2013 AUDI A4 SEDAN engine

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 !

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.
-

Braking
What affects braking efficiency?
New brake pads
During the first 250 miles (400 km), new
brake pads do not possess their full braking
effect, they have to be "broken in" first¢& .
You can compensate for this slightly reduced braking power by pushing harder on the brake
pedal. Avoid heavy braking loads during the
break-in per iod.
Operating conditions and driv ing habits
The brakes on today's automobi les are sti ll
subject to wear, depending largely on operat ­
ing conditions and driving habits¢.&. . On
vehicles that are e ither driven mostly in stop­
and-go city traffic or are driven hard, the
brake pads should be checked by your author­
ized Audi dealer more often than specified in
the
Warranty & Maintenance booklet . Failure
to have your b rake pads inspected can result
in red uced brake performance.
On steep slopes, you shou ld use the brak ing
effect of the engine. This way, you p revent un­
necessary wear on the brake system.
If you
must use yo ur brakes, do not hold the brakes
down continuously. Pump the brakes at inter­
va ls.
Operating noise
Noises may occur when braking depending on
the speed, braking force and outside condi­
tions such as temperature and humidity.
Effect of water and road salt
In certain situat ions, for example after driving
through water, in heavy ra in, after overnight
condensation or after washing your car, the
braking effect can be reduced by moisture or
ice on the brake roto rs and brake pads . The
brakes must be dried first with a few careful
brake applications .
A t hi gher speeds and with the windshield w ip­
ers turned on, the brake pads press against
the brake rotors for a short amount of time .
This occurs at regular intervals without the
Intelligent technology 187
driver noticing and provides for better brake
response time under wet conditions .
T he effectiveness of the brakes can be red uced
when the vehicle is driven on a sa lt-co vered
road and the b rakes are not used. Likewise,
you clean off accumulated salt coating from
brake discs and pads with a few cautious ap­
plications of the brake ¢ & .
Corrosion
There may be a tendency for dirt to build up
on the brake pads and corrosion to form on
the discs if the car is not driven regu larly or
on ly for short trips with litt le use of the
brakes.
If the brakes are not used frequently, or if cor ­
rosion has formed on the discs, it is advisable
to clean off the pads and discs by braking
firmly a few times from a moderately high
speed ¢.&. .
Faults in the brake system
If you should notice a sudden increase in
brake pedal trave l, then one of the two brake
c ircuits may have failed ¢.&. .
Low brake fluid level
Malfunctions can occur in the brake system if
the brake fluid level is too low. The brake fluid
level is monitored electronica lly.
Brake booster
T he brake booster increases the pressure that
you generate with the brake peda l. It works
only when the engine is runn ing .¢ .&.
Brake lining wear status
Brake lining wear may be checked by visual in­
spection of the condition of the brake pads
through the openings in the wheel. If neces­
sary, the wheel may be removed fo r this in­
spection ¢
page 252, Changing a wheel .
A WARNING
-
- New brake pads don't have the best stop­
ping power and must be "broken-in" dur-
ing the initial 100 to 150 miles (150 to
~
•
•

