2014 AUDI A8 brake

88 On the road
with the footbrake . The parking brake elimi­
nates the tendency to creep with a drive range
engaged . As soon as you dr ive off as usual,
the park ing brake is released automatically
and the vehicle starts to move.
Starting on slop es
When starting on inclines, the starting assist
prevents the vehicle from unintentiona lly ro ll­
ing back. The braking force of the parking
brake is not released until sufficient driving
force has been bu ilt up at the wheels.
For safety reasons, the park ing brake is re­
leased automatically only when the dr iv­
er's safety belt is engaged in the buckle.
Starting off with a trailer
To prevent rolling back unintentionally on an
incline, do the following:
.. Keep the switch(®) pulled and depress the
acce lerator. The parking brake stays applied
and prevents the vehicle from ro lling back­
ward.
.. You can release the switch (®) once you are
sure that you are develop ing enough for­
ward momentum at the wheels as you de­
press the accelerator.
Depending on the weight of the r ig (vehicle
and tra iler) and the severity of the incl ine, you
may roll bac kwards as you sta rt. You can pre­
vent roll ing backwards by holding the parking
b rake switch (®) p ulled out and acce lerat ing -
just as you would when starting on a hill with a conventional hand brake.
Emergency braking
In the event that the conventional brake sys ­
tem fails or locks .
.. In an emergency, pull the switch(®) and
contin ue to p ull it t o slow your vehicle down
with the parking brake.
.. As soon as you release the switch (®) or ac­
ce lerate, the braking process stops.
If you pull the switch(®) and hold it above a
speed of about 5 mph (8 km/h), the emergen­
cy bra king f unct ion is initiated. The vehicle is
braked at all four whee ls by activating the hy­
draulic brake system. The brake performance
is simila r to making an emergency stop
c> .&. .
In order not to act ivate the emergency brak­
ing by mistake, an audib le warning tone (buz­
zer) sounds when the switch(®) is pulled. As
soon as the sw itch (®) is re leased, or the accel­
erato r pedal is depressed, eme rgency braking
stops .
.&, WARNING
E mergency braking should only be used in
a n emergen cy, when t he norma l foot bra ke
has fa iled or the brake pedal is obstructed.
Using the par king brake to perform emer ­
gency b raking will s low your vehicle down
as if you had made a full brake application.
The laws of physics cannot be suspended
even with ESC and its associated compo­ nents (ABS, ASR, EDL). In corners and
when road o r weathe r cond itions are bad,
a full brake application can cause the v ehi­
cle to s kid or the rear end to break away -
r isking an a cci den t.
Start-Stop-System
Description
Appl ies to vehicles : wit h Start-Stop-System
The Start-Stop-System can help increase fuel
economy and reduce CO2 emissions .
In the Start -Stop -mode, the engine shuts off
automat ica lly when the veh icle is stopped,
such as at a traffic light. The ignition remains
switched on during this stop phase. The en­
gine wi ll be automat ica lly restarted when
needed .
The last Start-Stop-System setting (on/off us­
ing the button
l 0a• I) will be restored when the
ignition is turned on. The LED in the !09 ~1 but­
ton turns on when the Start-Stop-System is swit ched off manually.
IJ,,

Basic requirements for the Start-Stop
mode
-The driver's door is closed .
- The driver' seat belt is latched.
- The hood is closed.
- The vehicle must have been driven faste r
than 2.5 mph (4 km/h) since the last stop .
- A tra ile r is not hitched to the veh icle.
& WARNING
- Never let the vehicle roll with the engine
switched off. You could lose contro l
over
the vehicle. This can lead to a collision
and serious injuries.
- T he brake booster and the steering sup­
port do not work wh ile the engine is
switched off. More force is required to
stop and to steer the vehicle.
- To reduce the risk of injuries, make sure
that the Start-Stop-System is turned off
when working in the engine compart­ ment¢
page 90.
(D Note
Always switch off the Start -Stop -System
when driving through water¢
page 90.
Starting/stopping the engine
Applies to vehicles: with Start-Stop-System
Fig. 88 In st rum en t cluster : engi ne switc hed off (stop
phase)
.. Slow the vehicle to a stop using the brake
and keep pressing the brake pedal. The en­
gine will switch off. The
[I] indicator light
appears in the information line in the instru­
ment cluster d isplay.
On the road 89
.. When you take your foot off the brake ped ­
al, the engine restarts. The indicator light
turns off.
Additional information
The engine will switch off in the P, D, N and S
pos itions as well as in manual mode. In the P
position, the engine will also remain off if you
take your foot off the brake pedal. The engine
starts again when you select another selector lever position and take your foot off the brake
pedal.
If you se lect the R position during a Stop
phase, the engine will start again.
S hi ft from D to P quickly to prevent the engine
from starting unintentionally when shifting
through R .
You can determine for yourself if the engine
will stop or not by reducing or increasing the
amount of force you use to press the brake
pedal. For example, if you only lightly press
on the brake pedal in stop-and and-go traffic
or when turning, the engine will not switch off
when the vehicle is stationary. As soon as you
press the brake down harder, the engine will
switch off.
General information
Applies to vehicles: with Start-Stop-System
The standard Start-Stop-mode can be cancel­
led for different system-related reasons.
Fig. 89 Instrument cluster: engine -Stop temporarily
unavailable

