Subaru Legacy III (2000-2003 year). Service manual — part 807

VDC-264

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

7

CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Measure resistance between VDCH/U con-

nector and chassis ground.

Connector & terminal

(F91) No. 13 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 8.

Repair harness
between VDCH/U
and VDCCM.

8

CHECK BATTERY SHORT OF HARNESS.
Measure voltage between VDCH/U connector
and chassis ground.

Connector & terminal

(F91) No. 13 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified
value?

0.5 V

Go to step 9.

Repair harness
between VDCH/U
and VDCCM.

9

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

nector and chassis ground.

Connector & terminal

(F91) No. 13 (+) — Chassis ground (

−−−−

):

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

0.5 V

Go to step 10.

Repair harness
between VDCH/U
and VDCCM.

10

CHECK INPUT VOLTAGE OF PRESSURE
SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Remove cover from VDCCM. <Ref. to

VDC-19, REMOVE, VDCCM Connector
Cover.>

4) Connect connector to VDCCM.
5) Connect all connectors.
6) Turn ignition switch to ON.
7) Do not depress brake pedal.
8) Measure voltage between VDCCM connec-

tor terminals.

Connector & terminal

(F87) No. 77 (+) — No. 76 (

−−−−

):

Is the measured value within the specified
range?

0.48 — 0.72 V

Go to step 11.

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

11

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

There is poor contact.

Repair connector.

Go to step 12.

12

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 13.

13

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-265

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

MEMO:

VDC-266

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

BD:DTC 74 VOLTAGE INPUTTED TO PRESSURE SENSOR 2 EXCEEDS SPECI-

FICATION. (SECONDARY PRESSURE SENSOR)

DIAGNOSIS:
• Faulty secondary pressure sensor
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00181

78

36

77

76

F91

VDC5

F88

2
3

F88

F91

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

VDC HYDRAULIC

UNIT

PRIMAR

Y

PRESSURE SENSOR

SECOND

AR

Y

PRESSURE SENSOR

15

13

16

14

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

F87

VDC

CONTROL

MODULE

1

3

4 5 6

2

VDC-267

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

Step

Value

Yes

No

1

CHECK GROUND CIRCUIT OF PRESSURE
SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector (F91) from VDCH/U.
3) Measure resistance between VDCH/U con-

nector and chassis ground.

Connector & terminal

(F91) No. 15 — Chassis ground:

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

0.5

Ω

Go to step 4.

Go to step 2.

2

CHECK GROUND CIRCUIT OF VDCCM.
1) Disconnect connector from VDCCM.
2) Remove cover from VDCCM. <Ref. to

VDC-19, REMOVE, VDCCM Connector
Cover.>

3) Connect connector to VDCCM.
4) Measure resistance between VDCCM and

chassis ground.

Connector & terminal

(F87) No. 76 — Chassis ground:

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

0.5

Ω

Replace harness
between VDCH/U
and VDCCM.

Go to step 3.

3

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in VDCCM connector?

There is poor contact.

Repair or replace
VDCCM connec-
tor.

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

4

CHECK POWER SUPPLY OF PRESSURE
SENSOR.

NOTE:

When this inspection is carried out, DTC 51 AB-
NORMAL VALVE RELAY is memorized, but
this does not indicate valve relay malfunction.

1) Turn ignition switch to ON.
2) Measure voltage between VDCH/U con-

nector terminals.

Connector & terminal

(F91) No. 16 (+) — No. 15 (

−−−−

):

Is the measured value within the specified
range?

4.75 — 5.25 V

Go to step 7.

Go to step 5.

5

CHECK POWER SUPPLY OF VDCCM.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Remove cover from VDCCM. <Ref. to

VDC-19, VDCCM Connector Cover.>

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

tor terminals.

Connector & terminal

(F87) No. 78 (+) — No. 76 (

−−−−

):

Is the measured value within the specified
range?

4.75 — 5.25 V

Repair harness
between VDCH/U
and VDCCM.

Go to step 6.

6

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in VDCCM connector?

There is poor contact.

Repair or replace
VDCCM connec-
tor.

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