Subaru Legacy (2005 year). Manual — part 339

EN(H4DOTC)(diag)-125

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AA:DTC P0261 CYLINDER 1 INJECTOR CIRCUIT LOW

NOTE:
For the diagnostic procedure, refer to DTC P0270. <Ref. to EN(H4DOTC)(diag)-125, DTC P0270 CYLIN-
DER 4 INJECTOR CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AB:DTC P0264 CYLINDER 2 INJECTOR CIRCUIT LOW

NOTE:
For the diagnostic procedure, refer to DTC P0270. <Ref. to EN(H4DOTC)(diag)-125, DTC P0270 CYLIN-
DER 4 INJECTOR CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AC:DTC P0267 CYLINDER 3 INJECTOR CIRCUIT LOW

NOTE:
For the diagnostic procedure, refer to DTC P0270. <Ref. to EN(H4DOTC)(diag)-125, DTC P0270 CYLIN-
DER 4 INJECTOR CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

AD:DTC P0270 CYLINDER 4 INJECTOR CIRCUIT LOW

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Engine stalls.
• Erroneous idling
• Rough driving

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.

EN(H4DOTC)(diag)-126

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

WIRING DIAGRAM:

EN-03521

E

E

#4

1

2

SBF-7

#3

1

2

#2

1

2

B21

#1

1

2

48

42

43

44

45

C6

C5

C4

C3

1 2

5
3

6
4

2
1

B21

B136

B137

B136

E5

E5

E2

E6

E6

E16

E16

E17

B47

E17

B47

3

4

1

2

5

6

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

35

ECM

BATTERY

MAIN RELAY

FUEL INJECTORS

C:

B137

D:

D7

34

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

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

C:

D:

EN(H4DOTC)(diag)-127

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK POWER SUPPLY LINE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel injector.
3) Turn the ignition switch to ON.
4) Measure the voltage between fuel injector
and engine ground on faulty cylinders.

Connector & terminal

#1 (E5) No. 2 (+) — Engine ground (

−

):

#2 (E16) No. 2 (+) — Engine ground (

−

):

#3 (E6) No. 2 (+) — Engine ground (

−

):

#4 (E17) No. 2 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Go to step 2.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit of
harness between
main relay and fuel
injector connector
on faulty cylinders
• Poor contact in
coupling connector
• Poor contact in
main relay connec-
tor
• Poor contact in
fuel injector con-
nector on faulty
cylinders

2

CHECK FUEL INJECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between fuel injec-
tor terminals on faulty cylinder.

Terminals

No. 1 — No. 2:

Is the resistance less than 11
— 12

Ω?

Go to step 3.

Replace the faulty
fuel injector and
ECM. <Ref. to
FU(H4DOTC)-29,
Fuel Injector.>

3

CHECK OUTPUT SIGNAL FROM ECM.
1) Connect the connector to fuel injector.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector and chassis ground on faulty cylinders.

Connector & terminal

#1 (B136) No. 6 (+) — Chassis ground (

−

):

#2 (B136) No. 5 (+) — Chassis ground (

−

):

#3 (B136) No. 4 (+) — Chassis ground (

−

):

#4 (B136) No. 3 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 4.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ECM and fuel
injector connector
• Poor contact in
coupling connector

4

CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between ECM con-
nector and chassis ground.

Connector & terminal

(B137) No. 7 — Chassis ground:

Is the resistance less than 5
Ω?

Repair the poor
contact in fuel
injector and ECM
connector.

Repair the ground
open circuit in
ECM.

EN(H4DOTC)(diag)-128

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AE:DTC P0327 KNOCK SENSOR 1 CIRCUIT LOW (BANK 1 OR SINGLE SEN-

SOR)

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Poor driving performance
• Knocking occurs.

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-01953

E1

E14

B20

2

13

B136

ECM

33

25

E

E14

1 2

B20

KNOCK
SENSOR

B136

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

35

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16