2012 AUDI A8 brake

Cruise control
Switching on
The cruise control system makes it possible to
drive at a constant speed starting at 20 mph
(30 km/h).
0
f
~
0
Fig . 84 Control lever with set button
Fig . 85 D isplay: Selected speed
.,. Pull the lever to position (D ~ fig . 84 to
swit ch the system on .
.,. Drive at the speed you wish to set.
.,. Press button @to set that speed.
The stored speed and the ind icator light
[lj;(i)~1ij (US models) 1 11 (Canad ian models) ap­
pear in the instrument cluster display
¢ fig. 85. The display may vary, depending on
the type of disp lay in your vehicle. The indica­
tor light
Ill in the instrument cluster also illu­
minates.
The speed is kept constant via an engine out­
put adjustment or active 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.
On the road 85
-For safety reasons, the cruise control
should not be used in the city, in stop­
and-go traffic, on twisting roads and
when road conditions are poor (such as ice, fog, gravel, heavy rain and hydro­
plan ing) - risk of accident .
- Turn off the cruise control temporarily
when enter ing turn lanes, highway exit
lanes or in construction zones.
- Please note that inadvertently ''resting"
your foot on the accelerator pedal causes
the cruise control not to brake. This is
because the cruise control is overridden
by the driver's acceleration .
- If a brake system malfunction such as
overheating occurs when the cr uise con­
trol system is switched on, the braking
function in the system may be switched
off . The other cruise contro l functions re­
main active as long as the indicator light
tij;[i)~1ij (US models) 111 (Canadian mod­
els) is on.
(D Tips
The brake lights illuminate as soon as the brakes decelerate automatically.
Changing speed
.,. Press lever in the 0 or 0 direction
¢ page 85, fig . 84 to increase or decrease
your speed .
.,. Release the lever to save that speed.
Change speed in increments of 1 mph (1 km/ h) by lightly press ing the lever. If you keep the
lever pressed down , you will alter your speed
in 5 mph (10 km/h) increments.
You can also press the accelerator pedal down
to increase your speed, e.g. if you want to
pass someone. The speed you saved earlier
will resume as soon as you release the acceler­
ator pedal.
If, however, you exceed your saved speed by
6 mph (10 km/h) for longer than 5 m inutes,
the cruise control wil l turn off temporarily.
The green symbol
[ljlIJll (US models) ill in ..,_

86 On the road
the display is replaced with a white symbol.
The saved speed remains the same .
Presetting your speed
You con preset your desired spe ed while the
vehicle is not moving.
,.. Switc h on the ignition.
,.. Pull lever into pos ition
(D ~ page 85,
fig . 84 .
... Press the lever in the 0 or 0 direction to
increase or decrease your speed .
... Re leasethelevertosavethatspeed.
This funct ion makes it possible, for example,
to save the speed yo u want before driving on
the highway . Once on the highway, activate
the cruise contro l by pull ing the lever toward
(D .
Switching the system off
Temporary de activation
... Press the brake pedal, or
... Press the lever into pos ition @ (not clicked
into place)
~ page 85, fig . 84, or
,.. Drive for longer tha n 5 minutes at mo re
t h an 5 mph (10 km/h) above the sto red
speed.
Switching off completely
... Press leve r into posi tion @ (clicked into
place), or
,.. Swit ch 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 b rake ped­
a l and pull the lever to position
(D .
Sw itch ing the ign ition off erases the saved
speed .
A WARNING
You should only return to the saved speed
if it is not too fast for the current traffic
condi tions - risk of an accident!

