Subaru Legacy III (2000-2003 year). Service manual — part 762

VDC-84

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AE:DTC 45 CONTROL MODULE OUT OF SPECIFICATION

DIAGNOSIS:
• Control module out of specification
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.

Step

Value

Yes

No

1

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

Same DTC indicated.

Go to step 2.

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

2

CHECK VDCCM SPECIFICATIONS.
Check the VDCCM identification mark.

VDCCM identification mark

H4 engine model

K

OUTBACK H4 enigne model

M

OUTBACK H6 enigne model

N

H4 enigne model for Australia

J

H6 enigne model for Australia OUT-
BACK

Y

Does the VDCCM identification mark agree
with the vehicle specifications?

Agree.

Go to step 3.

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

3

CHECK TCM SPECIFICATIONS.
Check the TCM identification mark.

TCM identification mark

LHD H4 engine model

YZ

RHD H4 engine model

ZG

LHD OUTBACK H4 enigne model

ZB

RHD OUTBACK H4 enigne model

ZJ

LHD OUTBACK H6 enigne model

ZD

RHD OUTBACK H6 enigne model

ZL

Does the TCM identification mark agree with
the vehicle specifications?

Agree.

Go to step 4.

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

4

CHECK TCM.
1) Replace TCM. <Ref. to AT-76, Transmis-

sion Control Module (TCM).>

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.

Go to step 5.

The original TCM
has been faulty.

VDC-85

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

5

CHECK VDCCM.
1) Install original TCM.
2) Replace VDCCM. <Ref. to VDC-8, VDC

Control Module (VDCCM).>

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.

Go to step 6.

The original
VDCCM has been
faulty.

6

CHECK VDCCM.
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).>

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

Step

Value

Yes

No

VDC-86

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AF:DTC 46 ABNORMAL VOLTAGE OF 5 V POWER SUPPLY

DIAGNOSIS:
• 5 volt power supply is abnormal.
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00177

VDC CONTROL MODULE

63

70

64

76

77

78

15

13

16

36

14

5

3

6

10

12

9

F87

YAW RATE AND

LATERAL G SENSOR

F55

R49

R100

VDC HYDRAULIC UNIT

F91

VDC5

PRIMAR

Y

PRESSURE SENSOR

SECOND

AR

Y

PRESSURE SENSOR

F55

1 2 3

4 5

6 7 8 9 10 11 12

F91

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

R100

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

3

4 5 6

2

VDC-87

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK GROUND SHORT OF SENSOR AND
HARNESS.
1) Turn ignition switch OFF.
2) Disconnect connector from VDCCM.
3) Measure resistance between VDCCM con-

nector and chassis ground.

Connector & terminal

(F87) No. 63 — Chassis ground (Lateral
G sensor):
(F87) No. 78 — Chassis ground (Pres-
sure sensor):

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 3.

Go to step 2.

2

CHECK GROUND SHORT OF HARNESS.
1) Disconnect connector from faulty sensors.
2) Measure resistance between VDCCM and

chassis ground.

Connector & terminal

(F87) No. 63 — Chassis ground (Lateral
G sensor):
(F87) No. 78 — Chassis ground (Pres-
sure sensor):

Does the measured value exceed the spec-
ified value?

1 M

Ω

Replace faulty
sensors.

Repair or replace
harness connec-
tor between
VDCCM and faulty
sensor.

3

CHECK BATTERY SHORT OF SENSOR AND
HARNESS.
Measure voltage between VDCCM and chas-
sis ground.

Connector & terminal

(F87) No. 63 (+) — Chassis ground (

−−−−

)

(Lateral G sensor):
(F87) No. 78 (+) — Chassis ground (

−−−−

)

(Pressure sensor):

Is the measured value less than the specified
value?

0.5 V

Go to step 4.

Go to step 5.

4

CHECK BATTERY SHORT OF SENSOR AND
HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 63 (+) — Chassis ground (

−−−−

)

(Lateral G sensor):
(F87) No. 78 (+) — Chassis ground (

−−−−

)

(Pressure sensor):

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

0.5 V

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

Go to step 5.

5

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from faulty sensors.
3) Measure voltage between VDCCM and

chassis ground.

Connector & terminal

(F87) No. 63 (+) — Chassis ground (

−−−−

)

(Lateral G sensor):
(F87) No. 78 (+) — Chassis ground (

−−−−

)

(Pressure sensor):

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

0.5 V

Go to step 6.

Repair or replace
harness connec-
tor between
VDCCM and faulty
sensor.