Subaru Legacy III (2000-2003 year). Manual - part 759

VDC-72

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

4

CHECK BATTERY SHORT OF SOLENOID 
VALVE.
1) Turn ignition switch to ON.
2) Measure voltage between VDCH/U con-

nector and chassis ground.

Connector & terminal

DTC 32/(VDC5) No. 1 (+) — Chassis 
ground (

−−−−

):

DTC 34/(VDC5) No. 4 (+) — Chassis 
ground (

−−−−

):

DTC 36/(VDC5) No. 3 (+) — Chassis 
ground (

−−−−

):

DTC 38/(VDC5) No. 2 (+) — Chassis 
ground (

−−−−

):

DTC 63/(VDC5) No. 10 (+) — Chassis 
ground (

−−−−

):

DTC 64/(VDC5) No. 11 (+) — Chassis 
ground (

−−−−

):

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

1 V

Go to step 5.

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

5

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

DTC 32/(F87) No. 3 (+) — Chassis 
ground (

−−−−

):

DTC 34/(F87) No. 51 (+) — Chassis 
ground (

−−−−

):

DTC 36/(F87) No. 50 (+) — Chassis 
ground (

−−−−

):

DTC 38/(F87) No. 4 (+) — Chassis 
ground (

−−−−

):

DTC 63/(F87) No. 29 (+) — Chassis 
ground (

−−−−

):

DTC 64/(F87) No. 2 (+) — Chassis 
ground (

−−−−

):

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

1 V

Go to step 6.

Repair harness 
between VDCCM 
and VDCH/U.

6

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

tor and chassis ground.

Connector & terminal

DTC 32/(F87) No. 3 (+) — Chassis 
ground (

−−−−

):

DTC 34/(F87) No. 51 (+) — Chassis 
ground (

−−−−

):

DTC 36/(F87) No. 50 (+) — Chassis 
ground (

−−−−

):

DTC 38/(F87) No. 4 (+) — Chassis 
ground (

−−−−

):

DTC 63/(F87) No. 29 (+) — Chassis 
ground (

−−−−

):

DTC 64/(F87) No. 2 (+) — Chassis 
ground (

−−−−

):

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

1 V

Go to step 7.

Repair harness 
between VDCCM 
and VDCH/U.

Step

Value

Yes

No

VDC-73

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

7

CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Measure resistance between VDCCM con-

nector and chassis ground.

Connector & terminal

DTC 32/(F87) No. 3 — Chassis ground:
DTC 34/(F87) No. 51 — Chassis ground:
DTC 36/(F87) No. 50 — Chassis ground:
DTC 38/(F87) No. 4 — Chassis ground:
DTC 63/(F87) No. 29 — Chassis ground:
DTC 64/(F87) No. 2 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 8.

Repair harness 
between VDCCM 
and VDCH/U.

8

CHECK HARNESS/CONNECTOR BETWEEN 
VDCCM AND VDCH/U.
1) Connect connector (F91) to VDCH/U.
2) Measure resistance between VDCCM con-

nector and VDCH/U connector.

Connector & terminal

DTC 32/(F87) No. 3 — (VDC2) No. 1:
DTC 34/(F87) No. 51 — (VDC2) No. 1:
DTC 36/(F87) No. 50 — (VDC2) No. 1:
DTC 38/(F87) No. 4 — (VDC2) No. 1:
DTC 63/(F87) No. 29 — (VDC2) No. 1:
DTC 64/(F87) No. 2 — (VDC2) No. 1:

Is the measured value within the specified 
range?

3 — 6 

Ω

Go to step 9.

Repair harness/
connector 
between VDCCM 
and VDCH/U.

9

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between 
VDCCM and VDCH/U?

There is poor contact.

Repair connector.

Go to step 10.

10

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 11.

11

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-74

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

AA:DTC 41 ABNORMAL VDC CONTROL MODULE

DIAGNOSIS:
• Faulty VDCCM
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00143

VDC

CONTROL

MODULE

1

55

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-75

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK GROUND CIRCUIT OF VDCCM.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Measure resistance 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?

0.5 

Ω

Go to step 2.

Repair VDCCM 
ground harness.

2

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between 
battery, ignition switch and VDCCM?

There is poor contact.

Repair connector.

Go to step 3.

3

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

Tightened securely.

Go to step 4.

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

4

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

Installed properly.

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

Go to step 5.

5

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 6.

6

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.