Subaru Legacy III (2000-2003 year). Manual — part 799

VDC-232

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

AR:DTC 71 STEERING ANGLE SENSOR MALFUNCTION

DIAGNOSIS:
• Faulty steering angle sensor
TROUBLE SYMPTOM:
• 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-233

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

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 OUTPUT OF STEERING ANGLE
SENSOR USING SELECT MONITOR.
1) Select “Current data display & Save” on the

select monitor.

2) Read steering angle sensor output on the

select monitor display.
Does the steering angle sensor output
(value) change on the monitor display when
the steering wheel is turned in either direc-
tion?

Change

Go to step 3.

Replace steering
angle sensor.

3

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 4.

4

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 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.

VDC-234

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

AS:DTC 71 NO SIGNAL FROM 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-235

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

Step

Value

Yes

No

1

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 4.

Go to step 2.

2

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, VDC Sequence Control.>

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 3.

3

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).>

4

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 5.

Repair steering
angle sensor
ground harness.

5

CHECK HARNESS OF STEERING ANGLE
SENSOR.
1) Connect connector to steering angle sen-

sor.

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

nector terminals.

Connector & terminal

(F87) No. 81 — No. 83:

Is the measured value within the specified
range?

114 — 126

Ω

Repair harness
between steering
angle sensor and
VDCCM.

Go to step 6.

6

CHECK STEERING ANGLE SENSOR.
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.

Go to step 8.

Go to step 7.