90 On the road
Engine will not swit ch off
Before each stop phase, the system checks i f
certain cond itions have been met. For exam ­
p le, the engine will
n ot be switched off in the
following situations:
- T he eng ine has not reached the minimum
required temperature for Start -Stop-mode .
- The inter io r temperature selec ted by the A/C
system has not been reached .
- T he outs ide temperature is extremely h igh/
low .
- T he w indshield is being defrosted
¢page 82.
-The parking system* is switched on.
- The battery charge level is too low .
- The steering wheel is sharply turned or
there is a steering movement.
- After engaging the reverse gear.
- On sharp inclines.
The
tiij indica to r light appears in the informa­
tion line in the ins trument cluster disp lay
<=:>fig . 89 .
Engine automatically restarts
The stop phase is interrupted in the following
situations, for examp le. The engine restar ts
witho ut any act ion by the driver.
- T he interio r temperature varies from the
temperature selected in the A/C system .
- The w indshield is being defrosted
<=:> page 82.
- The brake pedal is pressed several times i n a
row .
- The battery charge level becomes too low .
- High power consumption.
Sw itching the ignition automatically
To prevent the battery from d raining, the igni­
tion will switc h off
automat ically when a ll of
the following conditions have been met:
- T he veh icle has already been driven.
- T he eng ine has been tu rned off by the Star t-
Stop-System*.
- The driver's door is opened.
- The driver's seat belt is removed.
- The brake pedal is not pressed dow n. -
The vehicle is stationa ry .
In this case, the activated low beam will be re­
placed by the side ma rke r lights. The s ide
marker lights w ill switch off after approxi­
mately 30 minutes or when you lock the vehi ­
cle .
If the Star t-Stop System h as n ot turned off
the engine or if you have sw itched the Start­
Stop system off man ua lly, the ignition will
not
be automatica lly switched off and the engine
will continue to ru n ¢ ,& .
A WARNING
=
Never allow the engine to run in confined
spaces -danger of asphyxiation.
(D Tips
If you shift into the D, Nor S posit ions af­
ter sh ifting into reverse, the vehicle must
be driven faster tha n 6 mph (10 km/h) in
order for the engine to sw itch off again.
Switching the Start-Stop -System on/off
manually
App lies to vehicles: wi th Start-Stop -System
If you do not wish to use the system, you con
switch it off manually.
F ig . 90 Ce nter console: Start-Stop -System button
.,. To swi tch the Start-Stop-Sys tem off/on
manually, p ress the
l(A) ~·I button. The L ED in
the button turns on when the system is
switched off .

92 On the road
• Pull the lever to position CD ¢ fig . 91 to
switch the system on.
• Drive at the speed you wish to set .
• Press button @to set that speed.
The stored spee d and the ind icator light
[ij;(i)~i~ (US mode ls) ,ii (Canadian mode ls) ap­
pear in the instrument cluster d isplay
¢ fig. 92. The display may vary, depending on
the type of d isplay in your vehicle .
The speed is kept constant via an engine o ut­
p ut adjustment or act ive brake intervention .
A WARNING
-Always pay attention to traffic even when
the cruise control is switched on . You are
always responsible for your speed and
the distance between your vehicle and other vehicles.
- For safety reasons, the cruise control
should not be used in the city, in stop­
and-go t raff ic, on twist ing roads and
when ro ad conditions are poor (such as
ice , fog, grave l, heavy rain and hydro­
planing) -risk of accident.
- T urn off the cruise control tempor aril y
when entering turn lanes, highway exit lanes or in construction zones.
- Please note tha t inadvertent ly "rest ing"
yo ur foot on the accelerator peda l causes
the cruise control not to brake. This is
because the cr uise control is overridden
by t he driver 's acce lerat ion.
- If a brake system malfunction such as
overheat ing occurs when the cru ise con­
tro l system is sw itched on, the braking
function in the system may be switched
off . The other cruise control functions re­
ma in active as long as t he indicator light
[ij;rn~i~ (US models) Iii.I (Canad ian mod­
els) is on.
(D Tips
The b rake lights illuminate as soon as the
brakes decelerate automat ica lly.
Changing speed
• To increase/decrease the speed in inc re ­
men ts, tap the lever in the
0 10 direction
¢ page 91, fig. 91 .
• To increase/decrease the speed quick ly, hold
the lever in the
0 10 direction until the de ­
sired speed is displayed.
You can also press the accelerator pedal down
to increase yo ur speed, e.g . if you want to
pass someone . The speed you saved earlier
will res ume as soon as you release the acce ler­
ator pedal.
If, however, you exceed your saved speed by
6 mph (10 km/h) for longer than 5 minutes,
the cr uise control w ill turn off temporari ly.
The green symbol
[ij;(l)~i~ (US mode ls) ,ii in
the d isplay is replaced with a white symbol.
T he saved speed remains the same .
Presetting your speed
You can preset your desired speed while the
vehicle is not moving.
• Switch on the ign ition.
• Pull lever into position
CD ¢ page 91,
fig . 91 .
• Press the lever in t he 0 o r 0 direction to
increase or decrease your speed .
• Release t he lever to save that speed .
Th is function makes it possib le, for examp le,
to save the speed you want before dr iv ing on
the highway. Once on the h ighway, act ivate
the cr uise con trol by pulling the leve r toward
CD -
Switching the system off
Temporary deactivation
• Press the brake pe dal , or
• Press the lever into posi tion @(not cl icked
into p lace)
¢ page 91, fig. 91, or
• Drive for longer t han S m in utes at more
than 5 mph (10 km/h) above the stored
speed.

