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