2008 AUDI S8 ESP

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Intelligent technology
Notice about data recorded by
vehicle control modules
Your vehicle is not equipped with an Event Data Recorder (EDRl,
installed by some manufacturers for the express purpose of
capturing data for retrieval after an accident or crash event . EDR's
are sometimes called "crash recorders".
Some state laws restrict the retrieva l or downloading of data stored
by EDR's that were insta lled in a vehicle for the express purpose of
retrieving data after an accident or cras h event without the owner's
consent.
Although your vehicle is not equipped with an EDR, it is equipped
with a number of electronic control modules for various vehicle systems such as, for example, engine function, emission contro l, as
we ll
as for the a irbags and safety belts.
These electronic control modules also record vehic le-related data
dur ing norma l ve hicle opera tion for diagnost ic and repair purposes .
The recording capacity of the electronic control modules is limited
t o data (no sound is recorded) and only a small amount of data is
actua lly 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 vehic le speed, d irection,
braking as we ll as restraint system use and performance in the
event of a crash o r other condition . Stored data can only be read and
downloaded with special equipment. •
Electronic Stabilization Program (ESP)
General information
The ESP improves the vehicle stability.
I~
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( ~ 1~ IA I 3-)
Fi g. 25 4 Cen ter
co nso le w it h ES P
sw itch
ESP is designed to he lp you maintain vehic le control in situations
where the car approaches the limits of "grip", especia lly when
acce lerating and cornering . ESP reduces the risk of skidding and
improves stabil ity under al l road conditions.
T he system operates across the entire speed range in combination
with the ABS system. If the Ant i-Lock Brake System (ABS) malfunc­
tions, the ESP wi ll also shut down .
How the syste m w ork s
The Anti -Lock Brake System (ABS), Electronic Differential Lock (EDU
and the Anti-Sl ip Regulation System (ASR) are integrated in the e lec­
tronic stabi lization program. In addition to the data provided by
t hese functions, the ESP control unit requires additional measure ­
ment data provided by high performance sensors . The rotational
speed of the veh ic le about its vertica l axis, the lateral acce lerat ion
acting on the vehicle, the brake pressure and the steering angle are
a ll measured . _,,,,

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T he direction in which the driver wishes to travel is determined with
t he aid of the steering angle and vehicle speed and is con tinua 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 stabi lized by the forces act ing 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 whee l that is on
the outside of the curve. In the case of a vehicle that is
understeering
(tendency to s lide out of the curve), t he brakes are applied a t the
rear wheel that is on the inside of the curve. An acoustic signal indi ­
cates when ESP brake app lication cuts in
=> & .
The system operates across t he entire speed range in comb inat ion
with the ABS system
=> page 272 . If the Anti -Lock Brake System
(ABS) malfunctions, the ESP wi ll be out of act ion as well.
Ac tivation
When you turn on the eng ine, ESP will automatically be activated
and wil l perform a self -test.
The system can be activated or deactivated by pressing the but ton
=> page 268, fig. 254 . The warning light comes on when the system
is switched off
=> page 18.
Normally, the ESP s hould 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 des ired such as:
• when driving with snow chains
• whe n driving in deep snow or on a loose surface (to allow the
whee ls to dig in to reach firm ground)
• whe n trying to
"rock" the vehicle free whe n it has become 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
& WARNING
The Ele
ctron ic Stabiliz ation Pr ogram i s ne verthele ss subje ct to the
laws of phy sic s. It is p articularl y important to pay attention to this
fa ct on wet and slipper y ro ad s. It i s therefore important th at you
alway s adapt your dr iving to the condit ion of the road and traffic
c ondition s. Do not allo w the in crea sed safety pro vided by the Ele c­
tronic Stabilization Program system to lull you into a ccepting
a ddition al safety ri sk s.
•
Electronic differential lock (EDL)
The elec tronic d ifferen tial lock moni tors the rotation al
s p eed of the drive wheels.
G en era l not es
The elect ronic d ifferential lock (EDU helps the ca r to start mov ing,
accelerate and c limb a grad ient on surfaces providing poor or
a lmost no grip . Without EDL, this would be difficult, if not impos ­
s ib le.
How the syst em works
The EDL operates automatical ly. It monitors the rotationa l speed of
t he drive wheels on an ax le with the he lp of the ABS senso rs
=> page 272. If a not iceable 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 bra ked, thereby transferring power
to the other drive wheel or wheels (a ll -whee l drive) . This is done up
t o a speed of ab out 60 mph (100 km/h). N oises from the brake
system signal that wheel spin is being control led .
Dri ving off
When driving off, always be sure to keep road conditions in mind as
you accelerate. I f one drive wheel spins because it is on a sur face
with less grip, gradual ly increase the pressure on the accelerator
pedal unt il the car star ts to move . The whee l less able to t ra nsfer
power spins.
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Vehicle care Do-it-yourself service Technical data

