Subaru Legacy (2005 year). Manual — part 797

VDC(diag)-53

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

• RHD model

VDC00326

38

23

25

41

40

24

6

B97

R72

R1

E

1

2

19

18

8

7

R73

1

2

1

2

1

2

B6

B15

B15

B6

R73

R72

B310

21

22

B310

B97

VDCCM & H/U

TWISTED WIRE

FRONT ABS

WHEEL SPEED

SENSOR LH

1 2 3 4

11 12 13 14
27 28 29 30

15 16 17 18
31 32 33 34

19 20 21 22
35 36 37 38

23 24 25 26
39 40 41 42

5

6

7

8

9

10

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

TWISTED WIRE

TWISTED WIRE

TWISTED WIRE

FRONT ABS

WHEEL SPEED

SENSOR RH

REAR ABS

WHEEL SPEED

SENSOR LH

REAR ABS

WHEEL SPEED

SENSOR RH

1 2

VDC(diag)-54

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK OUTPUT OF ABS WHEEL SPEED
SENSOR USING SUBARU SELECT MONI-
TOR.
1) Select {Current Data Display & Save} in
Subaru Select Monitor.
2) Read the ABS wheel speed sensor output
corresponding to the faulty wheel in Subaru
Select Monitor data display mode.

Does the speed indicated on
the display change in response
to the speedometer reading
during acceleration/decelera-
tion when the steering wheel is
in the straight-ahead position?

Go to step 2.

Go to step 7.

2

CHECK POOR CONTACT IN CONNECTOR.
Turn the ignition switch to OFF.

Is there poor contact in con-
nectors between VDCCM&H/U
and ABS wheel speed sensor?

Repair the con-
nector.

Go to step 3.

3

CHECK SOURCES OF SIGNAL NOISE.
Make sure the radio wave devices and electric
components are installed correctly.

Are the radio wave devices and
electric components installed
correctly?

Go to step 4.

Install the radio
wave device and
electric device
properly.

4

CHECK SOURCES OF SIGNAL NOISE.
Check if the noise sources (such as an
antenna) are installed near the sensor har-
ness.

Are noise sources installed?

Install the noise
sources apart from
sensor harness.

Go to step 5.

5

CHECK VDCCM&H/U.
1) Connect all the connectors.
2) Perform the clear memory mode.
3) Perform the inspection mode. <Ref. to
VDC(diag)-24, PROCEDURE, Inspection
Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM&H/U.
<Ref. to VDC-7,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Go to step 6.

6

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC.

It results from a
temporary noise
interference.

7

CHECK INSTALLATION OF ABS WHEEL
SPEED SENSOR.

Is the ABS wheel speed sen-
sor installation bolt tightened
7.5 N

⋅m (0.76 kgf-m, 5.5 ft-lb)?

Go to step 8.

Tighten the ABS
wheel speed sen-
sor installation
bolts.

8

CHECK ABS WHEEL SPEED SENSOR SIG-
NAL.
1) Install the ABS wheel speed sensor.
2) Prepare an oscilloscope.
3) Check the ABS wheel speed sensor. <Ref.
to ABS-13, ABS WHEEL SPEED SENSOR,
INSPECTION, Front ABS Wheel Speed Sen-
sor.>

Does the oscilloscope indicate
the waveform pattern like
shown in the figure when the
tire is slowly turned? Does the
oscilloscope indication repeat
the waveform pattern like
shown in the figure when the
tire is slowly turned in equal
speed for more one rotation?

Go to step 10.

Go to step 9.

9

CHECK ABS WHEEL SPEED SENSOR OR
MAGNETIC ENCODER.

Are there foreign materials,
breakage or damage in the
protrusion of ABS wheel speed
sensor or magnetic encoder?

Remove dirt
throughly. Also
replace the ABS
wheel speed sen-
sor or magnetic
encoder as a unit
with hub unit bear-
ing if it is broken or
damaged.

Go to step 10.

10

CHECK SOURCES OF SIGNAL NOISE.
Make sure the radio wave devices and electric
components are installed correctly.

Are the radio wave devices and
electric components installed
correctly?

Go to step 11.

Install the radio
wave device and
electric device
properly.

11

CHECK SOURCES OF SIGNAL NOISE.
Check if the noise sources (such as an
antenna) are installed near the sensor har-
ness.

Is the noise sources installed? Go to step 12.

Install the noise
sources apart from
sensor harness.

VDC(diag)-55

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

M: DTC C0029 ABS WHEEL SPEED SENSOR SIGNAL MALFUNCTION IN ONE

OF FOUR WHEELS

DTC DETECTING CONDITION:
• Defective ABS wheel speed sensor signal (noise, irregular signal, etc.)
• Defective magnetic encoder
• When a wheel is turned freely for a long time
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
• EBD may not operate.

NOTE:
Brake warning light comes on as well as ABS warning light when EBD does not operate.

12

CHECK VDCCM&H/U.
1) Connect all the connectors.
2) Perform the clear memory mode.
3) Perform the inspection mode. <Ref. to
VDC(diag)-24, PROCEDURE, Inspection
Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM&H/U.
<Ref. to VDC-7,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Go to step 13.

13

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC.

It results from a
temporary noise
interference.

NOTE:
Though the ABS
warning light re-
mains on at this
time, it is normal.
Drive the vehicle at
more than 12 km/h
(7 MPH) in order to
turn ABS warning
light off. Be sure to
drive the vehicle
and check the
warning light goes
off.

Step

Check

Yes

No

VDC(diag)-56

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

WIRING DIAGRAM:
• LHD model

B15

B6

R73

R72

B310

B98

1 2 3 4

11 12 13 14
27 28 29 30

15 16 17 18
31 32 33 34

19 20 21 22
35 36 37 38

23 24 25 26
39 40 41 42

5

6

7

8

9

10

VDC00299

38

23

25

41

40

24

6

B98

R72

R2

E

1

2

15

14

6

5

R73

1

2

1

2

1

2

B6

B15

21

22

B310

VDCCM & H/U

TWISTED WIRE

FRONT ABS

WHEEL SPEED

SENSOR LH

TWISTED WIRE

TWISTED WIRE

TWISTED WIRE

FRONT ABS

WHEEL SPEED

SENSOR RH

REAR ABS

WHEEL SPEED

SENSOR LH

REAR ABS

WHEEL SPEED

SENSOR RH

1 2

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16