wheel AUDI A6 2012 Service Manual

158 Airb ag sys te m
adult is properly seated and restrained at
one of the rear seating positions.
- Have the airbag system inspected by
your Audi dealer before transporting
anyone on the front passenger seat.
(D Tips
If the capacitive passenger detection sys ­
tem determines that the front passenger
seat is empty, the frontal airbag on the
passenger side will be turned off, and the
PA SSEN GER AIR B AG OFF light will stay
on .
Repair, care and disposal of the airbags
Parts of the a irbag system are installed at
many different places on your Audi. Installing,
removing, servicing or repairing a part in an
a rea of the vehicle can damage a part of an
airbag system and prevent that system from
working properly in a co llision.
There are some important things you have to know to make sure that the effect iveness of
the system will not be impaired and that dis­
carded components do not cause injury or po l­
lute the environment.
A WARNING
Improper care, servicing and repair proce­
dures can increase the risk of personal in­
jury and death by preventing an airbag from deploy ing when needed or deploying
an airbag unexpectedly:
- Never cover, obstruct, or change the steering wheel ho rn pad or airbag cover
or the instrument pane l or modify them
in any way .
- Never attach any objects such as cup
holders or telephone mountings to the
surfaces covering the airbag units.
- For cleaning the horn pad or instrument
pane l, use only a soft, dry cloth or one
moistened w ith plain water. Solvents or
cleaners cou ld damage the airbag cover
or change the stiffness or strength of the material so that the airbag cannot de­
ploy and protect properly.
- Never repair, adjust, or change any parts
of the airbag system.
- All work on the steering wheel, instru­
ment panel, front seats or electr ica l sys­
tem (including the installation of audio
equ ipment, cellu lar telephones and CB
radios, etc .) must be performed by a
qualified technic ian who has the training
and specia l equipment necessary.
- For any work on the airbag system, we strongly recommend that yo u see your
author ized Audi dealer or qualif ied work­
shop.
- Never modify the front b umper or parts
of the vehicle body.
- Always make sure that the s ide airbag
can inflate without inte rfe rence:
- Never install seat covers or rep lace­
ment upholstery over the front seat­
backs that have not been specifically
approved by Audi.
- Never use additional seat c ushions that
cover the areas where the side airbags
inflate.
- Damage to the orig inal seat covers or
to the seam in the area of the side a ir­
bag module must a lways be repaired
immediately by an author ized Audi
dealer .
- The airbag system can deploy on ly once.
After an a irbag has been deployed, it
must be replaced w ith new replacement
pa rts des igned and app roved especially
for your Aud i model version. Replace­
men t of comple te airbag systems or air­
bag components must be performed by
qua lified wor kshops only . Make sure that
any airbag service action is entered in
your Aud i Warranty
& Maintenance book­
let under
AIRBAG REPLACEMENT RE­
CORD.
- For safety reasons in severe accidents,
the alternator and starter a re separated
from the veh icle battery with a pyrotech-
n ic circuit inte rrupter . ..,.

-Work on the pyrotechnic circu it inter­
rupter must on ly be performed by a
qualified technic ians who have the ex­
perience, information and special tools necessary to perform the work safely.
- If the veh icle or the circuit interrupter
is sc rapped, all applicable safety pre­
cautions must be followed.
@) For the sake of the environment
Undep loyed airbag modules and preten­
sioners might be classified as Perchlorate Mate rial -special handling may apply, see
www.dtsc.ca .gov/haza rdo uswaste/per­
chlorate. When the vehicle or parts of the
restrai nt system inclu ding airbag modules
a nd safety bel ts w ith pretens ioners are
scrapped, a ll applicable laws and regula ­
tions must be observed. Your authorized
Aud i dea ler is familiar w ith these require­
ments and we recommend that you have
your dea ler perform this serv ice for you.
