Subaru Legacy III (2000-2003 year). Manual - part 765

VDC-96

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

5

CHECK POOR CONTACT IN ECM CONNEC-
TORS.
Is there poor contact in ECM connector?

There is poor contact.

Replace ECM.   
<Ref. to 
FU(H6DO)-46, 
Engine Control 
Module.>

Repair or replace 
ECM connector.

6

ERASE MEMORY.
1) Connect all connectors.
2) Erase the memory.

Can the memory be erased?

Can be erased.

Go to step 7.

Replace VDCCM.  
<Ref. to VDC-8, 
VDC Control Mod-
ule (VDCCM).>

7

CHECK DIAGNOSTIC TROUBLE CODE.
1) Perform inspection mode.
2) Read out the diagnostic trouble code.

Is the same diagnostic trouble code as in 
the current diagnosis still being output?

Same DTC indicated.

Replace ECM. 
<Ref. to 
FU(H6DO)-46, 
Engine Control 
Module.>

A temporary poor 
contact.

Step

Value

Yes

No

VDC-97

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

MEMO:

VDC-98

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AI: DTC 49 ABNORMAL ENGINE SPEED SIGNAL

DIAGNOSIS:
• Engine speed signal line is broken or short circuited.
TROUBLE SYMPTOM:
• VDC does not operate.
WIRING DIAGRAM:

VDC00180

C9

A30

9

VDC

CONTROL

MODULE

F87

F87

56 57

59 60

62 63

65

82 83

80

27

28

25

26

23

24

21

22

19

20

17

18

15

16

13

14

11

12

9

10

7

8

5

6

3

4

1

2

54

55

52

53

50

51

81

48

49

46

47

44

45

78

79

76

77

75

42

43

40

41

74

72

73

70

71

39

37

38

35

36

69

67

68

66

33

34

61

64

31

32

29

30

58

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

H6

RH4

A10

A10

WO

O

O

LH4

ENGINE

CONTROL

MODULE

B134

B136

A:

:

C:

:

H4

H6

B136

C:

: H6

B134

A:

: H4

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

: 4 CYLINDER ENGINE RHD MODEL

: 4 CYLINDER ENGINE LHD MODEL

RH4

LH4

: 4 CYLINDER ENGINE

: 6 CYLINDER ENGINE

H4

H6

: RHD MODEL

: LHD MODEL

R

L

: WITHOUT OBD MODEL

: WITH OBD MODEL

OO

WO

1 2 3

4 5 6

7 8 9 10 11 12 13 14

F96

L

:

F96

R

:

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

10

R

3

L

F96

B255

VDC-99

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK TACHOMETER OPERATION IN 
COMBINATION METER.
Does tachometer operate normally?

Operates properly.

Go to step 2.

Repair tachome-
ter.

2

CHECK HARNESS BETWEEN VDCCM AND 
ECM.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM and 

ECM.

3) Measure resistance between VDCCM con-

nector and ECM.

Connector & terminal

H4 engine RHD without OBD model

(F87) No. 9 — (B134) No. 10:

H4 engine RHD with OBD model

(F87) No. 9 — (B134) No. 30:

H4 engine LHD model

(F87) No. 9 — (B134) No. 10:

H6 engine model

(F87) No. 9 — (B136) No. 9:

Is the measured value less than the speci-
fied value?

0.5 

Ω

Go to step 3.

Repair harness 
connector 
between VDCCM 
and ECM.

3

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between 
VDCCM and ECM?

There is poor contact.

Repair connector.

Go to step 4.

4

CHECK VDCCM.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the diagnostic trouble code.

Is the same diagnostic trouble code as in 
the current diagnosis still being output?

Same DTC indicated.

Replace VDCCM.  
<Ref. to VDC-8, 
VDC Control Mod-
ule (VDCCM).>

Go to step 5.

5

CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODES APPEARANCE.
Are other diagnostic trouble codes being out-
put?

Other DTC indicated.

Proceed with the 
diagnosis corre-
sponding to the 
diagnostic trouble 
code.

A temporary poor 
contact.