Subaru Legacy IV (2008 year). Manual - part 346

EN(H4DOTC)(diag)-205

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BH:DTC P0417 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE “B“ 

CIRCUIT SHORTED

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-103, DTC P0417 SECONDARY AIR INJECTION SYS-
TEM SWITCHING VALVE “B“ CIRCUIT SHORTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.

EN(H4DOTC)(diag)-206

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

WIRING DIAGRAM:

EN-05678

B47

1

2

4

6

3

5

SBF-7

E

F9

13

12

11

14

1

2

2

1

3

4

16

15

5

6

B143

F37

B144

B21

E2

E41

E40

B134

A:

B136

C:

F37

F11

B21

E40

B47

B144

F9

B143

F37

E41

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

MAIN
SBF

10A

60A

9

10

8

7

E

E

11

5

20

8

C30
C19

C8

A19
A27
A29

6

1

28

47

3

2

1

6

4

1

2

9
2

16
18

14
12
10

4

14

4

F11

1 2

3

4

1

2

5

6

1

3

4 5 6

2

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

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

B136

1
5

7

6

2

8

3

4
9

1 2 3 4

5 6 7 8 9

10 11 12 13 14

15 16 17 18 19 20

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

5

6

3

1
2

9

10

12

11

13

14

4

7 8

15

16

46

MAIN RELAY

BATTERY

RELAY HOLDER

SECONDARY 
AIR
COMBINATION 
VALVE RELAY1

SECONDARY 
AIR
COMBINATION 
VALVE RELAY2

SECONDARY 
AIR PUMP
RELAY

SECONDARY 
AIR PUMP

MAIN FUSE 
BOX (M/B)

ECM

SECONDARY AIR 

COMBINATION VALVE  RH

(WITH BUILT-IN PRESSURE SENSOR)

SECONDARY AIR 

COMBINATION 

VALVE LH

EN(H4DOTC)(diag)-207

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND 
SECONDARY AIR COMBINATION VALVE 
RELAY 2.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and 
secondary air combination valve relay 2.
3) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B136) No. 19 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Repair the short 
circuit to power in 
the harness 
between ECM and 
secondary air com-
bination valve relay 
2.

Repair the poor 
contact of ECM 
connector.

EN(H4DOTC)(diag)-208

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BI: DTC P0418 SECONDARY AIR INJECTION SYSTEM CONTROL “A“ CIRCUIT 

OPEN

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-104, DTC P0418 SECONDARY AIR INJECTION SYS-
TEM CONTROL “A“ CIRCUIT OPEN, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
52, OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PRO-
CEDURE, Inspection Mode.>.