2014 AUDI S8 wheel

168 Airbag system
and safety belts with pretensioners are
scrapped, al l applicable laws and regula·
tions must be observed. Your authorized
Audi dea ler is familiar with these require·
ments and we recommend that you have
your dealer perform this service for you .
Other things that can affect Advanced
Airbag performance
Changing the vehicle's suspension system can
change the way that the Advanced Airbag Sys­
tem performs in a crash. For example, using
tire-rim combinations not approved by Audi, lowering the vehicle, chang ing the stiffness of
the suspension, including the spring s, suspen­
sion struts, shock absorbers etc. can change
the forces that are measured by the a irbag
sensors and sent to the electronic control
unit . Some suspension changes can, for exam­
ple, increase the force levels measured by the
sensors and make the airbag system deploy in
crashes in which it would not deploy if the
changes had not been made. Other kinds of
changes may reduce the force levels meas ­
ured by the sensors and prevent the airbag
from deploying when it should.
The sensors in the safety belt buckle for the
driver and front passenger seat tell the elec­
tronic control module if the safety belt is
latched or not. If the safety belt is being used,
the front airbag will deploy at a slightly high­
er rate of vehicle deceleration than if the safe ­
ty belt is not being used . Therefore, in a par­
ticular collision, it is possible that an airbag
will not deploy at a seating position where the
safety belt is being used but will inflate at the
position where the safety belt is not being
used . It is important that nothing interfere
with the safety belt buckles so that the sen­
sors can send the correct information about
safety belt use to the electronic control unit.
A WARNING
Changing the vehicle's suspension includ­
ing use of unapproved tire-rim combina­
tions can change Advanced Airbag per-formance and increase the risk of serious
personal injury in a crash.
- Never install suspension components
that do not have the same performance
characteristics as the components origi­ nally installed on your vehicle.
- Never use tire-rim combinations that
have not been approved by Audi.
A WARNING
--
Items stored between the safety belt buckle and the center console can cause
the sensors in the buckle to send the
wrong information to the e lectronic con­
trol module and prevent the Advanced Air­
bag System from working properly.
- Always make sure that nothing can inter­
fere with the safety belt buckles and that
they are not obstructed .
Knee airbags
Description of knee airbags
The knee airbag system con provide supple­
mental protection to properly restrained
front seat occupants.
Fig. 169 Driver 's knee airbag
The driver knee airbag is in the instrument
panel underneath the steering wheel
¢ fig . 169, the airbag for the passenger is at
about the same height in the instrument pan­
el underneath the glove compartment.
The knee airbag offers additional protection
to the driver's and passenger's knees and up­
per and lowe r th igh areas and supplements
the protection provided by the safety belts. ..,.

1 7 0 Airbag system
How knee airbags work
The risk of injury to the leg area can be re­
duced by fully inflated knee airbags.
Fig . 170 Inflated airbags protect ing in a frontal coll i­
sio n
The knee airbag system has been designed so
that the a irbags for the driver and front pas­
senger deploy in certain but not all frontal
collis ions ..
If the front airbags deploy, the knee airbags
also deploy i n frontal collisions when the de­
ployment threshold stored in the control unit
is met .
When the system deploys, the airbags fill
with a propellant gas, and inflate between the
lower part of the instrument panel and the
driver and the lower part of the instrument
panel and the front passenger
9 page 162,
fig. 167.
Although they a re not a soft pillow, they can
"cush ion " the impact and in this way they can
he lp to reduce the risk of injury to the lower
extremities.
All of this takes place in the blink of an eye, so
fast that many people don't even realize that
the airbags have deployed . T he ai rbags also
inflate with a great deal of force and it is im ­
po rtan t for occupant sa fety that not hing
should be in their way when they deploy.
