Subaru Legacy III (2000-2003 year). Service manual — part 750

VDC-36

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK IF OTHER WARNING LIGHTS TURN
ON.
Turn ignition switch to ON (engine OFF).
Do other warning lights turn on?

Warning lights turn on.

Go to step 2.

Repair combina-
tion meter. <Ref.
to IDI-14, Combi-
nation Meter
Assembly.>

2

CHECK LIGHT BULB.
1) Turn ignition switch to OFF.
2) Remove combination meter.
3) Remove ABS warning light bulb, VDC

warning light bulb, VDC operating indicator
light bulb or VDC OFF indicator light bulb
from combination meter.
Is light bulb OK?

OK.

Go to step 3.

Replace faulty
light bulb. <Ref. to
IDI-15, DISAS-
SEMBLY, Combi-
nation Meter
Assembly.>

3

CHECK BATTERY SHORT OF LIGHT HAR-
NESS.
1) Disconnect VDCCM connector from

VDCCM.

2) Place a sheet of thick paper [thickness 1.5

mm (0.059 in)] in switch area of VDCCM
connector.

3) Turn ignition switch to ON.
4) Measure voltage between VDC connector

and chassis ground.

Connector & terminal

ABS warning light

(F87) No. 54 (+) — Chassis ground (

−−−−

):

VDC warning light

(F87) No. 53 (+) — Chassis ground (

−−−−

):

VDC operating indicator light

(F87) No. 32 (+) — Chassis ground (

−−−−

):

VDC OFF indicator light

(F87) No. 52 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

3 V

Go to step 4.

Repair light har-
ness.

4

CHECK WIRING HARNESS.
1) Turn ignition switch to OFF.
2) Install ABS warning light bulb from combi-

nation meter.

3) Install combination meter.
4) Place a sheet of thick paper [thickness 1.5

mm (0.059 in)] in switch area of VDCCM
connector.

5) Turn ignition switch to ON.
6) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

ABS warning light

(F87) No. 54 (+) — Chassis ground (

−−−−

):

VDC warning light

(F87) No. 53 (+) — Chassis ground (

−−−−

):

VDC operating indicator light

(F87) No. 32 (+) — Chassis ground (

−−−−

):

VDC OFF indicator light

(F87) No. 52 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Go to step 5.

Repair wiring har-
ness.

5

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

There is poor contact.

Repair connector.

Go to step 6.

VDC-37

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

6

CHECK WARNING AND INDICATOR
LIGHTS.
1) Connect connector to VDCCM.
2) Turn ignition switch to ON.

Do ABS warning light, VDC warning light,
VDC operating indicator light and VDC OFF
indicator light turn on?

Turn(s) on.

A temporary poor
contact.

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

Step

Value

Yes

No

VDC-38

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

B: ABS AND VDC WARNING LIGHTS DO NOT GO OFF.

DIAGNOSIS:
• ABS warning light circuit is open or shorted.
• VDC warning light circuit is open or shorted.
• Diagnosis circuit is open.
TROUBLE SYMPTOM:
• When starting the engine and while ABS and/or VDC warning light is kept ON.
WIRING DIAGRAM:
• 3.0 L model

VDC00173

NO. 18 15A

SBF-4

DIAGNOSIS
TERMINAL

b5

a8

c7

L

b9

b3

c9

VDC W

ARNING

LIGHT

VDC

OPERA

TING

b2

R

c10

c6

b1

VDC OFF

ABS

W

ARNING

G1

E1

F1

H1

18

12

11

13

20

5

R

L

13

R

L

14

7

4

16

10

54

32

52

53

13

40

55

1

28

SBF-1 100A

NO. 5 15A

8

DIAGNOSIS
CONNECTOR

VDC OFF
SWITCH

VDC CONTROL MODULE

i1

B36

B81

B82

F87

i10

1 2 3 4 5 6 7

8 9 10 11 12 13 14

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

B82

1 2

3

4 5 6 7 8

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

B36

B4 B5 B6

A4 A5 A6

C5 C6

F6

D4 D5 D6

F1

H1

C4

G6

G1

C2

K1

M1 M2

K6

L1

D1 D2

A1 A2
B1 B2

I6

J6

L2

I1

J1

H6

M4 M5 M6

L4 L5 L6

N5 N6

O4 O5 O6

N4

P4 P5

N2

O1 O2

P1 P2

N3

O3

P3

P6

A3

B3

C3

E4 E5 E6

E1 E2

i10

a:

i11

b:

i12

B255

F96

c:

COMBINATION
METER

BATTERY

IGNITION

SWITCH

IGNITION

RELAY

i62

i61

i60

i1

B36

: LHD MODEL

: RHD MODEL

L

R

3
5

6

16

J1

i62

1

2

3 4 5 6

i12

1 2 3

8

9 10

4

11 12 13

14 15 16

5 6 7

17 18

i11

1 2 3
8 9 10

4

11 12 13 14 15 16

5 6 7

RHD

RHD

LHD

LHD

RHD

LHD

LHD

RHD

B62

L

:

B100

R

:

F45

L

:

F2

R

:

F2

i60

R

:

F96

R

:

F45

L

:

F96

L

:

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

1 2 3

4 5 6

7 8 9 10 11 12 13 14

1 2 3

8

9 10

4

11 12 13 14 15 16

5 6 7

17 18

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

VDC-39

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

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 2.

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

2

CHECK DIAGNOSIS TERMINAL.
Measure resistance between diagnosis termi-
nals (B81) and chassis ground.

Terminals

Diagnosis terminal (A) — Chassis
ground:
Diagnosis terminal (B) — Chassis
ground:

Is the measured value less than the specified
value?

0.5

Ω

Go to step 3.

Repair diagnosis
terminal harness.

3

CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal (B81) to diag-

nosis connector (B82) No. 8.

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

nector and chassis ground.

Connector & terminal

(F87) No. 13 — Chassis ground:

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

0.5

Ω

Go to step 4.

Repair harness
connector
between VDCCM
and diagnosis con-
nector.

4

CHECK WIRING HARNESS.
1) Place a sheet of thick paper [thickness 1.5

mm (0.059 in)] in switch area of VDCCM
connector.

2) Turn ignition switch to ON.

Do the ABS warning light and VDC warning
light remain off?

Warning lights remain off.

Go to step 5.

Repair front wiring
harness.

5

CHECK VDCCM TERMINAL.
1) Turn ignition switch to OFF.
2) Check, if there is any faulty condition of

VDCCM terminal.
Is there any faulty condition of VDCCM ter-
minal?

There is no problem.

Go to step 6.

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

6

CHECK POWER SUPPLY OF VDCCM.
1) Disconnect connector from VDCCM.
2) Start engine.
3) Idle the engine.
4) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 28 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Go to step 7.

Repair VDCCM
power supply cir-
cuit.

7

CHECK POOR CONTACT IN VDCCM CON-
NECTOR.
Is there poor contact in VDCCM connector?

There is poor contact.

Repair connector.

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