Switching off completely
"'Press leve r into position @(clicked into
place), or
"' Switch the ignition off.
The system reta ins the saved speed if you de­
activate the cru ise control temporarily. To re­
sume the saved speed, release the brake ped­
a l and pull the lever to position @.
Switching the ignition off erases the saved
speed .
& WARNING
You should only return to t he saved speed
if it is not too fast for the current traffic
conditions -risk of an accident!
On the road 93

94 Audi adapti ve cruise control and bra king gu ard
Audi adaptive cruise
control and braking
guard
Introduction
App lies to vehicles: with Audi adaptive cruise co ntrol
The adaptive cruise control system assists the
driver by regu lat ing vehicle speed and helping
to maintain a set distance to the vehicle
ahead, within the limits of the system.
If the
system detects a moving vehicle up ahead,
adaptive cruise control can brake and then ac­
celerate your vehicle. This helps to make driv­
ing more comfortable both on long highway
stretches and in stop-and-go traffic.
The braking guard system can warn you about
an impending collision and initiate braking
maneuvers¢
page 100.
Adaptive cruise control and braking guard
have technical limitations that you must
know, so please read this section carefully, un­
derstand how the system works and use them
properly at all times.
General information
General information
Applies to vehicles: with Audi adaptive cruise control
Fig. 93 Front of th e veh icle: senso rs and video camera
The areas that conta in the radar and ultrason­
ic sensors and the v ideo camera ¢
fig. 93
must never be covered by stic kers or other ob­
jects or obstructed w ith dirt, insects, snow or
i ce that will interfere with the adaptive cruise
control system and braking guard. For infor­
mation on cleaning, refer to¢
page 216. The same applies for any modifications made in
the front area.
T he function of the adaptive cru ise contro l
system and braking guard is limited under
some cond itions:
- Objects can only be de tected when they are
w ith in sensor range¢
page 96, fig. 96.
- The system has a limited ability to detect
objects that are a short d istance ahead, off
to the side of your vehi cle or mov ing into
your lane.
- Some kinds of ve hicles are hard to detect;
for examp le motorcycles, veh icles with high
ground clearance or overhanging loads may
be detected when it is too late or they may
not be detected at all.
-When driving through curves
¢page 95 .
-Stat ionary objec ts ¢page 95.
& WARNING
A lways pay attention to traffic when adap ­
tive cruise contro l is switched on and brak­
ing g uard is active. As the dr iver, you are
still respons ible for starting and for main­
taining speed and distance to other ob­
jects. Braking guard is used to assist you .
The dr iver must a lways take action to avo id
a collis ion . The driver is a lways respons ible
for braking a t the co rrec t time.
- Imp roper use of adaptive cru ise control
can cause collisions, other acc idents and
serious pe rsonal in jury.
- Never let the comfort and convenience
that adaptive cruise control and braking gua rd offer d istract you from the need to
be alert to traffic condit ions and the
need to rema in in fu ll control of your ve­
h icle at a ll times,
- Always remember that the adaptive
cruise control and braking guard have
limits -they will not s low the vehicle
down or maintain the set distance when
you drive towards an obstacle or some­
thing on or near the road that is not
mov ing, such as vehicles stopped in a
traffic jam, a stalled o r disabled vehicle.
I f registered by the radar sensors,

