2015 AUDI S4 ABS

138 Safet y belt s
with the vehicle interior has all the energy
they had just before the crash.
Neve r rely on airbags a lone for p rotec tion.
Even when they deploy, airbags provide only
addit io nal p rotection . Airbags are not sup­
posed to deploy in all kinds of accidents. Al­
though your Audi is equipped with a irbags, all
vehicle occupants, including the driver, must
wear safety belts correctly in order to min i­
mize the risk of severe injury or death in a
crash .
Remember too, that airbags wi ll deploy on ly
once and that your safety belts are always
there to offer protection in those accidents in
which airbags are not supposed to deploy or when they have a lready deployed . Unbelted
occupants can also be thrown out of the vehi­
cle whe re even more severe o r fatal in juries
can occu r.
It is also impo rtant for the rear passenge rs to
wear safety belts correctly. Unbelted passen­
gers in the re ar seats end anger no t on ly them­
selves but a lso the d river a nd other passen­
gers ~
fig. 146. In a frontal collision they will
be thrown forward violent ly, where they can
h it and injure the dr iver and/or front seat pas ­
senger.
Safety belts protect
People think it's possible to use the hands to
brace the body in a minor collision. It's simply
not true!
F ig . 14 7 Driver is co rrectly re st ra ined in a s udden b rak ·
i n g m an euve r
Safety belts used properly can make a big dif­
ference . Safety be lts he lp to keep passengers
in their seats, gradually reduce energy levels applied to the body in an accident, and help
prevent the
uncontrolled movement that can
ca use serio us in juries . In addition, safety be lts
reduce the danger of being thrown out of the
vehicle .
Safety be lts attach passengers to the car and
give them the benefit of being slowed down
more gently or "softly" through the "give" in
the safety belts, crush zones and other safety
features engineered into today's vehicles. By
"abso rbing" t he kinetic energy over a longer
per iod of t ime, the safety belts make the
forces o n the body more " tolerable" and less
l ikely to ca u se inju ry.
Although these examples are based on a fron­
ta l co llision, saf ety belts can a lso substantia l­
ly red uce the r isk of injury in other kinds of
cr ashes. So, whether you're on a long t rip o r
j u st going to the corner store, a lways buckle
u p and make sure others do, too. Accident sta­
tistics show that veh icle occupants properly
wearing safety belts have a lower risk of be ing
injured and a much better chance of surviving
an accident. Properly using safety be lts also
greatly increases the ability of the supplemen ­
tal airbags to do the ir job i n a collision. Fo r
t hi s reason, wea ring a safety belt is legally re­
quired in mos t countr ies includi ng mu ch of
t h e Un ited States and C anada .
Althoug h your Aud i is equipped with a irbags,
you still have to wear the safety be lts prov id­
ed . F ront ai rbags, fo r example , a re ac tivated
o nly in some front al coll isions. The fron t air­
bags are not act ivated in a ll fron tal collis ions,
in side and rear co llisions, in roll overs or in
cases where there is not eno ugh deceleration
through impact to the front o f the veh icle.
The same goes for the other a irbag systems in
your Audi. So, always wear your safety belt and make su re everybody in your veh icle is
properly restrai ned !

148 Airbag system
-Never place additional 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.
Fig. 153 L ocation of driver airbag: in steer ing wheel
Fig. 154 Locatio n of fro nt passenger's airbag: in the in ­
st rument panel
Your veh icle is equipped with an "Advanced
Airbag System" in compliance with United
States Federal Motor Vehicle Safety Standard (FMVSS) 208 as applicable at the time your
vehicle was manufactured. The safety belts
for the seats have "pretensioners" that help
to take slack out of the belt system. The pre­
tensioners are also activated by the electronic
control unit for the airbag system.
The front safety belts also have load limiters
to help reduce the forces applied to the body
in a crash.
The airbag for the driver is in the steering wheel hub
¢ fig. 153 and the airbag for the front
passenger is in the instrument panel
¢ fig. 154 . The general location of the airbags
is marked "AIRBAG".
There is a lot you need to know about the air­
bags in your vehicle . We urge you to read the
detailed information about airbags, safety
belts and child safety in this and the other
c h apters that make up the owner's literature.
Please be sure to heed the WARNINGS - they
are extremely important for your safety and
the safety of your passengers, especially in­
fants and small children.
_&. WARNING
Never rely on airbags alone for protection.
- Even when they deploy, airbags provide
only supplemental protect ion.
-Airbag work most effectively when used
with properly worn safety belts.
- Therefore, always wear your safety belts
and make sure that everybody in your ve­
h icle is properly restrained.
_&. WARNING
-A pe rson on the front passenger seat, es-
pecially infants and sma ll children, will re­
ceive serious injuries and can even be kil­
led by being too close to the airbag when
it inflates .
- Although the Advanced Airbag System in
your vehicle is designed to turn off the
front passenger airbag if an infant or a
small child is on the front passenger
seat, nobody can absolutely guarantee
that deployment under these special conditions is imposs ible in all conceiva­
ble situat ions that may happen during
the useful life of your vehicle.
- The Advanced Airbag System can deploy
in accordance with the "low risk" option
under the U.S. Federal Standard if a child
that is heavier than the typical one-year
old child is on the front passenger seat
and the other conditions for airbag de­
p loyment are met .

