2009 AUDI S8 wheel

llffll,___A_ ir_ b_ a.::g <-- s-- & WARN ING (continued )
• A tight tether or other strap on a rearward-facing child restraint
attached to the front passenger seat c an put too much p res su re
on the weight-sensing mat in the seat and reg ister more weight
than is actually on the seat . The heavier weight registered can
make the system work as though an adult were on the seat and
deploy the Advanced Airbag when it mu st be suppre ssed causing
serious or even fatal injury to the child .
• If, in exceptional circumstances , you must install a forward ­
f ac ing child restraint on the front passenger seat , always move the
seat into its rearmost position in the seat's fore and aft adjust ­
ment range , as far away from the airbag as possible . The ba ckrest
must be adju sted to an upright position. Make sure that the
PASSENGER AIR BAG OFF light comes on and stays on all the time
whenever the ignition is switched on .
& WARNING
• If the PASSENGER AIR BAG OFF light does not go out when an
adult is sitting on the front passenger seat after tak ing the steps
described above, make sure the adult i s properly seated and
restrained at one of the rear seat ing positions .
• Have the airbag system inspected by your Audi dealer before
transporting anyone on the front passenger seat .
[ i ] Tips
If the we ight -sens ing mat in the front passenger seat detects an
e m pty s eat, th e front airbag on the passenge r side wil l be tur ned
off , and the PASSENGER AIR BAG OFF li ght wil l stay on .•
Repair, care and disposal of the airbags
Parts of the airbag system are insta lled at many different places on
yo ur Audi. Ins tal li n g, r em oving, s ervicing o r rep airi ng a part in an area of the vehicle can damage a part of an airbag system and
p revent that sys tem from wo rking pr operly in a c ollisi on.
Th ere are some important th ings you have to know to ma ke sure
that the effectiveness of the system will not be impai red and that
discarded co mponents do no t cause i njury or po llute the enviro n­
ment.
& WARNING
Improper care , servicing and repair procedures can increase the
risk of personal injury and death by preventing an airbag from
deploying when needed or deploying an airbag unexpectedly :
• Never cover , obstruct , or change the steering wheel horn pad
or airbag cover or the instrument panel or modify them in any way.
• Never atta ch any objects su ch as cup holders or telephone
mountings to the surfaces covering the airbag units .
• For cleaning the horn pad or instrument panel , use only a soft ,
dry cloth or one moistened with plain water . Solvents or cleaners
could damage the airbag cover or change the stiffness or strength
of the material so that the airbag cannot deploy and protect prop ­
erly .
• Never repair , adjust, or change any parts of the airbag system .
• All work on the steering wheel , instrument panel , front seats or
electrical system (including the installation of audio equipment ,
cellular telephones and CB radios , etc .I must be performed by a
qualified technician who has the train ing and special equipment
necessary .
• For any work on the airbag system, we strongly recommend
that you see your author ized Audi dealer or qualified workshop .
• Never modify the front bumper or parts of the vehicle body .
• Always make sure that the side airbag can inflate without inter-
ference :
~

___ A_ ir_b _a_ g;:::;_ s--:.. y_s _t _e _m _________________________________________________ _
& WARNING
Changing the vehicle's su spension includ ing use of un approved
tire -rim combinations can change Advanced Airbag performance
and increase the ris k of serious personal injury in a crash .
• Never install suspen sion component s that do not have the
same performance chara cteristics as the components or iginally
installed on your vehicle.
• Never use tire-r im comb inations that have not been approved
by Audi.
& WARNING
Items stored between the safety belt bu ckle and the center
c onsole can cause the sensors in the buc kle to send the wrong
information to the electroni c control module and prevent the
Advanced Airbag System from working properly .
• Alway s make sure that nothing can interfere with the safety
belt buckles and that they are not obstructed .
<£> For the sake of the environment
Undeployed airbag modules a nd pretensioners might be classified
as Pe rchlorate Mat erial -spe cia l han dling may a pply, see
www.dtsc.ca.gov/hazardouswaste/perchlorate. When the vehicle or
par ts o f the restraint syst em i ncludi ng ai rbag modules and saf ety
belts with pretensioners are scrapped, a ll app licab le laws and regu­
latio ns must be observed . Yo ur au thori zed A udi dealer is fam ilia r
with these requirements and we recommend that you have your
dealer perfo rm this serv ice for you .•
Knee airbags
Description of knee airbags
T he airba g sys tem c an prov id e sup plemen tal prot ect ion
t o pro pe rly rest rained fron t seat occ upant s.
