Subaru Legacy IV (2008 year). Manual — part 382

EN(H4DOTC)(diag)-349

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK CURRENT DATA.
1) Turn the ignition switch to ON.
2) Read the data of secondary air piping pres-
sure signal using Subaru Select Monitor or gen-
eral scan tool.

NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.

Is the measured value less than
53.3 kPa (400 mmHg, 15.8 inHg)?

Go to step 2.

Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

2

CHECK POWER SUPPLY OF SECONDARY
AIR COMBINATION VALVE RH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the second-
ary air combination valve RH.
3) Turn the ignition switch to ON.
4) Measure the voltage between the second-
ary air combination valve RH connector and
chassis ground.

Connector & terminal

(E41) No. 1 (+) — Chassis ground (–):

Is the voltage 4.5 V or more?

Go to step 3.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and second-
ary air combination
valve RH connec-
tor
• Poor contact in
ECM connector
• Poor contact of
coupling connector

3

CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of the harness
between the ECM and secondary air combina-
tion valve RH connector.

Connector & terminal

(B134) No. 27 — (E41) No. 2:

Is the resistance less than 1

:? Go to step 4.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and second-
ary air combination
valve RH connec-
tor
• Poor contact of
coupling connector

4

CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
Measure the resistance between ECM and
chassis ground.

Connector & terminal

(B134) No. 27 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 5.

Repair the ground
short circuit of har-
ness between
ECM and second-
ary air combination
valve RH connec-
tor.

5

CHECK POOR CONTACT.
Check for poor contact in the ECM and second-
ary air combination valve RH connector.

Is there poor contact in the
ECM or secondary air combi-
nation valve RH connector?

Repair the poor
contact in the ECM
or secondary air
combination valve
RH connector.

Replace the sec-
ondary air combi-
nation valve RH.
<Ref. to
EC(H4DOTC)-22,
Secondary Air
Combination
Valve.>

EN(H4DOTC)(diag)-350

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EE:DTC P2433 SECONDARY AIR INJECTION SYSTEM AIR FLOW /PRESSURE

SENSOR CIRCUIT HIGH

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-230, DTC P2433 SECONDARY AIR INJECTION SYS-
TEM AIR FLOW /PRESSURE SENSOR CIRCUIT HIGH, Diagnostic Trouble Code (DTC) Detecting Crite-
ria.>

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)-351

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)-352

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK CURRENT DATA.
1) Turn the ignition switch to ON.
2) Read the data of secondary air piping pres-
sure signal using Subaru Select Monitor or gen-
eral scan tool.

NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.

Is the measured value 133.3 kPa
(1000 mmHg, 39.4 inHg) or
more?

Go to step 2.

Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

2

CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the second-
ary air combination valve RH.
3) Turn the ignition switch to ON.
4) Read the data of secondary air piping pres-
sure signal using Subaru Select Monitor or gen-
eral scan tool.

NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.

Is the measured value 133.3 kPa
(1000 mmHg, 39.4 inHg) or
more?

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

Go to step 3.

3

CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of the harness
between the secondary air combination valve
RH connector and engine ground.

Connector & terminal

(E41) No. 3 — Engine ground:

Is the resistance less than 5

:? Go to step 4.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and second-
ary air combination
valve RH connec-
tor
• Poor contact in
ECM connector
• Poor contact of
coupling connector

4

CHECK POOR CONTACT.
Check for poor contact of the secondary air
combination valve RH connector.

Is there poor contact of the sec-
ondary air combination valve
RH connector?

Repair the poor
contact of the sec-
ondary air combi-
nation valve RH
connector.

Replace the sec-
ondary air combi-
nation valve RH.
<Ref. to
EC(H4DOTC)-22,
Secondary Air
Combination
Valve.>