Subaru Legacy III (2000-2003 year). Manual - part 774

VDC-132

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

8

CHECK OUTPUT SIGNAL FOR VDCCM.
1) Turn ignition switch to ON.
2) Measure voltage between data link connec-

tor and chassis ground.

Connector & terminal

(B40) No. 5 (

++++

) — Chassis ground (

−−−−

):

(B40) No. 4 (

++++

) — Chassis ground (

−−−−

):

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

1 V

Repair harness 
and connector 
between each 
control module 
and data link con-
nector.

Go to step 9.

9

CHECK HARNESS/CONNECTOR BETWEEN 
VDCCM AND DATA LINK CONNECTOR.
Measure resistance between VDCCM connec-
tor and data link connector. 

Connector & terminal

(F87) No. 11 — (B40) No. 5: 
(F87) No. 38 — (B40) No. 4: 

Does the measured value exceed the specified 
value?

0.5 

Ω

Repair harness 
and connector 
between VDCCM 
and data link con-
nector.

Go to step 10.

10

CHECK INSTALLATION OF VDCCM CON-
NECTOR.
Turn ignition switch to OFF.
Is VDCCM connector inserted into VDCCM 
until the clamp locks onto it?

VDCCM connector is con-
nected and the clamp is 
locked.

Go to step 11.

Insert VDCCM 
connector into 
VDCCM until the 
clamp locks onto 
it.

11

CHECK POWER SUPPLY CIRCUIT.
1) Turn ignition switch to ON (engine OFF).
2) Measure ignition power supply voltage 

between VDCCM connector and chassis 
ground.

Connector & terminal

(F87) No. 28 (+) — Chassis ground (

−−−−

):

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

10 V

Go to step 12.

Repair open circuit 
in harness 
between VDCCM 
and battery.

12

CHECK HARNESS CONNECTOR BETWEEN 
VDCCM AND CHASSIS GROUND.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM and 

transmission.

3) Measure resistance of harness between 

VDCCM and chassis ground.

Connector & terminal

(F87) No. 1 — Chassis ground:
(F87) No. 55 — Chassis ground:

Is the measured value less than the speci-
fied value?
Does the measured value exceed the spec-
ified value?

1 

Ω

Go to step 13.

Repair open circuit 
in harness 
between VDCCM 
and inhibitor side 
connector, and 
poor contact in 
coupling connec-
tor.

13

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in control module power 
supply, ground line and data link connector?

There is poor contact.

Repair connector.

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

Step

Value

Yes

No

VDC-133

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

B: DTC 21 FRONT RIGHT ABS SENSOR CIRCUIT OPEN OR SHORTED BAT-

TERY

NOTE:
For diagnostic procedure, refer to DTC 27. <Ref. to VDC-134, DTC 27 REAR LEFT ABS SENSOR CIRCUIT
OPEN OR SHORTED BATTERY, Diagnostics Chart with Select Monitor.>  

C: DTC 23 FRONT LEFT ABS SENSOR CIRCUIT OPEN OR SHORTED BAT-

TERY

NOTE:
For diagnostic procedure, refer to DTC 27. <Ref. to VDC-134, DTC 27 REAR LEFT ABS SENSOR CIRCUIT
OPEN OR SHORTED BATTERY, Diagnostics Chart with Select Monitor.>  

D: DTC 25 REAR RIGHT ABS SENSOR CIRCUIT OPEN OR SHORTED BAT-

TERY

NOTE:
For diagnostic procedure, refer to DTC 27. <Ref. to VDC-134, DTC 27 REAR LEFT ABS SENSOR CIRCUIT
OPEN OR SHORTED BATTERY, Diagnostics Chart with Select Monitor.>  

VDC-134

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

E: DTC 27 REAR LEFT ABS SENSOR CIRCUIT OPEN OR SHORTED BATTERY

DIAGNOSIS:
• Faulty ABS sensor (Broken wire, input voltage too high)
• Faulty harness connector
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-135

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

Step

Value

Yes

No

1

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

select monitor.

2) Read the ABS sensor output corresponding 

to the faulty system in the select monitor 
data display mode.
Does the speed indicated on the display 
change in response to the speedometer 
reading during acceleration/deceleration 
when the steering wheel is in the straight-
ahead position?

Change

Go to step 2.

Go to step 9.

2

CHECK INSTALLATION OF ABS SENSOR.
Are the ABS sensor installation bolts tightened 
securely?

Tightening torque:

33

±±±±

10 N·m (3.3

±±±±

1.0 kgf-m, 24

±±±±

7 ft-lb)

Tightened securely.

Go to step 3.

Tighten ABS sen-
sor installation 
bolts securely.

3

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 4.

Adjust the gap.

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

4

CHECK TONE WHEEL RUNOUT.
Measure tone wheel runout.
Is the measured value less than the specified 
value?

0.05 mm (0.0020 in)

Go to step 5.

Repair tone wheel. 
Front  <Ref. to 
VDC-29, Front 
Tone Wheel.> 
Rear  <Ref. to 
VDC-30, Rear 
Tone Wheel.>

5

CHECK POOR CONTACT IN CONNECTORS.
Turn ignition switch to OFF.
Is there poor contact in connectors between 
VDCCM and ABS sensor?

There is poor contact.

Repair connector.

Go to step 6.

6

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 7.

7

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.

NOTE:
Check harness
and connectors
between VDCCM
and ABS sensor.