2013 AUDI A4 SEDAN ABS

Why safety belts?
Frontal collisions and the law of physics
Frontal crashes create very strong forces for
people riding in vehicles .
Fig. 130 Unbelted occupant s in a ve hicle heading for a
wall
Fig. 131 The vehicle c ras hes into the wall
The physical principles are simple. Both the
vehicle and the passengers possess energy
which varies with vehicle speed and body
weight . Engineers call this energy "kinetic en­
ergy ."
The higher the speed of the vehicle and the greater the vehicle's weight, the more energy
that has to be "absorbed" in the crash .
Vehicle speed is the most significant factor . If
the speed doubles from 15 to 30 mph (25 to
50 km/h) , the energy increases 4 times!
Because the passengers of this vehicle are not
using safety belts
r::;, fig. 130, they will keep
moving at the same speed the vehicle was
moving just before the crash, until something
stops them -here, the wall
c:> fig . 131 .
The same principles apply to people sitting in
a vehicle that is involved in a frontal collision .
Even at city speeds of 20 to 30 mph (30 to
50 km/h) , the forces acting on the body can Safety belts
13 7
reach one ton (2,000 lbs. or 1,000 kg) or
more . At greater speeds, these forces are
even
higher.
People who do not use safety belts are also
not attached to their vehicle. In a frontal colli­
sion they will also keep moving forward at the
speed their vehicle was travelling just before
the crash. Of course, the laws of physics don't
just apply to frontal collisions, they determine what happens in all kinds of accidents and col ­
lisions .
What happens to occupants not wearing
safety belts?
In crashes unbelted occupants cannot stop
themselves from flying forward and being in­
jured or killed. Always wear your safety belts!
Fig. 132 A driver not wear ing a safety belt is vio lently
thrown forward
Fig. 133 A rear passeng er not wearing a safety belt
w ill fly forward and strike the driver
Unbelted occupants are not able to resist the
tremendous forces of impact by holding tight
or bracing themselves . Without the benefit of
safety restraint systems, the unrestrained oc­
cupant will slam violently into the steer ing
wheel, instrument panel, windshield, or what­
ever else is in the way ¢ fig. 132 . This impact Ill-

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. 133. 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 . 13 4 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. 140 Locat ion of dr iver airbag: in stee ring wheel
Fig. 141 Loca tion of front pass enger's a irbag: in the in­
strument 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 system senses
the position of the front seats and controls
front airbag inflation with a valve, depend ing
on the distance between the respective seat
and the steering wheel or instrument panel.
The safety belts for the seats have "preten­
sioners" that help to take slack out of the belt
system. The pretensioners are also activated by the electronic contro l 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. 140 and the airbag for the
front passenger is in the instrument panel
~ fig. 141 . The general locat ion of the a irbags
i s 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
ch 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 protection.
-Airbag work most effectively when used
with properly worn safety bel ts.
- Therefore, always wear your safety belts
and make sure that everybody in your ve­
h icle is properly restrained.
_&. WARNING
A person 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
b le 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 heav ier than the typical one-year
-
.

150 Airbag sys te m
For exa mpl e, the air b ag ma y depl oy if:
- a small child that is heavier than a typical 1
year-o ld child is on the front passenger seat
(regardless of whe ther the child is in one of
the chi ld safety seats listed
¢ page 167),
-a ch ild who has outgrown child rest raints is
on the front passenger seat.
If the front passenger airbag is turned off, the
PA SSENGER AIR BAG OFF light in the cente r
of the instrument panel w ill come on and stay
on.
The front a irbag on the passenger side may
not deploy (the PAS SENGER AIR BAG OFF
light does not illuminate and stay lit) if:
- a small adult or teenager is on the front pas­
senger seat
- a passenger who is not sitt ing upright wit h
their back against a non-reclined backrest
with their feet on the veh icle floo r in front
of the seat is on the front passenger seat.
If the front passenger airbag deploys, the Federal Standard requires the airbag to meet
the "low risk" deployment criteria to help re­
d uce the risk of inju ry through interaction
with the airbag. " Low risk" deployment occurs
in those crashes that take place at lower de­
celerations as defined in the e lectronic control
un it.
¢ page 155
Alw ays remember : Even though you r 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 all of the WARNINGS.
A WARNING
To reduce the risk of injury when an airbag
inf lates, always wear safety belts properly.
- If you are unrestrained, lean ing forward,
sitting sideways or out of position in any
way, your risk of in jury is much higher.
- You w ill also receive serious injuries and
cou ld even be killed if you are up against
the a irbag or too close to it when it in- f
lates - even with an Advanced A irbag
¢page 144.
A WARNING
-A child in a rearward-fac ing ch ild safety
seat installed on the front passenger seat
will be serious ly injured and can be killed if
the front airbag inflates - even with an Ad­
vanced A irbag System.
- Although the Advanced Airbag System in your veh icle is designed to turn off the
front airbag when a rearward-facing child restraint has been instal led on the
front passenger seat, nobody can abso­
lutely g uarantee that dep loyment is im ­
possible in all conceivable situations that
may happen during the usefu l life of your
veh icle.
- The inflating airbag will hit the child
safety seat or infant carrier with great
force and will smash the child safety seat
and child aga inst the backrest, center
armrest, door, 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 exceptiona l circumstan­
ces and the
PASSENGER AIR BAG OFF
light does not come on and stay on, im­
mediately insta ll th e 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
insta 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.
~

