Subaru Legacy IV (2008 year). Manual - part 195

GD(H4SO)-82

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

180° Interval Difference Method

360° Interval Difference Method

Diagnostic value

domg 180 = (omg 1 – omg 0) – (omg 5 – omg 1)/4

Judge as a misfire in the following cases.

• domg 180 > judgment value of positive side
• domg 180 

d judgment value of negative side

(Judgement value before 180° CA)

Diagnostic value

domg 360 = (omg 1 – omg 0) – (omg 3 – omg 2)

Misfire judgment

domg 360 > Judgement value 

o Judge as misfire

Judged as misfire.

Threshold valve (positive number)

Threshold valve (negative number)

domg180

domg180

EN-02877

Judged as misfire.

Threshold valve 

domg360

domg360

EN-03273

GD(H4SO)-83

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

720° Interval Difference Method

• FTP 1.5 times misfire (Misfire occurrence level which influences exhaust gas)

• Abnormality Judgement

Time Needed for Diagnosis: 1000 engine revs.
Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
• Normality Judgement

Time Needed for Diagnosis: 1000 engine revs.

Diagnostic value

domg 720 = (omg 1 – omg 0) – (omg 5 – omg 4)

Misfire judgment

domg 720 > Judgement value 

o Judge as misfire

Judgement Value (Judge that malfunction occurs when the misfire ratio is high in 1000 engine revs.)

Malfunction Criteria

Threshold Value

FTP emission judgment value

t 18  × 100/2000% in 
1000 revs. (U5 model)
t 20  × 100/2000% in 
1000 revs. 
(Except for U5 model)

Judgement Value

Malfunction Criteria

Threshold Value

FTP emission judgment value

< 18  × 100/2000% in 
1000 revs. (U5 model)
< 20  × 100/2000% in 
1000 revs. 
(Except for U5 model)

Judged as misfire.

Threshold valve 

domg720

domg720

EN-03274

GD(H4SO)-84

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

• Catalyst damage misfire (Misfire occurrence level damaging catalyst)

• Abnormality Judgement

Map 3

Time Needed for Diagnosis: 200 engine revs.
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
• Normality Judgement

Time Needed for Diagnosis: 200 engine revs.

Judgement Value

Malfunction Criteria

Threshold Value

Catalyst damage misfire judgment value

t Value of Map 3

U5 MODEL

 Intake 

air 

(g(oz)/rev)

0.16 (0.01)

0.28 (0.01)

0.4 (0.01)

0.52 (0.02)

0.64 (0.02)

0.76 (0.03)

0.92 (0.03)

1.1 (0.04)

Engine 
speed 
(rpm)

700

100

100

100

100

90

80

64

48

1000

100

100

100

100

90

80

52

24

1500

100

100

90

80

69

57

39

22

2000

80

80

80

80

62

44

33

21

2500

67

67

58

50

40

31

25

20

3000

57

57

49

40

30

20

20

20

3500

44

44

34

24

20

20

20

20

4000

36

36

28

20

20

20

20

20

4500

27

27

20

20

20

20

20

20

5000

20

20

20

20

20

20

20

20

5500

20

20

20

20

20

20

20

20

6000

20

20

20

20

20

20

20

20

6300

20

20

20

20

20

20

20

20

EXCEPT FOR U5 MODEL

 Intake 

air 

(g(oz)/rev)

0.16 (0.01)

0.28 (0.01)

0.4 (0.01)

0.52 (0.02)

0.64 (0.02)

0.76 (0.03)

0.92 (0.03)

1.1 (0.04)

Engine 
speed 
(rpm)

700

100

100

100

100

90

80

64

48

1000

100

100

100

100

90

80

63

44

1500

100

100

90

80

73

67

54

40

2000

80

80

80

80

68

57

51

44

2500

80

80

73

67

62

57

51

44

3000

67

67

62

57

51

44

44

44

3500

67

67

56

44

40

36

34

31

4000

57

57

44

31

24

20

20

20

4500

44

44

33

31

20

20

20

20

5000

44

44

38

31

20

20

20

20

5500

36

36

31

27

20

20

20

20

6000

20

20

20

20

20

20

20

20

6300

20

20

20

20

20

20

20

20

Judgement Value

Malfunction Criteria

Threshold Value

Catalyst damage misfire judgment value

< Value of Map 3

GD(H4SO)-85

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

AU:DTC P0302 CYLINDER 2 MISFIRE DETECTED

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(H4SO)-79, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>

AV:DTC P0303 CYLINDER 3 MISFIRE DETECTED

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(H4SO)-79, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>

AW:DTC P0304 CYLINDER 4 MISFIRE DETECTED

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0301. <Ref. to GD(H4SO)-79, DTC P0301 CYLINDER 1 MISFIRE
DETECTED, Diagnostic Trouble Code (DTC) Detecting Criteria.>