Audi adapt ive crui se c ontrol an d bra kin g guard 8 7
Audi adaptive cruise
control and braking
guard
Introduction
App lies to vehicles: with Audi adaptive cruise control
The adaptive cruise control system assists the
driver by regu lating 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 . Th is he lps 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 93.
Adaptive cruise control and Audi braking
guard have technica l limitations that you
must know, so p lease read this section care­
fully, understand how the system works and use them properly at all times.
General information
General information
Applies to vehicles: with Audi adaptive cruise control
Fig. 86 Front of the veh icle: sensors and video came ra
The areas that conta in the radar and ultrason ­
ic sensors and the v ideo camera ¢
fig. 86
must neve r be covered by stickers or other ob­
jects or obstructed w ith dirt, insects, snow or
ice that will interfere w ith the adaptive cruise
control system and Audi braking guard. For in­
formation on cleaning , refer to ¢
page 205.
The same applies for any modifications made
in the front area.
T he function of the Adaptive cruise cont ro l
system and A udi braking guard is limited un­
der some conditions.
- Objects can on ly be detected when they are
w ith in sensor range
¢page 89, fig. 89 .
-The system has a limited ability to detect
objects that are a shor t distance ahead,
off
to the side of your vehicle or moving into
your lane.
- Some kinds of ve hicles are hard to detect;
for examp le motorcycles, vehicles with high
ground clearance or overhanging loads may
be detected when it is too late or they may
not be detected at a ll.
- Stationary objects¢
page 88.
-When driving throug h curves ¢ page 88.
& WARNING
Always pay attent ion to traffic when adap ­
tive cruise contro l is switched on and brak­
ing g uard is active. As the driver, you are
still respons ible for start ing and for ma in­
taining speed and distance to other ob­
jects . Braking guard is used to assist you .
The driver must a lways take action to avo id
a collis ion. The driver is a lways responsible
for braking at the co rrect time.
- Improper use of adaptive cru ise control
can cause collisions, other acc idents and
serio us pe rsonal in jury.
- Never let the comfort and conven ience
that adaptive cruise control and Audi
braking guard offer dist ra ct you from the
need to be a lert to t raff ic condi tions and
the need to remain in full con trol of yo ur
vehicle at a ll times,
- Always remember that the adaptive
cruise contro l and Audi braking guard
have limits -they will not s low the vehi ­
cle down or maintain the set d istance
when you drive towards an obstacle or
something on or near the road that is not
mov ing, such as vehicles stopped in a
traffic jam, a stalled or disabled vehicle .
I f regis tered by the radar sensors,

88 Audi adapti ve cruise control and bra king gu ard
vehicles or obstacles that are not moving
can trigger a collision warning and if con­
firmed by the v ideo camera, an acute col­
lis ion warn ing .
- For safety reasons, do not use adaptive
cruise co ntrol 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 it ions cou ld result in a co lli ­
sion .
- Swi tch adap tive 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
celerat ing to the set speed when in these
situations.
- The adapt ive cruise control system wi ll
not brake by itse lf if you put your foot on
the accelerator pedal. Doing so can over­
ride the speed and d istance regulation .
- When approaching stationary objects such as stopped traff ic, adaptive cruise
co ntrol 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
imals, objects c rossing the road or on­
coming objects .
- The function of the radar senso rs can be
affected by reflective objects such as
guard rai ls , the entrance to a tunnel,
heavy rain or ice.
- Never follow a ve hicle so closely that you
cannot stop your vehicle safe ly. The
adaptive cruise contro l canno t slow or
brake the vehicle safely when you follow
another vehicle too closely. Always re­
member that the automatic braking
function cannot br ing the vehicle to a
sudden or emergency stop under these condit ions.
- To prevent unintended operation, always switch ACC off when it is not being 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 ler or au ­
thorized Audi Service Facility check their
funct ion .
In curves
Applies to vehicles: with Audi adaptive cru ise contro l
I
Fig. 87 Ex ampl e: dri ving in to a curve
When d riving into a curve c> fig. 87 and out of
a curve, the ad aptive cruise control may react
to a vehicle in the next lane and apply the
brakes. You can override or prevent the brak­
i ng by pressing the acce lerator pedal b riefly .
' Stationary objects
Applies to vehicles: with Audi adaptive cruise control
Fig. 88 Exampl e: objec t ch anging l anes and sta tio nar y
object
T he adaptive cru ise control system only reacts
to objects that a re mov ing o r that the system
has already detected as moving . For examp le,
if a vehicle @, which has already been detect-
ed by the adaptive c ruise contro l, tu rns off o r
ch anges lane and ano ther stationary veh icle .,.