dealer is familiar with these requi rements
and we recommend that you have your
dea ler perform this serv ice for you.
Other things that can affect Advanced
Airbag performance
Changing the vehicle's suspension system can
change the way that the Advanced A irbag Sys­
tem performs in a crash. For example, us ing
tire-r im combinations not app roved by Aud i,
l owering the vehicle, changing the stiffness o f
the suspension, incl uding the sp rings, s uspen­
sion struts, shock absorbers etc. can change
the forces that are measured by the airbag sensors and sent to the electronic control
un it. Some suspension changes can, for exam­
ple, increase the force levels measured by the
sensors and make the airbag system deploy in
crashes in wh ic h it would not dep loy if the
changes had not been made. Other k inds of
changes may reduce the force levels meas ­
u red by the sensors and prevent the a irbag
from deploying when it shou ld .
The senso rs in the safety belt buckle fo r the
d river and front passenger sea t 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 dep loy at a slightly high­
er rate of vehicle deceleration than if the safe­
ty belt is not being used. Therefore, in a par­
ticular co llision, it is poss ible that an airbag
will not deploy at a seating position where the
safety belt is being use d but will inflate at the
position whe re the safety belt is not being
used. It is important tha t nothing i nterfe re
w it h the safety belt buckles so t hat the sen ­
sors can send t he correct information abo ut
safety belt use to the electronic contro l unit.
.&_ WARNING
Changing the vehicle 's s uspension includ­
ing use of unapproved tire-rim c ombina­
tions can change Advanced Airbag pe r­
formance and increase the risk of ser ious
personal i njury in a crash.
- Never install suspens ion components
that do not have the same performance
A irba g sy stem 159
characteristics as the components o rigi­
na lly installed on your vehicle.
- Never use tire-rim com binations that
have not been approved by Audi.
.&_ WARNING
= -
Items stored between the safety be lt
b uckle and the center console can cause
the sens ors in t he buckle to send the
wrong information to the e lectronic con­
trol module and prevent the Advanced Air­ bag Syst em from wo rking properly.
- Always make s ure that nothing can in ter-
fe re with the safety b elt buckles and that
they are no t obstructed.
Side airbags
Description of side airbags
The airbag system can provide supplemental
protection to properly restrained occupants.
Fi g. 144 Side airbag location in t he drive r's seat
The side airbags are located in the sides of the
front seat backrests¢
fig. 144 and the rea r
backrest faci ng the doors. They are ident ified
by the word "AIRBAG".
The side airbag system basically consists of :
-the electronic control modu le and external
side impact sensors
- the two a irbags located in the sides of the
front backrests and the two a irbags* located
in the rear backrest
- the airbag warn ing light in the instrument
cl uster .
T he airbag system is mo nitored e lec tronically
t o make ce rtain tha t it is f unction ing p ro perly
Ill-

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 186, fig. 159 or
~ page 186, fig. 160. 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 185
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*
function cannot overcome the laws of
physics. This is especially important on
slippery or wet roads . If the systems be­
gin acting to stabilize your vehicle, you
should immediately change yo ur speed
to match the road and traff ic conditions.
Do not let the increased safety provided
by these systems tempt you to take risks .
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* function
cannot prevent collisions.
•
•

