wheel AUDI S6 2008 Service Manual

__________________________________________________ A_ i_ r _b _a...; g::- s_ y=--- s_t _e _m __ fllll
& W ARNING (continued )
• If you must in stall a rearward facing child safety seat on the
front passenger seat because of 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 airbag system inspected by your
Audi dealer .
& WARNING
If, in exceptional circumstance s, you must install a forward-facing
c hild 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 .
• Never put the forward -facing child restraint up against or very
near the instrument panel.
• 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 forward -facing child
restraint. The backrest must be adjusted 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 .•
Advanced Airbag System components
T he front passenger seat in your vehicle has a lot of very important
p ar ts of th e A dva nced Air b ag System in it. T hese pa rts inc lu d e the
weight -sensing mat, sensors , w iring, brackets, and more. The func­
t ion o f the sys te m in the fr ont passenge r sea t is c hecked by th e e le c­
tronic contro l unit when the i gnition is on. The control unit monitors
th e Adva nced Ai rbag Syst em an d t urns t he air b ag in dicat or ligh t on
when a malfunction in the system components is detected. T he
function of the airbag indicator light is described in greater detail
Controls and equip­ ment Safety first Vehicle operation below
. B ecause the front passenger seat conta ins important par ts
o f th e Adva nced Ai rbag Sys te m , yo u m ust take care to prev ent it
from be ing damaged. Damage to the seat may pr event the
Advanced Air bag for the fr ont pas senge r sea t fr om doing i ts job i n
a cras h.
The front Advanced Airbag System consists of the
following :
• Crash sens ors in th e fro nt of th e vehi cle that meas ure vehic le
acce leration/dece leration to provide information to the Advanced
A irb ag System ab out the seve rity of the c rash .
• An electron ic control unit, with integrat ed crash sensors for front
and si de i mpac ts . T he co ntr ol unit "de cides" w heth er to f ir e th e
front airbags based on th e information received from the crash
se nsors . The con trol unit also "deci des" w hethe r the safet y belt
pretensioners should be activated.
• A dua l- st age A dvan ced Airb ag with gas ge nerato r for t he drive r
inside the steer ing wheel hub .
• A du al- s tage A dvanced Air bag a nd gas gene ra tor insid e the
instrument panel fo r the front passenger.
• A w eigh t-s e nsin g mat und er the u phols ter y padding of th e fron t
passenger seat cushion that measures the total weight on the seat.
Th e in form atio n r egis tered i s sen t co nti nuousl y to th e e lectr oni c
control unit to regu late dep loyment of th e fro nt Advanced Airbag o n
t he pas se nge r sid e.
• An airbag monito ring system and indicator light in the instru ­
m ent c luste r::::>
p age 22 3.
• T he PASSENGER AIR BAG OFF light comes on and stays on in the
ce nter of the i nstrume nt p anel ::::>
pa ge 224, fi g. 206 a nd tells y ou
when the front Advanced Airbag on the passenger side has been
tu rne d off .
• A sensor be low the safety belt latch for the front seat passenger
to mea sure the t ensio n on t he sa fet y b elt. The ten sion o n the safet y
belt and the weight registe red by t he weight -sensing mat help the
cont ro l un it "deci de" whe ther t he fro nt air bag fo r the front _,.
Vehicle care Do-it-yourself service Technical data

-L~A:::..:,: ir:....: b:!..::: a~g L.:: s:1y :...:s::..: t~ e:.: m:...:...:.. ________________________________________________ _
or the lower parts of the body. Front airbags only supp lement the
th ree p oint safe ty belts in som e front al co llis ions in which the
vehic le dece leration is h igh enou gh to deploy the a irba gs.
Front airbags will not deploy:
• if the ignition is switched off when a crash occurs,
• i n sid e collis io ns,
• i n rea r- e nd collisi ons ,
• in ro llovers,
• when th e c ras h de celerat io n measur ed by the a irba g system is
less than the minimum threshold needed for a irbag deployment as
r egi stere d by th e ele ctro nic con trol uni t.
