Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 269

EN(H4DOTC)(diag)-300

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK INPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Place the shift lever in a position other than
neutral.
3) Measure the voltage between ECM connec-
tor and chassis ground.

Connector & terminal

(B136) No. 35 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Repair the poor
contact of ECM
connector.

Go to step

2.

2

CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
neutral position switch.
3) Measure the resistance between ECM con-
nector and chassis ground.

Connector & terminal

(B136) No. 35 — Chassis ground:

Is the resistance 1 MΩ or
more?

Replace the neu-
tral position switch.
<Ref. to 5MT-33,
Switches and Har-
ness.> <Ref. to
6MT-41, Neutral
Position Switch.>

Repair the short
circuit to ground
harness between
ECM connector
and neutral posi-
tion switch connec-
tor.

EN(H4DOTC)(diag)-301

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

DJ:DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (MT MODEL)

DTC DETECTING CONDITION:

• Detected when 2 consecutive driving cycles with fault occur.

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-204, DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT

HIGH (MT MODEL), Diagnostic Trouble Code (DTC) Detecting Criteria.>

TROUBLE SYMPTOM:

Improper idling
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.>

EN-08739

35

B128

B128

T9

*

3

B136

B122

4

T12

B122

*

3

*

2

*

1

5M

6M

*

1

*

1

T12

1

2

B136

*

2

B128

3 4

1 2

6M

5M

2

6

5

4

3

1

2

1

35

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

8

7

6

5

4

3

2

1

:

:

ECM

: 5MT MODEL

: 6MT MODEL

: TERMINAL No.

OPTIONAL ARRANGEMENT

: 5MT MODEL : 1

6MT MODEL : 2

: 5MT MODEL : 3

6MT MODEL : 5

NEUTRAL

POSITION

SWITCH

EN(H4DOTC)(diag)-302

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

DK:DTC P1160 RETURN SPRING FAILURE

NOTE:

For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H4DOTC)(diag)-371, DTC P2101 THROT-

TLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Di-

agnostic Trouble Code (DTC).>

Step

Check

Yes

No

1

CHECK INPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Place the shift lever in neutral.
3) Measure the voltage between ECM connec-
tor and chassis ground.

Connector & terminal

(B136) No. 35 (+) — Chassis ground (–):

Is the voltage less than 1 V?

Repair the poor
contact of ECM
connector.
Replace the ECM if
defective. <Ref. to
FU(STI)-59,
Engine Control
Module (ECM).>
<Ref. to FU(w/o
STI)-57, Engine
Control Module
(ECM).>

Go to step

2.

2

CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
transmission harness connector (T9).
3) Measure the resistance of harness between
ECM connector and transmission harness con-
nector.

Connector & terminal

5MT model

(B136) No. 35 — (B128) No. 1:

6MT model

(B136) No. 35 — (B128) No. 2:

Is the resistance less than 1 Ω? Go to step

3.

Repair the open
circuit in harness
between ECM con-
nector and trans-
mission harness
connector.

3

CHECK HARNESS BETWEEN ECM AND
NEUTRAL POSITION SWITCH CONNEC-
TOR.
Measure the resistance of harness between
ECM connector and transmission harness con-
nector.

Connector & terminal

5MT model

(B128) No. 3 — (B136) No. 4:

6MT model

(B128) No. 5 — (B136) No. 4:

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 in
harness between
ECM

connector

and transmission
harness connector
• Poor contact of
coupling connector

4

CHECK NEUTRAL POSITION SWITCH.
1) Place the shift lever in neutral.
2) Measure the resistance between transmis-
sion harness connector terminals.

Connector & terminal

5MT model

(T9) No. 1 — No. 3:

6MT model

(T9) No. 2 — No. 5:

Is the resistance less than 1 Ω? Repair the poor

contact of trans-
mission harness
connector.

Repair the open
circuit of transmis-
sion harness, or
replace the neutral
position switch.
<Ref. to 5MT-33,
Switches and Har-
ness.> <Ref. to
6MT-41, Neutral
Position Switch.>

EN(H4DOTC)(diag)-303

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

DL:DTC P1400 FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT

LOW

DTC DETECTING CONDITION:

• Detected when 2 consecutive driving cycles with fault occur.

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-207, DTC P1400 FUEL TANK PRESSURE CONTROL

SOLENOID VALVE CIRCUIT LOW, 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

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

29 30 31

32 33

34 35

B135

B:

5

6

7

8

2

1

9

4

3

10

22 23

11 12 13 14 15

24 25

26

16 17

18 19 20 21

27

28 29

30 31

B137

D:

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

E52

E4

1 2

B3

D15

D6

E2

B21

44

11

4

8

E4

2

1

E52

2

1

R68

2

1

B135

B:

R57

R15

10

11

R1

B97

R2

B98

7

10

R68

1 2

B220

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32 35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

R57

B97

1 2

3 4 5

6 7 8 9 10 11 12

EN-09251

B98

2 3 4 5

6 7 8 9

11 12 13 14

17 18 19 20

1

10

15 16

B220

24

23

22

21

B220

4

3

B137

D:

SBF-7

E

FUSE

(RELAY BLOCK)

MAIN RELAY

BATTERY

PRESSURE CONTROL

SOLENOID VALVE ASSY

PURGE CONTROL

SOLENOID VALVE 2

PURGE CONTROL

SOLENOID VALVE 1