Fu lly inflated airbags in combination with
properly worn safety bel ts slow down and lim­
it the oc cupant's forwa rd movement and help
to reduce the risk of injury. Important safety instructions on the
knee airbag system
Airbags are only supplemental restraints
. Al­
ways wear safety belts correctly and ride in a
proper seating position.
The re is a lot that you and your passengers
must know and do to he lp the sa fety belts and
airbags to prov ide supplemen ta l protect ion.
A WARNING ~
An inflat ing knee a irbag can cause serio us
i njury . Wearing safety belts incorrectly and
improper seating positions increase the
risk of ser ious persona l injury and death
whenever a vehicle is being used.
- The knee airbag system cannot protect
you properly if you a re seated too close
to any of the airbag locations. When ad­
justing their seat pos itions, it is impor­
tant that both the driver and the front
passenger keep the ir upper bod ies and
knees at the following m inimum safe
d istances:
- at least 10 inches (25 cm) between the
chest and the steering wheel/instru­
ment panel.
- at least 4 inches (10 cm) between the
knees and the lower part of the instru­
ment panel.
- The risk of personal injury increases if
you lean forward or to the side, or if the
seat is improperly positioned and you are not wearing your safety belt . The risk in­
creases even more should the a irbag de­
p loy .
- Always make s ure that the knee airbag
can inf late without inte rfe rence. Objects
between yo u and the airbag can increase
the risk of injury in an accident by inter ­
fering w ith the way the airbag deploys or
by being pushed into you as the airbag
deploys.
- Never let anybody, espec ia lly children
o r anima ls ride in the footwell in front

178 Child Safety
-Always install rear-facing child safety
seats on the rear seat.
- If you must install a rearward facing
child safety seat on the front passenger
seat in exceptional circumstances and
the
PASSENGER AIR BAG OFF light does
not come on and stay on, immediately
install the rear-facing child safety seat in
a rear seating position and have the air­
bag system inspected immediately by
your Audi dealer.
_& WARNING
If, in exceptional circumstances, you must
install a forward-facing child restraint on
the front passenger's seat:
- Always make sure the forward-facing
seat has been designed and certified by
its manufacturer for use on a front seat
with a passenger front and side airbag.
- Always follow the manufacturer's in­
structions provided with the child safety
seat or carrier.
- Always move the passenger seat into its
rearmost position in the seat's fore and
aft adjustment range, as far away from
the airbag as possible before installing
the child restraint. The backrest must be
adjusted to an upright position .
- Always make sure that the
PASSENGER
AIR BAG OFF
light comes on and stays
on all the time whenever the ignition is
switched on.
(D Tips
Always replace child restraints that were
installed in a vehicle during a crash. Dam­
age to a child restraint that is not visible
could cause it to fail in another collision
situation.
Advanced front airbag system and children
Your vehicle is equipped with a front "Ad­
vanced Airbag System" in compliance with United States Federal Motor Vehicle Safety Standard (FMVSS) 208 as applicable at the
time your vehicle was manufactured.
The Advanced Airbag system in your vehicle
has been certified to meet the "low-risk" re­
quirements for 3- and 6-year old children on
the passenger side and small adults on th e
driver side. The low ris k deployment criteria
are intended to reduce the risk of injury
through interact ion with the airbag t hat can
occur, for example, by being too close to the
steering wheel and instrument panel when
the airbag inflates . In addition, the system
has been certified to comply with the "sup­
pression" requirements of the Safety Stand­
ard, to turn off the front airbag for infants up
to 12 months who are restrained on the front
passenger seat in child restraints that are list­
ed in the Standard.
Even though your vehicle is equipped with an
Advanced Airbag system , all children, espe­
cially those 12 years and younger, should al­
ways ride in the back seat properly restrained
for their age and size. The airbag on the pas­
senger side makes the front seat a potentially
dangerous place for a child to ride . The front
seat is not the safest place for a child in a for­
ward-facing child safety seat. It can be a very
dangerous place for an infant or a larger child
in a rearward-facing seat .
