2014 AUDI S4 brakes

-Do not ride the brakes or press the brake
pedal too often or too long when driving
down a hill. Constant braking causes the
brakes to overheat and substantially re­
duces braking performance, increases
braking distance or causes complete fail­
ure of the brake system.
- To prevent the vehicle from rolling back
when stopping on inclines, always hold it
in place with the brake pedal or parking
brake.
- Never hold the vehicle on an incline with
a slipping clutch. The clutch opens auto­
matically when it becomes too hot from
the overload. An indicator lamp
mJ illu­
minates and a driver message appears
¢ page 9 7 when the clutch is overload­
ed .
- If the engine must remain running, never
have any driving position engaged when
checking under the hood. Make sure the
selector lever has securely engaged and
is locked in P with the parking brake set
¢ page 214. Otherwise, any increase in
engine speed may set the vehicle in mo­
tion, even with the parking brake ap­ plied .
0 Note
-S tronic- and tiptronic transmission:
When stopping on an incline, do not try
to hold the vehicle in place by pressing
the accelerator pedal while a driving gear
is selected. This can cause the transmis­
sion to overheat and can damage it. Acti­
vate the parking brake or press the brake
pedal to prevent the vehicle from rolling.
- S tronic- and tiptronic transmission: Al­
lowing the vehicle to roll when the en­
gine is stopped and the selector lever is in N will damage the transmission be­
cause it is not lubricated under those cir­
cumstances .
(D Tips
For safety reasons, the parking brake is re­
leased automatically only when the driv ­
er's safety belt is engaged in the buckle.
Transmission 95
Hill descent control
App lies to vehicles : wi th mult itronic/ S tro nic/tiptro nic
The hill descent control system assists the
driver when driving down declines .
Hill descent control is activated when these­
lector lever is in D/S and you press the brake
pedal. The transmission automatically selects
a gear that is suitable for the incline. Hill de­ scent control tries to maintain the speed ach­
ieved at the time of braking, within physical
and technical limitations. It may still be nec­
essary to adjust the speed with the brakes.
Hill descent control switches off once the de­
cline levels out or you press the accelerator
pedal.
On vehicles with the cruise control system*
¢ page 89 , hill descent control is also activat­
ed when the speed is set.
.&_ WARNING
-
Hill descent control cannot overcome
physical limitations, so it may not be able
to maintain a constant speed under all
conditions. Always be ready to apply the brakes .

100 Audi adaptive cruise control and braking guard
confirmed by the video camera, an acute
collision warning.
- For safety reasons, do not use adaptive
cruise control when driving on roads with
many curves, when the road surface is in
poor condition and/or in bad weather
(such as ice, fog, gravel, heavy rain and
hydroplan ing). Using the system under
these conditions could result in a colli­
sion.
- Switch adaptive cruise control off tempo­
rar ily when driv ing in turning lanes, on
expressway exits or in construc tion
zones. This prevents the vehicle from ac­
celerating to the set speed when in these
situations.
- Th e adaptive cruise control system w ill
not brake by itse lf if you put your foot on
the accelerator pedal. Doing so can over­
ride the speed and distance regulation.
- When approaching stationary objects
such as stopped traffic, adaptive cruise
control will not respond and braking
guard w ill have limited function.
- The adaptive cr uise control system and
braking guard do not react to people, an­
ima ls, objects crossing the road or on­
coming objects .
- The function of the radar sensor can be
affected by reflective objects such as
guard rails, the entrance to a tunnel,
heavy rain or ice.
- Never follow a vehicle so closely that you cannot stop your vehicle safely. The
adaptive cruise control cannot slow or
brake the vehicle safely when you follow
ano ther vehicle too closely . Always re­
member that the automatic braking
function cannot bring the vehicle to a sudden or emergency stop under these
conditions.
- To prevent unintended operation, always
switch ACC off when it is not being used.
{[) Note
The sensor can be d isp laced by impacts or
damage to the bumper, whee l housing and
underbody . That could affect the adaptive cruise control system and b
raking guard.
Have your authorized Audi dea ler or au­
thorized Audi Service Facility check their
function.
, In curves
Applies to vehicles: wit h Aud i adapt ive cr uise contro l
Fig . 111 Examp le: driv ing into a curve
When driving into a curve <=> fig. 111 and out
of a curve, the adaptive cruise control may re­ act to a vehicle in the next lane and app ly the
brakes. You can override or prevent the brak­
ing by pressing the accelerator pedal briefly.
Stationary objects
Applies to vehicles: with Aud i adaptive crui se contro l
Fig. 112 Examp le: object chang ing lanes a nd station ­
a ry object
The adaptive cru ise control system only reacts
to objects that are moving or that the system
has a lready detected as moving. For example,
if a vehi cle@ , which has already been detect­
ed by the adaptive cruise control, turns or
changes lanes and another stationary vehicle
@ is located in front of that vehicle, the sys­
tem will not react to the stationary vehicle.

