
VDC(diag)-83
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Step Check Yes No
1CHECK THE VDCCM&H/U POWER VOLT-
AGE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the
VDCCM&H/U.
3) Turn the ignition switch to ON.
4) Measure the voltage between VDCCM&H/
U connector and chassis ground.
Connector & terminal
(B310) No. 1 (+) — Chassis ground (–):
Is the voltage 10 — 15 V? Go to step 2.Repair the power
supply circuit.
2CHECK THE VDCCM&H/U GROUND CIR-
CUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between
VDCCM&H/U connector and chassis ground.
Connector & terminal
(B310) No. 43— Chassis ground:
Is the resistance less than 0.5
Ω?
Go to step 3.Repair the
VDCCM&H/U
ground harness.
3CHECK PRESSURE SENSOR.
1) Connect the Subaru Select Monitor to the
vehicle.
2) Select {Current Data Display & Save} in
Subaru Select Monitor.
3) Depress the brake pedal.
4) Read the pressure switch output in Subaru
Select Monitor.
Do the values on the monitor
display change when the pedal
is depressed?
Go to step 4.Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
4CHECK THE VDCCM&H/U.
1) Connect all the connectors.
2) Erase the memory.
3) Perform the inspection mode.
4) Read the DTC.
Is the same DTC displayed? Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
Go to step 5.
5CHECK OTHER DTC DETECTION.Is any other DTC displayed? Perform the diag-
nosis according to
DTC.
Te m p o r a r y p o o r
contact occurs.

VDC(diag)-84
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
BB:DTC C0074 PRESSURE SENSOR 0 POINT
DTC DETECTING CONDITION:
Defective pressure sensor
TROUBLE SYMPTOM:
•ABS does not operate.
•VDC does not operate.
Step Check Yes No
1CHECK OUTPUT OF STOP LIGHT SWITCH
WITH SUBARU SELECT MONITOR.
1) Select {Current Data Display & Save} in
Subaru Select Monitor.
2) Release the brake pedal.
3) Read the stop light switch output in Subaru
Select Monitor.
Is OFF displayed on the dis-
play screen?
Go to step 2.Go to step 3.
2CHECK OUTPUT OF STOP LIGHT SWITCH
WITH SUBARU SELECT MONITOR.
1) Depress the brake pedal.
2) Read the stop light switch output in Subaru
Select Monitor.
Is ON displayed on the display
screen?
Go to step 4.Go to step 3.
3CHECK IF STOP LIGHTS COME ON.
1) Depress the brake pedal.
Does the stop light illuminate? Go to step 4.Repair the stop
light circuit.
4CHECK PRESSURE SENSOR.
1) Depress the brake pedal.
2) Read the pressure sensor output using the
Subaru Select Monitor.
Do the output values on the
monitor display change when
the pedal is depressed?
Go to step 5.Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
5CHECK THE VDCCM&H/U.
1) Connect all the connectors.
2) Erase the memory.
3) Perform the inspection mode.
4) Read the DTC.
Is the same DTC displayed? Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
Go to step 6.
6CHECK OTHER DTC DETECTION.Is any other DTC displayed? Perform the diag-
nosis according to
DTC.
Te m p o r a r y p o o r
contact occurs.

VDC(diag)-86
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Step Check Yes No
1CHECK THE VDCCM&H/U POWER VOLT-
AGE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the
VDCCM&H/U.
3) Turn the ignition switch to ON.
4) Measure the voltage between VDCCM&H/
U connector and chassis ground.
Connector & terminal
(B310) No. 1 (+) — Chassis ground (–):
Is the voltage 10 — 15 V? Go to step 2.Repair the power
supply circuit.
2CHECK THE VDCCM&H/U GROUND CIR-
CUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between
VDCCM&H/U connector and chassis ground.
Connector & terminal
(B310) No. 43 — Chassis ground:
Is the resistance less than 0.5
Ω?
Go to step 3.Repair the
VDCCM&H/U
ground harness.
3CHECK CAUSE OF SIGNAL NOISE.
Check if the noise sources (such as an
antenna) are installed near the VDCCU&H/U.
Are noise sources installed? Install the noise
sources apart from
the VDCCU&H/U.
Go to step 4.
4CHECK PRESSURE SENSOR.
1) Depress the brake pedal.
2) Read the pressure switch output in Subaru
Select Monitor.
Do the output values on the
monitor display change when
the pedal is depressed?
Go to step 5.Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
5CHECK THE VDCCM&H/U.
1) Connect all the connectors.
2) Erase the memory.
3) Perform the inspection mode.
4) Read the DTC.
Is the same DTC displayed? Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
Go to step 6.
6CHECK OTHER DTC DETECTION.Is any other DTC displayed? Perform the diag-
nosis according to
DTC.
Te m p o r a r y p o o r
contact occurs.

