2012 SUBARU IMPREZA WRX wheel

7-24Starting and operating
Limited slip differential (LSD) (STI)
The LSD provides optimum distribution of
power according to the difference in
revolutions between the right and left
wheels that may be caused by certain
driving conditions, thereby improving driv-
ing stability on snow-covered, muddy or
other slippery roads or when high speeddriving.
CAUTION
. Never start the engine while a tire
on one side is jacked up, as the
vehicle may move.
. If one tire is spinning in mud,
avoid continued spinning at high
speed as this could adversely
affect the LSD.
. If you use a temporary spare tire
to replace a flat tire, be sure to
use the original temporary spare
tire stored in the vehicle. Using
other sizes will adversely affect
the LSD. Power steering
The power steering system operates only
when the engine is running.
If you lose power steering assist because
the engine stops or the system fails to
function, you can steer but it will take
much more effort.
CAUTION
Do not hold the steering wheel at the
fully locked position left or right for
more than 5 seconds. This may
damage the power steering pump.
NOTE
Right after the engine has been started
and before it has warmed up, you may
hear a noise coming from areas adja-
cent to the power steering pump which
is located at the right-front area of the
engine compartment. This noise is
normal. It does not indicate power
steering system trouble. Braking &
Braking tips
WARNING
Never rest your foot on the brake
pedal while driving. This can cause
dangerous overheating of the
brakes and needless wear on the
brake pads and linings.
! When the brakes get wet
When driving in rain or after washing the
vehicle, the brakes may get wet. As a
result, brake stopping distance will be
longer. To dry the brakes, drive the vehicle
at a safe speed while lightly depressing
the brake pedal to heat up the brakes. ! Use of engine braking
Remember to make use of engine braking
in addition to foot braking. When descend-
ing a grade, if only the foot brake is used,
the brakes may start working improperly
because of brake fluid overheating,
caused by overheated brake pads. To
help prevent this, shift into a lower gear to
get stronger engine braking. ! Braking when a tire is punctured
Do not depress the brake pedal suddenly
when a tire is punctured. This could cause

7-26Starting and operating
ABS (Anti-lock Brake Sys- tem)
The ABS system prevents the lock-up of
wheels which may occur during sudden
braking or braking on slippery road sur-
faces. This helps prevent the loss of
steering control and directional stability
caused by wheel lock-up.
When the ABS system is operating, you
may hear a chattering noise or feel a slight
vibration in the brake pedal. This is normal
when the ABS operates.
The ABS system will not operate when the
vehicle speed is below approximately 6
mph (10 km/h).
WARNING
Always use the utmost care in driving –overconfidence because
youaredrivingwithanABS
equipped vehicle could easily lead
to a serious accident.
CAUTION
. The ABS system does not always
decrease stopping distance. You
should always maintain a safe
following distance from other vehicles.
. When driving on badly surfaced
roads, gravel roads, icy roads, or
over deep newly fallen snow,
stopping distances may be long-
er for a vehicle with the ABS
system than one without. When
driving under these conditions,
therefore, reduce your speed and
leave ample distance from othervehicles.
. When you feel the ABS system
operating, you should maintain
constant brake pedal pressure.
Do not pump the brake pedal
since doing so may defeat the
operation of the ABS system.
& ABS system self-check
Just after the vehicle is started, you may
feel on the brake pedal a vibration similar
to when the ABS operates, and you may
also hear the sound of the ABS working
from the engine compartment. This is
caused by an automatic functional test of
the ABS system being carried out and
does not indicate any abnormal condition. & ABS warning light
Refer to “ABS warning light ”F 3-18. Electronic Brake Force Dis-
tribution (EBD) system
The EBD system maximizes the effective-
ness of the brakes by allowing the rear
brakes to supply a greater proportion of
the braking force. It functions by adjusting
the distribution of braking force to the rear
wheels in accordance with the vehicle
’s
loading condition and speed.
The EBD system is an integral part of the
ABS system and uses some of the ABSsystem ’s components to perform its func-
tion of optimizing the distribution of brak-
ing force. If any of the ABS components
used by the EBD system malfunction, the
EBD system also stops working.
When the EBD system is operating, you
may hear a chattering noise or feel a slight
vibration in the brake pedal. This is normal
and does not indicate a malfunction.