Audi adapt ive crui se c ontrol an d bra kin g guard 95
vehicles or obstacles that are not moving
can trigger a collision warning and if con­
firmed by the video camera, an acute col­ lis ion warn ing.
- For safety reasons, do not use adaptive
cruise control when driving on roads with
many curves, when the road surface is in
poor condit ion and/or in bad weather
(such as ice, fog, gravel, heavy rain and
hydroplan ing). Using the system under
these cond itions cou ld result in a co lli ­
sion .
- Switch adaptive c ruise control off tempo­
rar ily when driv ing in turning lanes, on
expressway exits or in construction
zones . This prevents the vehicle from ac­
celerating to the set speed when in these
situations .
- The adapt ive cru ise 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 adapt ive cruise control system and
braking guard do not react to people , an­
ima ls, objects crossing the road o r on­
coming objects .
- The function of the radar sensors can be
affected by reflective objects such as
guard ra ils, the entra nce to a tunnel,
heavy rain or i ce.
- Never follow a veh icle so closely that you
cannot stop your vehicle safe ly. The
adaptive cruise cont ro l c anno t slow or
brake the veh icle safely when you follow
another vehicle too closely. Always re­
member that the automatic braking
funct ion cannot bring the veh icle to a
sudden or emergency stop under these
conditions .
- To prevent unintended operation, always
switch ACC off when it is not be ing used. (D Note
The sensors can be displaced by impacts or
damage to the bumper, wheel housing and
underbody. That cou ld affect the adaptive
cruise control system and brak ing guard .
Have your authorized Aud i dea le r or a u­
thorized Audi Serv ice Facility check their
funct ion.
In curves
Applies to vehicles: with Audi adaptive cruise control
I
F ig. 9 4 Exampl e: dri vin g in to a curve
When dr iving into a curve c:> fig. 94 and out of
a cu rve, the ad aptive cruise con trol m ay react
to a vehicle in the next lane and apply the
brakes . You can override or prevent the brak­
i ng by pressing the accelerator pedal b riefly.
Stationary objects
Applies to vehicles: with Audi adaptive cruise control
Fig. 95 Ex ampl e: object chang ing l anes and s ta tio nar y
objec t
The adaptive cru ise con tro l system only reacts
to objects that a re mov ing o r th at the system
has a lready detected as moving . For examp le,
if a veh icle @, which has a lready been detect-
ed by the adaptive c ruise contro l, tu rns o r
changes lane s and another stationary vehicle .,._

96 Audi adaptive cruise control and braking guard
@ is located in front of that vehicle, the sys­
tem will not react to the stationary vehicl e.
Audi adaptive cruise
control
Description
Applies to vehicles: with Audi adaptive cruise control
Fig. 96 Detectio n range
What can adaptive cruise control do?
The adaptive cruise control system uses video,
radar and ultrasou nd . Moving vehicles ahead
can be recognized up to about 650 feet (200 m) away.
On open roads w ith no traffic, adaptive cruise
control works like a regular cruise control sys­
tem . The stored speed is maintained . When
approaching a moving vehicle detected up
ahead, the adaptive cruise control system au­
tomatically s lows down to match that vehi­
cle's speed and then maintains the distance
that the driver previous ly stored. As soon as
the system does not detect a vehicle up
ahead, adaptive cruise control accelerates
back up to the stored speed.
In stop-and-go traffic, adapt ive cru ise control
can brake until the vehicle stops and acceler ­
ate again under certain conditions and if this
is possible within the system's limits and ca­
pabilities ¢
page 98. Adaptive cru ise control
will not make an emergency stop .
Which functions can be controlled?
When you switch adaptive cruise contro l on,
you can set the current speed as the "control speed" ¢
page 96, Swi tching on and off.
When driving, you can stop cruise control
¢
poge 98 or change the speed¢ page 97
at any time .
You can also set the distance to the object
ahead and set the adaptive cruise control driv­
ing program ¢
page 98.
Switching on and off
Applies to vehicles: with Audi adaptive cruise control
Fig. 97 Se le cto r lever: swit chin g on /off
Fig. 98 Instrume nt cl uste r: adapt ive cruis e cont rol
You can set any speed between 20 mph and
95 mp h (30 and 150 km/h) .
Ind icator lamps and messages in the instru ­
ment cluster d isplay inform you about the cur­
rent system status and settings .
Switching adaptive cruise control on
... Pull the leve r toward you into position (D
¢ fig. 97 . ACC standby appears in the in­
strument cluster display .
Setting the speed and activating
regulation
... To set the current speed, press the ISETI bu t­
ton ¢
fig. 97. T he set speed is shown in the
tachometer @and is a lso shown br iefly in
the display @¢
fig. 98 . ...,