102 Audi adaptive cruise control and braking guard
Switching on and off
Applies to vehicles: with Audi adaptive cruise control
Fig. 114 Se lec tor lever: switching on/off
Fig. 115 Instrument clus te r: A udi adap tive c ru ise co n·
trol
You can set any speed between 20 mph and
95 mph (30 and 150 km/h).
Indicator lamps and messages in the instru·
ment cluster display inform you about the cur·
rent system status and settings.
Switching Audi adaptive cruise control on
• Pull the lever toward you into position (D
¢fig. 114. ACC standby appears in the in ·
strument cluster display.
Setting the speed and activating
regulation
.. To set the current speed , press the !SE T! but·
ton
¢ page 11, fig . 4. The set speed is shown in
the tachometer @and is also
shown briefly in the display@¢
fig. 115.
Switching Audi adaptive cruise control off
• Push the lever away from you into position
@ until it clicks into place. The message
ACC off appears.
@ Indicator lights
11 · Adaptive cruise control is sw itched on.
No vehicles are detected up ahead. The stored
speed is maintained.
• · A moving vehicle is detected up ahead .
T he adaptive cru ise control system regulates
the speed and distance to the moving vehicle
ahead and accelerates/brakes automatically .
• · When automatic braking is not able to
keep enough distance to a previously detected
moving veh icle up ahead, you must take con·
trol and brake
¢ page 105, Request for driver
intervention.
© Display
If adapt ive cru ise control is not shown in the
display, you can call it up w ith the
I RESET I
button ¢ page 24.
Based on the symbols in the display, you can
determine if the system is maintain ing a d is ·
tance to the vehicle ahead and what that dis­
tance is.
No vehicle· No vehicle ahead was detected .
White vehicle -A vehicle ahead was detected .
Red vehicle -Prompt for the driver to take ac­
tion
,=;, page 105.
Both arrows on the scale © indicate the dis·
tance to the vehicle ahead. No arrow appears
when the vehicle is on an open road and there
is no object ahead. If an object is detected
ahead, the arrow moves on the scale .
T he green zone on the scale shows the stored
distance. For information on changing the
stored distance, refer tor=;,
page 104 . If the
distance se lected is too close or may soon be·
come too close , the arrows move into the red
zone on the sca le. .,.

104 Audi adaptive cruise control and braking guard
Setting the distance
Applies to vehicles: wit h Aud i adapt ive cru ise co ntrol
Fig. 118 Selector lever: setting the distance
~ Tap the switch to display the current set dis­
tance
¢fig. 118.
~ To increase or reduce the distance by incre­
ments, tap the switch again to the left or
right. The distance between the two vehicles
will change in the instrument cluster dis­
play.
When approaching a moving vehicle up ahead,
the adaptive cruise control system brakes to match that object's speed and then maintains
the stored distance. If the vehicle ahead ac­
celerates, adaptive cruise control will also ac­
celerate up to the stored speed.
The higher the speed, the greater the distance
in yards (meters)¢ ,&.. The
Distance 3 setting
is recommended.
The distances provided are specified values.
Depending on the driving situation and the
how the vehicle ahead is driving, the actual
distance may be more or less than these tar­
get distances.
The various symbols for the time increments
appear briefly in the information line @
c;, page 102, fig. 115 when you change the
settings.
c::::::,_c::::::, ___ Distance 1: This setting corre-
sponds to a distance of 92 feet/28 meters
when traveling at 62 mph (100 km/h), or a
time interval of 1 second.
c::::::, __ c::::::, __ Distance 2: This setting corre­
sponds to a distance of 118 feet/36 meters
when traveling at 62 mph (100 km/h), or a
time interval of 1.3 seconds.
c::::::, ___ c::::::,_ Distance 3: This setting corre-
sponds to a distance of 164 feet/SO meters
when traveling at 62 mph (100 km/h), or a
time interval of 1.8 seconds.
c::::::, ____ c::::::, Distance 4: This setting corre-
sponds to a distance of 210 feet/64 meters
when traveling at 62 mph (100 km/h), or a
time interval of 2.3 seconds.
A WARNING
Following other vehicles too closely in­
creases the risk of collisions and serious
personal injury .
- Setting short distances to the traffic
ahead reduces the time and distance
available to bring your vehicle to a safe
stop and makes it even more necessary
to pay close attention to traffic.
-
-Always obey applicable traffic laws, use
good judgment, and select a safe follow­
ing distance for the traffic, road and
weather conditions.
0) Tips
- Distance 3 is set automatically each time
you switch the ignition on.
- Your standard settings are automatically
stored and assigned to the remote con­
trol key being used.
Setting the driving program
Applies to veh icles: w ith Audi ada ptive c ruise control
Depending on the selected driving program
and distance, driving behavior when accelerat­
ing will vary from dynamic to comfortable.
Setting the driving program for vehicles
without Audi drive select*
~ In the radio/MM!*, select: ICARlfunction
button
> Adaptive cruise control > Driving
prog.
> comfort, standard or dynamic. Or
~ Select: !CAR I function button > Car systems*
control button > Driver assist > Adaptive
cruise control> Driving program*
> Com-
fort, Standard
or Dynamic . ll-

