Subaru Legacy IV (2008 year). Manual — part 530

EN(H6DO)(diag)-93

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

E: DTC P0026 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/

PERFORMANCE (BANK 1)

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-14, DTC P0026 INTAKE VALVE CONTROL SOLENOID
CIRCUIT RANGE/PERFORMANCE (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
Improper idling

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

EN-03913

B134

31

B20

E1

9

ECM

B134

B20

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

13 14 15 16

1

VVL DIAGNOSIS OIL

PRESSURE SWITCH RH

E71

8

5

6

10 11 12 13 14 15

7

2

1

3

4

16

30

19 20

22

28 29

9

17

18

25

21

23 24

32

31

26 27
33 34

EN(H6DO)(diag)-94

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
1) Warm up the engine.
2) Turn the ignition switch to OFF.
3) Disconnect the connectors from ECM and
variable valve lift diagnosis oil pressure switch.
4) Measure the resistance of harness between
ECM and variable valve lift diagnosis oil pres-
sure switch connector.

Connector & terminal

(B134) No. 31 — (E71) No. 1:

Is the resistance less than 1

:? Go to step 2.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and variable
valve lift diagnosis
oil pressure switch
connector
• Poor contact of
coupling connector

2

CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
Measure the resistance between variable valve
lift diagnosis oil pressure switch connector and
engine ground.

Connector & terminal

(E71) No. 1 — Engine ground:

Is the resistance 1 M

: or

more?

Go to step 3.

Repair the ground
short circuit of har-
ness between
ECM and variable
valve lift diagnosis
oil pressure switch
connector.

3

CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
1) Turn the ignition switch to ON.
2) Measure the voltage between variable valve
lift diagnosis oil pressure switch connector and
engine ground.

Connector & terminal

(E71) No. 1 (+) — Engine ground (–):

Is the voltage 10 V or more?

Repair the short
circuit of harness
to power supply
between ECM and
variable valve lift
diagnosis oil pres-
sure switch con-
nector.

Go to step 4.

4

CHECK DTC.
1) Perform the Clear Memory Mode.
2) After idling the engine, check the DTC.

NOTE:
For detailed procedure, refer to “Clear Memory
Mode”. <Ref. to EN(H6DO)(diag)-52, Clear
Memory Mode.>

Is DTC displayed?

Replace the oil
switching solenoid
valve. <Ref. to
ME(H6DO)-80, Oil
Switching Solenoid
Valve.>
Go to step 5.

End.

5

CHECK DTC.
1) Perform the Clear Memory Mode.
2) After idling the engine, check the DTC.

NOTE:
For detailed procedure, refer to “Clear Memory
Mode”. <Ref. to EN(H6DO)(diag)-52, Clear
Memory Mode.>

Is DTC displayed?

Check for oil rout-
ing.

End.

EN(H6DO)(diag)-95

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

F: DTC P0028 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/

PERFORMANCE (BANK 2)

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-16, DTC P0028 INTAKE VALVE CONTROL SOLENOID
CIRCUIT RANGE/PERFORMANCE (BANK 2), Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
Improper idling

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

EN-03914

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

13 14 15 16

1

8

5

6

10 11 12 13 14 15

7

2

1

3

4

16

30

19 20

22

28 29

9

17

18

25

21

23 24

32

31

26 27
33 34

B134

32

B20

E1

10

ECM

E72

VVL DIAGNOSIS OIL

PRESSURE SWITCH LH

B134

B20

EN(H6DO)(diag)-96

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
1) Warm up the engine.
2) Turn the ignition switch to OFF.
3) Disconnect the connectors from ECM and
variable valve lift diagnosis oil pressure switch.
4) Measure the resistance of harness between
ECM and variable valve lift diagnosis oil pres-
sure switch connector.

Connector & terminal

(B134) No. 32 — (E72) No. 1:

Is the resistance less than 1

:? Go to step 2.

Repair the harness
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and variable
valve lift diagnosis
oil pressure switch
connector
• Poor contact of
coupling connector

2

CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
Measure the resistance between variable valve
lift diagnosis oil pressure switch connector and
engine ground.

Connector & terminal

(E72) No. 1 — Engine ground:

Is the resistance 1 M

: or

more?

Go to step 3.

Repair the ground
short circuit of har-
ness between
ECM and variable
valve lift diagnosis
oil pressure switch
connector.

3

CHECK HARNESS BETWEEN ECM AND
VARIABLE VALVE LIFT DIAGNOSIS OIL
PRESSURE SWITCH.
1) Turn the ignition switch to ON.
2) Measure the voltage between variable valve
lift diagnosis oil pressure switch connector and
engine ground.

Connector & terminal

(E72) No. 1 (+) — Engine ground (–):

Is the voltage 10 V or more?

Repair the short
circuit of harness
to power supply
between ECM and
variable valve lift
diagnosis oil pres-
sure switch con-
nector.

Go to step 4.

4

CHECK DTC.
1) Perform the Clear Memory Mode.
2) After idling the engine, check the DTC.

NOTE:
For detailed procedure, refer to “Clear Memory
Mode”. <Ref. to EN(H6DO)(diag)-52, Clear
Memory Mode.>

Is DTC displayed?

Replace the oil
switching solenoid
valve. <Ref. to
ME(H6DO)-80, Oil
Switching Solenoid
Valve.>
Go to step 5.

End.

5

CHECK DTC.
1) Perform the Clear Memory Mode.
2) After idling the engine, check the DTC.

NOTE:
For detailed procedure, refer to “Clear Memory
Mode”. <Ref. to EN(H6DO)(diag)-52, Clear
Memory Mode.>

Is DTC displayed?

Check for oil rout-
ing.

End.