Subaru Legacy III (2000-2003 year). Manual - part 769

VDC-112

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

19

CHECK VDCCM MOTOR DRIVE TERMINAL.
1) Turn ignition switch OFF.
2) Remove VDC connector cover. <Ref. to 

VDC-19, REMOVE, VDCCM Connector 
Cover.>  

3) Connect all connectors.
4) Install motor relay and valve relay to relay 

box.

5) Operate the ABS check sequence.  <Ref. 

to VDC-16, ABS Sequence Control.>

6) Measure voltage between VDCCM connec-

tor terminals.

Connector & terminal

(F87) No. 22 (+) — No. 1 (

−−−−

):

Does the voltage drop from between 10 V 
and 13 V to less than 1.5 V, and rise to 
between 10 V and 13 V again when carry-
ing out the check sequence?

Drop from 10 — 13 V to less 
than 1.5 V, and rise to 10 — 13 
V again when carrying out the 
check sequence.

Go to step 20.

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

20

CHECK MOTOR OPERATION.
Operate the check sequence.  <Ref. to VDC-
19, VDC Sequence Control.>
Can motor revolution noise (buzz) be heard 
when carrying out the check sequence?

Noise heard

Go to step 21.

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

21

CHECK POOR CONTACT IN CONNECTORS.
Turn ignition switch to OFF.
Is there poor contact in connector between 
VDCH/U, relay box and VDCCM?

There is poor contact.

Repair connector.

Go to step 22.

22

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 23.

23

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.

Step

Value

Yes

No

VDC-113

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

MEMO:

VDC-114

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AL:DTC 71 ABNORMAL STEERING ANGLE SENSOR

DIAGNOSIS:
• Faulty steering angle sensor
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00178

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-115

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK THE STEERING WHEEL.
1) Drive the vehicle on a flat road.
2) Stop the vehicle in a straight line.
3) Check the angle of steering wheel.

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

5

°

Go to step 2.

Perform centering 
alignment of steer-
ing.

2

CHECK RUNNING FIELD.
Check if the vehicle was driven on banked 
road surfaces or sandy surfaces (not dirt road 
surfaces).
Was the vehicle driven on banked road sur-
faces or sandy surfaces (not dirt road sur-
faces)?

Driven

Driving on banked 
road surfaces or 
sandy surfaces 
(not dirt road sur-
faces) sometimes 
results in a 
VDCCM memory 
trouble code.

Go to step 3.

3

CHECK POWER SUPPLY OF STEERING AN-
GLE SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from steering angle 

sensor.

3) Turn ignition switch to ON.
4) Measure voltage between steering angle 

sensor and chassis ground.

Connector & terminal

(B231) No. 4 (

++++

) — Chassis ground (

−−−−

):

Is the measured value within the specified 
range?

10 — 15 V

Go to step 6.

Go to step 4.

4

CHECK OUTPUT VOLTAGE OF VDCCM.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Remove cover for VDCCM connector. 

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

4) Connect connector to VDCCM.
5) Turn ignition switch to ON.
6) Measure voltage between VDCCM and 

chassis ground.

Connector & terminal

(F87) No. 27 (

++++

) — Chassis ground (

−−−−

):

Is the measured value within the specified 
range?

10 — 15 V

Repair harness 
between yaw rate 
sensor and 
VDCCM.

Go to step 5.

5

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in yaw rate sensor con-
nector?

There is poor contact.

Repair or replace 
VDCCM connec-
tor.

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

6

CHECK GROUND CIRCUIT OF STEERING 
ANGLE SENSOR.
Measure resistance between steering sensor 
and chassis ground.

Connector & terminal

(B231) No. 3 — Chassis ground:

Is the measured value less than the specified 
value?

0.5 

Ω

Go to step 7.

Repair steering 
angle sensor 
ground harness.