188 Intelligent technology
200 kilometers) of normal city driving.
You can compensate for this by pressing
the brake pedal more firmly. This also applies later when new pads are instal­
led .
- You should perform braking maneuvers
for the purpose of cleaning the brake
system only if road conditions permit.
Other road users must not be put at risk -
you may cause an acc ident!
- Before descending a steep grade, reduce
speed and shift transmission into a lower
gear or lowe r driving range. Do not ride
the brakes or hold the pedal down too
long or too often. This could cause the
brakes to get hot and diminish braking
efficiency.
- Do not "ride the brakes" by resting your
foot on the pedal when you do not intend
to brake . This may cause the brakes to
overheat, premature wear and increased
stopping distance.
- Under certain climatic and operating
conditions such as passing through wa­
ter, driving in heavy rain or after washing
the vehicle, the effectiveness of the
brakes can be reduced. In winter, ice can
accumulate on the brake pads, linings,
discs and drums. Carefully apply brakes
for a test. Brakes will dry and ice coat­
ings will be cleaned off after a few care­
ful brake applications.
- Driving for an extended period of time on
salt-covered roads without using your
brakes can also affect braking efficiency.
Clean off accumulated salt coating from
brake discs and pads with a few careful
brake applications.
- If you damage the front spoiler, or if you
install a different spoiler, be sure the air
flow to the front brakes is not obstruct­
ed . Otherwise the brake system could
overheat reducing the effectiveness of
the entire brake system.
- Failure of one brake c ircuit will impair
the braking capability resulting in an in­
creased stopping distance. Avoid driv ing
the vehicle and have it towed to the near- est authorized Audi dealer or
qualified
workshop.
- Never let the vehicle roll to a stop with
the engine shut off.
- If the brake booster is not working, for
example when towing your vehicle, or
because the brake booster has somehow
been damaged, the brake pedal must be
pressed considerably harder to make up
for the lack of booster assistance.
Electro-mechanical
power assist, dynamic
steering
The electro-mechanical power assist helps
the driver when steering.
Power steering adapts electronically based on
the vehicle speed .
Indicator lights and messages
• Steering defective! Do not drive vehicle!
If this indicator light turns on and stays on
and this message appears, the power steering
may have failed.
Do
not continue driving . See your authorized
Audi dealer or other qualified repair facility
for assistance.
E!"4 Dynamic steering: System fault! You can
continue driving
If the indicator light turns on and the mes­
sage appears, the steering may be more diffi­
cult to move or more sensitive than usual. The
steering wheel may also be at an angle when
driving straight .
Drive slowly to your authorized Audi dealer or
qualified workshop to have the malfunction
corrected .
ls!'fl Dynamic steering: initializing
If this driver message appears and the indica­
tor light is flashing on the instrument panel,
dynamic steering* is being reinitialized. Once
you start the engine after this is finished, the ..,..

steering wheel wi ll be easy to move . Re­
initialization might be necessary if the steer ­
ing wheel was moved hard to the left and
right while the vehicle was not moving. The
d isplay goes out as soon as in itializat ion is
comp lete .
A WARNING
Have the dynamic steering* system mal­
function repaired as soon as poss ible by an
authori zed A udi dealer or any qualified
workshop -risk of accident!
@ Tips
- If the . or 1;r,ij indicator light only stays
on for a short t ime, you may continue
driving.
- The dynamic steering * stability systems
are not available in t he event of a system
malfunction.
- Fo r additional informat ion on dynamic
stee ring*, re fer to
c::> page 111.
Driving with your
quattro ®
Applies to vehicles: with all-wheel drive
With oil-wheel drive, oil four wheels ore driv­
en.
General information
W ith all -whee l dr ive, power is dis tributed to
a ll fo ur wheels. This happens automatica lly
depending on yo ur driving sty le and the road
conditions at the time. See also
c::> page 184 .
A center different ial d is tributes the dr iv ing
power var iably to the front and rear axle. It
wo rks together with se lective whee l to rque
contro l, which activates when driving throug h
curves
c::> page 185. With the sport d ifferen­
tial*, power distribution to the rear w heels is
variable and can be adjusted with Audi drive se lect
c::> page 111 .
The all-wheel drive concept is designed for
hi gh engine power. Your vehicle is exception­
ally powerful and has exce llent dr iving charac ­
ter ist ics both under normal d riving conditions
Int ellig ent technolog y 189
and on snow and ice . Always read and follow
safety precautions
c::> & .
Winter tires
When dr iving in t he winter, yo ur vehicle wi th
a ll -wheel drive h as an adv ant age, even w it h
regular tires. In wi nter 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 fou r
wheels .
See also c::> page 245, Winter tires.
Tire chains
Where tire chains a re mandatory on certain
roads, this no rma lly also app lies to veh icles
with all-wheel drive
c::> page 246 , Snow
chains .
Replacing wheels /tires
Vehicles wi th a ll-wheel drive must alw ays
have tires of the same s ize. A lso avoid tires
with different tread depths . For detai ls see
page
c::> page 241, New tires and replacing
tires and wheels.
Off-Road driving?
Your A udi does no t have enough g ro und cle ar­
ance to be used as an off -road vehi cle. It is
therefore best to avoi d rough tracks and un­
even te rrain as much as possib le . Also refer to
c::> page 192.
A WARNING
A lways ad just yo ur dr iv ing to road and traf­
fic conditions. Do not let the extra safety
afforded by all-wheel drive tempt you into
taking extra risks .
-Al tho ugh t he all-wheel driv e is ve ry ef­
fective, always remember that braking
capacity is lim ited by tire t raction. You
should t herefore not d rive a t excessive
speeds on i cy or slippery ro ad s urfa ces.
- On wet road surfa ces, be careful not to
d rive too fast bec ause the fron t whee ls
co uld begin to slide on top of the water
(aquaplani ng) . If th is should occur, yo u •
•