Advanced Airbags and the weight­
sensing mat in the front seat
The Advanced Airbag System in your vehicle
detects the presence of an infant or child in a
child restraint on the front passenger seat us­
ing the weight-sensing mat in the seat cush ­
ion and the sensor below the safety belt latch
on the front passenger seat that measures the
tension on the safety belt.
The weight -sensing mat measures total
weight of the child and the child safety seat
and a child blanket on the front passenger
seat. The weight on the front passenger seat
is related to the design of the child restraint
and its "footprint", the size and shape of the
bottom of the child restraint as it sits on the .,..

Intelligent technology Notice about data
recorded by vehicle
control modules
Your vehicle is not equipped with an Event Da­
ta Recorder (EDR), installed by some manu­
facturers for the express purpose of capturing
data for retrieval after an accident or crash
event. EDR's are sometimes called "crash re­
corders".
Some state laws restrict the retr ieval or down­
loading of data stored by EDR's that were in­
stalled in a vehicle for the express purpose of
retrieving data after an accident or crash
event without the owner's consent.
Although your vehicle is not equipped with an
EDR, it is equipped with a number of electron­
ic control modules for various vehicle systems
such as, for examp le, engine function, emis­
sion control, as well as for the airbags and
safety belts.
These electronic control modules also record
vehicle-related data during norma l vehicle op­
eration for diagnostic and repair purposes.
The recording capacity of the electronic con­
trol modules is limited to data (no sound is re­
corded) and only a small amount of data is ac­
tually recorded over a very limited period of
time and stored when a system fault or other
condition is sensed by a control unit. Some of
the data then stored may relate to vehicle
speed, direction, braking as we ll as restraint
system use and performance in the event of a
crash or other condition. Stored data can only be read and downloaded with special equip­
ment.
Electronic Stabilization
Control (ESC)
Description
ESC helps to improve road holding and vehicle
dynamics to help reduce the probability of
skidding and loss of veh icle control. It works
only when the engine is running. ESC detects
Intelligent technology 199
certain difficult driving situations, including
when the vehicle is beginning to spin (yaw)
out of control and helps you to get the veh icle
back under control by se lectively braking the
wheels, and/or reducing engine power and
providing steering ass istance to help hold the
vehicle on the driver's intended course. The in­
dicator light
JjJ in the instrument cluster
blinks when ESC is taking action to help you
control the vehicle.
ESC has limitations .
It is important to remem­
ber that ESC cannot overcome the laws of
physics.
It will not always be able to help out
under all conditions you may come up against.
For example, ESC may not always be able to
help you master situations where there is a
sudden change in the coefficient of friction of
the road surface. When there is a section of dry road that is suddenly covered with water,
slush or snow, ESC cannot perform the same
way it would on the dry surface. If the vehicle
hydroplanes (rides on a cushion of water in­
stead of the road surface), ESC will not be
able to help you steer the vehicle because con­
tact with the pavement has been interrupted
and the vehicle cannot be braked or steered .
During fast cornering, particularly on winding
roads, ESC cannot always deal as effectively
with difficult driving situations than at lower
speeds. When towing a trailer, ESC is not able
to help you regain control as it would if you
were not tow ing a trailer.
A lways adjust your speed and driving style to
road, traffic and weather conditions. ESC can­
not override the vehicle's physical limits, in­
crease the available traction, or keep a vehicle
on the road if road departure is a result of
driver inattention. Instead, ESC improves the
poss ibility of keeping the vehicle under con­
trol and on the road dur ing extreme maneu­
vers by using the driver's steering inputs to
help keep the vehicle going in the intended di­
rection. If you are traveling at a speed that
causes you to run off the road before ESC can
provide any assistance, you may not experi­
ence the benefits of ESC.
