2017 AUDI A4 brake sensor

also start driving again automatically under cer­
tain conditions
c!;> page 100.
In traffic jams or slow-moving traffic, congestion
assist can assist the driver¢
page 104 .
Which functions can be controlled?
When you switch adaptive cruise control on, you
can set the current speed as the "control speed "
c!;> page 98, Switching on/off.
When driving, you can stop cruise control
c!;> page 100 or change the speed ¢ page 99 at
any time .
You can also set the dist ance to the vehicle d riv­
ing ahead and set the driving mode of the adap ­
tive cruise control¢
page 101 .
General information
Appl ies to: ve hicles with Audi adaptive cruise co ntro l
Fig. 90 Fro nt o f th e ve hicle : sensor s and video c amer a
The areas wi th the radar and ul trasonic senso rs
and the video camera¢
fig. 90 must not be cov­
ered by stickers, deposits or any other objects ,
because this can interfere with the adaptive
cruise control function. For information on clean­ ing, refer to¢
page 337. The same applies for
any modifications made in the front area .
In some driving situations , the adaptive cruise
control function is restricted:
- Vehicle s can only be detected when they are
within the sensor detection zones
¢ page 96,
fig . 89 .
-The system has a limited ability to detect
vehicles that are a short distance ahead, off to
the side of your vehicle or moving into your lane .
Assist
-Objects that are difficult to detect such as mo­
torcycles, v ehicles with high ground clearance
or an overhanging load are detected late or not
detected at all.
- When driving through curv es
c!;> pag e 98.
- When the vehicle is stationary ¢ page 98.
A WARNING
Always pay attention to the traffic around you
when adaptive cruise control is switched on .
As the driver, you are still responsible for your
own speed and the distance to other vehicles.
The adaptive cruise control is used to assist
you . The driver must always take action to
avoid a collision . The driver is always responsi­
ble for braking at the correct time .
- For safety reasons, do not use adaptive
cruise control when the road surface is in poor condition and/or in bad weather condi ­
tions (such as ice, fog, gravel, heavy rain and
hydroplaning). Using the system under
these conditions increases the risk of an ac­ cident.
- Switch adaptive cruise control off tempora­ rily when driving in turning lanes, on ex­
pressway exits (except if predictive control
is switched on) or in construction zones.
This prevents the vehicle from accelerating
to the stored speed when in these situa ­
tions .
- The adaptive cruise control system will not
brake by itself if you put your foot on the ac ­
celerator pedal. Doing so can override the
speed and distance regulation.
- When approaching stationary obstacles
such as stopped traffic, adaptive cruise con­
trol will respond with limited function .
-Adaptive cruise control does not respond to
people, animals, or crossing or oncoming
objects.
- The function of the radar sensors can be af­
fected by reflective objects such as guard
rails, the entrance to a tunnel, heavy rain or
ice.
~
97

Assist
(D Note
The sensors can be displaced by impacts or
damage to the bumper , whee l housing and
underbody. This can impair the adaptive
cruise control. Have an authorized Audi dea ler
or authorized Audi Service Fac ility check their
function .
In curves
Applies to: vehicles with Audi adaptive cruise control
Fig . 9 1 Exa mple: drivin g in to a curve
When driving into a curve<=> fig. 91 and ou t of a
curve, the adaptive cruise control may react to a
veh icle in the neighboring lane and apply the
brakes . You can prevent that by pressing the ac­
celerator pedal b rief ly.
Stationary vehicles
Applies to : vehicles with Aud i adaptive cruise contro l
Fig. 92 Example: vehicl e chang ing lane s and sta tiona ry ve ­
hi cle
Adaptive cruise control can react to a limited ex­
tent to stationary vehicles
c:> fig . 92, as long as
you are driving slow er than SO km/h and the sys­
tem classifies as possible passing maneuver as
low . For example, if a vehicle that was already
detected @turns or changes lanes, the adaptive
98
cruise contro l reacts to the stationary vehicle
ahead of it@ .
Switching on/off
Applies to: vehicles with Audi adaptive cruise control
Fig. 93 Operating lever : sw itc hin g on and off
Fig. 94 Inst rument cluster : adap tive cr uise cont rol
You can set any speed between 20 and 9S mph
(30 and lSO km/h).
Indicator lights and messages in the instrument
cluster display inform you about the cu rrent sit­
uation and setting .
An add itional indicator appears in the Head-up
display *.
Switching adaptive cruise control on
.. Pull the lever toward you into position (D
c=> fig. 93. ACC: standby appears in the display.
Saving the speed and activating regulation
.. To store the current speed, press the ISE TI but­
ton
c:> fig . 93 . The stored speed is shown in the
speedometer in the LED line@ and appears
briefly in the status line
@ c:> fig. 94.
.. To activate the regulation while sta tionary, also
press the brake pedal. .,.

