Subaru Legacy III (2000-2003 year). Manual — part 771

VDC-120

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

7

CHECK GROUND CIRCUIT OF YAW RATE
AND LATERAL G SENSOR.
Measure resistance between yaw rate and lat-
eral G sensor and chassis ground.

Connector & terminal

(R100) No. 6 — Chassis ground:

Is the measured value less than the specified
value?

0.5

Ω

Go to step 10.

Go to step 8.

8

CHECK GROUND CIRCUIT OF VDCCM.
1) Disconnect connector from VDCCM.
2) Remove cover from VDCCM connector.

<Ref. to VDC-19, REMOVE, VDCCM Con-
nector Cover.>

3) Connect connector to VDCCM.
4) Measure resistance between VDCCM con-

nector and chassis ground.

Connector & terminal

(F87) No. 64 — Chassis ground:

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

0.5

Ω

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.

Go to step 9.

9

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

There is poor contact.

Repair or replace
VDCCM connec-
tor.

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

10

CHECK HARNESS OF YAW RATE AND LAT-
ERAL G SENSOR.
1) Disconnect connector from VDCCM.
2) Measure resistance between VDCCM and

yaw rate and lateral G sensor.

Connector & terminal

(F87) No. 65 — (R100) No. 4:
(F87) No. 66 — (R100) No. 1:
(F87) No. 67 — (R100) No. 2:

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

0.5

Ω

Go to step 11.

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.

11

CHECK GROUND SHORT OF HARNESS.
Measure resistance between VDCCM connec-
tor and chassis ground.

Connector & terminal

(F87) No. 65 — Chassis ground:
(F87) No. 66 — Chassis ground:
(F87) No. 67 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 12.

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.

12

CHECK BATTERY SHORT OF HARNESS.
Measure voltage between VDCCM connector
and chassis ground.

Connector & terminal

(F87) No. 65 (+) — Chassis ground (

−−−−

):

(F87) No. 66 (+) — Chassis ground (

−−−−

):

(F87) No. 67 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified
value?

0.5 V

Go to step 13.

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.

Step

Value

Yes

No

VDC-121

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

13

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between VDCCM and

chassis ground.

Connector & terminal

(F87) No. 65 (+) — Chassis ground (

−−−−

):

(F87) No. 66 (+) — Chassis ground (

−−−−

):

(F87) No. 67 (+) — Chassis ground (

−−−−

):

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

0.5 V

Go to step 14.

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.

14

CHECK YAW RATE AND LATERAL G SEN-
SOR.
1) Turn ignition switch to OFF.
2) Install yaw rate and lateral G sensor to

body.

3) Connect all connectors.
4) Turn ignition switch to ON.
5) Measure voltage between VDCCM connec-

tor terminals.

Connector & terminal

(F87) No. 66 (+) — No. 64 (

−−−−

):

Is the measured value within the specified
range?

2.1 — 2.9 V

Go to step 15.

Replace yaw rate
and lateral G sen-
sor. <Ref. to VDC-
22, Yaw Rate and
Lateral G Sensor.>

15

CHECK YAW RATE AND LATERAL G SEN-
SOR.
1) Turn ignition switch to ON.
2) Check oscilloscope signal pattern between

VDCCM connector terminals.<Ref. to VDC-
17, WAVEFORM, MEASUREMENT, Con-
trol Module I/O Signal.>

Connector & terminal

(F87) No. 67 (+) — No. 64 (

−−−−

):

Is the oscilloscope pattern the same as
shown in the figure?

Same pattern.

Go to step 16.

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

16

CHECK YAW RATE SENSOR.
Check oscilloscope pattern between yaw rate
and lateral G sensor terminals.<Ref. to VDC-
17, WAVEFORM, MEASUREMENT, Control
Module I/O Signal.>

Connector & terminal

(F87) No. 65 (+) — No. 64 (

−−−−

):

Is the oscilloscope pattern the same as shown
in the figure?

Same pattern.

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

Replace yaw rate
and lateral G sen-
sor. <Ref. to VDC-
8, VDC Control
Module
(VDCCM).>

Step

Value

Yes

No

VDC-122

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AN:DTC 73 ABNORMAL LATERAL G SENSOR

DIAGNOSIS:
• Faulty lateral G sensor
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00182

65

63

67

66

70

64

10

11

9

F88

F55

R49

4

3

12

2

4

5

8

1

5

6

R100

6

F88

R100

F55

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

F87

VDC

CONTROL

MODULE

YAW RATE

AND LATERAL G

SENSOR

1

3

4 5 6

2

1 2 3

4 5

6 7 8 9 10 11 12

3

1

3

4 5 6

2

VDC-123

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK INSTALLATION OF LATERAL G
SENSOR.
Check installation of lateral G sensor.
Is the yaw rate and lateral G sensor fixed
securely?

Fixed securely.

Go to step 2.

Install yaw rate
and lateral G sen-
sor securely.

2

CHECK INPUT VOLTAGE OF G SENSOR.
1) Turn ignition switch to OFF.
2) Remove console box.
3) Disconnect connector from yaw rate and

lateral G sensor.

4) Turn ignition switch to ON.
5) Measure voltage between yaw rate and lat-

eral G sensor connector terminals.

Connector & terminal

(R100) No. 3 (+) — No. 6 (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Go to step 3.

Repair harness/
connector
between yaw rate
and lateral G sen-
sor and VDCCM.

3

CHECK YAW RATE AND LATERAL G SEN-
SOR.
1) Turn ignition switch to OFF.
2) Measure resistance between yaw rate and

lateral G sensor terminals.

Terminals

No. 3 — No. 5:

Is the measured value within the specified
range?

4.3 — 4.9 k

Ω

Go to step 4.

Replace yaw rate
and lateral G sen-
sor. <Ref. to VDC-
22, Yaw Rate and
Lateral G Sensor.>

4

CHECK OPEN CIRCUIT IN YAW RATE AND
LATERAL G SENSOR OUTPUT HARNESS
AND GROUND HARNESS.
1) Connect connector to yaw rate and lateral

G sensor.

2) Disconnect connector from VDCCM.
3) Measure resistance between VDCCM con-

nector terminals.

Connector & terminal

(F87) No. 63 — No. 70:

Is the measured value within the specified
range?

4.3 — 4.9 k

Ω

Go to step 5.

Repair harness/
connector
between yaw rate
and lateral G sen-
sor and VDCCM.

5

CHECK GROUND SHORT IN YAW RATE
AND LATERAL G SENSOR HARNESS.
1) Disconnect connector from yaw rate and

lateral G sensor.

2) Measure resistance between VDCCM con-

nector and chassis ground.

Connector & terminal

(F87) No. 63 — Chassis ground:
(F87) No. 70 — Chassis ground:
(F87) No. 64 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 6.

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.

6

CHECK BATTERY SHORT OF HARNESS.
Measure voltage between VDCCM connector
and chassis ground.

Connector & terminal

(F87) No. 63 (+) — Chassis ground (

−−−−

):

(F87) No. 70 (+) — Chassis ground (

−−−−

):

(F87) No. 64 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified
value?

1 V

Go to step 7.

Repair harness
between yaw rate
and lateral G sen-
sor and VDCCM.