steering AUDI S4 2014 Owner's Manual

146 Airbag system
Airbag system
Important things to know
Importance of wearing safety belts and
sitting properly
Airbags are only supplemental restraints. For
airbags to do their job , occupants must al­
ways properly wear their safety belts and be
in a proper seating position.
F or your safety and the safety of your passen­
gers, before driving off, always:
• Adjust the driver's seat and steering wheel
properly ¢
page 129,
• Adjust the front passenger's seat properly
¢ page 59,
• Wear safety be lts properly ¢ page 141,
• Always properly use the proper child re-
straint to protect children¢
page 167.
In a collision airbags must inflate within the
blink of an eye and with considerable force.
The supplemental airbags can cause injuries if
the driver or the front seat passenger is not
seated properly . Therefore in order to help the
a ir bag to do its job, it is important, both as a
d river and as a passenger to sit prope rly at all
times.
By keeping room between your body and the
steering wheel and the front of the passenger
compartment, the airbag can inflate fully and
comp letely and provide supplemental protec­
tion in ce rtain frontal collisions
¢page 129,
Proper occupant seating positions.
F or details
on the operation of the seat adjustment con­
t rols ¢
page 60.
It's especially important that children are
properly restrained ¢
page 167.
There is a lot that the driver and the passen­
ge rs can and must do to help the individual
safety features installed in your A udi work to­
gether as a system.
Proper seating pos ition is important so that
the front airbag on the driver side can do its
job. If you have a physical impairment or con- dition that
prevents you from sitting properly
on the driver seat with the safety belt properly
fastened and reaching the pedals , spec ial
modifications to your vehicle may be necessa­
ry.
Contact your authorized Audi dea ler, or call
Audi C ustomer Re lations at 1-800-822-2834.
When the airbag system dep loys , a gas gener­
ator will f ill the airbags, break open the pad­
ded covers, and inflate between the steering
whee l and the dr iver and between the instru­
ment panel and the front passenger. The air­
bags will deflate immediately after deploy­
ment so that the front occupants can see
th rough the windshield aga in without inter­
ruption .
All of th is takes place in the blink of an eye , so
fast that many people don't even realize that
the a irbags have deployed . The airbags also
inflate with a great deal of force and nothing
shou ld be in their way when they deploy.
Front airbags in combination with properly
worn safety belts slow down and limit the oc­
cupant's forward movement. Together they
help to prevent the driver and front seat pas­
senger from hitting parts of the inside the ve­
hicle while reducing the forces acting on the
occupant dur ing the crash. In this way they
help to reduce the risk of injury to the head
and upper body in the crash . A irbags do not
protect the arms or the lower parts of the
body.
Both front a irbags w ill not inflate in all fronta l
collisions . The triggering of the airbag system
depends on the vehicle dece lerat ion rate
caused by the collision and registered by the
electron ic control unit. If this rate is below
the reference value programmed into the con­
trol unit, the airbags will not be trigge red ,
even though the car may be bad ly damaged as
a resu lt of the co llision . Vehicle damage, re­
pair costs or even the lack of veh icle damage
is no t necessarily an indication of whether an
airbag should inflate or not .
It is not possib le to define a range of vehicle
speeds that w ill cover every possib le kind and .,.

angle of impact that will always trigger the
airbags, since the circumstances will vary con­
siderably between one collision and another.
Important factors include, for example, the nature (hard or soft) of the object which the
car hits, the angle of impact, vehicle speed,
etc. The front airbags will also not inflate in
side or rear collisions, or in ro ll-overs .
Alwa ys rem ember : Airbags will deploy only
once, and only in certa in kinds of collisions .
Your safety belts are always there to offer pro­
tection in those s ituations in which airbags
are not supposed to deploy , or when they have
a lready deployed ; fo r example , when yo ur ve­
h icle strikes or is struck by another after the
first collision .
