Subaru Legacy III (2000-2003 year). Manual - part 777

VDC-144

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

20

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

There is poor contact.

Repair connector.

Go to step 21.

21

CHECK SOURCES OF SIGNAL NOISE.
Is the car telephone or the wireless transmitter 
properly installed?

Installed properly.

Go to step 22.

Properly install the 
car telephone or 
the wireless trans-
mitter.

22

CHECK SOURCES OF SIGNAL NOISE.
Are noise sources (such as an antenna) 
installed near the sensor harness?

Installed.

Install the noise 
sources apart from 
the sensor har-
ness.

Go to step 23.

23

CHECK SHIELD CIRCUIT.
1) Connect all connectors.
2) Measure resistance between shield con-

nector and chassis ground.

Connector & terminal

DTC 22 / (F45) No. 10 — Chassis 
ground:
DTC 22 / (F2) No. 17 — Chassis ground:
DTC 24 / (F45) No. 10 — Chassis 
ground:
DTC 24 / (F2) No. 17 — Chassis ground:

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

NOTE:

For the DTC 26 and 28, Go to step 25.

0.5 

Ω

Go to step 24.

Repair shield har-
ness.

24

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 pattern.

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

Go to step 25.

25

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 noise 
interference.

Step

Value

Yes

No

VDC-145

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

MEMO:

VDC-146

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

J: DTC 29 ANY ONE OF FOUR ABS SENSOR SIGNAL

DIAGNOSIS:
• Faulty ABS sensor signal (noise, irregular signal, etc.)
• Faulty tone wheel
• Wheels turning freely for a long time
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00174

F55

F88

B15

B6

2 1

R72

R73

F45

F2

1

2

2

1

7

6

2

1

4
1
3

F88

17

15

12

13

16

14

R

10

L

F45

B62

:

:

F2

B100

:

:

F55

R49

B15

R73

49

19

17

16

14

15

1

55

46

18

1

2

B6

2

1

R72

8

9

11

12

13

VDC CONTROL MODULE

FRONT ABS
SENSOR LH

FRONT ABS

SENSOR RH

LHD

RHD

REAR ABS

SENSOR LH

REAR ABS

SENSOR RH

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

: RHD MODEL 

:LHD MODEL

R

R

R

L

L

L

1

3

4 5 6

2

1 2

3 4 5

6 7 8 9 10 11 12

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16

3 4

1 2

8 9 10 11

12 13 14 15 16 17 18 19 20 21 22 23 24

5 6

7

VDC-147

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

Step

Value

Yes

No

1

CHECK IF THE WHEELS HAVE TURNED 
FREELY.
Check if the wheels have been turned freely for 
more than one minute, such as when the vehi-
cle is jacked-up, under full-lock cornering or 
when tire is not in contact with road surface.

Turned freely over 1 minutes.

The VDC is nor-
mal. Erase the 
diagnostic trouble 
code.

NOTE:
When the wheels
turn freely for a
long time, such as
when the vehicle is
towed or jacked-
up, or under full-
lock cornering
locked in full, this
trouble code may
sometimes occur.

Go to step 2.

2

CHECK TIRE SPECIFICATIONS.
Are the tire specifications correct?

Turned freely over 1 minutes.

Go to step 3.

Replace tire.

3

CHECK WEAR OF TIRE.
Is the tire worn excessively?

Worn excesiblely.

Replace tire.

Go to step 4.

4

CHECK TIRE PRESSURE.
Is the tire pressure correct?

Correct tire pressure.

Go to step 5.

Adjust tire pres-
sure.

5

CHECK INSTALLATION OF ABS SENSOR.

Tightening torque:

33

±±±±

10 N·m (3.3

±±±±

1.0 kgf-m, 24

±±±±

7 ft-lb)

Are the ABS sensor installation bolts tightened 
securely?

Tightened securely.

Go to step 6.

Tighten ABS sen-
sor installation 
bolts securely.

6

CHECK ABS SENSOR GAP.
Measure tone wheel to pole piece gap over 
entire perimeter of the wheel.
Is the measured value within the specified 
range?

Front wheel 0.3 - 0.8 mm 
(0.012 - 0.031 in) and Rear 
wheel 0.44 - 0.94 mm (0.0173 - 
0.0370 in)

Go to step 7.

Adjust the gap.

NOTE:
Adjust the gap us-
ing spacer (Part
No. 26755AA000).
If spacers cannot
correct the gap, re-
place worn sensor
or worn tone
wheel.

7

CHECK OSCILLOSCOPE.
Is an oscilloscope available?

Available

Go to step 8.

Go to step 9.

8

CHECK ABS SENSOR SIGNAL.
1) Raise all four wheels of ground.
2) Turn ignition switch OFF.
3) Remove VDCCM connector cover. <Ref. to 

VDC-19, REMOVE, VDCCM Connector 
Cover.>

4) Connect the oscilloscope to the connector.
5) Turn ignition switch ON.
6) Rotate wheels and measure voltage at 

specified frequency.  <Ref. to ABS-15, 
WAVEFORM, Control Module I/O Signal.>

NOTE:

When this inspection is completed, the VDCCM
sometimes stores the DTC 29.

Connector & terminal

(F49) No. 14 (+) — No. 15 (

−−−−

) (Front RH):

(F49) No. 49 (+) — No. 19 (

−−−−

) (Front LH):

(F49) No. 18 (+) — No. 46 (

−−−−

) (Rear RH):

(F49) No. 16 (+) — No. 17 (

−−−−

) (Rear LH):

Is oscilloscope pattern smooth, as shown in 
figure?

Smooth pattern.

Go to step 12.

Go to step 9.