Subaru Legacy IV (2008 year). Service manual — part 334

EN(H4DOTC)(diag)-157

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of fuel temperature sensor
signal using Subaru Select Monitor.

NOTE:
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>

Is the temperature less than
–40°C (–40°F)?

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 POOR CONTACT.
Repair any poor contact between the ECM and
fuel temperature sensor connectors.

Is there poor contact in the
ECM or fuel temperature sen-
sor connectors?

Repair any poor
contact between
the ECM and fuel
temperature sen-
sor connectors.

Go to step 3.

3

CHECK HARNESS BETWEEN ECM AND
FUEL TEMPERATURE SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
fuel temperature sensor.
3) Measure the resistance of the harness
between the ECM and fuel temperature sensor
connector.

Connector & terminal

(B135) No. 17 — (R58) No. 2:
(B135) No. 30 — (R58) No. 3:

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 fuel tem-
perature sensor
connector
• Poor contact of
coupling connector

4

CHECK HARNESS BETWEEN ECM AND
FUEL TEMPERATURE SENSOR CONNEC-
TOR.
1) Connect all connectors.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM and
chassis ground.

Connector & terminal

(B135) No. 17 (+) — Chassis ground (–):

Is the voltage 5 V or more?

Repair the short
circuit to power in
the harness
between the ECM
and fuel tempera-
ture sensor con-
nector.

Replace the fuel
temperature sen-
sor. <Ref. to
EC(H4DOTC)-13,
Fuel Temperature
Sensor.>

EN(H4DOTC)(diag)-158

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

AM:DTC P0222 THROTTLE/PEDAL POSITION SENSOR/SWITCH “B” CIRCUIT

LOW

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-72, DTC P0222 THROTTLE/PEDAL POSITION SEN-
SOR/SWITCH “B” CIRCUIT LOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance
• Engine stalls.

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.>.
WIRING DIAGRAM:

EN-05673

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

1 2

7 8

3
4

5
6

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

34 35

36 37 38 39 40 41

48 49

50 51 52 53 54

42 43

44 45

46 47

26 27 28 29 30 31 32 33

1 2 3 4
5 6 7 8

1

2

7

8 9

5

6

3

4

10 11 12

19 20 21

29

30 31

13 14 15 16 17

27

28

18

22 23

24 25

26

1

2

8 9

5

6

3

4

10 11 12

19 20 21

29 30

31

13 14 15 16

17

27

28

18

22 23 24 25 26

7

32 33 34 35

1 2 3 4 5 6

E57

B47

B137

D:

B21

B122

B136

C:

B362

B134

A:

36

40

34

35

37

E2

B21

C21

C1

A29

6

A18

C6

A28

6

4

25

*

*

B122

24

E

38

39

28

D5

D4

A19

A5

D7

D1

D2

D3

3

E57

2

1

5

B134

B362

B47

5

7

6

A:

B137

B136

D:

C:

*

E

SBF-7

8

6

4

E

3

4

1

2

5

6

ELECTRONIC
THROTTLE
CONTROL RELAY

MAIN RELAY

BATTERY

ECM

ELECTRONIC THROTTLE
CONTROL

: TERMINAL No. OPTIONAL
ARRANGEMENT

EN(H4DOTC)(diag)-159

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
electronic throttle control.
3) Measure the resistance between ECM and
chassis ground.

Connector & terminal

(B134) No. 19 — Chassis ground:
(B134) No. 28 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 2.

Repair the short
circuit to ground in
harness between
ECM and elec-
tronic throttle con-
trol connector.

2

CHECK SHORT CIRCUIT INSIDE THE ECM.
1) Connect the ECM.
2) Measure the resistance between electronic
throttle control connector and engine ground.

Connector & terminal

(E57) No. 4 — Engine ground:

Is the resistance 1 M

: or

more?

Replace the elec-
tronic throttle con-
trol. <Ref. to
FU(H4DOTC)-14,
Throttle Body.>

Repair the short
circuit to ground in
harness between
ECM and elec-
tronic throttle con-
trol connector.
Replace the ECM if
defective. <Ref. to
FU(H4DOTC)-52,
Engine Control
Module (ECM).>

EN(H4DOTC)(diag)-160

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

AN:DTC P0223 THROTTLE/PEDAL POSITION SENSOR/SWITCH “B” CIRCUIT

HIGH

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-73, DTC P0223 THROTTLE/PEDAL POSITION SEN-
SOR/SWITCH “B” CIRCUIT HIGH, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Improper idling
• Poor driving performance
• Engine stalls.

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.>.
WIRING DIAGRAM:

EN-05673

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

1 2

7 8

3
4

5
6

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

34 35

36 37 38 39 40 41

48 49

50 51 52 53 54

42 43

44 45

46 47

26 27 28 29 30 31 32 33

1 2 3 4
5 6 7 8

1

2

7

8 9

5

6

3

4

10 11 12

19 20 21

29

30 31

13 14 15 16 17

27

28

18

22 23

24 25

26

1

2

8 9

5

6

3

4

10 11 12

19 20 21

29 30

31

13 14 15 16

17

27

28

18

22 23 24 25 26

7

32 33 34 35

1 2 3 4 5 6

E57

B47

B137

D:

B21

B122

B136

C:

B362

B134

A:

36

40

34

35

37

E2

B21

C21

C1

A29

6

A18

C6

A28

6

4

25

*

*

B122

24

E

38

39

28

D5

D4

A19

A5

D7

D1

D2

D3

3

E57

2

1

5

B134

B362

B47

5

7

6

A:

B137

B136

D:

C:

*

E

SBF-7

8

6

4

E

3

4

1

2

5

6

ELECTRONIC
THROTTLE
CONTROL RELAY

MAIN RELAY

BATTERY

ECM

ELECTRONIC THROTTLE
CONTROL

: TERMINAL No. OPTIONAL
ARRANGEMENT