The front passenger airbag will also not deploy :
• when th e fr ont pass enger seat is no t occupi ed,
• when the weight on the front passenger seat a s sensed by the
A dvanced A irbag Syste m indica tes tha t the fr ont air bag o n the
passenger side has to be turned off by the e lectronic cont rol unit
(t he PASSENGER AIR BAG OFF li gh t comes o n and s tays o nl.
& WARNING
Sitting in the wrong position can increase the risk of serious injury
in crashes .
• To reduce the risk of injury when the airbags inflate , the driver
and passengers must always sit in an upright position , must not
lean against or place any part of their body too close to the area
where the airbags are located.
• Occupants who are unbelted , out of position or too close to the
airbag can be seriously injured by an airbag as it unfolds with
great force in the blink of an eye=> page
214.
& WARNING
A child in a rearward-facing child safety seat installed on the front
passenger seat will be seriously injured and can be killed if the
front airbag inflates -even with an Advanced Airbag System .
• The inflating airbag will hit the child safety seat or infant
carrier with great force and will smash the child safety seat and
child against the backrest, center arm rest, door or roof.
• 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 because of exceptional circumstances and
the PASSENGER AIR BAG OFF light does not come on and stay on, i mmediately install the rear-facing child safety seat in a rear
seating position and have the airbag system inspected by your
Audi dealer .
& WARNING
Objects between you and the airbag will increase the risk of injury
in a crash by interfering with the way the airbag unfolds or by
being pushed into you as the a irbag inflates .
• Never hold things in your hands or on your lap when the vehicle
is in use.
• Never transport items on or in the area of the front passenger
seat. Objects could move into the area of the front airbags during
braking or other sudden maneuver and become dangerous projec ­
tiles that can cause serious personal injury if the airbags inflate .
• Never place or attach accessories or other objects (such as
cupholders, telephone brackets , large, heavy or bulky objects) on
the doors , over or near the area marked "AIRBAG" on the steering
wheel , instrument panel , seat backrests or between those areas
and yourself . These objects could cause injury in a crash , espe­
cially when the airbags inflate .
• Never recline the front passenger's seat to transport object s.
Items can also move into the area of the side airbag or the front ..,

___ A_ ir_ b_ a-g _ s_y _s_ t_ e_ m _________________________________________________ _
& WARN ING (continued )
seating posit ion and have the airb ag system inspe cted by your
Audi dealer .
• A t ight tether or other strap on a rearward-fa cing child restr aint
att ached to the front pas senger se at can put too much pres sure
on the weight-sensing mat in the seat and reg ister more weight
than is actually on the seat. The heavier weight registered can
m ake the system work as though an adult were on the seat and
deploy the Advanced Airbag when it must be suppressed cau sing
ser ious or even fatal injury to the child .
• If, in exceptional circumstance s, you mu st in stall a forward ­
f a cing 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 po ssible . The ba ckrest
must be adjusted to an upright position. Make sure that the
PASSENGER AIR BAG OFF light comes on and stay s 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 step s
described above, make sure the adult i s properly seated and
restrained at one of the rear seating posit ions .
• Have the airbag system inspected by your Audi dealer before
transport ing anyone on the front passenger seat .
[ i ] Tips
If the weight -sensing mat in the front passenger seat detects an
e m pty seat , the front a irbag on the passenge r side wil l be tur ned
off, and PASSENGER AIR BAG OFF will stay on.•
Repair, care and disposal of the airbags
P arts of the airbag system are installed at many different p laces on
you r Aud i. Insta ll ing, r emoving, servic ing or repa iring a pa rt in an
area of the vehicle can damage a part of an airbag system and
p revent that sys tem from working pr operly in a c ollisi on.
There are some important things you have to know to ma ke sure
t h at the effective ness of the system will not be impai red and that
discarded co mponents do not cause injury or po llute the env iro n­
ment .
& WARNING
Improper care , servicing and repair procedures can increase the
risk of personal injury and death by pre venting 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 attach any objects such as cupholders 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 cleaner s
c ould 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 , adju st, or change any parts of the airbag sy stem .
• 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 training and special equipment
necessary .