&Steps to take if EBD system malfunctions
If a malfunction occurs in the EBD system,
the system stops working and the brake
system warning light and ABS warning
light illuminate simultaneously.
The EBD system may be malfunctioning if
the brake system warning light and ABS
warning light illuminate simultaneously
during driving.
Even if the EBD system malfunctions, the
conventional braking system will still func-
tion. However, the rear wheels will be
more prone to locking when the brakes
are applied harder than usual and thevehicle ’s motion may therefore become
somewhat harder to control.
If the brake system warning light and ABS warning light illuminate simultaneously,
take the following steps.
1. Stop the vehicle in the nearest safe,
flat location.
2. Shut down the engine, apply the
parking brake, and then restart it.
3. Release the parking brake. If both
warning lights turn off, the EBD system
may be malfunctioning. Drive carefully to
the nearest SUBARU dealer and have the
system inspected.
4. If both warning lights illuminate again
and remain illuminated after the engine
has been restarted, shut down the engine
again, apply the parking brake, and check
the brake fluid level. Refer to
“Brake fluid ”
F 11-18.
5. If the brake fluid level is not below the“ MIN ”mark, the EBD system may be
malfunctioning. Drive carefully to the
nearest SUBARU dealer and have the
system inspected.
6. If the brake fluid level is below the “ MIN ”mark, DO NOT drive the vehicle.
Instead, have the vehicle towed to the
nearest SUBARU dealer for repair.
WARNING
. Driving with the brake system
warning light illuminated is dan- gerous. This indicates your brake
system may not be working
properly. If the light remains
illuminated, have the brakes in-
spected by a SUBARU dealer
immediately.
. If at all in doubt about whether
the brakes are operating prop-
erly, do not drive the vehicle.
Have your vehicle towed to the
nearest SUBARU dealer for re-
pair. Starting and operating
7-27

7-28Starting and operating
Vehicle Dynamics Control system
WARNING
Always use the utmost care in driving –overconfidence because
you are driving with a Vehicle Dy-
namics Control system equipped
vehicle could easily lead to a ser-
ious accident.
CAUTION
. Even if your vehicle is equipped
with Vehicle Dynamics Control
system, winter tires should be
used when driving on snow-cov-
ered or icy roads; in addition,
vehicle speed should be reduced
considerably. Simply having a
Vehicle Dynamics Control sys-
tem does not guarantee that the
vehicle will be able to avoid
accidents in any situation.
. Activation of the Vehicle Dy-
namics Control system is an
indication that the road being
travelled on has a slippery sur-
face; since having Vehicle Dy-
namics Control is no guarantee that full vehicle control will be
maintained at all times and under
all conditions, its activation
should be seen as a sign that
the speed of the vehicle should
be reduced considerably.
. Whenever suspension compo-
nents, steering components, or
an axle are removed from a
vehicle, have an inspection of
that system performed by an
authorized SUBARU dealer.
. The following precautions should
be observed in order to ensure
that the Vehicle Dynamics Con-
trol system is operating properly: – All four wheels should be
fitted with tires of the same
size, type, and brand. Further-
more, the amount of wear
should be the same for all
four tires.
– Keep the tire pressure at the
proper level as shown on the
vehicle placard attached to
the driver ’s side door pillar.
– Use only the specified tem-
porary spare tire to replace a
flat tire. With a temporary
spare tire, the effectiveness
of the Vehicle Dynamics Con- trol system is reduced and
this should be taken into ac-
count when driving the vehi-
cle in such a condition.
. If non-matching tires are used,
the Vehicle Dynamics Control
system may not operate cor-
rectly.
. The Vehicle Dynamics Control
system helps prevent unstable
vehicle motion such as skidding
using control of the brakes and
engine power. Do not turn off the
Vehicle Dynamics Control sys-
tem unless it is absolutely ne-
cessary. If you must turn off the
Vehicle Dynamics Control sys-
tem, drive very carefully based
on the road surface condition.
In the event of wheelspin and/or skidding
on a slippery road surface and/or during
cornering and/or an evasive maneuver,
the Vehicle Dynamics Control system
adjusts the engine ’s output and the
wheels ’respective braking forces to help
maintain traction and directional control. . Traction Control Function
The traction control function is designed to
prevent spinning of the driving wheels on
slippery road surfaces, thereby helping to
maintain traction and directional control.

