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Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 540

VDC(diag)-59

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

Step

Check

Yes

WHETHER A WHEEL TURNED FREELY OR
NOT.
Check if the wheels have been turned freely for
one minute or more, such as when the vehicle is
jacked-up, under full-lock cornering or when the
wheels are not in contact with road surface.

Did the wheels turn freely?

VDC is normal.
Clear the memory.
NOTE:

This

diagnostic

trouble  code  may
sometimes occur if
the  wheels  turn
freely  for  a  long
time,  for  example
when the vehicle is
towed  or  jacked-
up, or when steer-
ing wheel is contin-
uously  turned  all
the way.

Go to step

CHECK TIRE SPECIFICATIONS.
Turn the ignition switch to OFF.

Are the tire specifications cor-
rect?

Go to step

Replace the tire.

CHECK WEAR OF TIRE.

Is the tire worn excessively?

Replace the tire.

Go to step

CHECK TIRE INFLATION PRESSURE.

Is the tire pressure correct?

Go to step

Adjust the tire
pressure.

CHECK INSTALLATION OF ABS WHEEL
SPEED SENSOR.

Are the ABS wheel speed sen-
sor installation bolts tightened to
7.5 N·m (0.76 kgf-m, 5.5 ft-lb)?
(For four wheels)

Go to step

Tighten the ABS
wheel speed sen-
sor installation
bolts.

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 VDC-25, 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

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

VDC(diag)-60

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

J: DTC C0031 FR HOLD VALVE MALFUNCTION

NOTE:

For the diagnostic procedure, refer to “DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION”. <Ref. to

VDC(diag)-62, DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION, Diagnostic Procedure with Di-

agnostic Trouble Code (DTC).>

K: DTC C0032 FR PRESSURE REDUCING VALVE MALFUNCTION

NOTE:

For the diagnostic procedure, refer to “DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION”. <Ref. to

VDC(diag)-62, DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION, Diagnostic Procedure with Di-

agnostic Trouble Code (DTC).>

L: DTC C0033 FL HOLD VALVE MALFUNCTION

NOTE:

For the diagnostic procedure, refer to “DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION”. <Ref. to

VDC(diag)-62, DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION, Diagnostic Procedure with Di-

agnostic Trouble Code (DTC).>

M: DTC C0034 FL PRESSURE REDUCING VALVE MALFUNCTION

NOTE:

For the diagnostic procedure, refer to “DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION”. <Ref. to

VDC(diag)-62, DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION, Diagnostic Procedure with Di-

agnostic Trouble Code (DTC).>

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-27,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
VDC(diag)-26, Inspection Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM only.
<Ref. to VDC-12,
REPLACEMENT,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Go to step

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC. <Ref. to
VDC(diag)-48, 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

VDC(diag)-61

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

N: DTC C0035 RR HOLD VALVE MALFUNCTION

NOTE:

For the diagnostic procedure, refer to “DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION”. <Ref. to

VDC(diag)-62, DTC C0064 NORMAL CLOSING VALVE 2 MALFUNCTION, Diagnostic Procedure with Di-

agnostic Trouble Code (DTC).>

O: DTC C0036 RR PRESSURE REDUCING VALVE MALFUNCTION