Subaru Legacy (2005 year). Manual — part 817

VDC(diag)-133

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

General Diagnostic Table

Vibration or
noise
• When brak-
ing suddenly
• When accel-
erating sud-
denly
• While driving
on a slippery
road

Excessive
brake pedal
vibration

• Road surface (uneven)
• Incorrect wiring or piping connections

• VDCCM&H/U
• Brake booster
• Suspension play or fatigue (poor damping)

Noise from
VDCCM&H/U

• VDCCM&H/U (mount bushing)
• Defective ABS wheel speed sensor or
sensor gap
• Brake pipe

• VDCCM&H/U
• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & lateral G sensor or
improper installation

Noise from the
front side of
vehicle

• VDCCM&H/U (mount bushing)
• Defective ABS wheel speed sensor or
sensor gap
• Master cylinder
• Brake caliper
• Brake pad
• Disc rotor
• Brake pipe
• Brake booster
• Suspension play or fatigue (poor damp-
ing)

• Axle and wheels
• Tire specifications, tire wear and air pressures

Noise inside
passenger seat

• VDCCM&H/U
• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & lateral G sensor or
improper installation

Noise from the
rear side of
vehicle

• Defective ABS wheel speed sensor or
sensor gap
• Brake caliper
• Brake pad
• Disc rotor
• Parking brake
• Brake pipe
• Suspension play or fatigue (poor damp-
ing)

• Axle and wheels
• Tire specifications, tire wear and air pressures

Engine does not accelerate or
goes into a stall when accelerat-
ing suddenly or driving on a slip-
pery surface.

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Master cylinder
• Brake caliper
• Parking brake
• Incorrect wiring or piping

• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & lateral G sensor or
improper installation
• Brake pad
• Brake pipe

Symptom

Main probable cause

Other probable cause

VDC(diag)-134

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

General Diagnostic Table

Poor change-
direction-opera-
tion stability of
TCS

Deviation to
right or left
direction

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Defective steering angle sensor or
improper neutral position
• Defective yaw rate & lateral G sensor
or improper installation
• Brake caliper
• Brake pad
• Wheel alignment
• Road surface (uneven)
• Road with crowns or banks
• Tire specifications, tire wear and air
pressures
• Incorrect wiring or piping connections

• Disc rotor
• Brake pipe
• Axle and wheels
• Suspension play or fatigue (poor damping)

Vehicle spin

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Defective steering angle sensor or
improper neutral position
• Defective yaw rate & lateral G sensor
or improper installation
• Brake pad
• Tire specifications, tire wear and air
pressures
• Incorrect wiring or piping connections

• Brake caliper
• Brake pipe

Steering wheel drag while driving

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Defective steering angle sensor or
improper neutral position
• Defective yaw rate & lateral G sensor
or improper installation
• Incorrect wiring or piping connections
• Power steering system

• Brake caliper
• Brake pad
• Disc rotor
• Wheel alignment
• Road surface (uneven)
• Road with crowns or banks
• Suspension play or fatigue (poor damping)
• Tire specifications, tire wear and air pressures

VDC operates while driving nor-
mally.

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Defective steering angle sensor or
improper neutral position
• Defective yaw rate & lateral G sensor
or improper installation
• Wheel alignment
• Road surface (uneven)
• Road with crowns or banks
• Suspension play or fatigue (poor damp-
ing)
• Tire specifications, tire wear and air
pressures
• Incorrect wiring or piping connections
• Power steering system

Symptom

Main probable cause

Other probable cause

VDC(diag)-135

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

General Diagnostic Table

VDC OFF indicator light does not
come on when the VDC OFF
switch is depressed.
NOTE:
When pressing VDC OFF switch
for more than 10 seconds, VDC
OFF indicator light goes off and
cannot operate any more. When
turning the ignition switch from
OFF to ON, the previous status is
restored.

• Harness
• Indicator light bulb
• VDC OFF switch

Symptom

Main probable cause

Other probable cause

VDC(diag)-136

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

General Diagnostic Table