This is just one of the reasons why an a irbag is
a supplementary restra int and is not a s ubst i­
tute for a safety belt . The airbag system
works most effectively when used with the
safety belts. Therefore, always properly wear
your safety belts
¢ page 138.
A WARNING
Sitting too close to the steer ing wheel or
instrument panel will decrease the effec­
tiveness of the airbags and will increase
the risk of pe rsonal injury in a co llision .
- Never sit closer than
10 inches (25 cm)
to the stee ring wheel or instrument pan­
el.
- If you cannot sit more than
10 i nches
(25 cm) from the steer ing whee l, investi­
gate whether adaptive equipment may
be available to help you reach the pedals
and increase your seating dis tance from
the steering wheel.
- If you are unrestrained, lean ing fo rward,
sitting sideways or out of position in any
way, yo ur risk of inj ury is much highe r.
- You w il l also receive serio us inju ries and
cou ld even be killed if you are up against
the airbag or too close to it when it in ­
flates -even with an Advanced Airbag.
- To reduce the r isk o f injury when an air ­
bag inflates, a lways wear safety belts
proper ly ¢
page 141, Safety belts .
Airbag system 147
-Always make certain that chi ld ren age 12
or younger a lways ride in the rear seat. If
children are not properly restrained, they may be severe ly inju red or killed when an
airbag inf lates .
- Never let ch ildren ride unrestra ined or
improperly restrained in the vehicle . Ad ­
just the front seats prope rly.
- Never ride with the backrest reclined.
- Always sit as far as possible from the
steer ing whee l or the instrument pane l
¢page 129.
-Always sit upright with your back against
the backrest of your seat.
- Never p lace your feet on the instrument
panel or on the seat. Always keep both
feet on the f loor in front of the seat to
he lp prevent serio us in juries to the legs
a nd h ips if the airbag inflates.
- Never recline the front passenger 's seat
to tra nsport objects. Items can a lso
move i nto the area of the s ide a irbag or
the front a irbag du ring bra king or in a
sud den maneuve r. Obje cts ne ar the air­
bags can become projectiles and cause
injury when an airbag inflates.
_&. WARNING ~
A irbags that have de ployed in a crash must
be replaced.
- Use on ly original equipment airbags ap­
proved by Audi and installed by a trai ned
technician who has the necessary too ls
and d iagnost ic equipment to properly re­
place any airbag in your vehicle and as­
sure system effectiveness in a crash .
- Never perm it salvaged or recycled air­
bags to be installed in your vehicle .
Child restraints on the front seat - some
important things to know
.,. Be su re to read t he importa nt information
and head the WARNINGS fo r important de­
tails about children and Advanced Airbags
¢ page 167. ..,.
•
•

150 Airbag system
-Never place additiona l items on the seat
that can increase the total weight regis­
tered by the weight-sensing mat and can
cause injury in a crash.
Front airbags
Description of front airbags
The airbag system can provide supplemental
protection to properly restrained front seat
occupants.
F ig . 153 Location of driver airbag: in steer ing whee l
Fig. 15 4 Location of front passenger's airbag: in the in ­
strument panel
Your veh icle is equipped with an "Advanced
A irbag System" in compliance with United
States Federal Motor Vehicle Safety Standard ( FM VSS) 208 as app licab le at the time your
ve hicl e was manufac tured. The system senses
the position of the front seats and controls
front airbag inflation with a valve, depending
on the distance between the respect ive seat
and the steering wheel or instrument panel.
The safety belts for the seats have "preten­
sioners" that he lp to take slack out of the belt
system . The pretensioners a re also activated
by the electron ic cont ro l unit for the ai rbag
system. T
he front safety belts also have load limiters
to help reduce the forces applied to the body
i n a crash .
T he airbag for the drive r is in the stee ring
whee l hub¢
fig. 153 and the airbag for the
front passenger is in the instrument panel
~ fig. 154 . The general locat ion of the a irbags
is marked "AIRBAG".