0
Fig. 2 36 Drive r's
airba g
The airbag for the driver is located in the instrument panel under ­
neath the steering wheel=> fig. 236, the airbag for the passenger is
at about the same height in the instrument panel und erneath the
glove compartment.
T he knee air bag offe rs addi tio nal pr ote cti on to the d river's a nd
passenger 's knees and upper and lower thigh ar eas as a supple ­
me nt to t he sa fety be lts.
I f the front airbags deploy , the knee airbags also deploy in frontal
collisions above a certain severity=> page
229, "M ore important
thi ngs to kno w about fron t a irba gs" .
B esides their normal safety function, safety belts wor k to help keep
t h e dri ver o r fr on t passeng er in pos itio n in case of a fro ntal col lis ion
so that the airbags can provide protection .
T he airbag system is not a substitute for your safety belt . Rathe r, it
i s part of the overa ll occupa nt res tra int system i n your ve hi cle.
A lwa ys re member that the airbag system can on ly help to protect
you if you a re wearing your safe ty belt and weari ng it properly . T hi s .,,_

1111 Airbag system
----==---=--------------------------------
If the front airbags deploy, the knee airbags also dep loy in frontal
c ollis ions ab ove a cer tai n se ver ity.
When the system is deployed, the airbags start to f ill with a prope l­
lant gas, and inf late between the lower part of the instrument pane l
and t he dr ive r and the lowe r pa rt o f the instrument pane l and t he
front passenger ~ page
229 , fig. 23 4.
Althoug h they are no t a so ft pi llow, t hey can "cushion" th e impac t
and in this way they can he lp to reduce the risk of injury to the lower
e xtr em it ies .
A ll t his takes p lace instantaneously, so fast t hat many people do n't
even realize that the ai rbags have deployed. The airbags a lso inflate
w it h a great deal o f force and it is impor tant for occupan t sa fety t hat
nothing shou ld be in their way when they dep loy.
F u lly infla ted ai rbags i n co mb ination with p roperly worn safety be lts
s low down and limit the occupant's forward movement and he lp to
r ed uce the ris k.•
Important safety instructions on the knee
airbag system
A irb ags ar e onl y supplemen tal r es tra in ts. Alw ays wea r
s af ety be lts cor re ctly and r ide i n a prop er seatin g position.
There is a lo t tha t you a nd your passengers must know a nd do to
help the safet y be lts and airbags to provide supp lemental protec ­
ti on .
& WARNING
An inflating knee airbag can cause serious injury. Wearing safety
belts incorrectly and improper seating positions increase the risk
of serious personal injury and death whenever a vehicle is being
used .
• The airbag system cannot protect you properly if you are
seated too clo se to any of the airbag locations. When adjusting
& WARNING (continued)
their seat positions , it is important that both the driver and the
front passenger keep their upper bodies and knees at the
follow ing min imum safe distances :
- 1 O inches (25 cm) between the chest and the steering
wheel /instrument panel .
- 4 inches (10 cm) between the knees and the lower part of the instrument 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 r isk increases even more should the
airbag deploy .
• Always make sure that the knee airbag can inflate without
interference . Objects between yourself and the airbag can
increase the risk of injury in an accident by interfering w ith the
way the airbag deploys or by being pushed into you as the a irbag
deploys.
-No persons (children) or animals should ride in the footwell
in front of the passenger seat . If the airbag deploys , this can
result in serious or fatal injuries .
- No objects of any kind should be carried in the footwell area
in front of the driver's or passenger's seat. Bulky objects (shop­
ping bags , for example) can hamper or prevent proper deploy ­
ment of the airb ag. Sm all objects can be thrown through the
vehicle if the airbag deploys and injure you or your passengers .
• Make sure there are no cracks , deep scratches or other damage
in the area of the instrument panel where the knee airbags are
located .
• If children are incorrectly seated , their risk of injury increases in
the case of an accident
~ page 245 , "Child Safety". •

-Child Safety -------=---------------------------------------
& WAR NIN G (co ntinued )
• Alw ays in sta ll re ar-facin g child safety s eats on the r ear seat .
• If you m us t in sta ll a rear ward f acing child saf ety s eat on th e
fr ont pa ssenger seat in exceptional circum stan ces and the
PA SSEN GER AIR BAG OFF light do es not come on and sta y on ,
immediately in sta ll the re ar-facing child safety s eat in a rear
s eating po sit ion and ha ve th e airb ag s ystem insp ected immedi ­
atel y by your Audi dea ler .
& WARNING
If, in exceptional circum stance s, you mu st in sta ll a forward -f a cing
c hild re str ain t on th e fr ont p assenger's s eat:
• Always mak e sure the forward -fac ing seat ha s been de signed
a nd ce rt ified by it s m anufa cturer for u se on a fr ont se at w ith a
pa ssenger front and side airbag.