Activation of this function is shown by
flashing the Vehicle Dynamics Control
operation indicator light. .Skid Suppression Function
The skid suppression function is designed
to help maintain directional stability by
suppressing the wheels ’tendency to slide
sideways during steering operations. Acti-
vation of this function is shown by flashing
the Vehicle Dynamics Control operation
indicator light. NOTE . The Vehicle Dynamics Control sys-
tem may be considered normal when
the following conditions occur.
–Slight twitching of the brake
pedal is felt. – The vehicle or steering wheel
shakes to a small degree.– An operating sound from the
engine compartment is heard
briefly when starting the engine
and when driving off after starting
the engine. – The brake pedal seems to jolt
when driving off after starting the engine.
. In the following circumstances, the
vehicle may be less stable than it feels
to the driver. The Vehicle Dynamics Control System may therefore operate.
Such operation does not indicate a
system malfunction.
–on gravel-covered or rutted
roads – on unfinished roads
– when the vehicle is fitted with
snow tires or winter tires
. Activation of the Vehicle Dynamics
Control system will cause operation of
the steering wheel to feel slightly
different compared to that for normalconditions. . It is always important to reduce
speed when appro aching a corner,
even if the vehicle is equipped with
Vehicle Dynamics Control. . Always turn off the engine before
replacing a tire as failure to do so may
render the Vehicle Dynamics Control
system unable to operate correctly.
& Vehicle Dynamics Control
system monitor
Refer to “Vehicle Dynamics Control warn-
ing light/Vehicle Dynamics Control opera-
tion indicator light ”F 3-20 and “Vehicle
Dynamics Control OFF indicator light/
Traction Control OFF indicator light (STI) ”
F 3-21. &
Vehicle Dynamics Control
mode switch (STI)
Indicator light
Vehicle Dynamics Control mode switch
When the switch is pressed briefly or for
more than approximately 3 seconds dur- Starting and operating
7-29
– CONTINUED –

Vehicle Dynamics Control OFF switch
Pressingtheswitchtodeactivatethe
Vehicle Dynamics Control system can
facilitate the following operations: . a standing start on a steeply sloping
road with a snowy, gravel-covered, or
otherwise slippery surface . extrication of the vehicle when its
wheels are stuck in mud or deep snow
When the switch is pressed during engine
operation, the Vehicle Dynamics Control
OFF indicator light on the combination
meter illuminates. The Vehicle Dynamics
Control system will be deactivated and the
vehicle will behave like a model not
equipped with the Vehicle Dynamics Con-
trol system. When the switch is pressed
again to reactivate the Vehicle Dynamics Control system, the Vehicle Dynamics
Control OFF indicator light turns off.
With the Vehicle Dynamics Control system
deactivated, traction and stability en-
hancement offered by Vehicle Dynamics
Control system is unavailable. Therefore
you should not deactivate the Vehicle
Dynamics Control system except under
above-mentioned situations.
NOTE . The Vehicle Dynamics Control sys-
tem will be activated automatically
when the engine is started.. If the switch is held down for 10
seconds or longer, the indicator light
turns off, the Vehicle Dynamics Control
system is activated, and the system
ignores any further pressing of the
switch. To make the switch usable
again, turn the ignition switch to the“ LOCK ”position and restart the en-
gine.. When the switch is pressed to
deactivate the Vehicle Dynamics Con-
trol system, the vehicle ’s running per-
formance is comparable with that of a
vehicle that does not have a Vehicle
Dynamics Control system. Do not de-
activate the Vehicle Dynamics Control
system except when absolutely neces-
sary. .
Even when the Vehicle Dynamics
Control system is deactivated, compo-
nents of the brake control system may
still activate. When the brake control
system is activated, the Vehicle Dy-
namics Control operation indicator
light illuminates. Starting and operating
7-31