T here is a lot you need to know about the ai r­
bags in your vehicle. We urge you to read the
detailed information about airbags, safety
belts and child safety in this and the other
chapters that make up the owner's literature.
P lease be sure to heed the WARNINGS -they
are extremely importa nt for your safety and
the safety of your passengers, especially in­
fants and small chi ldren.
_&. WARNING
Neve r rely on airbags alone for p rotection.
- Even w hen they deploy, airbags provide
only s upplement al pro te ctio n.
- Airbag work most effect ive ly when used
with p roperly wor n safety bel ts.
- Therefore, always wea r you r safety belts
a nd make sure tha t eve rybody in your ve­
h icle is p roperly res trained.
_&. WARNING
A pe rson on the front passenger seat, es­
pe cial ly infa nts and sm all ch ildren, w ill re­
ceive serio us inju ries and can even be kil­
l ed by being too close to the airbag when
it inflates .
- Although t he Advanced Airbag System in
your veh icle is designed to tur n off the
front passenger airbag if an infant or a
small child is on the front passe nger
seat, nobody can absolutely guarantee
that deployment under these special
conditions is imposs ible in all conceiva­
b le sit uat ions that may happen during
the useful life of your vehicle.
- The Advanced Airbag System can dep loy
i n acco rdance with the "low risk" option
unde r the U.S . Feder al Standard if a child
that is heav ie r than the typical one -year
-
.

160 Airbag system
-Never attach any objects such as cu­
pholders or telephone mountings to the
surfaces covering the airbag units.
- For cleaning the horn pad or instrument
panel, use only a soft, dry cloth or one
moistened with plain water. Solvents or
cleaners could damage the airbag cover
or change the stiffness or strength of the
material so that the airbag cannot 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 electrical sys­
tem (including the installation of audio
equipment, cellular telephones and CB
radios, etc.) 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
authorized Audi dealer or qualified work­
shop.
- Never modify the front bumper or parts
of the vehicle body.
- Always make sure that the side airbag
can inflate without interference:
- Never install seat covers or replace­
ment upholstery over the front seat­
backs that have not been specifically
approved by Audi.
- Never use additional seat cushions that
cover the areas where the side airbags
inflate.
- Damage to the original seat covers or
to the seam in the area of the side air­
bag module must always be repaired
immediately by an authorized Audi
dealer.
- The airbag system can be activated only
once. After an airbag has inflated, it
must be replaced by an authorized Audi
dealer or qualified technician who has
the technical information, training and
special equipment necessary.
- The airbag system can be deployed only once. After an airbag has been deployed,
it must be replaced with new replace- ment parts designed and approved espe­
cially for your Audi model version . Re­
placement of complete airbag systems
or airbag components must be per­
formed by qualified workshops only. Make sure that any airbag service action
is entered in your Audi Warranty
& Main­
tenance booklet under
AIRBAG REPLACE­
MENT RECORD.
- In accidents when an airbag is deployed,
the vehicle battery separates the alterna­
tor and the starter from the vehicle elec­
trical system for safety reasons with a pyrotechnic circuit interrupter.
- Work on the pyrotechnic circuit inter­ rupter must only be performed by a
qualified dealer -risk of an accident!
- If the vehicle or the circuit interrupter
is scrapped, all applicable safety pre­
cautions must be followed.
@ For the sake of the environment
Undeployed airbag modules and preten­
sioners might be classified as Perchlorate
Material -special handling may apply, see
www .dtsc.ca.gov/hazardouswaste/per­
chlorate. When the vehicle or parts of the restraint system including airbag modules
safety belts with pretensioners are scrap­
ped, all applicable laws and regulations
must be observed. Your authorized Audi
dealer is familiar with these requirements
and we recommend that you have your
dealer perform this service for you.