• Always follow the m anufacturer's instru ctions provided w ith
the child safety seat or carr ier.
• Alwa ys mo ve the pa ssenger seat into it s rea rmost positi on in
the seat' s fore and aft adju stment range , as far aw ay from the
ai rbag as possib le bef ore installing the ch ild r estr aint . The ba ck­
re st mu st b e adjusted to an upright po sition.
• Alway s m ake sure that the PASSENGER AIR BAG OFF l ight
c om es on and sta y s on all the time whenever the ignition is
s w it c hed on . •
Advanced front airbag system and children
Your vehicle is equipped with an "Advanced Airbag System" in
complia nce with United States Federa l Motor Vehicle Safety Stan ­
dard (FMVSS) 208 as applicable at the time your vehicle was manu ­
factu red. T
he Advanced Airbag system in your vehicle has been certified to
meet the " low -risk" requirements for 3 and 6 year -old chi ldren on
the passenger side and smal l adults on the driver side . The low risk
deployment criteria are intended to reduce the risk of injury through
interaction with the airbag that 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 "suppression" requirements of the Safety Standard, 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 listed in the
S tandard.
Even though your vehicle is equipped with an Advanced Airbag
system, all ch ildren, especially those 12 years and younger, should
always ride in the back seat properly restrained for their age and
size . The airbag on the passenger side makes the front seat a poten­
tially dangerous p lace for a child to ride. The front seat is not the
safest p lace for a child in a forward -facing child safety seat. It can be
a very dangerous p lace for an infant or a larger ch ild 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 chi ld restraint on the front passenger seat
using the weight -sensing mat in the seat cushion 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 chi ld 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 seat . The weight of a child
restraint and its "footprint" vary for different kinds of child ..,.

The direction in which the driver wishes to travel is determined with
t he aid of the steering angle and vehicle speed and is continua lly
compared with the actual behavior of the vehicle. If the two do not
match, for example, when the vehic le starts hydrop laning on a wet
road, ESP will automatically brake the appropriate whee l to correct
the prob lem.
The vehicle is then stab ilized by the forces acting on the whee l
during braking. If the vehicle is oversteering (rear tends to skid out
of the turn), the brakes are mainly app lied on the wheel that is on
the outside of the curve. In the case of a vehicle that is understeering
(tendency to sl ide out of the curve), the brakes are applied at the
rear wheel that is on the inside of the curve . An acoustic signal indi­
cates when ESP brake application cuts in
~ & .
The system operates across the entire speed range in combination
with the ABS system
~ page 274 . If the Anti -Lock Brake System
(ABS) malfunctions, the ESP wi ll be out of action as well.
Ac tivat ion
When you turn on the eng ine, ESP will automatically be activated
and will perform a self -test.
The system can be activated or deactiva ted by pressing the button
~ page 270, fig. 256. The warning light comes on when the system
is switched off
~ page 18.
Normally , the ESP should always be on, however, it may be advanta­
geous to turn off the system in certain special cases when some
degree of wheel spin is desired such as :
• when driving with snow chains
• when driving in deep snow or on a loose surface (to allow the
wheels to dig in to reach firm ground)
• when trying to "rock" the vehicle free when it has beco me stuck.
T he system should be reactivated once you are no longer in such
situations .
Both the ABS and EDS systems are still functioning even if the ESP
is switched off .
Controls and equip­
ment Safety first Vehicle operation
In
te llig ent tec hn olo gy
& WARNING
The Ele ctron ic St abiliz ation Progr am i s ne ve rt h el ess s ubject to the
laws of ph ysics. It i s particularl y important t o pay attention t o th is
f ac t on wet an d slipp ery road s. It i s th ere fore important that you
alway s adapt your driving to the condition of the road and traffic
c onditio ns. Do n ot allow the in crease d sa fety p ro vi ded by t he El ec­
tronic Stabiliz ation Program sy stem to lu ll you into a ccepting
a dditional safety ri sk s.
c
Electronic differential lock (EDL)
The electronic differential lock monitors the rotation al
s p eed of the drive wheels.
G en era l not es
The elect ronic differential lock (EDU helps the car to start moving,
accelerate and c limb a gradient on surfaces providing poor or
a lmost no grip . Without EDL , this would be difficult, if not impos ­
s ib le.
How the system works
The EDL operates automatical ly. It monitors the rotational speed of
the drive wheels on an axle with the he lp of the ABS sensors
~ page 274. If a noticeable difference in rotational speed between
the drive wheels on one axle is detected (e.g. on slippery ground on
one side), the spinning w heel is braked, thereby transferring power
to the other drive wheel or wheels (all -whee l drivel. This is done up
to a speed of about 60 mph (100 km/h) . Noises from the brake
system signal that wheel spin is being control led .