• For any work on the airbag system, we strongly recommend
that you see your author ized Audi dealer or qual ified workshop .
• Never modify the front bumper or parts of the vehicle body .

Child Safety -
--------------------''---
& WARNIN G (continu ed )
• Always install rear-facing child safety seat s on the rear seat.
• If you mu st in stall a re arw ard fa cing child safety sea t on the
front pa ssenger seat in exceptional cir cum stances and the
PASSENGER AIR BAG OFF light doe s not come on and stay on,
immediate ly in sta ll the re ar-facing child safety seat in a rear
s eating po sition and h ave the airbag sy stem inspected immedi ­
atel y by your Audi dea ler .
& WARNING
If, in exceptional circum stance s, you mu st install a forward -facing
c hild re st raint on the fro nt p ass enger's seat :
• Alway s make sure the forward -facing seat has been de signed
and cert ified by it s manufa cturer f or use on a front se at with a
p assenger front and side airbag .
• Always follow the manufacturer's instructions provided with
the child safety seat or carrier.
• Always mov e the passenger sea t into it s rea rmo st p osition in
the seat' s fore and aft adju stment r ange , as far away from the
airb ag as possible before in stalling the ch ild r estr aint . The b ack­
r es t must be adju sted to an upr ight po sition.
• Alway s ma ke sure th at the PASSENGER AIR BAG OFF l ight
c ome s on and stay s on all the time whenever the ignition is
s witched on. •
Advanced front airbag system and children
Your vehicle is equipped with a dual -stage front "Advanced Airbag
System" in comp liance with United States Federal Motor Vehicle
Safety Standard ( FMVSS) 208 as applicab le at the time your vehic le
was manufactured.
Controls and equip­ ment Safety first Vehicle operation
The Advanced Airbag system in your vehicle has been certified to
meet the " low -risk" requirements for 3 and 6 year -old children on
the passenger side and small adu lts on the driver side. The low risk
deployment crite ria are intended to reduce the risk of injury th rough
interaction with the airbag that can occur, for example, by being too
close to the steering wheel and instrument panel when the airbag
inf lates . In addit ion, the system has been cert ified 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
Standard.
Even though your vehic le is equipped with an Advanced Airbag
system, all children, especially those 12 years and younger, should
a lways ride in the back seat properly restrained for their age and
s ize . The airbag on the passenger side makes the front seat a poten­
tia lly dangerous p lace for a chi ld 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 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 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 be lt .
The weight -sensing mat measures t otal weight of the child and the
child safety seat and a chi ld blanket on the front passenger seat. The
we ight o n 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
~
Vehicle care Do-it-yourself service Technical data

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 262 . If the Anti -Lock Brake System
(ABS) malfunctions, the ESP wi ll be out of action as well.
Ac tivat ing
When you turn on the eng ine, ESP will automatically be activated
and will perform a se lf -test . As soon as the test is comp leted, the
system is in norma l operating mode.
You can activate a deactivated ESP or deactivated ESP/ASR if required by pressing the~
page 258, fig. 225 button . When they are
activated, the message
E S P/AS R on appears briefly in the display.
D eactiv ating
The ESP should normally be activated al l the time . If necessary, you
can deactivate An ti- Slip Regulation (ASR) or the E lectronic Stabiliza ­
tion Program (ESP) by pressing the button~
page 258, fig. 225.
• Dea ct ivat ing A SR: Tap the button . In certain exceptional situa ­
tions (e.g. driving with t ire chains) , the Anti-Sl ip Regulation (ASR)
can be deactivated ~
page 260. The message ASR off appears in the
display as we ll.
• Dea ctiv at ing E SP/ASR Press the button for more than 3 seconds.
With the ESP/ASR deactivated, the ESP check light comes on, see
Controls and equip­
ment Safety first Vehicle operation
In
te llig ent tec hn olo gy
~ page 19 . The message ES P sw itched off appears in the disp lay as
we ll.