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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
stabili zation 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 272, 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 336, "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 which are driven mostly in stop-and-go city traffic or
which are driven hard, the brake pads should be checked by your
authorized Audi dealer more often than specified in the
Warranty &
Maintenance booklet. _,,,

-Intelligent technology
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& WARNING
• Never let the vehi cle roll to a stop with the engine shut off .
• If the brake boo ster i s not working, for example when towing
your vehicle , or because the brake booster has so mehow been
damaged, the brake pedal must be pres sed considerably harder to
make up for the la ck of booster as sistan ce . •
Functioning of Anti-Lock Brake System (ABS)
AB S pre vent s th e wh eels fr o m lo ckin g up un der braking .
The ABS contributes effective ly to ve hicle control s ince it prevents
th e whee ls from
lo cking w hen t he brakes are a ppl 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 . Just hold the brake
pedal down.
H owever, do not expect the ABS to shorten braking distance under
all cir cum stances. W hen drivin g on g ravel o r on new ly fallen s now
on top of icy surfac es, bra king distance may be even longer, there ­
fo re, unde r th ese circum stances, i t is especially i mporta nt th a t yo u
drive slow ly and with great care .
How the ABS system works
An automatic check is made when a speed of about 4 mph (6 km/h)
is reac hed . When this ha p pens, a pumping n oise can be hea rd.
If an indiv idua l wheel begins to rotate too s lowly in relation to
vehic le speed and tends to lock, the ABS automatica lly reduces
brake pressure to prevent that whee l from loc king .
T his automat ic adjustment process wil l cause a
slight vibration of
th e br ak e pe dal a nd some noises to ale rt you th at ve hic le sp eed
must be adapted to existing road and traffic conditions.
& WARNING
Although the ABS is very effe ctive , always remember that braking
capability is limited by tire traction. Alway s adjust your driving
speed a ccording to the road and traffi c conditions . Do not let the
extra safety afforded by the ABS tempt you into taking extra risks.
The ABS cannot overcome the laws of physics.
[ i ] Tips
• I f ABS is not funct io ni ng properl y, a wa rn ing li ght will co me o n.
See ~ page 21.
• I f a fault occurs in the A BS, the EDL is also not functioning. This
i s indica ted by the ABS wa rn ing l igh t.•
Brake assistant
The brake assis tant is desig ned to ach ieve the o ptim um
brakin g eff ec t.
The br ake assistan t helps to in cr eas e the effec tive b raki ng pow er
and thus to achieve a shorter stopping distance . If the driver
p re sses the b rake pe dal very q uick ly, the brake assistan t auto mati ­
ca lly boosts the brakin g force to the maximum level, up to th e point
whe re the a nti-lock b rake functi on (AB S) int ervenes to sto p the
w hee ls from loc king . You s hou ld t hen k eep th e br ake pedal pressed
until t he vehicle ha s braked to the required speed . The brake a ssis ­
t ant s witches itse lf off as soo n as you re lease t he bra ke pedal.
T he b rake assistant will not be ope rative if there is a malfunction in
th e ABS .
& WARNING
Please remember that the accident risk always increases if you
drive too fast , especially in corners or on a slippery road , or if you
follow the vehicle ahead of you too closely . Increased risk of an
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& WAR NIN G (c onti nued )
acc ident canno t b e co mp ensat ed for even b y th e br ake assis tant,
s o alway s maintain a safe sp eed . •
Servotronic® - advanced power
steering system
The power steering systems uses the power of the
running engine to allow precise s teering with little effor t.
The advanced Servotronic® power steering system senses the road
speed and electronically adjusts power assistance to provide
comfortab le and safe steer ing response exactly matched to the
vehic le speed.
Power s teeri ng will not work if the engine is off . As a result, the
steering whee l wil l be hard to turn .
The power steering fluid level is checked during the scheduled
maintenance serv ices.
0 Note
If there is an electron ic ma lfunction, servotronic will sti ll funct ion
like a conventiona l power steering system, providing a constant
steer ing suppor t force that is no longer proportionate to the vehicle
speed . This is most noticeable when turning the steering wheel at
low speeds (for examp le w hen parking), -more effor t wi ll be
required than usual.
• Be aware of the different than usua l steering response and
adjust your steering force accordingly .
• Have the problem checked and set right by an Aud i dea ler as
soon as possib le.
Controls and equip­ ment Safety first Vehicle operation
[
i ] Tip s
• When the engine is running, never hold the steer ing whee l
turned all the way to the right or to the left for longer than 15
seconds. The power steer ing pu mp wil l overheat the hydraul ic fluid
if you keep ho lding the steering whee l turned a ll the way. This is
like ly to damage the power steering system.
• I f the power steering system shou ld fail entire ly, or if the engine
is not runn ing ( for examp le, wh ile be ing towed), you w ill st ill be able
to steer the vehicle . However, considerably more effort will be
requ ired to do so.
• I f the power steering system shou ld have a leak, or is not func ­
tioning properly, contact your author ized Audi dealer im mediately.
• The power stee ring system requires a special ly formulated
hydrau lic fluid . The power steer ing reservo ir is the one located most
forward on the left side of the engine
compartment => page 308. The
correct flu id level in the reservo ir is important for proper func ­
tioning of the power steering. •
Driving with your quattro®
With All Wheel Drive, all four wheels are driven.
Genera l inf orm ati on
With All Whee l Drive, power is d istributed to all fo ur wheels. This
happens automatically depending on your driving style and the
road condi tions at the time . See
a lso => page 269, "Electronic differ ­
entia l lock ! EDU" .
Winter tires
When driving in the winter, your vehicle with All Wheel Drive has an
advantage, even with regular tires . In winter road conditions it may
be advisable to mount winter tires (or all-season tires) for improved
driveabi lity and braking: these ti res must be mounted on all four
wheel s. See
also=> page 341, "Winter tires". ~
Vehicle care Do-it-yourself service Technical data