Other things that can affect Advanced
Airbag performance
Changing the vehicle's suspension system can
change the way that the Advanced Airbag Sys­
tem performs in a crash. For example, using
tire-rim combinations not approved by Audi, lowering the vehicle, changing the stiffness of
the suspension, including the springs, suspen­
sion struts, shock absorbers etc. can change
the forces that are measured by the airbag sensors and sent to the electronic control
unit. Some suspension changes can, for

168 Child Safety
-If you must install a rearward facing
child safety seat on the front passenger
seat in exceptional circumstances and
the
PASSENGER AIR BAG OFF light does
not come on and stay on, immediately
install the rearward-facing child safety
seat in a rear seating position and have
the airbag system inspected immediately
by your authorized Audi dealer.
.&, WARNING
If, in exceptional circumstances, you must
install a forward-facing child 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.
- Always follow the manufacturer's in­
structions provided with the child safety
seat or carrier.
- 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 child restraint. The backrest must be adjusted to an upright position .
- Always make sure that the
PASSENGER
AIR BAG OFF
light comes on and stays
on all the time whenever the ignition is
switched on.
(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.
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
child restraint on the front passenger seat us­
ing the weight-sensing mat in the seat cush­
ion and the sensor below the safety belt latch
on the front passenger seat that measures the
tension on the safety belt.
The weight-sensing mat measures total
weight of the child and the child safety seat
and a child blanket on the front passenger
seat. The weight on the front passenger seat
is related to the design of the child restraint
and its "footprint", the size and shape of the
bottom of the child restraint as it sits on the
seat. The weight of a child restraint and its "footprint" vary for different kinds of child re -
straints and for the different models of the .,.

186 Intelligent technology
Intelligent technology
Notice about data
recorded by vehicle
control modules
Your veh icle is not equipped with an Event Da­
ta Recorde r (EDR), ins talled by some manu­
facture rs fo r the express p urpose of capturing
data for retrieval after an accident or cras h
event . EDR's are sometimes ca lled "crash re­
corders".
Some state laws restr ict 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.
A ltho ugh yo ur vehicle is not equ ipped wit h an
EDR, it is equipped with a number of electron­
ic control modules for various vehicle systems
such as, for examp le, eng ine f unction, em is­
sion control, as well as for the airbags and
safety belts.
These electronic contro l modules also record
vehicle-re lated data during norma l vehicle op­
erat ion for diagnostic and repa ir 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 ove r a ve ry limited pe riod of
time and stored when a sys tem faul t or o ther
cond ition is sensed by a cont ro l u nit. Some of
the data then stored may re late to vehicle
speed, direction, braking as we ll as restraint
system use and performance in the event of a
crash or other condit ion. Stored data can only
be read and downloaded w ith special equip­
ment.
Electronic Stabilization
Control (ESC)
Description
ESC helps to improve road holding and vehicle
dynamics to help reduce the probability of
skidd ing and loss of ve hicle control. It works
only when the eng ine is running. ESC detects certain difficult driving situat
ions, including
when the vehicle is beginning to spin (yaw)
o ut of control and he lps you to get the veh icle
back under control by se lectively braking the
whee ls, and/or reducing eng ine power and
providing steer ing ass istance to he lp hold the
vehicle o n the dr iver's intended course. The in­
dicator light
J.i) in the instrument cluster
blinks when ESC is ta king action to help yo u
control the veh icle.
ESC has limitations.
It is importa nt to remem­
ber that ESC cannot overcome the laws of
physics. It will not always be able to help out
under a ll cond it ions you may come up aga inst.
F or example, ESC may not always be able to
help you master situations where there is a
s u dden change in the coefficient of friction of
the road surface. When there is a section of dry road that is sudden ly covered w ith water,
s lush or snow, ESC cannot perform the same
way it wou ld on the dry surface . If the ve hicle
hydroplanes (rides on a cushion of water in­
stead of the road surface), ESC will not be
able to help you steer the vehicle be cause con­
tact with the pavement has been in terrupted
and the vehicle cannot be braked or steered .