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200 Intellig ent technol ogy
ESC includes and/or works together with the
anti-lock braking system (ABS), brake assist
system, anti-slip regulat ion (ASR), electronic
d ifferential lock (EDL), dynamic steering* and
electronic interaxle differential lock*. ESC is
switched on all the time. In certain situations
when you need less tract ion, you ca n sw itch
off ASR by pressing the button above
~ page 201, fig. 188 the se lector lever. Be
sure to sw itch ASR on aga in when you no lon­
ger need less traction.
Anti -lock braking system (ABS )
ABS prevents the wheels from locking up
when braking. The vehicle can still be steered
even du ring ha rd b raking . Apply steady pres­
sure to the brake pedal. Do not pump the ped­
a l. A pulsing in the brake peda l indicates that
the system is he lping you to brake the vehicle.
Br ake assist system
The brake assist system can decrease brak ing
d istance. It increases braking power when the
d river p resses the brake pedal q uick ly in emer­
gency situations. You must press and hold the brake peda l until the situation is over. In
vehicles with adaptive cruise control*, the brake assist system is more sensitive if the
d istance detected to the vehicle ahead is too
small.
Anti- slip regulati on (ASR )
ASR reduces engine power when the drive
wheels begin to spin and adapts the force to
the road condit ions. This makes it easier to
start, accelerate and drive up hills.
El ectronic diff erential lo ck (EDL )
The ED L brakes wheels that are spinning and
transfers the drive power to the other drive
wheel or whee ls if the vehicle is equipped with
all whee l drive*. This funct ion is available up
to about 7S mph (120 km/h).
In extreme cases, EDL a utomatica lly switches
off to help keep the brake on the braked whee l
from overheating. EDL will switch on again au­
tomatically when conditions have returned to normal.
Dynamic ste ering *
On vehicles with dynamic s teering, ES C helps
stabilize the steering in certain situations.
Electronic interaxle differential lock
function*
T he electronic interaxle differentia l lock f unc­
tion activates when driving thro ugh curves.
Braking is targeted toward the wheels on the
inside of the curve as needed . This he lps to
minimize front whee l skid, improves traction
and allows for more precise driving through
curves .
A WARNING
- ESC, ABS, ASR, EDL, dynamic steering*
and the electronic interaxle differential loc k function* cannot overcome the laws
of physics. This is espec ially impo rtant
on slippery o r we t roads.
If the systems
begin acting to stabilize your vehicle, you
should immediately change yo ur speed
to match the road and traffic conditions .
Do not let the increased safety provided
by these systems tempt you to take risks. Doing so will increase the risk of a loss of
veh icle control, collision and ser ious per­
sonal injur ies.
-Always adapt your speed to road, traffic and weather conditions. The risk of los­ing control of the vehicle increases when
d riving too fast, espec ially through
curves and on slippery or wet roads, and
when driving too close to vehicles up
ahead. ESC, ABS, the brake ass ist sys ­
tem, EDL, ASR, dynamic steering * and
the electron ic interaxle differential lock
function* cannot prevent collisions.
- Always accelerate with special care on
even, smooth s urfaces such as those that
are wet or covered with ice and snow.
The drive wheels can spin even w ith
these assistance systems that cannot al­
ways he lp to red uce the risk of loss of ve­
h icle control.
-

@ Tips
-ABS and AS R on ly wor k co rrectly when
a ll fo ur wheels are eq uipped w ith identi­
ca l tires . Different tire s izes can lead to a
r educt io n in eng ine power.
- You may hear noises when the sys tems
desc ribed are working.
Switching on and off
Intelligent technology 201
- If the ind ica tor li ght DJ o r til1 (U SA
mo dels)/ [!] (Canada models) appea rs,
there may be a malfunc tion
r:::> page 19,
¢page 18.
ESC turns on automatically when you start the engine.