Other things that can affect Advanced
Airbag performance
C hanging the vehicle's suspension system can
ch ange the way that the Advanced A irbag Sys­
tem pe rforms in a crash. For example, us ing
tire-rim combinations not app rove d by Audi,
lowe ring the vehicle, changing the stiffness of
the suspension, incl uding the springs, suspen­
sion struts, shock absorbers etc. can change
the forces that are measured by the a irbag
se nsors and sent to the electron ic control
un it . Some suspension changes can, for exam­
p le, increase the force levels measured by the
se nsors and make the airbag system deploy in
crashes i n w hich it would not dep loy if the
ch an ges had not been made. Ot her kinds of
cha nges may reduce the force levels meas ­
ured by the sensors and prevent the airbag
from deploying when it shou ld.
The senso rs in the safety belt buckle fo r th e
d river and front passenger seat tell the elec ­
tronic control module if the safety belt is
l atched or not. If the safety belt is being used,
the front airbag will deploy at a slightly high-
A irba g sy stem 159
er rate of vehicle deceleration than i f the safe­
ty belt is not being used. Therefore, in a par ­
ticu lar collis ion, it is possible t hat an airbag
will not deploy at a seating pos ition where the
safety belt is be ing used but w ill inflate at the
position w here the safety belt is not be ing
used. It is impo rtant that noth ing interfere
with the safety be lt b uckles so that the sen­
sors can send the cor rec t info rmation abou t
sa fe ty belt use to the elec tronic con trol un it.
_&. WARNING ~-
Changing the vehicle's suspension includ-
ing use of unapprove d tire -rim combina ­
tions can change Advanced Airbag per­
formance and increase the risk o f serious
personal injury in a crash.
- Never install s uspension components
that do not have the same performance
characteristics as the components origi­
na lly installed on your vehicle .
- Never use tire-rim combinations that
have not been approved by Audi.
Knee airbags
Description of knee airbags
Appl ies to vehicles: wi th knee airbags
The knee airbag system can provide supple­
mental prot ection to properly r estrain ed
front seat occupants.
Fi g. 14 8 Drive r's airbag
T he driver knee airbag is i n the instrument
panel underneath the steering wheel
i=> fig . 148, the airbag for the passenger is at
about the same height in the instrument pan-
el underneath the glove compartment . ..,_

How knee airbags work
Applies to vehicles: with knee airb ags
The risk of injury to the leg area can be re­
duced by fully inflated knee airbags.
Fig. 149 Inflated airbags protecting in a frontal coll i­
sio n
The knee airbag system has been designed so
that the airbags for the driver and front pas­
senger deploy in certain but not all frontal
collisions .
If the front airbags deploy, the knee airbags
also deploy in frontal collisions when the de­ ployment threshold stored in the control unit
is met .
When the system deploys, the airbags fill
with a propellant gas, and inflate between the lower part of the instrument panel and the
driver and the lower part of the instrument panel and the front passenger¢
page 152,
fig. 146.
Although they are not a soft pillow, they can
"cush ion" the impact and in this way they can
help to reduce the risk of injury to the lower
extremities.
All of this takes place in the blink of an eye, so
fast that many people don't even realize that
the airbags have deployed . The airbags also
inflate with a great deal of force and it is im­
portant for occupant safety that nothing
should be in their way when they deploy.
Fully inflated airbags in combination with
properly worn safety belts slow down and lim­
it the occupant's forward movement and help
to reduce the risk of injury.
Airbag system 161
Important safety instructions on the
knee airbag system
Applies to vehicles: wit h knee airbags
Airbags are only supplemental restraints . Al­
ways wear safety belts correctly and ride in a
proper seating position.
There is a lot that you and your passengers
must know and do to help the safety belts and
airbags to provide supplemental protection.
_&. WARNING .. -
An inflating knee airbag can cause serious injury. Wearing safety belts incorrectly and
imprope r seating positions increase the
risk of serious personal injury and death
whenever a vehicle is being used.
- The knee airbag system cannot protect
you properly if you a re seated too close
to any of the airbag locations. When ad­
justing their seat positions, it is impor­
tant that both the driver and the front passenger keep their upper bodies and
knees at the following minimum safe
distances:
- at least 10 inches (25 cm) between the
chest and the steering wheel/instru­
ment panel.