D uring fast cornering, particularly on winding
roads, ESC cannot always deal as effectively
with difficult driving situations than at lower
speeds. When towing a trailer, ESC 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, traffic and weather condit ions. ESC can­
not override the vehicle's physical limits, in­
crease the availab le tract ion, or keep a ve hicle
on the road if road departure is a result of
driver inattent io n. Instead, ESC imp roves the
poss ibil ity of keeping the vehi cle under con ­
trol and on the road during extreme maneu­
vers by using the d river's steering inputs to
help keep the vehicle going in the intended di­
rection . If you are traveling at a speed that
ca uses you to run off the road before ESC can
provide any assistance, you may not experi­
ence the benefits of ESC.

ESC includes and/or works together with the
anti-lock brake system (ABS), brake assist sys ­
tem, anti -slip regulation (ASR) , e lectronic dif­
ferential lock (EDL), dynamic steering* and electronic i nteraxle differential lock* /selective
wheel torque control* . ESC is switched on all
the t ime. I n certain s ituations when you need
less traction, you can switch
off ASR by press­
i ng the button~~
page 188, fig. 174 or
~ page 188, fig. 175. Be sure to sw itch ASR
on again when you no longer need less trac­
tion.
Anti-lock b ra king s ystem (ABS)
ABS prevents the wheels from locking up
when braking. The vehicle can still be steered
even d uring hard brak ing . Apply ste ady p res­
sure to the brake pedal. Do not pump the ped­
a l. A pulsing in the brake peda l indicates t hat
the system is he lping you to brake the vehicle .
Brake assist system
The brake assist system can decrease bra king
d istance. It increases braking power when the
d river presses the brake pedal quick ly in eme r­
gency situations . You must press and hold the
brake peda l until the situation is over. In
veh icles w ith adaptive cru ise contro l*, the
brake assist system is more sensit ive if the
d istance detected to the veh icle ahead is too
small.
Anti- slip regulati on (ASR)
ASR reduces engine power when the drive
wheels begin to spin and adapts the force to
the road condit ions. This makes it eas ier to
start, accelerate and drive up hills.
Elect ronic diffe renti al lo ck (EDL )
The ED L brakes wheels that are spinning and
transfers the drive power to the other drive
wheel or wheels if the vehicle is equipped with
all-wheel drive*. This function is available up
to about 60 mph (100 km/h) .
In extreme cases, EDL automatica lly switches
off to help keep the brake on the braked whee l
from overheating. EDL w ill switch on again au-
Intellig ent technolog y 187
tomat ica lly when conditions have returned to
norma l.
Dynamic steering*
On vehicles with dynam ic steering*, ESC helps
stab il ize the s teer ing in crit ica l sit uat io ns.
Electronic interaxle differential lock* /
selective wheel torque control*
T he electronic i nteraxle differential lock (front
whee l dr ive) or the se lective whee l to rque
control (all-whee l dr ive) opera tes when dr iv­
ing thro ugh curves. The front wheel on the in­
side of the c urve or both whee ls on the inside
of the curve are braked selectively as needed .
This min imizes sliding in the front wheels and
allows for more precise driving through
cu rves . The applicable system may not acti­
vate when dr iv ing in wet or snowy conditions.
A WARNING
- ESC, ABS , ASR, EDL dynam ic steering*
a nd the elect ronic interaxle differential
loc k* /se lective wheel torque control*
cannot overcome the laws of physics .
This is especially important on slippery
or wet roads. If the systems begin acting
to stabilize your veh icle, yo u should im­
mediately change your speed to match
the road and traff ic conditions. Do not
let the increased safety provided by
these systems tempt you to take r isks.
Doing so will increase the risk of a loss of
veh icle contro l, col lision and ser ious per­
sonal injuries.
- Always adapt your speed to road, traffi c
and wea ther conditions. The risk of los­
ing con tro l of the vehicle increases when
driving too fast, espec ially through
curves and on slippery or wet roads, and
when dr iv ing too close to vehicles up
ahead. ESC, ABS, the brake ass ist sys­
tem, ASR, EDL dynam ic steering* and the
electronic interaxle differentia l lock*/se­
lective whee l torque control* cannot p re-
vent co llisions . ..,.
