2015 AUDI A4 steering

158 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

166 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 .,.

@ Tips
Your vehicle may be equipped with Audi
connect. Your use of certain Aud i connect
features req uires wireless serv ices that are
provided by a third party wireless telecom­
municat ions provider. For details regard­
ing how information obtained through
Aud i connect is collected, processed,
transmitted, used, and shared, please see
your contra ct w ith the wire less telecom ­
municat ions provider and the "About A udi
connect" tab in your vehicle's MMI*:
!MENU ! button> Audi connect > About
Audi con nect .
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 veh icle control. It works
only when the eng ine is running. ESC detects
certain difficult driv ing situations, including
when the vehicle is beginning to spin (yaw) out of cont ro l and he lps you to get the vehicle
back under control by select ively b rak ing the
wheels, and/or red ucing engine powe r and
p roviding steering assistance to help hold the
ve hicle on the driver's intended course . The in­
dicator light
DJ in the instrument cluster
blinks when ESC is taking action to help you
control the vehicle.
ESC has limitations.
It is important to remem­
ber that ESC cannot overcome the laws of
phys ics. It will not a lways be able to help out
under all conditions you may come up against.
For example, ESC may not always be able to
h elp you master situat ions where there is a
sudden change in the coefficient of fr iction of
the road surface. When there is a sect io n of
d ry road that is s udden ly cove red with water,
slush o r snow, ESC canno t perform the same
way it would on the dry su rface.
If the vehicle
hydroplanes (rides on a c ush ion of wate r in­
stead of the road surface), ESC wi ll not be
ab le to he lp you steer the veh icle because con-
Int ellig ent technolog y 185
tact with the pavement has been interrupted
and the vehicle cannot be braked or steered .
D uring fast corner ing, particular ly on wind ing
roads, ESC cannot always deal as effectively
with difficult dr iv ing s ituations 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 conditions . ESC can­
not override the vehicle's physical lim its, in­
crease the availab le tract ion, or keep a veh icle
o n the road if road departu re is a result of
driver ina ttent io n. Instead , ESC imp roves the
poss ibility of keep ing t he vehicle under con­
trol and on the road during extreme maneu­
vers by using the driver's steering i nputs to
help keep the vehicle go ing in the intended di­
rect ion. If you are traveling at a speed that
causes you to run off the road before ESC can
provide any assistance, you may not experi­
ence the benefits of ESC.
ESC is switched on all the time. In certain sit­
uat ions when you need less traction, you can
switch off ASR by pressing the butto n
[ill
~ page 187, fig. 174 or~ page 187,
fig. 175. Be sure to sw itch ASR on aga in when
you no lo nger need less traction.
The following systems are integrated in the
ESC:
Anti-lock bra king sy stem (ABS )
ABS prevents the whee ls from locking up
when brak ing. T he vehicle can st ill be steered
even dur ing hard braking. App ly steady pres­
su re to the brake peda l. Do not pump the ped­
al. A pulsing in the brake pedal ind icates that
the system is helping you to brake the veh icle .
Brake assi st system
The brake ass ist system can decrease braking
distance. It increases brak ing power when the
drive r presses the brake peda l quickly in emer­
gency s ituations. You must press and hold the
brake pedal unti l the s ituation is over. In
vehicles wi th adap tive c rui se control*, the
brake assis t system is more sensitive if the
•
•