- at least 4 inches (10 cm) between the
knees and the lower part of the instru­
ment panel.
- The risk of personal injury increases if
you lean forward or to the side, or if the seat is improperly positioned and you are
not wearing your safety belt . The risk in­
creases even more should the airbag de­
ploy.
- Always make sure that the knee airbag
can inflate without interference. Objects
between you and the airbag can increase
the risk of injury in an accident by inter­
fering with the way the airbag deploys or
by being pushed into you as the airbag
deploys.
- Never let anybody, especially children
or animals ride in the footwell in front

1 70 Child Safety
c::> page 168, Important things to
know.
(D Tips
Always replace child restraints that were
installed in a vehicle during a crash. Dam­
age to a child restraint that is not visible
could cause it to fail in another collision
situation.
Advanced front airbag system and children
Your vehicle is equipped with a front "Ad­
vanced Airbag System" in compliance with United States Federal Motor Vehicle Safety
Standard (FMVSS) 208 as applicable at the
time your vehicle was manufactured.
The Advanced Airbag system in your vehicle
has been certified to meet the "low-risk " re­
quirements for 3-and 6-year old children on
the passenger side and small adults on 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 "sup­
pression" requirements of the Safety Stand­
ard, to turn off the front airbag for infants up
to 12 months who are restrained on the front
passenger seat in child restraints that are list­
ed in the Standard.
Even though your vehicle is equipped with an
Advanced Airbag system, all children, espe­
cially those 12 years and younger, should al­
ways ride in the back seat properly restrained
for their age and size. The airbag on the pas­
senger side makes the front seat a potentially
dangerous place for a child to ride. The front
seat is not the safest place for a child in a for­
ward-facing child safety seat. It can be a very
dangerous place for an infant or a larger child
in a rearward-facing seat.
The vehicle's Advanced Airbag System has a
capacitive passenger detection system in the front passenger seat cushion that can detect
the presence of a baby or a child in a child
re­
straint system on this seat.
The capacitive passenger detection system
registers the changes that result in an electri­
cal field when a child, a child restraint, and a
baby blanket are on the front passenger seat .
The change in the measured capacitance due
to the presence of a child, a child restraint,
and a baby blanket on the front passenger
seat is related to the child restraint system
resting on the seat. The measured capacitance
of a child restraint system varies depending
on the type of system and specific make and
model.
The electrical capacitance of the various
types, makes, and models of child restraints
specified by the U.S.National Highway Traffic
Safety Administration (NH TSA) in the relevant
safety standard are stored in the Advanced
Airbag System control unit together with the capacitances typical of infants and a 1-year
old child. When a child restraint is used on the
front passenger seat with a typical 1 year-old infant, the Advanced Airbag System compares
the capacitance measured by the capacitive passenger detection system with the data
stored in the electronic control unit.
Child restraints and Advanced front
airbag system
Regardless of the child restraint that you use,
make sure that it has been certified to meet
United States Federal Motor Vehicle Safety
Standards and has been certified by its manu­
facturer for use with an airbag. Always be sure
that the child restraint is properly installed at
one of the rear seating positions. If in excep­
tional circumstances you must use it on the
front passenger seat, carefully read all of the
information on child safety and Advanced Air­
bags and heed all of the applicable WARN­
INGS. Make certain that the child and child re­
straint are correctly recognized by the capaci­
tive passenger detection system in the front passenger seat, that the front passenger air­
bag is turned off, and that the airbag status is .,.

Audi pre sense Preventative passenger
protection
App lies to veh icles: with Audi p re se nse
Audi pre sen se can ini tiate steps to help pro­
t ect vehicle occupants in certain situations.
The funct ions descr ibed depend on equipment
installed in your vehicle:
Audi pre sense basic*
The following functions can be triggered in
cert ain driving situations :
- Tightening of the safety belts (for example,
during heavy braking) : the front safety belts
have reversible belt pretensione rs. If a colli ­
sion does not occur, the safety belts loosen
slightly and are ready to be tightened again .
