Subaru Legacy III (2000-2003 year). Manual - part 808

VDC-268

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. 14 — 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. 14 (+) — 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 (

−−−−

):

(F91) No. 14 (+) — 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. 36 (+) — 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-269

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

BE:DTC 74 PRESSURE SENSOR 1 OFFSET IS TOO BIG. (PRIMARY PRESSURE 

SENSOR)

NOTE:
For diagnostic procedure, refer to DTC 74. <Ref. to VDC-270, DTC 74 PRESSURE SENSOR 2 OFFSET IS
TOO BIG. (SECONDARY PRESSURE SENSOR), Diagnostics Chart with Select Monitor.>

VDC-270

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

BF:DTC 74 PRESSURE SENSOR 2 OFFSET IS TOO BIG. (SECONDARY PRES-

SURE SENSOR)

DIAGNOSIS:
• Faulty 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-271

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

Step

Value

Yes

No

1

CHECK DRIVING TECHNIC.
Check the driver's technic.
Are the accelerator and brake pedals 
depressed simultaneously while  driving?

Depressed.

The VDC is nor-
mal. Erase the 
diagnostic trouble 
code.

NOTE:
Driving the vehicle
with both the ac-
celerator pedal
and brake pedal
depressed may
store a diagnostic
trouble code in the
memory.

Go to step 2.

2

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

select monitor.

2) Read pressure sensor output on the select 

monitor display.
Is the measured value within the specified 
range when brake pedal is depressed?

0.48 — 0.72 V

Go to step 3.

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

3

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 4.

4

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.