•
•

th e brakes or hold the pedal down too
long or too ofte n. This cou ld cause the
brakes t o get hot and dimi nish b raking
efficiency .
- Do not "r ide t he b rakes" by resting your
foot on the pedal when you do n ot intend
t o brake . Th is may cause the brakes to
overheat, premature wear and increased
stopp ing distance.
- Under certa in climat ic and operating
condit ions such as passing through wa­
ter, driving i n heavy rai n or after wash ing
the vehicle, the effe ct iveness of the
brakes can be re duced. In winter, ice can
acc umulate on the brake pads, linings,
discs and drums. Carefully apply brakes
f or a test. Brakes will dry and ice coat­
ings will be cleaned off after a few care­
ful brake app lications.
- Driv ing for an extended period of time on
salt-covered roads w ithout using your
brakes can also affect braking efficiency .
Clean off accumulated salt coating from
brake discs and pads w ith a few caref ul
brake applicat io ns.
- If you damage the front spo iler, or if you
install a diff ere nt spoiler, be sure the air
flow to t he front b ra kes is not obstr uct­
ed . Otherwise the br ake sys tem co uld
overheat red ucing the effectiveness of
the ent ire brake sys tem.
- F ailure of one br ake circui t will im pair
the brakin g capability res ulting in an in­
creased stop ping distance . Avoid driving
the vehicle and have it towed to t he near­
est author ized Audi dealer or qualified
workshop.
- Never let the vehicle ro ll to a stop w ith
the engine shut off.
- If the brake booster is not work ing, the
brake pedal must be pressed considera­
bly harder to make up for the lack of
booster assistance.
Int ellig ent technolog y 191
Electro-mechanical
power assist, dynamic
steering
The electro-mechanical power assist helps
t he driver when steering.
Power steer ing adap ts electronically based on
t he ve hicl e spee d.
Indicator lights and messages
• Steering defect ive! Do not drive vehicle!
If this indicator light turns on and stays on
and t his message appears, the power steer ing
may have failed.
Do
not continue driving. See your authorized
Audi dealer or a qualified repair facility for as­
s istance.
':rij Dynamic steering: Sy stem fault! You can
continue dr iving
If the indic ator ligh t turns on and the mes­
sage appears, the steering may be more diffi­
cu lt to move o r more sensitive tha n usual. The
steering wheel may a lso be at an ang le when
driv ing straight.
Drive slowly to your a uth orized Audi dea ler or
qualified workshop to have the ma lf u nction
corrected.
(;rij Dynamic ste ering : initializing
If this drive r message appea rs and the indica­
tor light is flas hing on the instrument panel,
dynam ic steer ing* i s being rein itia lized. After
sta rting the engine, the stee ring w heel will
move s light ly . Re- initializa tion might be nec ­
essary if the stee ring wheel was moved hard
to the left and right whi le the vehicle was not
moving. The display goes out as soon as initi­
alization is complete .
A WARNING
-Have the dy namic stee ring* system mal­
f u nction repa ired as soon as possible by an
authorized Audi dealer or qualified work­
shop - risk of acc ident!
-
•
•

192 Intelligent technology
(D Tips
-If the . or 'Tj indicator light only stays
on for a short time, you may continue
driving.
- The dynamic steering* stability systems
are not available in the event of a system
malfunction.
- For additional information on dynamic
steering*, refer to
c:> page 113.
Driving with your
quattro
App lies to vehicles: with a ll-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 style and the road
conditions at the time . See also
c:> page 186.
A center differential distributes the driving
power variably to the front and rear axle .
It
works together with selective wheel torque
control , which activates when driving through
curves
c:> page 187. With the sport differen­
tial*, power distribution to the rear wheels is
variable and can be adjusted with drive select
c:>page 113.