90 Audi adaptive cruise control and braking guard
• You must also press the brake pedal when
the vehicle is stopped.
Switching adaptive cruise control off
• Push the lever away from you into position
@ until it clicks into p lace. The message
ACC off appears.
@ Indicator lights
II-Adaptive cruise control is switched on . No
vehicles are detected up ahead. The stored
speed is maintained.
I-A moving vehicle is detected up ahead .
The adaptive cruise control system regulates
the speed and d istance to the moving vehicle
ahead and acce lerates/bra kes automatica lly.
f§ . Adaptive cru ise control is switched on . A
mov ing vehicle up ahead was detected. Your
vehicle remains stopped .
I -When automatic braking is not able to
keep enough distance to a p reviously detected
mov ing vehicle up ahead, you must take con­
trol and brake¢
page 92, Prompt for driver
intervention.
© Display
If adap tive cruise control is not shown in the
d isplay, you can call it up with the multifunc ­
tion steering wheel buttons~
page 23.
Based on the symbols in the display , you can
determ ine if the system is maintaining a dis­
tance to the vehicle ahead and w hat 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 92.
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.
The green zone on the scale shows the stored d istance. For information on changing the stored distance, refer to
¢
page 91. If the
distance se lected is too close or may soon be­
come too close, the arrows move into the red
z one on the sca le.
A WARNING
Improper use of the adaptive cruise con­
trol can cause collisions, other accidents
and serious personal injur ies .
- Pressing the
!SET ! button when driving at
speeds below 20 mph (30 km/h), w ill au­
tomatically accelerate the vehicle to 20
mph (30 km/h), which is the minimum
speed that can be set .
(D Tips
-If you switch the ignit ion or the adaptive
cruise control off, the set speed is erased
from the system memory.
- You cannot switch the Electron ic Stabili­
ty Control (ESC) to the SPORT mode
when adaptive cruise control is switched
on .
Changing the speed
Applies to vehicles: with Audi adaptive cru ise control
0
f
• 0
Fig. 92 Selecto r lever : chang ing t he spee d
• To increase or reduce the speed in incre ­
ments,
tap the lever up or down.
-
-a)
N
q :r
~
"' To increase or reduce the speed qu ickly,
hold the lever up or down until the red L ED
@ reaches the desired speed ¢ page 89,
fig . 91.
Following any changes, the new stored speed
will be displayed briefly in the display @
¢page 89, fig. 91.

Audi adaptive cruise control and braking guard 91
Driving in stop-and-go traffic
Applies to vehicles: with Audi adaptive cruise control
The adaptive cruise control system also as­
sists you in stop-and -go traffic. If a previous
detected vehicle ahead s tops, yo ur vehicle will
brake to a stop, within the limits of the sys ­
tem .
.,. To resume driv ing with adap tive cruise con ­
tro l, tap the accelerator peda l or
.,. Pull the lever toward you into position @
¢ page 89, fig. 90.
(D Tips
-If adaptive cru ise contro l is active and
your vehicle does not start driving as ex­
pected after pulling the lever once, you
can start out aga in by tapping the accel­
erator pedal.
- If an obstacle is detected when your ve­
hicle starts dr iv ing, the system w ill
prompt you to take over
¢ page 92.
Your vehicle w ill drive more slowly when
starting. This may also happen in some
s ituations when there no obstacle is ap­
parent.
Interrupting cruise control
Ap plies to vehicles: with Audi adaptive cruise control
Fig. 93 Selecto r level
Requirement: adaptive cruise control must be
switched on .
Overriding crui se control
.,. To accelerate manua lly, pull the lever to­
ward you into position @and hold it there.
The message
ACC override appears. Or
.,. press the accelerator pedal. .,.
To resume cruise contro l, release the lever
or take your foot off the accelerator pedal.
Canceling cruise control while driving
.,. Move the lever into position @. The mes­
sage
ACC standby appears . Or
.,. press the brake pedal.
.,. To resume the stored speed, move the lever
into position @ .
Canceling cruise control when stopped
.,. Push the lever away from you into pos ition
@ . Th e message
ACC standby appears.
.,. To resume cruise control, press the brake
pedal and pu ll the lever toward you into po­
sition @.
A WARNING
-
Never resume the stored speed if the
speed is too high for prevailing road, traf­
fic or weather conditions.
Setting the distance
App lies to vehicles: with Audi adapt ive cr uise contro l
Fig. 94 Selector lever: setting th e dista nce
.,. Tap the switch to display the current set dis­
tance
¢ fig. 94 .
.,. To increase or reduce the distance by incre­
ments, tap the switch again to the left or
right. The distance between the two vehicles
w ill change in the instrument cluster dis ­
play.
When approaching a moving vehicle up ahead,
the adapt ive cruise control system automati­
cally brakes to match that object's speed and
then maintains the stored distance . If the ve-
hicle ahead accelerates, adaptive cruise ..,.

