Subaru Legacy 2005 Service Manual page 3202

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Step
1 WHETHER A WHEEL TURNED FREELY OR
NOT.
Check if the wheels have been turned freely for
more than one minute, such as when the vehi-
cle is jacked-up, under full-lock cornering or
when the wheels are not in contact with road
surface.
2 CHECK TIRE SPECIFICATIONS.
Turn the ignition switch to OFF.
3 CHECK WEAR OF TIRE.
4 CHECK TIRE INFLATION PRESSURE.
5 CHECK INSTALLATION OF ABS WHEEL
SPEED SENSOR.
6 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.>
7 CHECK ABS WHEEL SPEED SENSOR OR
MAGNETIC ENCODER.
8 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.
Check
Did the wheels turn freely?
Are the tire specifications cor-
rect?
Is the tire worn excessively?
Is the tire pressure correct?
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)
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?
Are there foreign materials,
breakage or damage in the
protrusion of ABS wheel speed
sensor or magnetic encoder?
Is the same DTC displayed?
VDC(diag)-58
Yes
VDC is normal. Go to step 2.
Perform the clear
memory mode.
NOTE:
When the wheels
turn freely for a
long time, such as
when the vehicle is
towed or jacked-
up, or when steer-
ing wheel is contin-
uously turned all
the way, this diag-
nostic trouble code
may sometimes
occur.
Go to step 3. Replace the tire.
Replace the tire. Go to step 4.
Go to step 5. Adjust the tire
pressure.
Go to step 6. Tighten the ABS
wheel speed sen-
sor installation
bolts.
Go to step 8. Go to step 7.
Remove dirt Go to step 8.
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.
Replace the Go to step 9.
VDCCM&H/U.
<Ref. to VDC-7,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>
No