Subaru Legacy III (2000-2003 year). Manual - part 795

VDC-216

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

7

CHECK BATTERY SHORT IN HARNESS BE-
TWEEN RELAY BOX AND VDCCM.
Measure voltage between VDCCM connector 
and chassis ground.

Connector & terminal

(F87) No. 10 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified 
value?

1 V

Go to step 8.

Repair harness 
between VDCCM 
and relay box.

8

CHECK BATTERY SHORT IN HARNESS BE-
TWEEN RELAY BOX AND VDCCM.
1) Turn ignition switch to ON.
2) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 10 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 9.

Repair harness 
between VDCCM 
and relay box.

9

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 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-217

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

MEMO:

VDC-218

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

AN:DTC 52 MOTOR AND MOTOR RELAY ON FAILURE

DIAGNOSIS:
• Faulty motor relay
• Faulty harness connector
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00155

VDC HYDRAULIC UNIT

87

87a

VDC2

VDC1

4

6

86

1

85

30

30

86

85

87

5

VDC4

F90

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

SBF HOLDER 50A

VDC7

VDC6

MOTOR RELAY

VALVE RELAY

VDC CONTROL MODULE

22

10

27

47

F87

1

VDC3

F89

2

SBF-1 100A

RELAY BOX

F89

VDC1

1 2

F90

VDC6

1

3

4 5 6

2

85

86

87

30

85 87a 86

87

30

VDC7

BATTERY

VDC-219

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

Step

Value

Yes

No

1

CHECK RESISTANCE OF MOTOR RELAY.
1) Turn ignition switch to OFF.
2) Remove motor relay from relay box.
3) Measure resistance between motor relay 

terminals.

Terminals

No. 85 — No. 86:

Is the measured value within the specified 
range?

70 — 90 

Ω

Go to step 2.

Replace motor 
relay.

2

CHECK CONTACT POINT OF MOTOR RE-
LAY.
1) Connect battery to motor relay terminals 

No. 85 and No. 86.

2) Measure resistance between motor relay 

terminals.

Terminals

No. 30 — No. 87:

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

0.5 

Ω

Go to step 3.

Replace motor 
relay.

3

CHECK SHORT OF MOTOR RELAY.
Measure resistance between motor relay ter-
minals.

Terminals

No. 85 — No. 30:
No. 85 — No. 87:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 4.

Replace motor 
relay.

4

CHECK INPUT VOLTAGE OF RELAY BOX.
1) Disconnect connector (F89) from relay box.
2) Disconnect connector from VDCCM.
3) Turn ignition switch to ON.
4) Measure voltage between relay box con-

nector and chassis ground.

Connector & terminal

(F89) No. 2 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified 
range?

10 — 15 V

Go to step 5.

Repair harness/
connector 
between battery 
and relay box, and 
check fuse SBF 
holder.

5

CHECK INPUT VOLTAGE OF MOTOR RE-
LAY.
1) Turn ignition switch to OFF.
2) Connect connector (F89) to relay box.
3) Turn ignition switch to ON.
4) Measure voltage between relay box and 

chassis ground.

Connector & terminal

(VDC7) No. 87 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified 
range?

10 — 15 V

Go to step 6.

Replace relay box.