92 Audi adaptive cruise control and braking guard
control will also accelerate up to the stored
speed.
The higher the speed , the greater the distance
in yards (meters)¢ .&.. T he
Distance 3 setting
is recommended .
The distances p rov ided are spec ified values.
Depending on the driving situation and the
how the vehicle ahead is dr iving, the actual
distance may be more or less than these tar­
get distances .
The various symbols for the time increments
appear briefly in the info rmation line @
¢ page
89, fig. 91 when you change the set­
tings .
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:::, __ Distan ce 2: Thi s setting corre­
sponds to a dis tance of 118 feet/36 meters
when traveling at 62 mph ( 100 km/h), or a
time interva l 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 interva l 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.
.&_ 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 t ime and distance
available to br ing 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 .
(D 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
tro l key being used.
Selecting the driving mode
Applies to veh icles: w ith Audi adapt ive cr uise contro l
.,. Select the desired driving mode in dr ive se­
lect
¢ page 103 .
@ Tips
Your settings are automatically stored and
assigned to the remote control key being
used.
Prompt for driver intervention
Applies to vehicles : w it h Audi ada ptive cr uise cont ro l
Fig. 95 Instrument cluster: request for driver inte rven ­
tio n
In certa in s ituations, the system will prompt
yo u to take action . Thi s could happen, for ex­
amp le, if braking by the adaptive cruise con­
trol system is not enough to maintain enough
distance to the veh icle ahead .
The indicator light
I and the symbol in the
display will warn you about the situa tion
¢fig.
95. You w ill also hear an acoustic signal.
- Press the brake pedal to slow your vehicle
down.

Audi adaptive cruise control and braking guard 93
Audi braking guard
Description
Applies to vehicles: with Audi adaptive cruise control
Fig. 96 Instrument cluster: approach warning
Audi braking guard uses radar sensors and a
video camera. It also functions within the lim­
its of the system when adaptive 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 . Audi brak­
ing guard does not react if it cannot detect
the situation.
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 collis ion. The indicator
light
I i n the display comes on .
- The
approach warning is given when a de­
tected vehicle up ahead in your lane is mov ­
i ng much more slowly than you are or if it
brakes sharply . When this warning is given,
it may only be possible to avoid a collision
by swerving or braking sharply. The indicator
light
I and indicator in the display will warn
you about the danger
c::> fig . 96. You will a lso
hear an acoustic signal.
If you do not react fast enough or do not react
at all to the situation, Aud i braking guard will
11
This is not ava ilable in som e coun tri es.
intervene by braking and the message braking
guard intervention
will appear.
- If a coll is ion is imminent, the system wi ll
first provide an
acute warning by briefly and
sharply applying the brakes.
- If you do not react to the acute warning,
braking guard can brake with increas ing
force within the limits of the system. This
reduces the vehicle speed in the event of a
collision.
- The system can initiate complete dece lera­
tion shortly before a collision
1>. Full deceler­
ation at high speeds occurs only in vehicles
with adaptive cruise control and side assist
(pre sense plus).
- If the Audi braking guard senses that you
are not braking hard enough when a colli­
sion is immi nent, it can increase the braking
force.
- The pre sense functions also engage when a
collision is imm inent
c::> page 185 .
Which function s can be controlled?
You can switch Audi braking guard and the
distance/approach warning on or off in the
MMI c::> page 94, Settings in the MMI.
A WARNING
Lack of attention can cause collisions, oth­
er accidents and serious personal injuries .
The Audi braking guard is an assist system
and cannot prevent a collision by itself.
The driver must always intervene. The driv­
er is always responsib le for braking at the
correct time.
- Always pay close attention to traffic,
even when the Audi braking guard is
switched on. Be ready to intervene and
be ready to take complete control when ­
ever necessary. Always keep the safe and
legal distance between your veh icle and
veh icles up ahead.
- Audi brak ing guard works within limits
and will not respond outside the system
lim its, for example when approaching a