The all-wheel drive concept is designed for
high engine power . Your vehicle is exception­
ally powerful and has excellent driving charac­
teristics both under normal driving conditions
and on snow and ice. Always read and follow
safety precautions
c:> & .
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-sea­
son tires) for improved driveability and brak­
ing: these tires must be mounted on
all four
wheels .
See also c:> page 246, Winter tires .
Tire chains
Where tire chains are mandatory on certain
roads, this normally also applies to vehicles
with all-wheel drive
c:> page 247, Snow
chains.
Replacing wheels/tires
Vehicles with all-wheel drive must always have tires of the same size. Also avoid tires
with different tread depths. For details see
page
c:> page 242, 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
c:> page 195.
A WARNING
-
Always adjust your driving 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.
- On wet road surfaces, be careful not to
drive too fast because the front wheels
could begin to slide on top of the water
(aquaplaning). If this should occur, you
will have no warning from a sudden in­ crease in engine speed as with a front­
wheel drive vehicle. Always drive at
speeds which are suited to the road con­
ditions -risk of crash.

202 Trailer towing
Tire pressure
When towing a trailer, inflate the tires of your
vehicle to the cold tire pressure listed under
"Full load" on the label located on the driver's
side B-pillar (visible when the door is open).
Inflate trailer tires to trailer and tire manufac ­
turers' specifications.
Lights
The headlight settings should be checked with
the trailer attached before driving off. Check
to make sure both vehicle and trailer lights
are working properly.
Safety chains
Be sure trailer safety chains are properly con­
nected from the trailer to the hitch on the ve­
hicle. Leave enough slack in the chains to per­
mit turning corners. When you install safety
chains, make sure they will not drag on the road when you are driving.
The chains should cross under the trailer
tongue to prevent it from dropping in case of
separation from the hitch.
Driving instructions
Driving with a trailer always requires extra
care and consideration.
To obtain the best possible handling of vehicle
and trailer, please note the following:
.,. Do not tow a loaded trailer when your car it­
self is not loaded.
.,. Be especially careful when passing other
vehicles.
.,. Observe speed limits .
.,. Do not drive at the maximum permissible
speed.
.,. Always apply brakes early.
.,. Monitor the temperature gauge.
Weight distribution
Towing a loaded trailer with an empty car re­
sults in a highly unstable distribution of
weight . If this cannot be avoided, drive at very
low speeds only to avoid the risk of losing
steering control. A "balanced" rig is easier
to operate and con­
trol. This means that the tow vehicle should be loaded to the extent possible and permissi­
ble, while keeping the trailer as light as possi­
ble under the circumstances. Whenever possi­
ble, transfer some cargo to the luggage com ­
partment of the tow vehicle while observing
tongue load requirements and vehicle loading
considerations.
Speed
The higher the speed, the more difficult it be­
comes for the driver to control the rig. Do not
drive at the maximum permissible speed. Re­
duce your speed even more if load, weather or
wind conditions are unfavorable -particularly
when going downhill.
Reduce vehicle speed
immediately if the trail­
er shows the slightest sign of swaying .
Do not
try to stop the swaying by accelerating.
Observe speed limits. In some areas, speeds
for vehicles towing trailers are lower than for
regular vehicles .
Always apply brakes early. When driving downhill, shift into a lower gear to use the en ­
gine braking effect to slow the vehicle . Use of
the brakes alone can cause them to overheat
and fail.
Coolant temperature
The coolant temperature gauge c> page 10
must be observed carefully . If the needle
moves close to the upper end of the scale, re­
duce speed immediately and/or turn off the
air conditioner.
If the coolant temperature warning light •
in the instrument cluster starts flashing, pull
off the road, stop and let the engine
idle for
about two minutes to prevent heat build-up .
_& WARNING
Anyone not properly restrained in a mov­
ing vehicle is at a much greater risk in an
accident. Never let anyone ride in your car
who is not properly wearing the restraints
provided by Audi.
-