186 Intelligent technology
distance detected to the vehicle ahead is too
smal l.
Anti-slip regulation (ASR )
ASR reduces eng ine power when the drive
wheels begin to spin and adapts the fo rce to
the road condit ions. This makes it eas ier to
start, accelerate and drive up hills .
Electronic differential lock (EDL)
The EDL brakes wheels that are spinn ing and
transfers the d rive powe r to the other drive
wheel or whee ls if the vehicle is equipped with
a ll-wheel drive* . This function is not avai lab le
at higher speeds.
I n extreme cases , EDL automat ica lly switches
off to help keep the brake on the braked whee l
from ove rheating . EDL wi ll switch on again au­
tomatically when conditions have returned to
normal.
Steering recommendation
The ESC helps to stabilize the ve hicle by
changing the steering torque.
In vehicles with dynam ic steeri ng*, ESC also
he lps to stabilize the stee ring in critical s itua­
tions.
Electronic interaxle differential lock* /
selective wheel torque control*
The electronic interaxle d ifferential lock (front
wheel drive) or the select ive wheel torque
con trol ( all wheel d rive) oper ates when driving
through curves . The front whee l on the inside
of the cu rve or both whee ls on the inside of
the curve are b raked se lectively as needed.
This a llows more prec ise driving in c urves. The
applicable system may not activate when driv­ ing i n wet or snowy conditions.
A WARNING
- The ESC and its integrated systems can­
not overcome the laws of physics. This is
especially important on slippery o r wet
roads . If the systems begin acting to sta·
b iliz e your veh icle, you s hou ld immed i­
a tely c ha n ge your speed to match the
road and traffic cond itions. Do not let
the increased safety provided by these
systems tempt you to take risks. Do ing
so will increase the risk of a loss of vehi­
cle control, collision and serious personal
inj uries.
-Always adapt your speed to road, traffic and weather conditions. The risk of los­
ing control of the vehicle increases when
d riving too fast, espec ially through
curves and on slippe ry or wet roads, and
when dr iv ing too close to vehicles up
ahead. The ESC a nd its integrated sys­
tems canno t always p reven t collisions -
there is still a risk of acc idents!
- Always accelera te wi th spe cial care on
even, smooth s urfaces such as those that
are wet or covered with ice and snow.
The drive wheels can spin even with these assistance systems that cannot al­
ways he lp to red uce the risk of loss of ve­
h icle control.
(D Tips
- ABS and ASR only work cor rectly when
all four wheels are equipped with identi­
cal tires. D ifferent tire sizes can lead to a
reduction in engine power .
- Yo u may hear noises when the systems
descr ibed are working.
- If the ind icator light
DJ or ml (USA
mode ls)l iiJ (Canada models) appears,
there may be a malfunction<=>
page 18,
<=>page 19 .

190 Intelligent technology
overheat re ducin g the effectiveness of
the ent ire brake system.
- Failure of one brake circuit will impair
the braking capability resulting in an in­
creased stopp ing distance. Avoid driv ing
the vehicle and have it towed to the 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 working, the
brake pedal must be pressed conside ra­
bly harder to make up for the lac k of
booster assistance.
Electro-mechanical
power assist, dynamic
steering
The electro-mechanical power assist helps
the driver when steering.
Power stee ring adapts electronically based on
the vehicle speed.
Indicator lights and messages
• Steering defective! Do not drive vehicle!
If this ind icator lig ht tu rns on and stays on
an d th is message appears, t he power steer ing
may have f ailed.
D o
not cont in ue d riving. See yo ur autho rized
Aud i deale r or a q ua lifi ed r epa ir facility for as­
sistance.
'1:I Dynamic steering : System fault! You can
cont inue driv ing
If the indicator light t urns on and the mes­
sage appears, the steer ing may be more diffi­
cul t to move or more se nsitive than usual. The
steer ing wheel may also be at an angle whe n
d riving straight .
Drive s low ly to your author ized Audi dealer or
q ua lified workshop to have the malfunction
cor rected .
'y.ij Dynamic steering: initializing
If this driver message appears and the indica ­
tor light is f lashing on the instrument panel,
dynam ic steer ing * is being re in it ia lized. After
starting the engine, the steering wheel will move s light ly. Re- initialization might be nec­
essary if the steering wheel was moved hard
to the left and right wh ile the vehicle was not
moving . Th e display goes out as soon as ini ti­
ali za tion is complete.
_& WARNING
Ha ve the dy namic stee ring * system m al­
f u nction repa ired as soon as possib le by an
a uthorized Audi dea ler or qua lified work ­
shop -risk of acc ident !
@ Tips
-If the . or '1:I indic ator li ght only s tays
on fo r a shor t time, you m ay continue
dr iving.
- T he dynamic s teering * stabi lit y syste ms
are no t av ail ab le in the even t of a system
ma lf u nction.
- F or ad di tion al information on dynamic
steering *, refe r to
¢page 115 .
-
Driving with your
quattro
App lies to vehicles: wi th all-w hee l drive
With a/I-wheel drive, all four wheels are driv­
en .
General information
With a ll-wheel d rive, power is distr ib uted to
all four wheels. This happens automatically
depending on your driving style and the road
co ndit ions at the time . See also
¢ page 185.
A center d ifferential distributes the driving
power variably to the front and rear axle. It
wor ks together with selective w heel torque
co ntrol, wh ich activates when dr iving t hrough
c ur ves
c::;,page 186. With the sport differe n­
t ia l* , pow er d istr ibut ion to the rea r wheels is
variable a nd can be adjusted w ith drive se lect
c::;, page 115. .,..