Dri ving off
When driving off, always be sur e to ke ep road conditions in mind as
you accelerate. I f one drive wheel spins because it is on a surface
with less grip, gradual ly increase the pressure on the accelera tor
pedal unt il the car star ts to
move . The whee l less able to t ra nsfer
power spins. _.,
Vehicle care Do-it-yourself service Technical data

-Intelligent technology --=---=-=-------------
Overheating
of brakes
To prevent the disc brake of the braked wheel from overheating if
subjected to excessive loads, the EDL cuts out temporarily . The
vehicle remains operational and behaves in the same way as a
vehicle without EDL.
As soon as the brake has cooled down, EDL switches on again auto ­
matically.
& WARNING
• When accelerating on slippery surfaces, such as on ice or snow,
always be careful when depressing the accelerator pedal. Even
with the EDL working, the drive wheels can spin and reduce your ability to control your car. Risk of crash!
• The increased safety afforded by EDL does not mean that you
can take safety risks . Always adapt your driving style to the road
conditions and traffic situation.
[ i] Tips
If a fault occurs in the ABS, the EDL is also not functioning. This is
indicated by the ABS warning light=>
page 21. •
Anti-Slip Regulation System (ASR)
The Anti-Slip Regulation System prevents the driven
wheels from spinning when the car is accelerating.
General notes
The Anti-Slip Regulation System (ASR) is integrated in the electronic
stabilization program (ESP). When the vehicle starts up and acceler­
ates, the wheels are prevented from spinning by adjusting the
engine power to match the amount of grip available from the road
surface.
How the system works
ASR performs automatically, i.e. without the driver's intervention.
With the aid of the ABS sensors=>
page 274, ASR monitors the
speed of the driven wheels. If the wheels start to spin, the engine
power is reduced automatically until the tires find enough grip to
lock onto the road surface. The system is active across the entire
speed range.
The ASR works in conjunction with the ABS. If a malfunction should
occur in the ABS, the ASR will also be out of action.
& WARNING
The increased safety afforded by ASR does not mean that you can
take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i] Tips
To ensure that the ASR works properly, all four wheels must be fitted
with identical tires Any differences in rolling radius of the tires can
cause the system to reduce engine power when this is not desired.
See also=>
page 338, "New tires and replacing tires and wheels".
Braking
General information
What affects braking efficiency?
Operating conditions and driving habits
The brakes on today's automobiles are still subject to wear,
depending largely on operating conditions and driving habits=>& .
On vehicles that are either driven mostly in stop-and-go city traffic
or are driven hard, the brake pads should be checked by your autho ­
rized Audi dealer more often than specified in the
Warranty & Main- ~

tenance boo klet. Failure to have your brake pads inspected can
r esult i n reduce d brake pe rfor mance .
On steep slopes , you s hou ld use the braking effect of the engine .
T his way, you prevent unnecessary wear on the bra ke system . If you
must use your brakes, do not hold the brakes down con tinuo usly.
P ump the brakes at intervals.
Moisture or road salt
U nder ce rtain conditions, for example, when driving through water
or very heavy rain, or even after washing your vehicle, the brak ing
effect can be reduced due to moisture (or in freezing conditions ice)
on the b rake pads. A few carefu l brake appl icat io n s sh ould d ry o ff
the brake pads or remove any ice coatings.
Th e eff ectiveness of the b rakes ca n b e re d uce d whe n the ve hicle is
driven on a salt -covered road and the brakes are not used . Here too,
you sh ould clean off acc umulated sa lt coat ing from brake d iscs and
pads with a few careful app lications of the brake~&.
Corrosion
T here may be a tendency for dirt to build up on the brake pads and
co rrosion to form o n the discs if the car is not d rive n regu lar ly or
only for short trips with little use of the brakes .
I f the brakes are not used frequently, or if corrosion has fo rmed on
t he d iscs, i t is a dv isab le to clea n off th e pads an d discs by braking
firmly a few times from a moderate ly high speed~& .
Faults in the brake system
I f you shou ld notice a sudden increase in brake pedal trave l, then
one of the two brak e circu its may have failed~ &.
Low brake fluid level
Ma lfunctions can occur in the brake system if the brake fluid leve l is
t oo low. T he b rake fl uid level is mon ito red e lect ro nica lly .