Intellig ent tec hnol ogy -
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vidual components . It regulates consumption, so that more elec­
t rical energy is not be ing used than is be ing genera ted and ensures
an optimal state of charge for the battery .
[ i ] Tip s
• But even energy management cannot negate the limits of
physics. Consider that the power and life of a battery are limited.
• If starting ability is threatened, you are informed by a warning
~ page 275, "Driver notification in the instrument cluster
display" .•
What you should know
The highest priority is given to maintaining starting capa ­
bility.
T he battery is severely taxed in short -distance driving, in city traffic
and during t he co ld time of year . Abundant e lectrica l energy is
required, but on ly a little is generated . It is also critical if the engine
is not running and e lectrical components are turned on. In this
instance energy is being consumed but none is being generated .
I t is in precisely these situations that you wi ll notice energy manage ­
ment active ly regulating the d istr ibut ion of energy.
Vehicl e stands for an extended period
If you do not drive your vehicle over a per iod of several days or
weeks, electrica l components are gradually cut back or switched off.
This reduces energy consu mpt ion and maintains starting capability
over a longer period .
Be aware t hat when you unlock you r ve hicle, some o f the conve ­
nience functions may not operate, such as the Advanced Key, the
remote contro l or t he power seat adjustment. T he convenience
functions will be available again when you turn on the ignition and start the engine .
Controls and equip­
ment Safety first Vehicle operation With th
e engin e turned off
If you listen to the radio, for examp le, with t he engine tu rned off or
use other MMI functions, the battery is being discharged.
I f starting capabi lity is jeopardized due to energy consumption, the
f o llow ing warn ing appears in t he MMI display:
Ple ase start engine , other wise sy stem will s witch off in 3
minute s.
The warning indicates that the system wi ll be turned off au tomat i­
ca lly after 3 minutes. If you wish to continue using the functions,
you have to start the engine .
With the engine running
Although e lectrica l energy is generated when the vehic le is being
driven, the battery can become discharged. This happens mostly
when little energy is being generated and a great deal co nsumed
and the battery's state of charge is not optimal.
To br ing the ene rgy balance bac k into equi librium , cons umers
which require especially large amounts of energy are temporar ily
cu t back or switched off . Heating systems in part icu lar require a
great deal of energy. If you notice, for example, that the heated
seats* o r the heated rear w indow are not heating, they have been
temporari ly cut back or switc hed off. These systems wil l be avai lable
again as soon as the energy balance has been restored.
You wil l also notice t hat engi ne idle speed has been increase d
s lightly . This is norma l and not a cause for concern . By increasing
engine idle speed the addi tiona l energy required is ge nerated a nd
the battery is charged. •
Driver notification in the instrument cluster
display
I f the battery's state of charge is not in the optima l range, this driver
no tificat io n ap pears in the instrument cl uster d isplay:
t:3 Low battery ch arge : battery will be charged while dri ving .,_
Vehicle care Do-it-yourself service Technical data

