Subaru Legacy IV (2008 year). Manual - part 166

 

  Index      Subaru     Subaru Legacy IV - service repair manual 2008 year

 

Search            

 

 

 

 

 

 

 

  

 

Content   ..  164  165  166  167   ..

 

 

Subaru Legacy IV (2008 year). Manual - part 166

 

 

EN(H4SO)(diag)-267

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

23

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL RE-
LAY.
Measure the resistance between ECM and 
electronic throttle control relay connector.

Connector & terminal

(B136) No. 21 — (B362) No. 6:
(B136) No. 1 — (B362) No. 7:

Is the resistance less than 1 

:? Go to step 24.

Repair the open 
circuit in harness 
between ECM and 
electronic throttle 
control relay con-
nector.

24

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. 18 — Chassis ground:
(B134) No. 18 — (B136) No. 6:
(B134) No. 28 — Chassis ground:

Is the resistance 1 M

: or 

more?

Go to step 25.

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

25

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

Connector & terminal

(E57) No. 6 — Engine ground:
(E57) No. 4 — Engine ground:

Is the resistance 1 M

: or 

more?

Go to step 26.

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(H4SO)-39,
Engine Control 
Module (ECM).>

26

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Disconnect the connectors from ECM.
2) Measure the resistance of harness between 
ECM and electronic throttle control connector.

Connector & terminal

(B134) No. 18 — (E57) No. 6:
(B134) No. 28 — (E57) No. 4:
(B134) No. 29 — (E57) No. 3:

Is the resistance less than 1 

:? Go to step 27.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and electron-
ic throttle control
connector
• Poor contact of
coupling connector

27

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Connect the connector to ECM.
2) Measure the resistance between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 3 — Engine ground:

Is the resistance less than 5 

:? Go to step 28.

Repair the harness 
and connector.

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

Step

Check

Yes

No

EN(H4SO)(diag)-268

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

28

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 6 (+) — Engine ground (–):
(E57) No. 4 (+) — Engine ground (–):

Is the voltage 4.85 V or more?

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control connector.

Go to step 29.

29

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance between ECM con-
nectors.

Connector & terminal

(B134) No. 19 — (B134) No. 18:
(B134) No. 19 — (B134) No. 28:

Is the resistance 1 M

: or 

more?

Go to step 30.

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control connector.

30

CHECK SENSOR OUTPUT.
1) Connect all connectors.
2) Turn the ignition switch to ON.
3) Read the data of main throttle sensor signal 
using Subaru Select Monitor.

NOTE:
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO)(diag)-33, Subaru Select Moni-
tor.>

Is the voltage 0.81 — 0.87 V?

Go to step 31.

Repair poor con-
tact of the elec-
tronic throttle 
control connector. 
Replace the elec-
tronic throttle con-
trol if defective. 
<Ref. to 
FU(H4SO)-12,
Throttle Body.>

31

CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal 
using Subaru Select Monitor.

NOTE:
SUBARU SELECT MONITOR
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO)(diag)-33, Subaru Select Moni-
tor.>

Is the voltage 1.64 — 1.70 V?

Go to step 32.

Repair poor con-
tact of the elec-
tronic throttle 
control connector. 
Replace the elec-
tronic throttle con-
trol if defective. 
<Ref. to 
FU(H4SO)-12,
Throttle Body.>

32

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

Connector & terminal

(B137) No. 5 — (E57) No. 2:
(B137) No. 4 — (E57) No. 1:

Is the resistance less than 1 

:? Go to step 33.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and electron-
ic throttle control
connector
• Poor contact of
coupling connector

33

CHECK HARNESS BETWEEN ECM AND 
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Connect the connector to ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic 
throttle control connector and engine ground.

Connector & terminal

(E57) No. 2 (+) — Engine ground (–):
(E57) No. 1 (+) — Engine ground (–):

Is the voltage 5 V or more?

Repair the short 
circuit to power in 
the harness 
between ECM and 
electronic throttle 
control.