Controls and equip­ ment Safety first
Vehicle operation
Intelligent technology
Brake lining wear status
Brake l ini ng w ear may be checke d by visua l ins pec tion of the co nd i­
tion of the brake pads throu gh the open ings in the wheel. If neces ­
sa ry, the wheel may be removed for this i nspectio n
~ page 353,
"Changin g a whee l".
& WARNING
• You should perform braking maneuvers for the purpose of
cleaning the brake system only if road conditions permit . Other
road use rs must not be put at r isk -you may cause an accident !
• Before descending a steep grade , reduce speed and shift trans ­
mi ssion into a lower gear or lower driving range . Do not ride the
brakes or hold the pedal down too long or too often . This could
cau se the brakes to get hot and diminish braking efficiency .
• Do not "ride the brakes" by resting your foot on the pedal when
you do not intend to brake. This may cause the brakes to overheat ,
premature wear and increased stopping distance.
• Under certain climati c and operating conditions such as
passing through water , driving in heavy rain or after washing the
vehi cle , the effectiveness of the brakes can be reduced. In winter ,
ice can accumulate on the brake pads , linings , discs and drums .
Carefully apply brakes for a test. Brakes will dry and ice coatings
will be cleaned off after a few careful brake applications .
• Driving for an extended period of time on salt -covered roads
without using your brakes can also affect braking efficiency. Clean off accumulated salt coating from brake disc s and pads with a few
careful brake applications .
• If you damage the front spo iler , or if you install a different
spoiler, be sure the air flow to the front brakes is not obstructed.
Otherwise the brake sy stem could overheat reducing the effective ­
ness of the entire brake system.
• Failure of one brake cir cuit will impair the braking capability
resulting in an increased stopping distance. Avoid driving the
Vehicle care Do-it-yourself service Technical data

___ ln_ t _e_ ll-'"ig ...,_ e_ n_t _t_ e_ c_ h _ n_o _ l_o _,.g= y,_ __________________________________________ _
& WARN ING (continued )
vehicle and have it towed to the nearest Aud i dealer or qualified
workshop.
;:a
Brake booster
The brake booster a dds ex tra braking power.
The bra ke booster works wit h vacuu m pressure w hich is created
only when the engine is running =>& .
& WARNING
• Never let the vehicle roll to a stop with the engine shut off .
• If the brake boo ster i s not wor king , for e xample when towing
your vehicle, or because the brake booster has somehow been
damaged , the brake pedal must be pre ssed considerably harder to
make up for the lack of booster as sistance. •
Functioning of Anti-Lock Brake System {ABS)
A BS prevents the wheels from l ocking up under braking.
The ABS contributes effective ly to vehicle contr ol since i t preven ts
t he whee ls from
locking whe n the brakes are appl ied. This mea ns
that the vehicle remains steerable and is less likely to skid .
With ABS you do not need to pump the brake. Ju st hold the brake
pedal down .
However, do no t ex pect the ABS to sho rten braking distance u nder
all circumstances. When drivin g on gravel or on new ly fallen snow
on top of icy surfaces, bra king distance may be even longer, there­
f ore, under these c ircu msta nces, it is especially importa nt that you
drive slow ly and with great care.
How the ABS system works
An au toma tic c heck is made when a s peed of about 4 mph (6 km/h)
is reached. When this happens, a pumping no ise can be heard.
I f an individual wheel begins to rotate too slowly in relation to
veh ic le speed and tends to lock, the ABS au tomat ically reduces
brake pressure to prevent that whee l from locking.
Th is au tomatic a djust ment pr oces s wi ll cause a
slight vibration o f
the brake peda l and some noises to alert you that vehicle speed
m ust be ada pted to e xisting road and traff ic conditio ns.
& WARNING
Although the ABS is very effective , alway s remember that braking
capability is limited by tire traction . Always adjust your driving
speed according to the road and traffi c conditions. Do not let the
extra safety afforded by the ABS tempt you into tak ing extra risks.
The ABS cannot overcome the laws of physics.
[ i ] Tips
• I f ABS is not functioning properly, a wa rning light will come on .
See=>
page 27.
• I f a faul t occurs in t he ABS, t he EDL is also n ot fu nctio ning . Th is
is indicated by the ABS warning light. •
Brake assistant
T he brak e assi stant i s designe d to ac hie ve th e optimu m
bra kin g eff ec t.
The bra ke assistant helps to increase the effective braking power
an d th us to achieve a shorter s top ping dis tan ce. If the dr iver
presses the brake pedal very quic kly, the brake assistant automati ­
c a lly bo osts t he braking force to the max imum level, up to th e point
where the anti -lock brake function (ABS) intervenes to stop the
whee ls from locking. You shou ld then keep the brake peda l pressed .,