150 Airbag sys te m
- a small child that is heavier than a typical 1
year-o ld child is on the front passenger seat
(regardless of whether the child is in one of
the child safety seats listed
q page 167),
-a chi ld who has outgrown child restraints is
on the front passenger seat.
I f the front passenger airbag is turned off , the
PA SSENGER AIR BAG OFF light in the center
of the instrument panel wi ll come on and stay
on.
The front ai rbag on the passenger side may
not deploy (the PASSENGER A IR BAG OFF
light does not illuminate and stay lit) if:
- a small ad ult or teenager is on the front pas­
senger seat
- a passenger who is not sitt ing upr ight w it h
their back against a non-reclined backrest
with their feet on the vehicle floo r in front
of the seat is on the front passenger seat .
I f the front passenge r airbag deploys, the
F ederal Standard requires the airbag to meet
the " low risk" deployment criteria to help re ­
duce the risk of injury through interact ion
with the airbag. " Low risk" deployment occurs
in those crashes that take place at lower de­
celerations as defined in the electronic control
un it .
q page 154
Al way s remember: Even tho ugh your vehicle
is equipped with Advanced Airbags, the safest
p lace for children is properly restrained on the
back seat . Please be sure to read the impor­
tant information in the sect ions that follow
and be sure to heed a ll of the WARNINGS .
A WARNING
To reduce the ris k of injury whe n an airbag
inflates, a lways wear safety belts properly.
- If you are unrestrained, lean ing fo rward,
s itting sideways or out of position in any
way, your risk of in jury is much higher.
- You w ill also receive serio us inju ries and
cou ld even be killed if you are up against
the a irbag or too close to it when it in­
fla tes - even with an Advanced Airbag
q page 144.
A WARNING
A child in a rearward-fac ing ch ild safety
seat installed on the front passenger seat
will be seriously injured and can be killed if
the front airbag inflates - even with an Ad­
van ced A irbag System.
- Altho ugh the Advanced Airbag System in
your veh icle is designed to tur n
off the
front airbag when a rea rward-facing
chi ld res traint has been instal le d on the
front passenger seat, nobody can abso ­
lutely g uarantee that dep loyment is im­
possible in all conceivable situations that
may happen dur ing the usefu l life of your
veh icle.
- The inflating airbag will h it the ch ild
safety seat or infant carrier with great
force and will smash the child safety seat
and chi ld aga inst the backrest, center
armrest, doo r, or roof.
- Always install rearward-facing ch ild re­
straints in the back seat.
- If you must install a rearward fac ing
child safety seat on the front passenger
seat because of exceptional c ircumstan­
ces and t he
PASSENGER AIR BAG OFF
light does not come on and s tay on, im­
mediately inst all the rear -fac ing ch ild
safety seat in a rear seating position and
have the airbag system inspected by your
authorized Audi dealer .
A WARNING
If, in exceptional circumstances, you m ust
i nsta ll 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 s ide a irbag .
- Never p ut the forward-facing child re­
straint up against or very near the instru­
ment panel.
- Always move the passenger seat into its
rearmost pos ition in the seat's fore and
aft adjustment range, as fa r away from
the airbag as possible, before installing

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

@ 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
•
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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 .