& WARNING
The Electroni c Stabili zation Program i s never thele ss subject to the
la ws o f physics . It is p articularl y import ant t o pay a ttent ion t o th is
f a ct on wet and slippery road s. It is ther efore important tha t y ou
a lw ays a dapt your dr iving to the c ondit ion of th e ro ad and t raffi c
c ondition s. Do n ot allow the inc rea sed safety pro vided b y th e Elec ­
tr on ic S ta bili zatio n Pr ogram sys tem to lull you in to acc epting
add iti onal safet y risk s. C
Electronic differential tock (EDL)
The electronic differential lock monitors the rotational
speed of the drive wheels.
Gener al note s
The electronic differential lock (EDU helps the car to start moving,
accelerate and c limb a gradient on surfaces providing poor or
almost no grip . Without EDL, this would be difficult, if not impos ­
sib le .
How th e sys te m wo rk s
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 262 . 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 wheel is braked, thereby transferring power
to the other drive wheel or whee ls (a ll -whee l drive) . Th is 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 .
Dr iving off
When driving off , always be sure to keep road conditions in mind as
you accelerate. If one drive wheel spins because it is on a surface
Iii>
•
Vehicle care Do-it-yourself service Technical data

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with less grip, gradually increase the pressure on the accelerator
pedal until the car starts to move.
Overheating of brakes
To prevent the disc brake of the braked wheel from overheating if
subjected to excessive loads on this wheel, the EDL cuts out tempo ­
rarily. 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 22. •
Ant"-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 262, ASR monitors the
speed of the driven wheels. If the wheels start to spin, the engine
torque is reduced automatically until the tires find enough grip to
lock onto the road surface. The system is active across the entire
speed range.
Th e ASR works in conjunction with the ABS. If a malfunction should
occur in the ABS, the ASR will also be out of action.
Activating
The ESP is automatically activated when the engine is started and it
performs a self -test . You can activate a deactivated ASR if required
by pressing the =>
page 258, fig. 225 button . When it is activated,
the message
ESP/ASR on appears briefly in the display. Vehicles
with front-wheel drive a deactivated ASR automatically re-activates
itself at a speed of 40 mph (70 km/h) .
Deactivating
You can deactivate the ASR if required by pressing the button (for
less than 3 seconds)=>
page 258, fig. 225. With the ASR deactivated,
the ESP check light comes on, see=>
page 19. The message ASR off
appears in the display as well. On vehicles with front-wheel drive:
deactivation is possible only up to 30 mph (50 km/h) for safety
reasons . Vehicles with all -wheel drive: the ASR can be deactivated
at any speed .
The ASR should normally be activated all the time. Only in certain
exceptional situations when some slip is desirable does it make
sense to deactivate the ASR. Examples:
• when driving with tire chains
• when driving in deep snow or on loose ground and
• when rocking the vehicle loose after it has become stuck .

When the abnormal situation is over, you should activate the ASR
again.
& 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 325, "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
Mainte­
nance
& Warranty booklet.
On steep slopes, you should use the braking effect of the engine.
This way, you prevent unnecessary wear on the brake system. If you
must use your brakes, do not hold the brakes down continuously.
Pump the brakes at intervals.
Controls and equip­
ment Safety first Vehicle operation
Intelligent technology
Moisture or road salt
If
you are driving faster than 50 mph (80 km/h) and the windshield
wipers are on, the brake pads will briefly touch the brake discs in regular intervals so as to improve reaction time when braking on
wet surfaces. You, the driver, will not notice anything.
Under certain conditions, for example, when driving through water
or very heavy rain, or even after washing your vehicle, the braking
effect can be reduced due to moisture (or in freezing conditions ice)
on the brake pads. A few careful brake applications should dry off
the brake pads or remove any ice coatings .
The effectiveness of the brakes can be reduced when the vehicle is driven on a salt-covered road and the brakes are not used. Here too,
you should clean off accumulated salt coating from brake discs and
pads with a few careful applications of the brake ~& .
Corrosion
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 driven regularly or
only for short trips with little use of the brakes.
If the brakes are not used frequently, or if corrosion has formed on
the discs, it is advisable to clean off the pads and discs by braking
firmly a few times from a moderately high speed~&.
