Subaru Legacy III (2000-2003 year). Manual — part 761

VDC-80

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

5

CHECK HARNESS/CONNECTOR BETWEEN
VDCCM AND ECM.
1) Turn ignition switch to OFF.
2) Connect connector to ECM.
3) Turn ignition switch to ON.
4) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 21 (+) — Chassis ground (

−−−−

):

(F87) No. 43 (+) — Chassis ground (

−−−−

):

(F87) No. 8 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Go to step 6.

Go to step 9.

6

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

There is poor contact.

Repair connector.

Go to step 7.

7

CHECK VDCCM.
1) Turn ignition switch to OFF.
2) Connect all connectors.
3) Erase the memory.
4) Perform inspection mode.
5) 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 8.

8

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.

9

CHECK ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM connector

terminal and chassis ground.

Connector & terminal

H4 engine RHD without OBD model

(B136) No. 7 (+) — Chassis ground (

−−−−

):

(B136) No. 8 (+) — Chassis ground (

−−−−

):

(B136) No. 2 (+) — Chassis ground (

−−−−

):

H4 engine RHD with OBD model

(B135) No. 6 (+) — Chassis ground (

−−−−

):

(B135) No. 5 (+) — Chassis ground (

−−−−

):

(B135) No. 18 (+) — Chassis ground (

−−−−

):

H4 engine LHD model

(B136) No. 7 (+) — Chassis ground (

−−−−

):

(B136) No. 8 (+) — Chassis ground (

−−−−

):

(B136) No. 2 (+) — Chassis ground (

−−−−

):

H6 engine model

(B134) No. 12 (+) — Chassis ground (

−−−−

):
(B134) No. 4 (+) — Chassis ground (

−−−−

):

(B134) No. 11 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Repair harness/
connector
between ECM and
VDCCM.

Go to step 10.

10

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connector ECM?

There is poor contact.

Repair connector.

Go to step 11.

Step

Value

Yes

No

VDC-81

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

11

CHECK ENGINE.
Is the engine functioning normally?

Operates properly.

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

Repair engine.

Step

Value

Yes

No

VDC-82

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AD:DTC 44 A COMMUNICATION WITH AT CONTROL ABNORMAL

DIAGNOSIS:
• Communication with AT control faults
TROUBLE SYMPTOM:
• VDC does not operate.
WIRING DIAGRAM:

VDC00176

B234

STEERING ANGLE SENSOR

9

18

4

2

1

3

2
3
1
5
6
4

81

27

83

1

15

R

2

5

9

L

6

B231

VDC

CONTROL

MODULE

F96

B225

F87

B56

1 2

7

8

9

5 6

3 4

10 11 12
19 20 21

13

14 15

16

17

18

22

23

24

B231

1 2 3 4

B234

1 2 3 4 5 6

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

B56

TCM

1 2 3

4 5 6

7 8 9 10 11 12 13 14

F96

L

:

F96

R

:

R

L

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

: RHD MODEL

: LHD MODEL

VDC-83

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK RESISTANCE OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect two connectors from TCM.
3) Measure resistance between TCM connec-

tor terminals.

Connector & terminal

(B56) No. 9 — No. 18:

Is the measured value within the specified
range?

57 — 63

Ω

Go to step 2.

Repair harness
between TCM and
VDCCM.

2

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in TCM connectors?

There is poor contact.

Repair connector.

Go to step 3.

3

CHECK TCM.
1) Turn ignition switch to OFF.
2) Connect all connectors.
3) Erase the memory.
4) Perform inspection mode.
5) Read out the diagnostic trouble code.

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

Same DTC indicated.

Replace TCM.
<Ref. to AT-76,
Transmission Con-
trol Module
(TCM).>

Go to step 4.

4

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.