ABS AUDI S8 2008 User Guide

Child Safety -
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child is available . In these exceptional situations, the use of a lap
belt is better than permitting the child to remain totally unre ­
strained . But remember: a lap belt cannot provide the same level of
protection as a proper child restraint or a three -point lap and
shoulder belt if the child is big enough. Also, using a lap belt for
younger children, who should be using a child restraint, may violate
laws in your state or Province .
Never use a lap belt alone to restrain a child that weighs less than
about 80 lbs (36 kg) and who is less than 4'9" tall. Always remember
that children do not have the pronounced pelvic structure required
for the proper function of lap belts. If a lap belt is only restraint
system available, then the child's safety absolutely requires that the
lap belt be fastened snugly and as low as possible around the pelvis
let a lap belt pass over the child's stomach or abdomen .
& WARNING
Using wrong child restraints or improperly installed child
restraints can cause serious personal injury or death in a crash.
• Failure to properly route safety belts over a child's body will
cause severe injuries in a crash. The lap belt portion of the three
point belt as well as any lap belt alone must always pass as low as
possible across the pelvis, never over the stomach or abdomen.
• An improperly worn safety belt will not provide the best protec­
tion in a crash and may cause serious personal injury. Always make sure that children and other vehicle occupants properly
wear available restraint systems. Carefully follow the instructions provided by the manufacturers of child restraints. •
Controls and equip­
ment Safety first
Vehicle operation
Installing a child safety seat
Securing a child safety seat using a safety
belt
Safety belts for the rear seats and the front passenger can
be locked with the convertible locking retractor to prop­
erly secure child safety seats.
The safety belts emergency locking retractors for the rear seats
safety belts and for the front passenger's seat safety belt have a
convertible locking retractor for child restraints. The safety belt
must be locked so that belt webbing cannot unreel. The retractor
can be activated to lock the safety belt and prevent the safety belt
webbing from loosening up during normal driving. A child safety
seat can only be properly installed when the safety belt is locked so
that the child and child safety seat will stay in place.
Always remember: Even though your vehicle is equipped with an
Advanced Airbag system, all children, especially those 12 years and
younger, should always ride in the back seat properly restrained for
their age and size.
& WARNING
Improperly installed child safety seats increase the risk of serious
personal injury and death in a collision.
• Always make sure that the safety belt retractor is locked when
installing a child safety seat. An unlocked safety belt retractor
cannot hold the child safety seat in place during normal driving or
in a crash.
• Always buckle the child safety seat firmly in place even if a
child is not sitting in it. A loose child safety seat can fly around
during a sudden stop or in a collision
• Always make sure that the rear seat backrest to which the
center rear safety belt is attached is securely latched whenever
the rear center safety belt is being used to secure a child restraint.
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Vehicle care Do-it-yourself service Technical data

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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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Trailer towing
Driving with a trailer
General information
Your Audi was designed primarily for passenger transpor­
tation.
If you plan to tow a trailer, please remember that the add it ional load
wi ll affect durability, economy and performance.
Tra iler towing not on ly p laces more stress on the vehicle, it a lso ca lls
for more concentration from the driver.
For this reason, always fol low the ope rating and driv ing instruc tions
provided and use common sense.
(D Note
If you are go ing to tow a trai ler, you must activate the trailer opera ­
tion
mode => page 189, "Towing a Trailer". •
Technical requirements
Traile r hit ch
Use a we ight-carrying hitch conforming to the gross trai ler weight.
The hitch must be suitable for your vehic le and trailer and must be
mounted secure ly on the ve hicle's chass is at a
technically sound
location. Use only a trailer hitch with a removable ball mount.
Always check wit h the trai ler hitch manufacturer to make s ure that
you are using the correct hitch .
Do not use a bumper hit ch.
The hitc h must be installed in such a way t hat it does not interfere
with the impact-absorbing bumper system. No modifications
should be made to the veh ic le exhaust a nd brake systems. F rom time to time, check that all hitch mounting bolts remain secure
ly
fastened .
When yo u are no t towing a trailer, re move the tra ile r hitch ball
mount. This prevents the hitch from causing damage shou ld your
vehic le be struck from
behind =>& .
Traile r br ake s
If your tra iler is equipped with a braking syste m, check to be sure
that it conforms to al l regu lations .
The tra iler hydraul ic brake sys tem must not be di rect ly co nnected to
t he vehic le's hydrau lic brake system .
Safety chains
Always use safety chains between your vehicle and the trailer.
Trailer light s
Trai ler lights must meet a ll regulations. Be sure to check with your
Aud i dea ler for correc t wir ing, sw itch es and relays .
Mirrors
If you are unable to see the traf fic behind you using the regu lar
outside mirrors, then you
must instal l extended mirrors. It is impor ­
t ant that you
always have c lear v ision to the rear.
& WARNING
After removing the tr ailer hitch , do not store it in your vehi cle . In
ca se of sudden braking , the hitch could fl y forward and injure you
or your p assenger s.•