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-2
General Description
VEHICLE DYNAMICS CONTROL (VDC)
1. General Description
A: SPECIFICATION
B: COMPONENT
1. ABS WHEEL SPEED SENSOR
Item Specification or identification
ABS wheel speed
sensor
ABS wheel speed sensor
gap (for reference)
Fr o nt 0 . 55 — 1. 4 5 m m ( 0. 0 2 2 — 0. 0 57 i n)
Rear 0.50 — 1.50 mm (0.020 — 0.059 in)
Identifications of harness
(marks, color)
Fr o nt W1 ( Wh i te )
Rear W3 (White)
VDCCM&H/U IdentificationW1
(1) Front ABS wheel speed sensor (4) Hub unit bearingTightening torque: N·m (kgf-m, ft-lb)
(2) Front housing (5) Magnetic encoderT: 7.5 (0.76, 5.5)
(3) Rear ABS wheel speed sensor
VDC00340
T
T
(3)
(4)
(5)
(2)
(1)
VDC-4
General Description
VEHICLE DYNAMICS CONTROL (VDC)
4. VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U)
(1) VDC control module and hydraulic
control unit (VDCCM&H/U)
(5) Secondary inlet (10) Stud bolt
(6) Primary inlet
(2) Bracket (7) Front LH outletTightening torque: N·m (kgf-m, ft-lb)
(3) Rear RH outlet (8) Front RH outletT1: 7.5 (0.76, 5.5)
(4) Rear LH outlet (9) DamperT2: 33 (3.4, 24)
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
VDC-8
VDC Control Module & Hydraulic Control Unit (VDCCM&H/U)
VEHICLE DYNAMICS CONTROL (VDC)
4) Connect the VDCCM&H/U connectors.
NOTE:
•Be sure to remove all foreign matter from inside
the connector before connecting.
•Make sure the VDCCM&H/U connector is se-
curely locked.
5) Bleed air from the brake system.
C: INSPECTION
1) Check the condition of connection and settle-
ment of connector.
2) Check the mark used for VDCCM&H/U identifi-
cation.
Refer to “SPECIFICATION” for the identification
mark.
1. CHECKING THE HYDRAULIC UNIT ABS
OPERATION BY PRESSURE GAUGE
1) Lift-up the vehicle and remove the wheel.
2) Remove the air bleeder screws from FL and FR
caliper bodies.
3) Connect two pressure gauges to FL and FR cal-
iper bodies.
CAUTION:
•Use a pressure gauge used exclusively for
brake fluid measurement.
•Do not use the pressure gauge used for the
measurement of transmission oil. Doing so will
cause the piston seal to expand and deform.
NOTE:
Wrap sealing tape around the pressure gauge.
4) Bleed air from the pressure gauges and the FL
and FR caliper bodies.
5) Perform ABS sequence control.
6) When the hydraulic unit begins to work, first the
FL side performs decompression, hold and com-
pression, and then the FR side performs decom-
pression, hold and compression.
7) Read values indicated on the pressure gauge
and check if the fluctuation of the values between
decompression and compression meets the stan-
dard values. Depress the brake pedal and check
that the kick-back is normal, and tightness is nor-
mal.
8) Disconnect the pressure gauges from FL and FR
caliper bodies.
9) Install the air bleeder screws of FL and FR cali-
per bodies.
10) Remove the air bleeder screws from RL and
RR caliper bodies.
11) Connect two pressure gauges to RL and RR
caliper bodies.
(1) Identification mark
VDC00345
(1)
Front wheelRear wheel
Initial value
3,500 kPa
(36 kgf/cm2, 511
psi)
3,500 kPa
(36 kgf/cm2, 511
psi)
When depres-
surized
500 kPa
(5 kgf/cm2, 73 psi)
or less
500 kPa
(5 kgf/cm2, 73 psi)
or less
When pressur-
ized
3,500 kPa
(36 kgf/cm2, 511
psi)
or more
3,500 kPa
(36 kgf/cm2, 511
psi)
or more
ABS00134
VDC-9
VDC Control Module & Hydraulic Control Unit (VDCCM&H/U)
VEHICLE DYNAMICS CONTROL (VDC)
12) Bleed air from the brake system.
13) Bleed air from RL and RR caliper bodies, and
pressure gauge.
14) Perform ABS sequence control.
15) When the hydraulic unit begins to work, first the
RR side performs decompression, hold and com-
pression, and then the RL side performs decom-
pression, hold and compression.
16) Read values indicated on the pressure gauge
and check if the fluctuation of the values between
decompression and compression meets specifica-
tion. Depress the brake pedal and check that the
kick-back is normal, and tightness is normal.
17) Disconnect the pressure gauge from the RL
and RR caliper bodies.
18) Install the air bleeder screws of RL and RR cal-
iper bodies.
19) Bleed air from the brake system.
2. CHECKING THE HYDRAULIC UNIT ABS
OPERATION WITH THE BRAKE TESTER
1) Set wheels other than the one to measure free
rollers.
2) Prepare for the ABS sequence control operation.
3) Set the front wheels or rear wheels on the brake
tester and set the select lever position to the “N”
range.
4) Operate the brake tester.
5) Perform ABS sequence control.
6) When the hydraulic unit begins to work, check
the following work sequence.
(1) The FL wheel performs decompression,
hold and compression in sequence, and subse-
quently the FR wheel repeats the cycle.
(2) The RR wheel performs decompression,
hold and compression in sequence, and subse-
quently the RL wheel repeats the cycle.
7) Read values indicated on the brake tester and
check if the fluctuation of the values between de-
compression and compression meets specifica-
tion.