- Closing the windows and the sunroof* : the
windows and the sunroof* close leaving a
small open gap .
Audi pre sense basic functions can be trig­
gered at speeds above 20 mph (30 km/h) .
Vehicles with Audi drive select*: the deploy­
ment time is adapted in dynamic mode.
Audi pre sense front (vehicles with
adaptive cruise control*)
Audi pre sense front includes the functions in
Audi pre sense basic. In addition, within the
limits of the system, the likelihood of a colli­
sion with the vehicle immediately ahead is al­
so calculated . If the system senses an immi­
nent collision the following functions can be
triggered:
-Audi braking guard
¢ page 84
- Tightening the safety belts
- Closing the windows and the sunroof* ( leav-
ing a small open gap)
Audi pre sense rear (vehicles with Audi
side assist*)
Audi pre sense rear includes the functions in
Audi pre sense basic. In addition, the likeli­
hood of a rear-end col lision with the vehicle
coming from behind is also calcu lated. If the
Audi pre sense 187
risk of a co llision is detected, the following
functions can be triggered :
- Tightening the safety belts
- Closing the windows and the sunroof* (leav-
ing a small open gap)
Audi pre sense plus*
Audi pre sense plus includes the functions in
Audi pre sense front and Aud i pre sense rear .
Error message
Audi pre sense: not available
Preventative passenger protection is not avail­
able. See your authorized Audi dealer immedi­
ate ly to have the malfunction corrected.
A WARNING
-=
Audi pre sense cannot overcome the laws
of physics. It cannot prevent a collision. Do
not let the increased safety provided
tempt you to take risks . This will increase
the r isk of a coll is ion and serious personal
injuries .
- The sensors cannot always detect all ob­ jects . This increases the risk of a colli­
s10n .
-Audi pre sense does not detect people or
an imals or objects that are crossing the
veh icle's path ¢
page 78.
-The radar sensor's v is ion can be reduced
by heavy rain, ice, snow, heavy road spray
and reflections from guard rails, tunnel
entrances, etc. These and similar condi­
tions can prevent vehicles from being ac­
curately detected and in some cases they may not be detected at all.
Q) Note
The sensors can be displaced by impacts or
damage to the bumper, wheel housing and
underbody. This can affect the function of
the Audi pre sense system. Have your au­
thorized Audi dealer check to make sure
that the system is working properly.
•
•

Intelligent technology Notice about data
recorded by vehicle
control modules
Your vehicle is not equipped with an Event Da­
ta Recorder (EDR), installed by some manu­
facturers for the express purpose of capturing
data for retrieval after an accident or crash
event. EDR's are sometimes called "crash re­
corders".
Some state laws restrict the retr ieval or down­
loading of data stored by EDR's that were in­
stalled in a vehicle for the express purpose of
retrieving data after an accident or crash
event without the owner's consent.
Although your vehicle is not equipped with an
EDR, it is equipped with a number of electron­
ic control modules for various vehicle systems
such as, for examp le, engine function, emis­
sion control, as well as for the airbags and
safety belts.
These electronic control modules also record
vehicle-related data during norma l vehicle op­
eration for diagnostic and repair purposes.
The recording capacity of the electronic con­
trol modules is limited to data (no sound is re­
corded) and only a small amount of data is ac­
tually recorded over a very limited period of
time and stored when a system fault or other
condition is sensed by a control unit. Some of
the data then stored may relate to vehicle
speed, direction, braking as we ll as restraint
system use and performance in the event of a
crash or other condition. Stored data can only be read and downloaded with special equip­
ment.
Electronic stabilization
program (ESP)
Description
ESP helps to improve road holding and vehicle
dynamics to help reduce the probability of
skidding and loss of veh icle control. It works
only when the engine is running. ESP detects
Intelligent technology 189
certain difficult driving situations, including
when the vehicle is beginning to spin (yaw)
out of control and he lps you to get the veh icle
back under control by se lectively braking the
wheels, and/or reducing engine power and
providing steering ass istance to help hold the
vehicle on the driver's intended course. The in­
dicator light
lf.1 in the instrument cluster
blinks when ESP is taking action to help you
control the vehicle.