'"" N
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,...., ..,., ,....,
Trailer towing Driving with a trailer
General information
Your Audi was designed primarily for passen­
ger transportation .
If you plan to tow a tra iler, p lease remember
that the addit ional load will affect durab ility,
economy and performance .
T railer towing not on ly places more stress on
the vehicle, it also calls for more concentra­
tion from the driver.
F or this reason, a lways fo llow the operating
and driving instructions provided and use
common sense.
Technical requirements
Traile r hitch
Use a weight-carrying hitch conforming to the
gross trailer we ight. The hitch must be suita­
b le for your veh icle and trailer and must be
mounted secure ly on t he veh icle's chassis at a
technically sound location . Use only a t railer
h itch w ith a removab le ball moun t. A lways
check with the tr ailer hitch man ufac tur er to
make sure that you are using the correct
hitch.
Do not use a bumper hitch.
T he hitc h must be installed in such a way that
it does not inte rfe re with the impac t-absorb­
i ng b umper syst em. No modifica tions should
be made to the vehicle exhaus t and b rake sys­
tems . From t ime to time, check that a ll hitch
mo unt ing bolt s remain securely fas tened.
W hen you are not tow ing a trailer, remove the
trai le r hi tch ball moun t. T h is prevents the
hi tch from causing damage sho uld your ve hi­
cle be str uck from be hind
¢ &. .
Trailer brakes
If yo ur tra iler is equ ipped w it h a braking sys­
tem, check to be su re that it conforms to a ll
r eg ulat io ns .
Trailer towin g 199
The trailer hyd ra ulic bra ke system must not be
direct ly connected to the vehicle's hydraulic
brake system
¢ &. .
Safety chains
Alw ays use s afety chains between your ve hicle
and t he tra ile r.
Trailer lights
Tra ile r lights m ust meet all reg ulations . Be
su re to check w ith your authorized Audi dealer
fo r c orrec t w iri ng, sw itches, and relays.
Mirrors
If you a re unable to see the traffic behind you
u sing the regula r outside m irrors, then you
must insta ll ext ended mir ro rs. It is important
t h at you
always have clea r vis io n to the rear .
.8, WARNING
- If a trai ler has elec trica l br ake s plea se
no te th at t hese bra kes are not activat ed
by the fa ctory -fit ted control unit -risk of
accident!
- After removing the t railer hi tch, do no t
s to re it in yo ur vehicle . In case of sudden
brak ing, the hitch could fly fo rward and
in ju re you or yo ur passenge rs .
Operating instructions
Maximum traile r we ight
-
A trai ler fo r you r vehicle is limited to a typical
class 1 or class 2 tra iler.
Trailer load distribution
B e sure the lo ad in the tra iler is h eld secure ly
i n p lace to p reven t it from shifting fo rward,
backward or sideways.
Never allow a passenger to ride in a trailer
¢ &. in Driving instru ctions on page 200.
Engine cooling system
T owing a t railer ma kes t he engine wor k hard ­
er . It is impo rta nt that the cooling system's
perfo rman ce is up to the additional load.
Make sure tha t the coo ling sys tem h as enough
f lu id . .,..
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•

Trailer towing tips
Important to know
Your vehicle hand les different ly when tow ing
a trailer because o f the addit ional weight and
d iffe ren t weight distribution . Safety, pe rform ­
ance and economy w ill greatly depend on how
caref ully you load your trailer and operate
your rig.
B efore you actua lly tow your trailer, pr actice
turning, stopp ing and bac king up in an area
away from traffic. Keep practicing until you have become comp lete ly fam iliar with the way
your veh icle-trailer comb ination behaves and
responds.
Backing up is d ifficu lt a nd requires practice .
Backing up with a tra iler genera lly requires
steer ing action opposite to that when backing
up your vehicle without a trailer.
M aintain a g reater distance betwee n your ve­
h icle and the one in front o f you . You will need
mo re room to stop. To compensate for the
trailer, you will need a larger than normal
turning radius .
W hen pass ing, remember that yo u cannot ac ­
celerate as fast as yo u normally wo uld be­
cause of the added load. Ma ke s ure you have
e nough room to pass . After passing , allow
p lenty o f room fo r your tra iler before chang­
in g la nes aga in .
Avoid jerky starts, sharp turns or rap id lane
changes.
(D Tips
- Do not tow a tra iler during the break-in
period of you r vehicle.
- If you tow a trailer, your A udi may re­
quire more frequent maintenance due to
the extra load
o page 283.
Trailer towin g 201
Parking on a slope
Do not park on a slope with a trailer . If it can­
not be avoided, do so only after doing the fol­ lowing:
When parking:
.. App ly the foot brake.
.. Have someone p lace chocks under both the
veh icle and the tra iler wheels .
.,. With chocks in place, slowly release t he
bra kes unt il t he whee l choc ks absorb the
load .
.. Tu rn the whee ls towards the curb.
.,. App ly the par king b rake .
.. Place an a utomatic transm ission* in P, re ­
spectively a manual transmission in first or
reverse gear.
When restarting after parking:
.,. App ly th e foot br ake .
.. Start t he en gine.
.. Move the selector lever to D/S , respect ively
a man ual transmiss ion in first gea r.
.. Release the parking bra ke and s low ly pull
out and away from the wheel chocks .
.. Stop and have someone retr ieve the wheel
chocks.
@ Tips
If you move the selector leve r of the auto­
matic transmissio n* to P before applying
the pa rking brake and before blocking the
whee ls, you may hav e to use mor e forc e
l ater to m ove the le ver out of the P posi­
tion.
•
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