VDC(diag)-87
General Diagnostic Table
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
13.General Diagnostic Table
A: INSPECTION
Symptom Main probable cause Other probable cause
Po or b rake pe r -
for mance
Long braking/
stopping dis-
tance
•VDCCM&H/U
•Brake pad
•Aeration to brake line
•Tire specifications, tire wear and air pressures
•Incorrect wiring or piping connections
•Defective ABS wheel speed sensor or
sensor gap
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
•Master cylinder
•Brake caliper
•Disc rotor
•Brake pipe
•Brake booster
Wheel lock • VDCCM&H/U
•Defective ABS wheel speed sensor or sensor
gap
•Incorrect wiring or piping connections
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
•Brake caliper
•Brake pipe
Brake drag • VDCCM&H/U
•Defective ABS wheel speed sensor or sensor
gap
•Master cylinder
•Brake caliper
•Parking brake
•Axle and wheels
•Brake pedal play
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
•Brake pad
•Brake pipe
Long brake
pedal stroke
•Aeration to brake line
•Brake pedal play
•VDCCM&H/U
•Master cylinder
•Brake caliper
•Brake pad
•Brake pipe
•Brake booster
Ve h i c l e v e r t i -
cal pitching
•VDCCM&H/U
•Road surface (uneven)
•Suspension play or fatigue (reduced damping)
•Incorrect wiring or piping connections
•Defective ABS wheel speed sensor or
sensor gap
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
Po or b rake pe r -
for mance
Unstable or
uneven brak-
ing
•VDCCM&H/U
•Defective ABS wheel speed sensor or sensor
gap
•Brake caliper
•Brake pad
•Road surface (uneven)
•Tire specifications, tire wear and air pressures
•Incorrect wiring or piping connections
•Defective ABS wheel speed sensor or
sensor gap
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
•Master cylinder
•Disc rotor
•Brake pipe
•Axle and wheels
•Road with crowns or banks
•Suspension play or fatigue (poor damp-
ing)

VDC(diag)-88
General Diagnostic Table
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Vibration or
noise
•When braking
suddenly
•When acceler-
ating suddenly
•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 damp-
ing)
Noise from
VDCH/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 & 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 damping)
•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 & 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 damping)
•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 & G sensor or
improper installation
•Brake pad
•Brake pipe
Symptom Main probable cause Other probable cause

VDC(diag)-89
General Diagnostic Table
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Po or ch a ng e -
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 & 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 damp-
ing)
Ve h i c l e s p i n • V D C C M & H / U
•Defective ABS wheel speed sensor or sensor
gap
•Defective steering angle sensor or improper
neutral position
•Defective yaw rate & 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 & 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 damp-
ing)
•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 & G sensor or improper
installation
•Wheel alignment
•Road surface (uneven)
•Road with crowns or banks
•Suspension play or fatigue (poor damping)
•Tire specifications, tire wear and air pressures
•Incorrect wiring or piping connections
•Power steering system
TCS OFF indicator light does not
come on when the TCS OFF
switch is depressed.
NOTE:When pressing TCS OFF switch
for more than 10 seconds, TCS
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
•TCS OFF switch
Symptom Main probable cause Other probable cause

VDC-5
General Description
VEHICLE DYNAMICS CONTROL (VDC)
5. RELAY BOX
C: CAUTION
Please clearly understand and adhere to the follow-
ing general precautions. They must be strictly fol-
lowed to avoid any injury to the person doing the
work or people in the area.
1. OPERATION
•Wear work clothing, including a cap, protective
goggles and protective shoes during operation.
•Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust and dirt.
•Before disconnecting connectors of sensors or
units, be sure to disconnect the ground cable from
the battery.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly and replacement.
•Be careful not to burn yourself, because each
part on the vehicle is hot after running.
•Be sure to tighten fasteners including bolts and
nuts to the specified torque.
•Place shop jacks or rigid racks at the specified
points.
2. OIL
When handling oil, follow the rules below to prevent
unexpected accidents.
•Prepare container and waste cloths when per-
forming work which oil could possibly spill. If oil
spills, wipe it off immediately to prevent from pene-
trating into floor or flowing outside, for environmen-
tal protection.
•Follow all government and local regulations con-
cerning waste disposal.
3. BRAKE FLUID
If brake fluid gets in your eyes or on your skin, do
the following:
•Wash eyes and seek immediate medical atten-
tion.
•Wash your skin with soap and then rinse thor-
oughly with water.
Follow all government and local regulations con-
cerning waste disposal.
(1) Relay box (4) Fuel safe relay (green)Tightening torque: N·m (kgf-m, ft-lb)
(2) Cover (5) Vacuum pump relay (black)T: 18 (1.8, 13.0)
(3) Motor relay (blue)

VDC-7
VDC Control Module & Hydraulic Control Unit (VDCCM&H/U)
VEHICLE DYNAMICS CONTROL (VDC)
2. VDC Control Module & Hy-
draulic Control Unit (VDC-
CM&H/U)
A: REMOVAL
1) Disconnect the ground cable from the battery.
2) Use compressed air to remove moisture and
dust around the VDCCM&H/U.
NOTE:
If the terminals become dirty, it may cause improp-
er contact.
3) Lift the lock lever and Disconnect the VDC-
CM&H/U connector.
CAUTION:
Do not pull on the harness when disconnecting
the connector.
4) Disconnect the brake pipes from the VDC-
CM&H/U.
5) Wrap the brake pipe with a vinyl bag so as not to
spill the brake fluid on the vehicle body.
CAUTION:
If brake fluid is spilled on the vehicle body,
wash it off immediately with water and wipe
clean.
6) Remove the nuts and remove the VDCCM&H/U.
CAUTION:
•The VDCCM&H/U cannot be disassembled.
Do not attempt to loosen the bolts and nuts.
•Do not drop or bump the VDCCM&H/U.
•Do not turn the VDCCM&H/U upside down or
place it sideways during storage.
•Be careful not to let foreign matter enter the
VDCCM&H/U.
•Be careful that no water enters the connec-
tors.
7) Remove the VDCCM&H/U bracket.
B: INSTALLATION
1) Install the VDCCM&H/U bracket.
Tightening torque:
33 N·m (3.3 kgf-m, 24 ft-lb)
2) Install the VDCCM&H/U to the bracket.
Tightening torque:
7.5 N·m (0.76 kgf-m, 5.5 ft-lb)
CAUTION:
Attach so that the protrusion of the stud bolt is
at the position shown in the figure.
3) Connect the brake pipes to their correct VDC-
CM&H/U positions.
Tightening torque:
VDC00343
VDC00344
(1) Stud bolt
(2) Protrusion por tion
(3) Bracket