200 Trailer towing
Tire pressure
When towing a trai le r, inflate the tir es 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 dr iving off. Check
to make sure both vehicle and tra iler lights
are working properly.
Safety chains
Be sure trailer safe ty cha ins are properly con­
nected from the trailer to the hitch on the ve­
hicle. Leave eno ugh slack in the chains to per ­
mit turning corners. When you install safety
cha ins, make sure they w ill not drag on the
road when you are driving.
The chains shou ld cross under the trai ler
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 trai ler, p lease note the following:
.,. Do not tow a loaded trailer when your car it­
self is not loaded .
.,. Be especia lly 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 trai ler with an empty car re­
sults in a highly unstable distribution of
weight . If this cannot be avo ided, drive at very
low speeds only to avoid the risk of losing
steering control. A "ba
lanced" rig is easier to operate and con­
tro l. This means that the tow vehicle should
be loaded to the extent possible and permissi­
ble, while keep ing the trai ler as light as possi­
ble under the c ircumstances. Whenever poss i­
ble, transfer some cargo to the luggage com ­
partment of the tow veh icle while obse rving
tongue load requi rements and vehicle load ing
considerations.
Speed
The higher the speed, the more d iff icu lt 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 -pa rticularly
whe n going downhill.
Reduce veh icle speed
immediately if the trail­
er shows the slightest s ign of sway ing.
Do not
try to stop the swaying by accelerating.
Observe speed limits . In some areas, speeds
for vehicles tow ing tra ilers are lower than for
regular vehicles .
Always apply brakes early. When driving
downh ill, 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 •
i n the i nstrument cluster starts flashing, pull
off the road, stop and let the engine
idle for
abo ut 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 p roper ly wea ring the restraints
provided by Audi.
-

-If you notice unusual vibra­tion or if the vehicle pulls to one side when driving, al­
ways stop as soon as it is safe to do so and check the
wheels and tires for dam­ age.
(D Note
-Please note that summer and winter tires are de­
signed for the conditions
that are typical in those sea­
sons. Audi recommends us­ing winter tires during the
winter months. Low tem­ peratures significantly de­
crease the elasticity of
summer tires, which affects
traction and braking ability.
Tires and wheels 229
If summer tires are used in
very cold temperatures, cracks can form on the tread bars, resulting in perma­
nent tire damage that can
cause loud driving noise and unbalanced tires. Audi is not
responsible for this type of
damage.
-Burnished, polished or chromed rims must not be used in winter road condi­
tions. The surface of the
rims does not have suffi­
cient corrosion protection
for this and could be perma­
nently damaged by road salt
or similar substances.
•
•
'
Glossary of tire and loading terminology
Accessory weight
means the combined weight (in
excess of those standard items
which may be replaced) of auto­ matic transmission, power
steering, power brakes, power
windows, power seats, radio, and heater, to the extent that
these items are available as fac­
tory-installed equipment (whether installed or not).
Aspect ratio
means the ratio of the height to
the width of the tire in percent. Numbers of 55 or lower indi­
cate a low sidewall for im­ proved steering response and
better overall handling on dry
pavement.

246 Tires and whee ls
symbols) indicate the positions
of the tread wear indicators .
Worn tires must be replaced. Different figures may apply in
other countries
s> .1:. .
Tire pressure
Incorrect tire pressure causes
premature wear and can cause
sudden tire blow-out. For this
reason, tire pressure must be
checked at least once a month
r::::>page239 .
Driving style
Driving fast around curves,
heavy acceleration and hard
b raking increase tire wear .
Rotating tires for more even
wear
For all four tires on your vehic le
to have the same service life,
we recommend that the front and rear tires are rota ted ac­
cord ing to the tire man ufactur ­
er's s uggested tire rotat ion in­
tervals. Please remember the
following:
-Tire rotation intervals may dif­ fer from the vehicle service in ­
tervals outlined in your Main­
tenance and Warranty Book­ let . -
The longer one tire is used in
o ne location on the ve hicle,
the more it wears at certain points; therefore, we recom­
mend tha t you follow the tire
manufact ure r's suggested tire
rotat ion interva ls .
- Vehicles with front -wheel
drive expe rience more tread
wear on the front whee ls com­
p ared to all wheel drive (q uat­
tro).
-Please rota te t ires as shown
r::::> fig . 192 .
-Extra care must be taken when
rotat ing direction-speci fic
tires c:> page 26 7.
Wheel balancing
The wheels on new vehicles are
balanced . Howeve r, various sit ­
uations d uring everyday drivi ng
can cause them to become un­
balanced , resulting in vibra ­
tions you can usu ally feel
through the s teering wheel.
Unbalanced wheels must be re­
ba lanced to avoid excessive
wea r on steering, suspension
and tires. A wheel must also be
rebalanced when a new tire is
insta lled .