186 Intelligent technology
-Always accelerate with special care on
even, smooth surfaces 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 help to reduce the risk of loss of ve­ hicle control.
(i_) Tips
- ABS and ASR only work correctly when
all four wheels are equipped with identi­
cal tires . Different tire sizes can lead to a
reduction in engine power.
- You may hear noises when the systems
described are working .
- If the indicator light
I] or l;S (USA
models);tl] (Canada models) appears,
there may be a malfunction ¢
page 19,
¢page 19.
Switching on /off
ESC turns on automatically when you start
the engine .
Fig. 159 Vers ion A: low er ce nter c onsol e, 1', OFF but­
to n
.... .. [ I _j nw· 1-_, .. _ , 1 -- - .-=---1
I;· . i-a~ -~ ~-,' I ' .;- c;.il..-~ -~ 1,1
~' . -' ' 1 ' ...... ~ ... ~- ;. '"~ l __,
Fig. 160 Versio n B: upper ce nter console,!'> OFF but­
to n
Turning off ASR
In some situations, it may be useful to switch
ASR
off to allow the wheels to spin. For exam­
ple:
- Rocking the vehicle to free it when it is stuck
- Driving in deep snow or on loose ground
- Driving with snow chains
Qu ickly press the
i.i, OFF I button ¢ fig. 159
and¢ fig. 160. The fi indicator light turns on
and the message
Traction control (ASR): Off.
Warning! Restricted stability
appears in the
display .
It is only possible to turn off the ASR up to
30 mph (SO km/h) for vehicles with front
wheel drive . At about 45 mph (70 km/h) it au ­
tomatically turns on again .
It is possible to
turn
off the ASR at any speed for vehicles with
all wheel drive.
Turning off ESC
Press and hold the I B OFFI button for three
seconds . The
Ii ESC indicator light turns on
and the message
Stabilization control (ESC):
off. Warning! Restricted stability
appears in
the display. ASR is also switched
off when ESC
is switched off.
Switching on
Press the 1 .$ OFFI button again. The 11 indica­
tor light turns on and the message
Stabiliza­
tion control (ESC): On
appears in the display .
_&. WARNING
- Drive wheels can spin and you can lose
control of the vehicle more easily when
ASR and ESC are switched off, especially
when the road is slippery .
- Switch ASR/ESC
off only when your driv­
ing skills, traffic and weather conditions
permit.
(D Tips
You cannot switch ASR and ESC
off when
adaptive cruise control* is working.
-

196 Trailer towing
Trailer towing Driving with a trailer
General information
Your Audi was designed primarily for passen­
ger transportation .
If you plan to tow a trai ler, p lease remember
that the additional load will affect durability,
economy and performance .
Trailer towing not on ly places more stress on
the vehicle, it also calls for more concentra­
tion from the driver.
For this reason, always fo llow the operating
and driving instructions provided and use
common sense.
Technical requirements
Trailer hitch Use a weight-carrying hitch conforming to the
gross trailer weight. The hitch must be suita­
ble for your vehicle and trailer and must be
mounted securely on the veh icle's chassis at a
technically sound location. Use only a trailer
hitch with a removable ball mount. Always
check with the trailer hitch manufacturer to
make sure that you are using the correct
hitch.
Do not use a bumper hitch.
The hitch must be installed in such a way that
it does not interfere with the impact-absorb­
ing bumper system . No modifications should
be made to the vehicle exhaust and brake sys­
tems . From time to time, check that all hitch
mounting bolts remain securely fastened.
When you are not towing a trailer, remove the
trailer hitch ball mount. This prevents the
hitch from causing damage should your vehi­
cle be struck from behind
¢ A.
Trailer brakes
If your tra iler is equipped with a braking sys­
tem, check to be sure that it conforms to a ll
regulations . The trailer
hydraulic brake system must not be
direct ly connected to the vehicle's hydraulic
brake system
~ A.
Safety chains
Always use safety chains between your vehicle
and the trai le r.
Trailer lights
T railer lights must meet all regulations. Be
sure to check w ith your authorized Audi dealer
for correct wiring, sw itches, and relays.
Mirrors
If you are unable to see the traffic behind you
using the regular outside mirrors, then you
must install extended mirrors . It is important
that you
always have clear vis io n to the rear.
,8. WARNING
- If a trailer has electrical brakes please
note that these brakes are not activated
by the factory-fitted control unit -risk of
accident!
- Afte r removing the trailer hitch, do not
store it in your vehicle. In case of sudden
braking, the hitch could fly forward and
injure you or your passengers.
Operating instructions
Maximum trailer weight
-
A trailer for your vehicle is limited to a typical
class 1 or class 2 tra iler.
Trailer load distribution Be sure the load in the trailer is held secure ly
in place to prevent it from shifting forward,
backward or sideways.
Never allow a passenger to ride in a trailer
¢ A in Driving instructions on page 197.
Engine cooling system
T owing a trailer makes the engine work hard ­
er. It is important that the cooling system's
performance is up to the additional load.
Make sure that the cooling system has enough
fluid . .,..