190 Intelligent technology
will have no warning from a sudden in­
crease in engine speed as with a front­
wheel drive vehicle. Always drive at speeds wh ich are suited to the road con­
ditions -risk of c rash .
Energy management
Starting ability is optimized
Energy management controls the distribution
of electrical energy and thus optimizes the
availability of electrical energy for starting
the engine.
I f a vehicle with a conven tional energy system
i s not d riven for a long period of time , the bat­
tery is discharged by idling c urrent consumers
(e .g. immobilizer) . In certain circumstances it
can result in there being insuffic ient energy
avai lab le to start the engine.
I ntelligent energy management in your veh i­
cle hand les the distribution of electrical ener­
gy . Starting abi lity is marked ly improved and
the life of the battery is extended .
B asically , energy management consists o f
battery diagno sis, idling current manage­
ment
and dynami c ene rg y man agement.
Battery diagnosis
Battery d iagnosis con tinuously dete rm ines
the state of the battery. Senso rs determ ine
battery vo ltage, batte ry cur rent and battery
temperature. This determines the current
state of charge and the power of the battery.
Idling current management
I dling c urrent managemen t red uces energy
consumption while the vehicle is stand ing.
With the ignition switched off, it contro ls the
energy s upply to the various e lectrica l compo­
nents . Data from battery diagnosis is consid­
ered.
D epending on the battery's state of charge,
individual consumers are grad ually turned off
to prevent excess ive d ischarge of the battery
and thus ma inta in start ing cap ability .
Dynamic energy management
While the vehi cle is being driven, dynamic en­
ergy management distr ibutes the energy gen ­
erated according to the needs of the indiv id u­
al components.
It regulates consumption, so
that more electrical energy is not being used
t h an is being generated and ensures an opti­
mal state of c harge for the battery.
(!) Tips
- But even ene rgy management cannot
negate the limits of physics. Consider
that the power and life of a battery are limited.
- If start ing ability is threatened, the indi­
cator light(•] appears¢
page 17 .
What you should know
The highe st priori ty is given to main taining
starting capability.
T he battery is seve re ly taxed in short -d istance
driv ing, in city traff ic and during the cold time
o f year. Abundant electrical energy is re­
quired, but on ly a little is generated . It is also
critical if the engi ne is not r unning and electri­
ca l components are tu rned on. In this in­
sta nce ene rgy is be ing consumed bu t none is
being genera ted .
It is in precisely these s ituations t hat you will
notice ene rgy management active ly regu lat­
i ng t he d istribu tion of ene rgy.
Vehicle stands for an extended period
If you do not drive your vehicle over a period
of several days or weeks, e lectr ica l compo ­
nents a re g radually cut back or sw itched off .
T h is reduces energy consumption and ma in­
ta ins s tart ing capability over a longer pe riod .
Some of the convenience func tions may not
opera te, such as the interior ligh ts or the
power seat adjustment. The convenience
functions will be available again wh en you
switch on the ignition and start the eng ine .