Audi adaptive cruise control and braking guard 105
Setting the driving mode for vehicles with
Audi drive select*
Refer to r=;,poge 114 .
(D Tips
Your settings are automatically stored and
assigned to the remote control key being
used.
Request for driver intervention
Applies to vehicles: with Audi adaptive cruise control
Fig. 119 Instrumen t cl us ter: reques t for drive r inte r·
vention
I n ce rtain situat ions, the system will prompt
you to take action . This cou ld happen, for ex­
ample, if braking by the adaptive cruise con­
trol system is not enough to maintain enough
distance to the vehicle ahead.
The instrument cluster will warn you about
the danger
r=;,fig. 119:
- A red vehicle is pict ured in the disp lay.
- The text
DISTANCE! appears in the status
bar.
- T he red ind icator light . blinks.
- In add ition, a warning tone sounds.
Audi braking guard
Description
Applies to vehicles: with Audi adaptive cruise control
Fig. 120 Instr ument cluster: approach warning
Braking guard uses a radar sensor. It also
functions within the limits of the system
when adapt ive cruise control is switched off.
What can Audi braking guard do?
When detected in time, the system can assess
situations when a vehicle ahead brakes sud­
denly or if your own vehicle is traveling at a
high speed and approaching a vehicle up
ahead that is moving more slowly. Braking
guard does not react if it cannot detect the
s ituation.
The system advises you of various situations:
- The
distance warning is given if you are too
close to the vehicle ahead for a long time. If
the vehicle ahead brakes sharply, you will
not be able to avoid a collision . The indicator
light . in the display comes on .
- The
approach warning is given when a de­
tected vehicle up ahead in your lane is mov­
ing much more slowly than you are or if it
brakes sharply. When thi s war ning is given,
it may on ly be possible to avoid a co llision
by swerving or brak ing sharp ly. The indicator
light . and indicator in the display will
warn you about the danger¢
fig. 120. You
wi ll also hear an acoustic signal.
If you do not react fast enough or do not react
at all to the situation, Braking guard will in­
te rvene by brak ing and the message
braking
guard intervention
wi ll appear.

106 Audi adap tive cruise control and br aking guard
- If a co llision is imminent, the system will
first provide an
acute warning by bri efly and
sharp ly app ly ing the brakes .
- If you do not react to the ac ute warning ,
braking guard can brake within the limits of
the system. This reduces the veh icle speed
in the event of a collision.
- At speeds under 20 mph (30 km/h), the sys ­
tem can in it iate a complete deceleration
s hortly before a collision
l) .
-If the braking guard senses that you are not
braking hard enough when a collision is im­
minent, it can increase the braking force.
Which funct ion s can be contr oll ed ?
You can switch braking guard and the dis­
tance/approach warning on or off in the radio
or MM I c> poge 106, Settings in the radio/
MMI.
A WARNING
Lack of attention can cause col lisions, oth­
er accidents and serious personal injuries.
The braking guard is an assist system and
cannot prevent a collis ion by itself. The
driver m ust always intervene . T he d river is
always responsib le for bra king at the cor­
rect time.
- Always pay close attention to traffic,
even when the brak ing guard is switched
on. Be ready to intervene and be ready to
take complete control whenever necessa­
ry. A lways keep the safe and legal dis­
tance between your vehicle and vehicles
up ahead.
- Braking guard works w ith in limits and
will not respond outs ide the system lim­
its, for example when approaching a
stopped vehicle or stationary obstacle
(end of a traff ic jam or veh icle that has
broken down in traffic).
- Always remember that the radar sensor
for the braking guard works only within
defined detection and range limits that
l ) Th is is not available in some c oun tri es.
may prevent the proper detection of oth­
er vehicles.
- The radar sensor's function and range
can be reduced by rain, snow and heavy
spray. Moving veh icles up ahead may not
be prompt ly detected or may not be de­
tected at all .
- Reflective surfaces including crash barri­
ers or tunne l entrances may impair the
function of the radar sensor .
(D Tips
- You can cancel the braking that is in it iat­
ed by the system by braking yourse lf, by
accelerating not iceably or by swerving .
- Braking guard error messages
c>poge 107.
- Keep in mind that braking guard can brake unexpectedly. Always secure any
cargo or objects that you are transport­
ing to reduce the risk of damage or in­
jury .
Settings in the radio/MMI
App lies to vehicles : wit h Audi ada ptive cr uise contro l
.,. Select: !CARI function button> Car sy ste m s*
contro l but ton > Driv er a ssi st> Audi brak ­
ing guard .
Or
.,. Select: !CAR I function button> Audi b raking
gua rd.
Sys tem -
Switch A udi braking guard On and
Off . When you switch the ignition on, the
message
Audi b raking gu ard off appears if
the system is switch ed off .
Ea rly warnin g -The distance and approach
warnings in the display can be switched
On/
Off .
(D Tips
-Yo ur settings are automatically s tored
and assigned to the remote contro l key
being used at the times the settings are
made.