Fig . 188 Center co nsole with ESC O FF bu tton
ESC levels
Sport mode on
The following si tua tions are exceptions whe re
it may be usefu l to switch o n sport mo de to
allow the w heels to spi n:
- Rockin g the vehicle to free it when i t is st uck
- Dr iv ing in deep s now o r on loose g ro un d
- Dr iving with snow chains
Sport mode off
Behavior
T he E SC and AS R sta bilization f unct io ns The fu ll sta biliz ati on f uncti on o f the ES C
are limited¢ ,&.
Operation Press the [ru button .
Indicator II turns on .
lights
Driver mes· Stabilization control (ESC): Sport
sages Warning! Reduced stability
A WARNING
Yo u should o nly sw itch sport mo de on i f
your dr iv ing abili ties and road cond itions
permit.
- The stabilization function is limited
when sport mode is sw itched on. The
dr iv ing whee ls co uld spin and the vehicle
cou ld swe rve , especially on slick or slip ­
pery road surfaces.
(D Tips
Sport mode cannot be switched o n when
adapt ive cr uise c ontrol* is sw itched on.
-
and AS R is availab le again .
Press the
[ru button again .
II tur ns off.
Stabilization control (ESC): On
Braking
General information
What affects braking efficiency?
Operating conditions and driving habits
The bra ke s on today's au to m obiles a re s till
sub ject t o wear, depe nding la rgely o n ope rat ­
i ng con dit ions and d riving habits¢
A . On
vehicles that are either driven most ly in stop­
and-go city traff ic or are driven hard , the
brake pads should be checked by your author­
ized Audi dealer more often than specif ied in
t h e
Warranty & Maintenance booklet . Failure .,..

202 Intellig ent technol ogy
to have your brake pads inspected can result
in reduced brake performance.
On steep slopes, yo u shou ld use the b rak ing
effect of the engine. Th is way, you prevent un­
necessary wear on the brake system. If you
must use your brakes, do not hold the brakes
down continuously. P ump the brakes at inter ­
vals.
Operating nois e
Noises may occur when braking depending on
the speed, braking force and outside condi­
tions such as temperature and humidity.
E ff ect of water and road salt
In certain situat ions, for example after driving
through water , in heavy ra in , after overn ight
condensation or after washing your car, the braking effect can be reduced by moisture or
ice on the brake rotors and brake pads. The
brakes must be dried first with a few careful
brake applications.
At higher speeds and with the windshield wip­
ers turned on, the brake pads press against
the brake rotors for a short amount of time.
This occurs at regular intervals without the
driver noticing and provides for bet ter brake
response time under wet condit ions .
The effectiveness of the brakes can be reduced
when the vehicle is dr iven on a salt-covered
road and the brakes are not used . Likew ise,
you clean off accumulated salt coating from
brake discs and pads with a few caut ious ap­
plications of the brake
9 .&, .
Cor ro sion
There may be a tendency for dirt to build up
on the brake pads and corrosion to form on
the discs if the car is not dr iven regularly or
only for short t rips with little use of the
b rakes .
If the brakes are not used frequently , or if cor­
rosion has formed on the discs, it is advisable
to clean off the pads and discs by braking
firm ly a few times from a mode rately high
speed
9 .&, .
Faults in the brake syste m
If you shou ld notice a sudden increase in
brake pedal trave l, then one of the two brake
circuits may have fai led
9 & .
Low bra ke fluid lev el
Malfunctions can occu r in the bra ke system if
the b rake fluid level is too low. The brake flu id
level is monitored electro nica lly.
Brake lining we ar statu s
Brake lining wear may be checked by visual in­
spect ion of the condition of the brake pads
th rough the open ings in the wheel. If neces ­
sary, the wheel may be removed for t his i n­
spect ion
9 page 2 72, Changing a wheel.
A WARNING
- You shou ld perform braking maneuvers
for the purpose of cleaning the brake system only if road conditions permit.
Other road users must not be put at risk -
you may cause an accident!