ESP has limitations.
It is important to remem­
ber that ESP cannot overcome the laws of
physics.
It will not always be able to help out
under all conditions you may come up against.
For example, ESP may not always be able to
help you master situations where there is a
sudden change in the coefficient of friction of
the road surface. When there is a section of dry road that is suddenly covered with water,
slush or snow, ESP cannot perform the same
way it would on the dry surface . If the vehicle
hydroplanes (rides on a cushion of water in­
stead of the road surface), ESP will not be
able to help you steer the vehicle because con­
tact with the pavement has been interrupted
and the vehicle cannot be braked or steered .
During fast cornering, particularly on winding
roads, ESP cannot always deal as effectively
with difficu lt driving situations than at lower
speeds. When towing a trailer, ESP is not able
to help you regain control as it would if you
were not tow ing a trailer.
Always adjust your speed and driving style to road, traffi<; and weather conditions. ESP can­
not override the vehicle's physical limits, in­
crease the available traction, or keep a vehicle
on the road if road departure is a result of
driver inattention. Instead, ESP improves the
possibility of keeping the vehicle under con­
trol and on the road dur ing extreme maneu­
vers by using the driver's steering inputs to
help keep the vehicle going in the intended di­
rection. If you are traveling at a speed that
causes you to run off the road before ESP can
provide any assistance, you may not experi­
ence the benefits of ESP .
•
•

190 Intelligent technology
ESP includes and/or works together with the
anti-lock brake system (ABS), brake assist sys ­
tem, anti-slip regulation (ASR) , e lectronic dif­
f erential lock ( ED L) and e lectronic interax le
d ifferential lock* . ESP is switched on all the
time . In certain situat ions when you need less
traction , you can switch off ASR by pressing
the button
I!] c:;, page 191 , fig. 164 . Be sure
to switch ASR on again whe n you no longe r
need less tra ct ion.
Anti-lock braking system (ABS )
ABS prevents the wheels from locking up
when braking. The vehicle can still be steered
even du ring hard b rak ing . Apply steady p res­
sure to the brake pedal. Do no t pu mp the ped­
a l. A puls ing in the b ra ke ped al ind icates that
the system is he lp ing you to b rake the vehicle .
Brake assist system
The brake assist system can decrease brak ing
d ista nce. It increases braking power w hen the
d river p resses the brake pedal quic kly in eme r­
gen cy situa tions. You mus t press and hold the
b rake peda l until the si tuation is over. In veh i­
cles with adaptive cruise control*, the brake
assist system is more sensitive if the distance
detected to the vehicle ahead is too smal l.
Anti-slip r egulation (ASR)
ASR reduces engine power when the d rive
wheels begin to spin and adapts the fo rce to
the road conditions. This makes it easier to
start, accelerat e and drive up hills .
Electronic differential lock (EDL )
The ED L brakes wheels that are spinn ing and
transfers the drive power to the o ther d rive
wheel or whee ls i f th e vehi cle is equipped with
a ll-whee l drive *. This function is available up
to about 7S mph (120 km/h).
I n extreme cases, EDL automat ica lly switches
off to help keep the brake on the braked whee l
from overheating . EDL wi ll switch on again au­
tomatically when conditions have returned to
normal.
Electronic interaxle differential lock */
selective wheel torque control*
The electronic interaxle differential lock (front
whee l drive) or the se lective whee l torque
control (all-wheel dr ive) operates when d riv­
ing t hrough curves . The front wheel on the in­
s ide of the curve or both whee ls on the inside
of the curve a re b raked select ively as needed .
T his m inimizes sliding in th e front wheels and
allows for mo re p reci se d rivi ng throug h
c ur ves . The appl icable system may not acti­
vate when dr iving in we t or snowy conditions.
