Subaru Legacy IV (2008 year). Service manual - part 348

 

  Index      Subaru     Subaru Legacy IV - service and repair manual 2008 year

 

Search            

 

 

 

 

 

 

 

  

 

Content   ..  346  347  348  349   ..

 

 

Subaru Legacy IV (2008 year). Service manual - part 348

 

 

EN(H4DOTC)(diag)-213

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

3

CHECK WAVEFORM DATA ON THE SUBA-
RU SELECT MONITOR (WHILE IDLING).
1) Run the engine at idle.
2) In the condition of step 1), use the Subaru 
Select Monitor to read the waveform data.
• At normal condition

• At abnormal condition 1 (numerous inversion)

• At abnormal condition 2 (noise input)

Is normal waveform pattern dis-
played?

Go to step 4.

• The waveform is 
displayed at abnor-
mal condition 1:Go 
to step 4.
• The waveform is 
displayed at abnor-
mal condition 2:Go 
to step 5.

4

CHECK CATALYTIC CONVERTER.

Is the catalytic converter dam-
aged?

Replace the cata-
lytic converter. 
<Ref. to 
EC(H4DOTC)-5, 
Front Catalytic 
Converter.>

Go to step 5.

5

CHECK REAR OXYGEN SENSOR CONNEC-
TOR AND COUPLING CONNECTOR.

Has water entered the connec-
tor?

Completely 
remove any water 
inside.

Go to step 6.

Step

Check

Yes

No

EN-06668

1

0

10 sec/div

REAR OXYGEN 
SENSOR VOLTAGE 
                           (V)

EN-06669

1

0

10 sec/div

REAR OXYGEN 
SENSOR VOLTAGE 
                           (V)

EN-06670

1

0

10 sec/div

REAR OXYGEN 
SENSOR VOLTAGE 
                           (V)

EN(H4DOTC)(diag)-214

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

6

CHECK HARNESS BETWEEN ECM AND 
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and 
rear oxygen sensor.
3) Measure the resistance of harness between 
ECM and rear oxygen sensor connector.

Connector & terminal

(B135) No. 4 — (T6) No. 3:
(B135) No. 30 — (T6) No. 4:

Is the resistance less than 1 

:? Go to step 7.

Repair the harness 
and connector.

NOTE:
Repair the follow-
ing locations.
• Open circuit in
harness between
ECM and rear oxy-
gen sensor con-
nector
• Poor contact of
coupling connector

7

CHECK HARNESS BETWEEN ECM AND 
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between rear oxygen 
sensor connector and chassis ground.

Connector & terminal

(T6) No. 3 (+) — Chassis ground (–):

Is the voltage 0.2 — 0.5 V?

Go to step 8.

Repair the harness 
and connector.

NOTE:
Repair the follow-
ing locations.
• Open circuit of
harness between
the ECM and rear
oxygen sensor
• Poor contact in
ECM and rear oxy-
gen sensor
• Poor contact in
ECM connector

8

CHECK REAR OXYGEN SENSOR SHIELD.
1) Turn the ignition switch to OFF.
2) Expose the rear oxygen sensor connector 
body side harness sensor shield.
3) Measure the resistance between the sensor 
shield and chassis ground.

Is the resistance less than 1 

:? Replace the rear 

oxygen sensor. 
<Ref. to 
FU(H4DOTC)-48, 
Rear Oxygen Sen-
sor.>

Repair the open 
circuit in the rear 
oxygen sensor har-
ness.

Step

Check

Yes

No

EN(H4DOTC)(diag)-215

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BK:DTC P0441 EVAPORATIVE EMISSION SYSTEM INCORRECT PURGE FLOW

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-107, DTC P0441 EVAPORATIVE EMISSION SYS-
TEM INCORRECT PURGE FLOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>

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.>.

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check the appro-
priate DTC using 
the “List of Diag-
nostic Trouble 
Code (DTC)”. 
<Ref. to 
EN(H4DOTC)(diag)
-81, List of Diag-
nostic Trouble 
Code (DTC).>

Go to step 2.

2

CHECK PURGE LINE OF THE PURGE CON-
TROL SOLENOID VALVE 2.

Is there any clogging, flattened 
part or bent in the purge line of 
purge control solenoid valve 2?

Repair or replace 
the purge line of 
purge control sole-
noid valve 2.

Go to step 3.

3

CHECK PURGE CONTROL SOLENOID 
VALVE 2.
1) Connect the delivery (test) mode connector.
2) Turn the ignition switch to ON.
3) Operate the purge control solenoid valve 2 
using the Subaru Select Monitor.

NOTE:
Purge control solenoid valve 2 can be operated
using the Subaru Select Monitor. For the proce-
dures, refer to “Compulsory Valve Operation
Check Mode”. <Ref. to EN(H4DOTC)(diag)-53,
Compulsory Valve Operation Check Mode.>

Does the purge control sole-
noid valve 2 operate?

Repair the poor 
contact of ECM 
connector.

Replace the purge 
control solenoid 
valve 2. <Ref. to 
EC(H4DOTC)-9, 
Purge Control 
Solenoid Valve.>

EN(H4DOTC)(diag)-216

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

BL:DTC P0442 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED 

(SMALL LEAK)

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-108, DTC P0442 EVAPORATIVE EMISSION CON-
TROL SYSTEM LEAK DETECTED (SMALL LEAK), Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
• Fuel odor
• There is a hole of more than 1.0 mm (0.04 in) dia. in evaporation system or fuel tank.

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-05679

SBF-7

E4

B47

E

5
3

6
4

2
1

2

1

C17

C28

D29

C7

R15

R213

R68

R144

R1

B97

14

15

2

2

1

1

7

1

5

E52

2

1

E52

R144

E4

B47

R67

B97

R213

R68

1 2

3

4

1

2

5

6

B21

1 2

1 2

3

4 5 6 7 8

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

1

2

3 4 5 6

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

R46

R67

6

B21

E2

11

48

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

B136

C:

B137

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

D:

B136

C:

B137

D:

44

MAIN RELAY

ECM

BATTERY

DRAIN VALVE

PRESSURE 

CONTROL 

SOLENOID VALVE

PURGE CONTROL 

SOLENOID VALVE  1

PURGE CONTROL 

SOLENOID VALVE  2

 

 

 

 

 

 

 

Content   ..  346  347  348  349   ..