Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 226

EN(H4DOTC)(diag)-128

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

5

CHECK FOR POOR CONTACT.
Check for poor contact of ECM and manifold
absolute pressure sensor connector.

Is there poor contact of ECM or
manifold absolute pressure
sensor connector?

Repair the poor
contact of ECM or
manifold absolute
pressure sensor
connector.

Replace the mani-
fold absolute pres-
sure sensor. <Ref.
to FU(STI)-43,
Manifold Absolute
Pressure Sen-
sor.> <Ref. to
FU(w/o STI)-43,
Manifold Absolute
Pressure Sensor.>

Step

Check

Yes

No

EN(H4DOTC)(diag)-129

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

S: DTC P0108 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE

CIRCUIT HIGH INPUT

DTC DETECTING CONDITION:

• Immediately at fault recognition

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-42, DTC P0108 MANIFOLD ABSOLUTE PRESSURE/

BAROMETRIC PRESSURE CIRCUIT HIGH INPUT, 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.>.

WIRING DIAGRAM:

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

Engine Electrical System.>

• Engine electrical system, with SI-DRIVE <Ref. to WI-48, WITH SI-DRIVE, WIRING DIAGRAM, Engine

Electrical System.>

ECM

EN-08724

6

2

8

23

1

3

2

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

B134

A:

A29

D20

A19

2

3

1

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

3

2

1

B137

D:

B134

A:

B21

E21

E21

E2

B21

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

ES

SI

SI

ES

: WITHOUT SI-DRIVE

: WITH SI-DRIVE

MANIFOLD

ABSOLUTE

PRESSURE

SENSOR

EN(H4DOTC)(diag)-130

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK CURRENT DATA.
1) Start the engine.
2) Read the value of «Mani. Absolute Pres-
sure» using the Subaru Select Monitor or a gen-
eral scan tool.
NOTE:

• Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.

Is the value of «Mani. Absolute
Pressure» 119.5 kPa (896.5
mmHg, 35.29 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,
temporary open or
short circuit of har-
ness may be the
cause.

2

CHECK HARNESS BETWEEN ECM AND
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from manifold
absolute pressure sensor.
3) Start the engine.
4) Read the value of «Mani. Absolute Pres-
sure» using the Subaru Select Monitor or a gen-
eral scan tool.
NOTE:

• Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.

Is the value of «Mani. Absolute
Pressure» 119.5 kPa (896.5
mmHg, 35.29 inHg) or more?

Repair the short
circuit to power in
harness between
ECM connector
and manifold abso-
lute pressure sen-
sor connector.

Go to step

3.

3

CHECK HARNESS BETWEEN ECM AND
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between
manifold absolute pressure sensor connector
and engine ground.

Connector & terminal

Models without SI-DRIVE

(E21) No. 1 — Engine ground:

Models with SI-DRIVE

(E21) No. 2 — Engine ground:

Is the resistance less than 5 Ω? Go to step

4.

Repair the harness
and connector.
NOTE:

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

connector

and manifold abso-
lute pressure sen-
sor connector
• Poor contact of
ECM connector
• Poor contact of
coupling connector

EN(H4DOTC)(diag)-131

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

4

CHECK FOR POOR CONTACT.
Check for poor contact of manifold absolute
pressure sensor connector.

Is there poor contact of mani-
fold absolute pressure sensor
connector?

Repair the poor
contact of manifold
absolute pressure
sensor connector.

Replace the mani-
fold absolute pres-
sure sensor. <Ref.
to FU(STI)-43,
Manifold Absolute
Pressure Sen-
sor.> <Ref. to
FU(w/o STI)-43,
Manifold Absolute
Pressure Sensor.>

Step

Check

Yes

No