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- Lack of proper maintenance as wel l as improper use of the
vehic le will impair the func tion of the emission con tro l system
and cou ld lead to damage .
<£> For the sake of the envir onment
Even when the Emission Control System is operating properly, the
exhaust gas can have a su lfur -like exhaust gas smell under some
operating states . This depends on the sulfur content of the fuel
being used. Using a different b rand of fue l may help, or fil ling the
tank with lead-free super grade gasol ine. •
Avoid damaging the vehicle
When you are driving on poor roads, or over curbs, steep ramps,
etc., make certain that low- lying parts such as spoi lers and exhaust
system parts do not bottom out and get damaged.
T his is especial ly true for vehicles with low -s lung chassis (sports
chassis)* and ful ly loaded vehicles .•
Operate your vehicle economically
and minimize pollution
General
Y o ur personal style of driving will determine the economy
of your vehicle , as well as exhaust and noise levels.
Fuel economy, environmenta l impact, and wear on your engine,
brakes and t ires largely depend on three factors :
• your personal driving style
• operat ing cond it ions
• t echnica l limitations
Controls and equip­
ment Safety first Vehicle operation
I
f you anticipate what you need to do next and drive economica lly,
you can eas ily cut your fuel consumptio n by 10 -15 percent . This
section wil l give you some tips on how you can help the environ­
ment and your poc ketboo k.
[ i ] Tips
The consumption estimates as published by ENV IRO NME NTA L
PRO TECTION AGENCY (EPA) and Transport Canada may not corre ­
spond to your actua l consumption on the road, which wi ll vary
depe nding upon veh ic le load and speed, road and weather condi­
tions, trip length, etc. •
Drive smoothly and keep a lookout ahead
Vehicles use the most fuel when they ore accelerating .
-Avo id unnecessary accelerat ing a nd braking .
Vehicles use the most fue l when they are accelerating . If you antici ­
pate what is going to happen
ne xt, you wi ll need to brake less and,
thus, acce lerate less. Let the vehicle coast whenever possib le -for
examp le when you see that the next traffic light is red. •
Avoid full throttle
Driving at moderate speeds saves fuel and improves your
mileage.
- Try and keep we ll below your car 's max imum speed.
Acce lerating gently reduces fue l consumption, engine wear, and
does no t disturb the envir onment.
Fue l consumption, exhaust emissions and engine noise increase
dispropo rtionately at h ig h speeds . If yo u drive at approxi mate ly
three quarters of top speed, fuel consumpt ion wil l be reduced by
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Vehicle care Do-it-yourself service Technical data

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one half. Never drive faster than the posted speed limit and weather
co nditions permit. •
Reducing unnecessary idling
Even when your car is just idling it burns up fuel.
- Shut the eng ine off when you are not driving the vehicle .
- Do not warm up the vehicle by letting the engine run at
id le .
It makes sense to shut off the engine in traff ic jams, when waiting
for trains to pass at rai lroad crossings, or at traffic lights that have
long waits on red. Turning the engine off for just 30 -40 seconds
saves more fue l than is burned starting the engine again .
It takes a long time for the engine to warm up fu lly when it is
running at idle. However, wear and noxious em issions are espec ially
high when the engine is warming up . So you should drive away as
soon as you start the engine and avoid running at high rpms while
the engine is sti ll warming up.
0 Note
Do not leave engine idling unattended after starting . If warning
lights should come on to indicate improper operation, they would
go unheeded. Extended idling also produces heat, which could
result in overheating or other damage to the vehicle or other
property .•
Regular maintenance
A badly tuned engine unnecessarily wastes a lot of fuel.
- H ave your vehicle serviced at regular intervals .
By having your vehicle regularly serviced by an Audi dealer helps to
ensure t hat it runs properly and economical ly . The condit ion of your
vehic le not only affects its safety and abi lity to hold its va lue, it also
affects
fuel con sumpt ion .
C hec k your oil each time you fill your tan k.
The amount of oil used is related to engine load and speed.
I t is norma l for the oi l consumption of a new engine to reach its
lowest va lue after a certain mileage has been driven.
You must drive your vehicle about 3,000 miles (5,000 kilometers) before you can properly assess oil consumption .
T his also applies to fuel consump tion and engine output .
0 Note
• Have your vehicle maintained properly and in accordance with
t he service recommendat ions in your Warranty
& Maintenance
booklet. Lack of proper ma intenance as well as improper use of the
vehic le wi ll impair the function of the emission control system and
cou ld lead to damage.
• Do not alter or remove any component of the Emission Contro l
System unless approved by the manufacturer.
• Do not alte r or remove any device, such as heat sh ields,
switches, ignition wires, valves, which are designed to protect your
vehic le's Emission Control System and other important vehic le
components .•
Fewer short trips
Fuel consumption will always be relatively high on short
trips.
- Try to avoid driving short dista nces with a cold engine. ~