Faults in the brake system
If you should notice a sudden increase in brake pedal travel, then
one of the two brake circuits may have failed~& .
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is
too low . The brake fluid level is monitored electronically .
& WARNING
• You should 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!
Vehicle care Do-it-yourself service Technical data

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& WARN ING (continued )
• Before des cending a steep grade , reduce speed and shift trans­
mission into a lower gear or lower dr iving range. D o not r ide the
brakes or hold the pedal down too long or too often . This could
c au se the brake s to get hot and dimin ish braking effi ciency.
• Do not "ride the brakes " by resting your foot on the pedal when
you do not intend to b rake. This may cause the brakes to overheat ,
premature wear and in crea sed stopping distan ce.
• Under certain climat ic and oper ating condit ion s s uch as
passing through water, driving in heavy rain or after washing the
vehicle , the effectiveness of the brakes can be reduced. In winter ,
ice c an a ccumulate on the brake pads , linings , discs and drums .
Carefully apply brakes fo r a test. Brakes will dry and ice coatings
will be cleaned off after a few careful brake applications .
• Driving for an e xtended pe riod of time on salt-covered road s
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 spoile r, or if you install a different
spoiler , be sure the air flow to the front brakes is not obstructed .
Otherwise the brake system could overheat reducing the effective ­
ness of the entire br ake system .
• Failure of one brake circuit will impair the braking capability
resulting in an increased stopping distance . Avo id driving the
vehicle and have it towed to the nearest Audi dealer or qualified
workshop .
u
Brake booster
T he brake boo ster ad ds e xtra bra kin g pow er.
T he brake booster works with vacuum pressure which is created
only when t he en gine is run ning~ &.
& WARNING
• Never let the vehi cle roll to a stop with the engine shut off .
• If the brake boo ster is not working, for example 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 assistance . •
Functioning of Anti-Lock Brake System (ABS)
-- --
ABS preven ts the wheels from l ocking up und er bra kin g.
T he ABS contributes effectively to vehicle contro l since it prevents
th e w hee ls fr om lo cking when the brakes a re app lied . T hi s m ea ns
that the vehicle remains steerable and is less l ikely to skid.
With ABS you do not need to pump the brake . Just hold the brake
pedal down .
H owever, do not expect the AB S to shorten braking distance under
all circu ms tances. When drivi ng on grave l or on newly fa lle n sn ow
on top of icy surfaces, braking distance may be even longer, there ­
f o re, unde r these c ircums ta nces , it is es pecially imp ortant th at you
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)
i s r eac hed . W he n th is happens, a pumping n oise ca n be heard.
I f a n indiv idual wheel be gins to rotat e too slowly in relation to
vehic le speed and tends to lock, the ABS automatically reduces
brake pressur e to p revent that whee l from loc king .
T his automatic adjustment p rocess will cause a slight vibration of
t he brake peda l a nd some noi ses t o a le rt yo u th at ve hicle speed
must be adapted to ex isting road and traffic conditions. .,

& WARNING
Although the ABS is very effective, always remember that braking
capability is limited by tire traction. Always adjust your driving
speed according to the road and traffic 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
• If ABS is not functioning properly, a warning light will come on .
See
=> page 22.
• If a fault occurs in the ABS , the EDL is also not functioning. This
is indicated by the ABS warning light. •
Brake assistant
The brake assistant is designed to achieve the optimum
braking effect.
The brake assistant helps to increase the effective braking power
and thus to achieve a shorter stopping distance . If the driver
presses the brake pedal very quickly, the brake assistant automati ­
cally boosts the braking force to the maximum level, up to the point
where the anti-lock brake function (ABS) intervenes to stop the
wheels from locking. You should then keep the brake pedal pressed
until the vehicle has braked to the required speed. The brake assis ­
tant switches itself off as soon as you release the brake pedal.
The brake assistant will not be operative if there is a malfunction in
the ABS.
