Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 250

EN(H4DOTC)(diag)-224

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK POWER SUPPLY OF CAMSHAFT
POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between camshaft
position sensor connector and engine ground.

Connector & terminal

(E65) No. 1 (+) — 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 or
short circuit to
ground in harness
between main re-
lay connector and
camshaft position
sensor connector
• Poor contact of
coupling connector

2

CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between ECM con-
nector and camshaft position sensor connector.

Connector & terminal

(B137) No. 29 — (E65) No. 2:
(B137) No. 30 — (E65) No. 3:

Is the resistance less than 1 Ω? Go to step

3.

Repair the harness
and connector.
NOTE:

In this case, repair
the following item:
• Open circuit in
harness between
ECM

connector

and camshaft posi-
tion sensor con-
nector
• Poor contact of
coupling connector

3

CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
Measure the resistance between camshaft
position sensor connector and engine ground.

Connector & terminal

(E65) No. 2 — Engine ground:

Is the resistance 1 MΩ or
more?

Go to step

4.

Repair short circuit
to ground in har-
ness between
ECM connector
and camshaft posi-
tion sensor con-
nector.

4

CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
Measure the voltage between camshaft posi-
tion sensor connector and engine ground.

Connector & terminal

(E65) No. 2 (+) — Engine ground (–):

Is the voltage 5 V or more?

Repair the short
circuit to power in
the harness
between ECM con-
nector and cam-
shaft position
sensor connector.

Go to step

5.

5

CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.

Is the camshaft position sensor
installation bolt tightened
securely?

Go to step

6.

Tighten the cam-
shaft position sen-
sor installation bolt
securely. <Ref. to
FU(STI)-37, Cam-
shaft Position Sen-
sor.>

6

CHECK CAMSHAFT POSITION SENSOR.
Check the waveform of the camshaft position
sensor. <Ref. to EN(H4DOTC)(diag)-23,
Engine Control Module (ECM) I/O Signal.>

Is there any abnormality in
waveform?

Replace the cam-
shaft position sen-
sor. <Ref. to
FU(STI)-37, Cam-
shaft Position Sen-
sor.>

Repair the follow-
ing item.
• Poor contact of
ECM connector
• Poor contact of
camshaft position
sensor connector
• Poor contact of
coupling connector

EN(H4DOTC)(diag)-225

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BY:DTC P0391 CAMSHAFT POSITION SENSOR B CIRCUIT RANGE/PERFOR-

MANCE (BANK 2)

NOTE:

For the diagnostic procedure, refer to DTC P0390. <Ref. to EN(H4DOTC)(diag)-223, DTC P0390 CAM-

SHAFT POSITION SENSOR “B” CIRCUIT (BANK 2), Diagnostic Procedure with Diagnostic Trouble Code

(DTC).>

EN(H4DOTC)(diag)-226

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BZ:DTC P0410 SECONDARY AIR INJECTION SYSTEM

DTC DETECTING CONDITION:

• Detected when 2 consecutive driving cycles with fault occur.

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-139, DTC P0410 SECONDARY AIR INJECTION SYS-

TEM, Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-63,

OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-49, PROCE-

DURE, Inspection Mode.>.

EN(H4DOTC)(diag)-227

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

WIRING DIAGRAM:

• Models without SI-DRIVE <Ref. to WI-32, WITHOUT SI-DRIVE, WIRING DIAGRAM, Engine Electrical

System.>

EN-08734

F9

13

12

11

14

1

2

2

1

3

4

16

15

5

6

B143

F37

B144

B21

E2

E41

E40

B134

A:

A:

B135

B:

B135

B:

B137

D:

F37

F11

B144

F9

B143

F37

E41

10A

60A

9

10

8

7

11

5

20

8

B8

B20
B27
A19

D9

A29

6

1

2

8

47

3

2

1

6

4

1

2

9
2

16
18

14
12
10

4

14

4

E40

B134

46

B220

24

23

22

21

B137

D:

31

30

29

28

27

21

20

19

18

17

16

26

25

24

15

14

13

12

11

23

22

10

3

4

9

1

2

8

7

6

5

1 2

F11

29

4

3

1

2

7

6

5

10 11 12 13 14 15

25

24

16

30

9

8

17 18 19

20
28

21 22 23

32

31

26 27

33

34 35

B220

18

19

6

7

4

3
5

2

1

12

11

10

9

8

40

36 39

38

37

34

33

35

32

28 31

30

29

23

22

21

20

26

25

24

27

17

16

15

14

13

4

3

B220

15A

16

15

8

7

4

14

13

11

12

10

9

2

1

3

6

5

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

3
8

2
6

7

1
5

4
9

31

30

32

29

34

33

21

20

19

18

17

16

28

27

26

15

14

13

12

11

25

23

22

24

10

3

4

9

1

2

8

7

6

5

2

6

5

4

3

1

2

1

54

52 53

50 51

48 49

46 47

45

44

42 43

40 41

38 39

36 37

34 35

33

32

31

30

29

28

27

26

25

24

23

22

21

20

11

10

9

19

18

17

16

8

7

6

5

15

14

13

12

4

3

2

1

B21

E

E

E

ECM

SBF-7

FUSE

(RELAY BLOCK)

MAIN RELAY

SECONDARY

AIR COMBINATION

VALVE RELAY 2

MAIN SBF

SECONDARY

AIR PUMP

RELAY

SECONDARY

AIR COMBINATION

VALVE LH

SECONDARY

AIR COMBINATION

VALVE RH

(WITH BUILT-IN

PRESSURE SENSOR)

SECONDARY

AIR COMBINATION

VALVE RELAY 1

SECONDARY

AIR PUMP

MAIN FUSE BOX

(M/B)

RELAY HOLDER

BATTERY