- Before descending a steep grade, reduce
speed and sh ift transmission into a lower
gear or lower dr iving range. Do not ride
the brakes or hold the pedal down too
long or too often . This could cause the
b rakes to get hot and diminish braking
efficiency.
- Do not "ride the brakes" by rest ing your
foo t on the pedal when you do not intend
to brake. This may cause the brakes to
overheat, premature wear and increased
stopping distance.
- Unde r certain cl imatic and operat ing
conditions such as passing thro ugh wa ­
ter, driving in heavy rain or after washing
the vehicle, the effectiveness of the brakes can be reduced. In winter, ice can
accumu late on the brake pads, linings,
d iscs and drums. Carefully app ly brakes
for a test. Brakes will dry and ice coat­ ings will be cleaned off after a few care­
fu l brake applicat ions.
- Driving for an extended period of t ime on
salt-covered roads without using your brakes can a lso affect bra king efficiency.
~

Clean off accumulated salt coating from
brake discs and pads with a few careful
brake applicat ions .
-If you damage the front spoiler, or if you
install a different spoiler, be sure the air
flow to the front brakes is not obstruct­ ed . Otherwise the brake system could
overheat reducing the effectiveness of
the ent ire brake system.
- Failure of one brake c ircuit will impair
the braking capability resulting in an in­
cr eased stopp ing distance. Avoid driv ing
the vehicle and have it towed to the near­ est Aud i dea ler or q ualified wor kshop .
- Never let the vehicle rol l to a stop w ith
t he engine shu t off.
- If the brake booster is not work ing, the
brake pedal must be pressed conside ra­
bly harder to make up for the lac k of
booster assistance.
Brake booster
The brake booster adds extra braking power.
The brake booster works w ith vacuum pres ­
sure which is created only when the engine is
ru nning
9 ,&. .
,&. WARNING
-Never le t the vehicle ro ll to a stop w ith
t he engine shu t off.
- If the brake booster is not work ing, fo r
ex ample when towing your ve hicl e, or
because the b rake booste r has somehow
been damaged, the brake pedal must be
pressed considerab ly harder to make up
for the lack of booster assistance.
Servotronic - advanced
power steering system
-
The power steering systems use the power of
the running engine to allow precise steering
with little effort.
The advanced Servotronic power steering sys­
tem senses the road speed and electron ically
ad ju sts powe r ass istance to provide comfor ta-
Int ellig ent technolog y 203
ble and safe steering response exactly match ­
ed to th e vehicle speed .
Power steer ing will not work if the engine is
off . As a result, the steering wheel will be h ard
to tu rn.
T he powe r stee ring fluid level is checked d ur­
i ng t he sched uled maintena nce services.
(D Note
If there is an e lectronic malfunction, ser­
votronic
will s till fu nction like a conven­
tiona l powe r steering system, providing a
constant steering s upport force tha t is no
l onge r proportionate to the vehicle speed.
This is most noticeab le when t urni ng the
steering wheel at low speeds (for example
when parking), -more effort w ill be re­
quired than usual.
- Be aware of the different than usual steering response and adjust your steer­
ing force accordingly.
- Have the problem checked and set right by an Audi dealer as soon as possible.
(D Tips
-When the engine is running, never hold
the steering wheel turned all the way to
the right or to the left for longer than 15
seconds . The power steering pump will
overheat the hydraulic fluid if yo u keep
holding the stee ring wheel turned all the
way. This is likely to damage the power
steering sys tem.
- If the powe r stee ring system should fa il
entire ly, o r if t he engine is not runn ing
(for example, wh ile be ing towed), you
w ill still be able to steer the veh icle .
However,
considerably more effort will
be required to do so .
- If the powe r steering system sho uld
have a leak, or is not functioning proper­
ly, contact your author ized Audi dealer
immediately.
- The power steering system req uires a
specially formu lated hydraulic fluid. The
power steering fluid reservoir is located
in the engine compartment
9 page 233. IJJ,,
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