In vehicles with Adaptive Cruise Control* (ACC), the distance to the
vehicle ahead is continuously calculated using a radar sensor,
within the limits of the system=>
page 135. If the radar system
detects a short distance to the vehicle ahead, the brake system
exerts a small braking force to reduce the brake response time in
Controls and equip­
ment Safety first Vehicle operation
Intelligent technology
case of braking. In this way, the brake application can be quickened
and
the stopping distance reduced.
& 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 accident cannot be compensated for even by the brake assistant,
so always maintain a safe speed.
n
Servotronic® -advanced power
steering system
The power steering systems uses the power of the
running engine to allow precise steering with little effort.
The advanced Servotronic ® power steering system senses the road
speed and electronically adjusts power assistance to provide
comfortable and safe steering response exactly matched to the
vehicle speed.
Power steering will not work if the engine is off. As a result, the
steering wheel will be hard to turn.
The power steering fluid level is checked during the scheduled
maintenance services.
0 Note
If there is an electronic malfunction, servotronic will still function
like a conventional power steering system, providing a constant
steering support force that is no longer proportionate to the vehicle
speed. This is most noticeable when turning the steering wheel at
low speeds (for example when parking), -more effort will be
required than usual.
II-
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,_ __________________________________________ _
• Be aware of the different than usual steering response and
adj ust you r steer ing for ce accordingly.
• Have the problem checked and set right by an Audi dealer as
s o on as possible .
[ i ] Tip s
• When th e engine is running, never hold the steering whee l
turned all the way to the right or to the left for longer than 15 seconds. The power steering pump will overheat the hydrau lic
fluid if you keep ho lding the steering wheel turned all the way. This
is like ly to damage the power steering system.
• If the power steering system should fail entirely, or if the engine
is not running (for example, while being towed), you wil l still be able
to steer the vehicle . However,
considerably more effort will be
required to do so.
• If the power steering system should have a leak, or is not func ­
tioni ng properly, contact your authorized Audi dealer immediately.
• The power steering system requires a specially formulated
hydraulic fluid . The power steering reservoir is the one located most
forward on the left side of the engine compartment~
page 298. The
correct fluid level in the reservoir is important for proper func ­
tioning of the power steering.
App lies to vehic les: with A ll Wheel Dr ive
Dr iving with your quattro®
With All Wheel Drive, all four wheels are driven.
Gen era l i nfo rm ati on
With All Wheel Drive, power is d istr ibuted to all four whee ls. Th is
happens automatica lly depending on your driving style and the
road conditions at the time. See also ~
page 259, "Electronic differ ­
entia l lock (EDU".
Wint er tir es
When driving in the winte r, 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
driveability and braking: these tires must be mounted on
a ll fou r
wh eel s.
See also ~ page 329, "Winter tires".
Tire chains
Where tire chains are mandatory on certain roads, this normally
a lso app lies to veh icles with A ll Wheel Drive~
page 330, "Snow
chains".
R epl acing w hee ls/t ires
Vehicles with All Wheel Drive must always have tires of the same
size. Also avoid tires with different tread depths . For details see
page ~
page 325, "New tires and replacing tires and wheels" .
Off-R oa d dri ving?
Your Audi does no t have enough ground c learance to be used as an
off -road vehic le. It is therefore best to avoid rough tracks and
uneven terrain as much as possible . Also refer to~
page 269.
& WARNING
Always a djust yo ur driving to r oad and traffi c condition s. Do not
let the e xtr a s afet y affor ded b y All Whee l Dri ve tempt you into
taking extr a risks.
• Although the All Wheel Dr ive i s very effe ct ive , a lwa ys
r e member that braking capacity i s limited b y tire trac tion. You
s hould therefore not d riv e at e xcess iv e speed s on icy or slipp ery
road surfaces .
• On we t road surf aces, be care fu l no t to d riv e t oo fas t beca use
the front whe els could b egin to slid e on top of the w ater (aqu a­
planing ). If t his sho uld occ ur, you will h ave no warn ing from a
s udden incr ease in engine sp eed a s with a front -wh eel drive
v ehicl e. Alwa ys dri ve at spee d s w hic h are s uited to th e road condi ­
tion s - risk of cra sh.
;:i