8) After the inspection, depress the brake pedal
and check that it is not abnormally hard, and tight-
ness is normal.
3. CHECKING THE HYDRAULIC UNIT VDC
OPERATION USING A PRESSURE GAUGE
1) Lift-up the vehicle and remove the wheel.
2) Remove the air bleeder screws from FL and FR
caliper bodies.
3) Connect two pressure gauges to FL and FR cal-
iper bodies.
CAUTION:
•Use a pressure gauge used exclusively for
brake fluid measurement.
•Do not use a pressure gauge used for the
measuring transmission oil pressure, as the
piston seal may expand and deform.
NOTE:
Wrap sealing tape around the pressure gauge.
4) Bleed air from the pressure gauge.
5) Perform VDC sequence control.
(1) Brake tester
ABS00136
(1)
ABS00137
(1)
Front wheelRear wheel
Initial value2,000 N
(204 kgf, 450 lb)
2,000 N
(204 kgf, 450 lb)
When depressur-
ized
500 N
(51 kgf, 112 lb)
or less
500 N
(51 kgf, 112 lb)
or less
When pressurized
2,000 N
(204 kgf, 450 lb)
or more
2,000 N
(204 kgf, 450 lb)
or more
ABS00134
VDC-10
VDC Control Module & Hydraulic Control Unit (VDCCM&H/U)
VEHICLE DYNAMICS CONTROL (VDC)
6) When the hydraulic unit begins to work, first the
FL side performs compression, hold, and decom-
pression, and then the FR side performs compres-
sion, hold, and decompression.
7) Read values indicated on the pressure gauge
and check if the fluctuation of the values between
decompression and compression meets specifica-
tion. Depress the brake pedal and check that it is
not abnormally hard, and tightness is normal.
8) Disconnect the pressure gauges from FL and FR
caliper bodies.
9) Install the air bleeder screws of FL and FR cali-
per bodies.
10) Remove the air bleeder screws from RL and
RR caliper bodies.
11) Connect two pressure gauges to RL and RR
caliper bodies.
12) Bleed air from RL and RR caliper bodies, and
pressure gauge.
13) Perform VDC sequence control.
14) When the hydraulic unit begins to work, first the
RR side performs compression, hold, and decom-
pression, and then the RL side performs compres-
sion, hold, and decompression.
15) Read the values indicated on the pressure
gauges and check if it is within specification. De-
press the brake pedal and check that it is not abnor-
mally hard, and tightness is normal.
16) Disconnect the pressure gauge from the RL
and RR caliper bodies.
17) Install the air bleeder screws of RL and RR cal-
iper bodies.
18) Bleed air from the brake line.
4. CHECK HYDRAULIC UNIT VDC OPERA-
TION WITH BRAKE TESTER
1) Set wheels other than the one to measure free
rollers.
2) Prepare to operate the VDC sequence control.
3) Set the front wheels or rear wheels on the brake
tester and set the select lever position to the “N”
range.
4) Operate the brake tester.
5) Perform VDC sequence control.
6) When the hydraulic unit begins to work, check
the following work sequence.
(1) The FL wheel performs compression, hold
and decompression in sequence, and subse-
quently the FR wheel repeats the cycle.
(2) The RR wheel performs compression, hold
and decompression in sequence, and subse-
quently the RL wheel repeats the cycle.
7) Read values indicated on the brake tester and
check if the fluctuation of the values between de-
compression and compression meets specifica-
tion.
8) After the inspection, depress the brake pedal
and check that it is not abnormally hard, and tight-
ness is normal.
Front wheelRear wheel
When pressur-
ized
3,000 kPa
(31 kgf/cm2, 441
psi) or more
3,000 kPa
(31 kgf/cm2, 441
psi) or more
When depres-
surized
500 kPa
(5 kgf/cm2, 73 psi)
or less
500 kPa
(5 kgf/cm2, 73 psi)
or less
(1) Brake tester
Front wheelRear wheel
When pressurized
2,000 N
(204 kgf, 450 lb)
or more
2,000 N
(204 kgf, 450 lb)
or more
When depressur-
ized
500 N
(51 kgf, 112 lb)
or less
500 N
(51 kgf, 112 lb)
or less
ABS00136
(1)
ABS00137
(1)
VDC-11
VDC Control Module & Hydraulic Control Unit (VDCCM&H/U)
VEHICLE DYNAMICS CONTROL (VDC)
D: ADJUSTMENT
When the following replacement, removal and in-
stallation are performed, be sure to perform center-
ing of the steering angle sensor and zero point
setting of the yaw rate & G sensor.
•VDCCM&H/U
•Steering angle sensor
•Yaw rate & lateral G sensor
•Steering wheel parts (Including airbag)
•Suspension parts
•Wheel alignment adjustment
1) Park the vehicle straight on a level surface. (En-
gine operation in the “P” or “N” range)
2) Check that steering wheel is positioned at the
center. (When the center position is not correct, ad-
just the wheel alignment.)
3) Set the Subaru Select Monitor to the vehicle,
and select {Set up mode for Neutral of Steering An-
gle Sensor & Lateral G Sensor 0 point} in the
“Function check sequence” screen. (Follow the
procedures shown in the display.)
4) On the “Brake Control System” display screen,
select {Current Data Display & Save}, and check
that the steering angle sensor shows “0 deg”.
5) When the “0 deg” is not displayed, repeat the
above steps and check that the “0 deg” is dis-
played.
6) Drive the vehicle for 10 minutes, and check that
the ABS and VDC warning light is not illuminated.
7) Check that there is no unnecessary VDC opera-
tion or steering control loss. If there is a problem,
repeat the steps above.