_& WARNING ~
- ESP , ABS, AS R, E DL and the e lectronic in­
terax le d iffe rential lock function* cannot
overcome the laws of physics . This is es­
pecially important on slippery or wet
roads. If the systems begin acti ng to sta­
b ili ze your ve hicle , you s hould immed i­
ately c hange yo ur speed to match the
road and traffic cond itions. Do not let
t he incre ased safety provide d by the se
systems tempt you to take risks. Do ing
so will increase the r is k of a loss of vehi­
cle control, collision and serious persona l
in jur ies.
-Always adapt your speed to road, traffic and weather conditions . The risk of los­
ing control of the vehicle increases when
driving too fast, espec ially through
curves and o n slippery or wet roads, and
when dr iv ing too close to vehicles up
ahead . ESP, ABS, the brake ass ist system,
E DL, ASR and the e lectronic interax le dif­
fe ren tial lo ck fu nction * can not prevent
coll is ions.
- Always ac celerate with spe cial care on
even, smooth s urfaces such as tho se th at
ar e we t or covered with i ce and snow.
The drive wheels can spin eve n with
these assistance systems t hat cannot al­
ways he lp to red uce the risk of loss of ve -
hicle control. ..,.

@ Tips
-ABS and AS R on ly wor k co rrectly when
a ll fo ur wheels are eq uipped w ith identi­
ca l tires . Different tire s izes can lead to a
r educt io n in eng ine power.
- You may hear noises when the sys tems
desc ribed are working.
- If the indicato r light
D] or m (USA
models) ;£1 (Canada models) appea rs,
there may be a malfunctio n ¢
page 19 ,
¢ pag e 19.
Switching on and off
ESP turns on automatically when you start
the engine .
Fig. 1 64 Center co nsole wit h ESP OFF button
Switching sport mode on
Press th e I,$ OF F I button ¢ fig. 164. The ac­
tions tak en by the ES P syst em to stabili ze th e
ve hicl e are lim ited. In ve hicl es w it h fro nt
wheel drive, the an ti-s lip reg ulat ion (ASR) is
limited . In vehicles wi th a ll-wheel d rive, t he
AS R is switc hed off. The
I ES P i ndicator lig ht
turns on and the message
Caution! Reduced
tract ion ¢.&
appears in the driver informa ­
tion system d isplay.
The fo llow ing examples a re u nusua l situa­
tions where it may make sense to switc h sport
mode on in order to a llow the whee ls to spin:
- Rocking the vehi cle back and forth when it is
stuck
- D rivin g in d eep snow or on loose groun d
- D riving wi th s now cha ins
Intelligent technology 191
Switching sport mode off
Press the In OF FI but ton ag ain. T he ltJ in dica ­
tor lig ht tur ns off an d the message
Stability
program on
appears in t he d river info rmation
system display .
&_ WARNING
-- Drive whee ls can sp in and you can lose
contro l of t he ve hicle more eas ily w hen
ASR and ESP are in sport mode, especial­
ly whe n th e road is slippery.
- Sw itch to sport mode only when your
driving sk ills, traff ic and weat her co ndi­
tions perm it.
@ Tips
You cannot sw itch sport mode on whe n
adaptive c ruise control* is w orki ng.
Braking
General information
Wha t affe cts bra king effici ency?
-
Operating conditions and driving habits
The brakes on today's automobiles a re still
subject to wear, depending largely on operat­ i ng co nd it io ns and driving habits ¢,& . On ve­
hi cles that a re e it h er dr iven most ly in stop­
and-go city t raff ic or are dr iven hard, the
br ake pa ds should be check ed by yo ur au thor­
iz ed Audi dea ler m ore often th an spec ified in
the
Warranty & Maintenance booklet. Failure
to have yo ur brake pads ins pected can result
in reduced brake performance .
On stee p slopes, you sho uld use the br aking
e ff ect o f the engine. This way, you prevent un ­
necessary wear on t he brake system. If you
must use your bra kes, do not hold the brakes
down cont in uous ly. Pump the brakes at inter­
vals.
Moisture or road salt
U nder certa in conditions, for exam ple, when
driving th roug h water or very heavy rain, or
even after washing your veh icle , the b raking
effect can be reduced due to m oist ure (or in ..,.