7-32Starting and operating
Tire pressure monitoring
system (TPMS) (U.S.-spec.models)
The tire pressure monitoring system pro-
vides the driver with a warning message
by sending a signal from a sensor that is
installed in each wheel when tire pressure
is severely low.
The tire pressure monitoring system will
activate only when the vehicle is driven at
speeds above 20 mph (32 km/h). Also,
this system may not react immediately to a
sudden drop in tire pressure (for example,
a blow-out caused by running over a
sharp object).
WARNING
If the low tire pressure warning light
illuminates while driving, never
brake suddenly and keep driving
straight ahead while gradually redu-
cing speed. Then slowly pull off the
road to a safe place. Otherwise an
accident involving serious vehicle
damage and serious personal injury
could occur.
Check the pressure for all four tires
and adjust the pressure to the COLD
tire pressure shown on the tire
placard on the door pillar on thedriver ’s side.
Even when the vehicle is driven a
very short distance, the tires get
warm and their pressures increase
accordingly. Be sure to let the tires
cool thoroughly before adjusting
their pressures to the standard
values shown on the tire placard.
Refer to “Tires and wheels ”F 11-23.
The tire pressure monitoring system
does not function when the vehicle
is stationary. After adjusting the tire
pressures, increase the vehicle
speed to at least 20 mph (32 km/h)
to start the TPMS re-checking of the
tire inflation pressures. If the tire
pressures are now above the severe low pressure threshold, the low tire
pressure warning light should turn
off a few minutes later.
If this light still illuminates while
driving after adjusting the tire pres-
sure, a tire may have significant
damage and a fast leak that causes
the tire to lose air rapidly. If you have
a flat tire, replace it with a spare tire
as soon as possible.
When a spare tire is mounted or a
wheel rim is replaced without the
original pressure sensor/transmitter
being transferred, the low tire pres-
sure warning light will illuminate
steadily after blinking for approxi-
mately one minute. This indicates
the TPMS is unable to monitor all
four road wheels. Contact your
SUBARU dealer as soon as possible
for tire and sensor replacement and/
or system resetting.
Do not inject any tire liquid or
aerosol tire sealant into the tires,
as this may cause a malfunction of
the tire pressure sensors. If the light
illuminates steadily after blinking for
approximately one minute, promptly
contact a SUBARU dealer to have
the system inspected.

7-34Starting and operating
When parking on a hill, always turn the
steering wheel. When the vehicle is
headed up the hill, the front wheels should
be turned away from the curb.
When facing downhill, the front wheels
should be turned into the curb.
WARNING
. Never leave unattended children
or pets in the vehicle. They could
accidentally injure themselves or
others through inadvertent op-
eration of the vehicle. Also, on
hot or sunny days, the tempera-
ture in a closed vehicle could
quickly become high enough to
cause severe or possibly fatal
injuries to people.
. Do not park the vehicle over
flammable materials such as dry
grass, waste paper or rags, as
they may burn easily if they come
near hot engine or exhaust sys-
tem parts.
. Be sure to stop the engine if you
take a nap in the vehicle. If
engine exhaust gas enters the
passenger compartment, occu-
pants in the vehicle could die
from carbon monoxide (CO) con-
tained in the exhaust gas.
CAUTION
If your vehicle has a front under-
spoiler and rear underspoiler (both
optional), pay attention to blocks and other obstructions on the
ground when parking. The under-
spoilers could be damaged by con-
tact with them.