Subaru Legacy IV (2008 year). Manual - part 932

 

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Subaru Legacy IV (2008 year). Manual - part 932

 

 

VDC(diag)-43

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

H: DTC C0028 REAR LEFT ABS SENSOR SIGNAL

DTC DETECTING CONDITION:
• Defective ABS wheel speed sensor signal (noise, irregular signal, etc.)
• Defective harness connector
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

4

3

1

26

27

2

25

B98

R72

R2

E

1

2

15

14

6

5

R73

1

2

B6

B15

R73

R72

1

2

1 2

2 1

6

5

B310

2

1

B15

B6

VDCCM & H/U

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

1

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23

24

22

25

VDC00501

B98

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

FRONT ABS 

WHEEL SPEED 

SENSOR LH

FRONT ABS 

WHEEL SPEED 

SENSOR RH

REAR ABS 

WHEEL SPEED 

SENSOR LH

REAR ABS 

WHEEL SPEED 

SENSOR RH

VDC(diag)-44

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK OUTPUT OF ABS WHEEL SPEED 
SENSOR USING SUBARU SELECT MONI-
TOR.
1) Select {Current Data Display & Save} in the 
Subaru Select Monitor.
2) Read the defective ABS wheel speed sen-
sor output.

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 connec-
tors between VDCCM&H/U and 
ABS wheel speed sensor?

Repair the connec-
tor.

Go to step 3.

3

CHECK CAUSE OF SIGNAL NOISE.
Make sure the radio wave devices and elec-
tronic components are installed correctly.

Are the radio wave devices and 
electronic components 
installed correctly?

Go to step 4.

Install the radio 
wave devices and 
electronic compo-
nents properly.

4

CHECK CAUSE OF SIGNAL NOISE.
Check if the noise sources (such as an 
antenna) are installed near the sensor harness.

Are noise sources installed?

Install the noise 
sources apart from 
sensor harness.

Go to step 5.

5

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-23, 
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to 
VDC(diag)-22, PROCEDURE, Inspection 
Mode.>
4) Read the DTC. 

Is the same DTC displayed?

Replace the 
VDCCM only. 
<Ref. to VDC-10, 
REPLACEMENT, 
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. <Ref. to 
VDC(diag)-34, List 
of Diagnostic Trou-
ble Code (DTC).>

It results from a 
temporary noise 
interference.

7

CHECK INSTALLATION OF ABS WHEEL 
SPEED SENSOR.

Is the ABS wheel speed sensor 
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-14, 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 one rotation or more?

Go to step 10.

Go to step 9.

9

CHECK ABS WHEEL SPEED SENSOR OR 
MAGNETIC ENCODER.

Are there foreign matter, break-
age or damage at the tip of ABS 
wheel speed sensor or mag-
netic encoder?

Remove dirt thor-
oughly. 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 CAUSE OF SIGNAL NOISE.
Make sure the radio wave devices and elec-
tronic components are installed correctly.

Are the radio wave devices and 
electronic components 
installed correctly?

Go to step 11.

Install the radio 
wave devices and 
electronic compo-
nents properly.

VDC(diag)-45

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

11

CHECK CAUSE OF SIGNAL NOISE.
Check if the noise sources (such as an 
antenna) are installed near the sensor harness.

Is the noise sources installed? Go to step 12.

Install the noise 
sources apart from 
sensor harness.

12

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-23, 
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to 
VDC(diag)-22, PROCEDURE, Inspection 
Mode.>
4) Read the DTC. 

Is the same DTC displayed?

Replace the 
VDCCM only. 
<Ref. to VDC-10, 
REPLACEMENT, 
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. <Ref. to 
VDC(diag)-34, List 
of Diagnostic Trou-
ble Code (DTC).>

It results from a 
temporary noise 
interference.

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

Step

Check

Yes

No

VDC(diag)-46

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

I:

DTC C0029 ANY OF WHEEL SENSORS SIGNAL

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 illuminates as well as ABS warning light when EBD does not operate.
WIRING DIAGRAM:

4

3

1

26

27

2

25

B98

R72

R2

E

1

2

15

14

6

5

R73

1

2

B6

B15

R73

R72

1

2

1 2

2 1

6

5

B310

2

1

B15

B6

VDCCM & H/U

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

1

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23

24

22

25

VDC00501

B98

1 2 3

4 5 6 7

8 9 10 11 12 13 14 15 16

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

TWISTED P

AIR LINE

FRONT ABS 

WHEEL SPEED 

SENSOR LH

FRONT ABS 

WHEEL SPEED 

SENSOR RH

REAR ABS 

WHEEL SPEED 

SENSOR LH

REAR ABS 

WHEEL SPEED 

SENSOR RH

 

 

 

 

 

 

 

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