192 Intelligent technology
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
Q & .
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 cor­
rosion has formed on the discs, it is advisable
to clean off the pads and discs by braking
f irmly a few times from a moderately high
speed
Q & .
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
Q & .
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.
Brake booster
The brake booster works with vacuum pres­
sure which is created only when the engine is
running
Q & .
Brake lining wear status
Brake lining wear may be checked by visual in­
spection of the condition of the brake pads
through the openings in the wheel. If neces­
sary, the wheel may be removed for this in­
spection
Q page 258, Changing a wheel.
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!
- Before descending a steep grade, reduce
speed and shift transmission 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 cause 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 climatic and operating
conditions such as passing through wa­
ter, driving in heavy rain or after washing
the vehicle, 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 coat­
ings will be cleaned off after a few care­
ful 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 discs and pads with a few careful
brake applications.
- If you damage the front spoiler, or if you
install a different spoiler, be sure the air
flow to the front brakes is not obstruct­
ed. Otherwise the brake system could
overheat reducing the effectiveness of
the entire brake system.
- Failure of one brake circuit will impair
the braking capability resulting in an in­
creased stopping distance. Avoid driving
the vehicle and have it towed to the near­
est Audi dealer or qualified workshop.
- Never let the vehicle roll to a stop with
the engine shut off.
- If the brake booster is not working, for
example when towing your vehicle, or
because the brake booster has somehow
been damaged, the brake pedal must be
~

pressed considerably harder to make up
for the lack of booster assistance.
Electro-mechanical
power assist
The electro-mechanical power assist helps
the driver when steering.
Power steering adapts electronically based on
the vehicle speed .
Indicator lights and messages
• Steering defective! Stop the vehicle
If this indicator light turns on and stays on
and this message appears, the power steering may have failed.
Do
not continue driving. See your authorized
Audi dealer or other qualified repa ir facility
for assistance.
t -r- fl Steering: System malfunction! You may
c ontinue driving
If the indicator light turns on and the mes­
sage appears, the steer ing may be more diffi­
cult to move or more sensitive than usual.
Drive slowly to your authorized Audi dealer or
qualified workshop to have the malfunction
corrected.
@ Tips
If the . or t~fl indicator light only stays
on for a short time, you may continue driv­
ing .
Driving with your
quattro ®
Applies to vehicles: with all-wheel drive
With all-wheel drive, all four wheels are driv­
en.
General information
With all-wheel drive, power is distributed to
all four wheels. This happens automatically
depending on your driving sty le and the road
conditions at the time. See also¢
page 189. Intelligent technology 193
T
he all -whee l dr ive concept is designed for
high engine power. Your vehicle is exception­
ally powerfu l and has excellent driving charac­
teristics both under normal driving conditions
and on snow and ice. Always read and follow
safety precautions¢ ,&..
Winter tires
When driving in the winter, your vehicle with
all-wheel drive has an advantage, even w ith
regular tires. In winter road conditions it may
be advisable to mount winter tires (or all-sea­
son tires) for improved driveability and brak­
ing: these tires must be mounted on
all four
wheels.
See also¢ page 250, Winter tires.
Tire chains
Where tire chains are mandatory on certain
roads, this normally also applies to vehicles
with all-wheel drive¢
page 251, Snow
chains .
Replacing wheels/tires
Vehicles with a ll-wheel drive must always
have tires of the same size. Also avoid tires
with different tread depths. For deta ils see
page ¢
page 246, New tires and replacing
tires and wheels.
Off-Road driving?
Your Audi does not have enough ground clear­
ance to be used as an off-road vehicle. It is
therefore best to avoid rough tracks and un­ even terrain as much as possible. Also refer to
¢page 197 .
A WARNING
Always adjust your dr iv ing to road and traf­
fic conditions. Do not let the extra safety
afforded by all-wheel drive tempt you into
taking extra risks.
-Although the all-wheel drive is very ef­
fective, always remember that braking
capacity is limited by tire traction. You
should therefore not drive at excessive
speeds on icy or slippery road surfaces.
•
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