector.

4

CHECK POOR CONTACT.
Check poor contact of ECM and EGR valve 
connectors.

Is there poor contact in ECM or 
EGR valve connector?

Repair the poor 
contact in ECM or 
EGR valve con-
nector.

Replace the EGR 
valve. <Ref. to 
FU(H6DO)-27, 
EGR Valve.>

EN(H6DO)(diag)-291

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

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

(HIGH INPUT)

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-177, DTC P1493 EGR SOLENOID VALVE SIGNAL #1
CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Trouble Code (DTC) Detecting Criteria.> <Ref. to
GD(H6DO)-179, DTC P1495 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION (HIGH IN-
PUT), Diagnostic Trouble Code (DTC) Detecting Criteria.> <Ref. to GD(H6DO)-179, DTC P1497 EGR SO-
LENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Trouble Code (DTC)
Detecting Criteria.> <Ref. to GD(H6DO)-179, DTC P1499 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT
MALFUNCTION (HIGH INPUT), Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance
• Engine breathing

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.

EN(H6DO)(diag)-292

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

WIRING DIAGRAM:

Step

Check

Yes

No

1

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

Connector & terminal

DTC P1493; (B134) No. 8 (+) — Chassis 
ground (–):
DTC P1495; (B134) No. 9 (+) — Chassis 
ground (–):
DTC P1497; (B134) No. 10 (+) — Chassis 
ground (–):
DTC P1499; (B134) No. 20 (+) — Chassis 
ground (–):

Is the voltage 10 V or more?

Repair the power 
supply short circuit 
of harness 
between ECM and 
EGR valve con-
nector.

Repair the poor 
contact of ECM 
connector.

E

B47

E18

2

5

1

4

3

6

B21

E2

E76

E77

48

3

4

7

6

SBF-7

B134

ECM

B47

3

4

1

2

5

6

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

B134

10

E76

E77

21

32

33

22

B21

E2

E18

1

3

4 5 6

2

1 2

3 4

5

6

7

8

9

10

E77

MAIN RELAY

BATTERY

EGR VALVE

6
4

9

10

8

20

EN-06877

B21

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25 26 27 28 29 30 31 32 33

34

35

42

43

36

37

38

39

48

49

50

51

52

53

54

40

41

44

45

46

47