Go to step 34.

Step

Check

Yes

No

EN(H4SO)(diag)-269

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CY:DTC P2096 POST CATALYST FUEL TRIM SYSTEM TOO LEAN (BANK 1)

NOTE:
Refer to DTC P2097 for diagnostic procedure. <Ref. to EN(H4SO)(diag)-270, DTC P2097 POST CATALYST
FUEL TRIM SYSTEM TOO RICH (BANK 1), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

34

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

Connector & terminal

(E57) No. 2 — Engine ground:
(E57) No. 1 — Engine ground:

Is the resistance 1 M

: or 

more?

Go to step 35.

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

35

CHECK ELECTRONIC THROTTLE CON-
TROL MOTOR HARNESS.
Measure the resistance between the electronic 
throttle control connector terminals.

Connector & terminal

(E57) No. 2 — (E57) No. 1:

Is the resistance 1 M

: or 

more?

Go to step 36.

Repair the short 
circuit of harness 
between ECM and 
electronic throttle 
control connector.

36

CHECK ELECTRONIC THROTTLE CON-
TROL GROUND CIRCUIT.
Measure the resistance between ECM and 
chassis ground.

Connector & terminal

(B134) No. 5 — Chassis ground:
(B137) No. 1 — Chassis ground:
(B137) No. 2 — Chassis ground:
(B137) No. 3 — Chassis ground:
(B137) No. 7 — Chassis ground:

Is the resistance less than 5 

:? Go to step 37.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and engine
ground
• Poor contact of
coupling connector

37

CHECK ELECTRONIC THROTTLE CON-
TROL.
Measure the resistance between electronic 
throttle control terminals.

Terminals

No. 2 — No. 1:

Is the resistance 50 

: or less? Go to step 38.

Replace the elec-
tronic throttle con-
trol. <Ref. to 
FU(H4SO)-12,
Throttle Body.>

38

CHECK ELECTRONIC THROTTLE CON-
TROL.
Move the throttle valve to the fully open and fully 
closed positions with fingers.
Check that the valve returns to the specified 
position when releasing fingers.

Does the valve return to the 
specified position? Standard 
value: 3 mm (0.12 in) from fully 
closed position

Repair the poor 
contact of ECM 
connector.

Replace the elec-
tronic throttle con-
trol. <Ref. to 
FU(H4SO)-12,
Throttle Body.>

Step

Check

Yes

No

EN(H4SO)(diag)-270

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

CZ:DTC P2097 POST CATALYST FUEL TRIM SYSTEM TOO RICH (BANK 1)

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H4SO)-180, DTC P2097 POST CATALYST FUEL TRIM SYS-
TEM TOO RICH (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4SO)(diag)-50,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4SO)(diag)-41, PROCEDURE,
Inspection Mode.>.
WIRING DIAGRAM:

EN-06835

B137

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

31

26 27

3

4

1

2

5

6

B327

SBF-5

E

E

E

B327

E22

6

4

5

3

2
1

6

4

1

3

B1

B9

B8

C3

C2

A5

D7

D1

D2

D3

36

52

34

35

37

B134

A:

B135

B:

B136

C:

B137

D:

B21

E2

ECM

B21

E2

50

51

3

4

E2

B21

E

E22

B138

B134

B135

A:

B:

B136

C:

D:

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

BATTERY

FRONT OXYGEN 

(A/F) SENSOR

A/F, OXYGEN 
SENSOR RELAY

B138

*

*

 : TERMINAL No. OPTIONAL  
 ARRANGEMENT

*

3

1

6 5 4

2

5

6

7

2

1

3

4

29

10 11 12 13 14 15

25

24

16

30

9

8

17 18 19

20
28

21 22 23

32

31

26 27

33

34 35

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

27

26

33 34 35

3 4

5 6

1 2

7 8

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

 

 

 

 

 

 

 

Content   ..  164  165  166  167   ..