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

190 Intelligent technology
Operating conditions and d riving hab it s
The brakes on today 's automob iles are st ill
subject to wear, depending largely on operat ­
ing conditions and driving habits
c::> ,& . On
vehicles that are either 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
W arranty & M ainte nance booklet . Failure
to have your brake pads inspected can result
in reduced b rake pe rformance.
On steep slopes, you should use the brak ing
effect of the eng ine . This way, you prevent un ­
necessa ry wear on the brake system. If you
must use you r brakes, do not hold the brakes
down continuously . P u mp the b rakes at inter­
va ls.
Operating nois e
Noises may occur when braking depending on
the speed, braking force and outside condi­
tions such as temperature and humidity .
Effect of w ater and ro ad sa lt
In certain situat ions, for example after driving
through wate r, in heavy ra in, after overn ight
condensation or after washing your car, the brak ing effect can be reduced by moistu re or
i ce on the bra ke roto rs and b rake pads . The
b rakes must be dried fi rst with a few ca ref ul
brake app lications .
At h igher speeds and with the w indshie ld w ip­
e rs turned on, the brake pads press agains t
the bra ke rotors for a short amount of time.
This occurs a t regular intervals without the
driver noticing and provides for better brake response time under wet conditions.
The effectiveness of the brakes can be reduced
when the vehicle is driven on a salt-covered
road and the brakes are not used. Likewise,
you clean off accumulated sa lt coating from
brake discs and pads with a few caut ious ap ­
plications of the brake
c::> ,& .
Cor rosion
There may be a tendency for dirt to bui ld up
on the brake pads and corrosion to form on the d
iscs if the car is not driven regu larly or
o n Ly for short trips with litt le use of the
brakes.
If t he brakes a re not used frequently, o r if cor­
r os ion has formed on the discs, it is adv isable
to clean off the pads and discs by braking
firmly a few times from a moderately h igh
speed
c::> .&. .
Fault s in the brak e syst em
If you shou ld notice a sudden increase in
brake pedal trave l, then one of the two brake
circuits may have fai led
c::> .& .
Low br ake fluid lev el
Malfunctions ca n occu r in the b ra ke system if
t h e b rake fluid level is too low. The brake flu id
l evel is monitored electronica lly.
Brake booster
The brake booster inc reases the pressure that
you generate with the b rake peda l. It works
o n ly when the engine is runn ing
.c::> .&
Brake lining wear status
Brake lining wear may be checked by visual in­
spect io n of the condition of the brake pads
th rough the open ings in the wheel. If neces­
sary, the wheel may be removed fo r thi s i n­
spe ct ion
c::> page 255, Changing a wheel.
.&, WARNING
- New b rake pads don' t have the bes t stop­
ping power and m ust be "bro ken -in" dur ­
ing the initial 100 to 150 miles (150 to
200 kilometers) of normal c ity driving.
You can compensate for this by pressing the brake pedal more firmly. Th is also
applies later when new pads are instal­
led.
- You shou ld perform braking maneuvers
for the purpose of cleaning the brake
system only if road conditions permit.
Othe r road use rs must no t be put at risk -
you may ca use an accident!
- Before descend ing a steep grade, reduce
speed and sh ift transmission into a lower
gear or lower dr iving range. Do not ride
~