Assist
Messages
Applies to: vehicles with Audi adaptive cruise control
II ACC with Conge stion assist: unavailable. See
owner 's manual
Th e system c annot guarantee that it w ill detec t
ve hicl es co rre ctly and it h as swit ched
off. T he ra ­
dar senso rs have s hifted o r are faul ty . D rive to an
authorized Audi dealer or authorized Audi Se rvice
Facility immediately to have t he mal function cor­
rected.
II ACC with Congestion assist: currently un­
available. Sensor v ision restricted due to sur­
roundings. See owner 's manual
T hi s message appears if the radar sensor view is
obs truc ted, for example by leaves, snow, heavy
spray or dirt. C lean the sensors ~
page 97,
fig . 90.
IIJ ACC with Congestion assist : currently un­
available. Gradient too steep
T he road exceeds the maximu m possib le grade
for safe ope ra tion. The systems c annot be swi tch ­
e d on.
IIJ ACC with Congestion assist: only available in
D, Sor M
Select the D/S o r M selector lever position .
Bl ACC with Congestion assist: currently un·
a vailable . Parking brake applied
The systems sw itch off if yo u set the pa rk in g
brake. The systems a re availab le again after you
release the pa rking brake .
IIJ ACC with Congestion assist : currently un­
available. Stabilization control (ESC ) input
This message appea rs if the Ele ct ro nic St abiliza­
tion Cont rol (ESC) is ta king a ction to s tabilize the
ve hicl e. The sys tems sw itch
o ff in this s cenar io.
IIJ ACC with Congestion assist: manual control!
This message appea rs if the veh icle rolls bac k
when starting on a slight incl ine , even thoug h the
sys tems are ac tive . P ress the b rake pedal to pre ­
ve nt the vehicle from rolling o r sta rting to move.
106
ilJ ACC with Congestion a ssist: currently un­
available. Downhill assist activated
Y ou canno t activ ate the sys te m when hill hold as­
s ist is active.
tei ACC with Congestion assist: manual control!
This message appears if the driver does not take
over steering after multiple driver i ntervention
r equests and the system sw itches
o ff . The veh icle
brakes un til it is sta tionary .
tei Congestion assist: unava ilable . See owner's
manual
The system can no longer ensu re that the vehicle
will stay in t he lane and switches
off. Have your
vehicle checked by an authorized Audi dealer o r
aut horize d Aud i Serv ice Facility if the ma lf u nc­
t ion is continuous .
II Congestion assist: Please take over steering!
This message app ears as soon as t he system
stops detect ing steering act iv ity when the system
li mits a re reached . Always keep your hands o n
t h e steer ing whee l so you can be ready to steer at
any t ime.
@ Conge stion assist: currently unavailable.
Please fasten seat belt
The system swi tches off when the drive r's safety
b elt is unfas tene d.
II ACC: efficiency as sist not available in thi s
country
The adaptation to speed lim its and rou tes ahead
i s not available in this co unt ry .
ii ACC: efficiency assist currently unavailable .
See owner's manual
The adaptation to speed lim its and routes ahead
switches off at speed limits under 20 mph
(30 km/h).
The message can also appear if the adaptation to speed limits and routes ahead has a temporary
failure. Have your vehicle checked by an a uthor­
i zed Audi dealer or author ized Audi Se rvice Facili­
ty if the malfunction is cont inuous.
Distance warning: malfunction! Please contact
Service
...

<( a, .... N ,....
N .... 0 0
3 a,
The system cannot guarantee that it will detect
vehicles correctly and it has switched off. The ra ­
da r senso rs have sh ifted o r are faulty . Drive to an
author iz ed Audi dealer or author iz ed Audi Se rvice
Faci lity immediately to have the malfunction cor­
rected .
Distance warning : currently una vailable . Sensor
v iew restricted due to surroundings. See own ­
er's manual
This message appears if the radar sensor view is
obstructed, for example by leaves, snow, heavy
spray or dirt . C lean the sensors ¢
page 97,
fig. 90 .
Distance warning: currently unavailable. See
owner 's manu al
This message appea rs if the sys tem has a tempo ­
rary fai lure. If this occ urs mult iple times, d rive to
an authorized Audi dealer or authorized A udi
Service Facility immediately to have the malfunc­
tion corrected.
ACC: Please fa sten seat belt
The system is no t comp lete ly available if the d riv ­
e r' s sea t belt is u nfastened .
Stationary object ahead
This message appears if you would like to switch
the system o n and there is a stationary object di­
rect ly in front of your vehicle.
Door open
The system is no t availab le when the door is
open .
Audi pre sense
Introduction
Applies to: ve hicles with Audi pre sense
W ith in the lim its of the system, t he pre sense
f u nctions can init iate measures in part icularly
dangerous sit uat ions to protect t he ve hicle pas ­
sengers and ot her road users.
- Because different veh icle systems such as the
ESC are i nterconnected , the
pre sense b asic in ­
t roduces p reempt ive safety meas ures for the
Assist
passengers i f an unstable driving si tuation is
detected.
- The
pre sen se front system uses the data from
the adaptive cruise contro l* radar sensors and
the camera to ca lculate the probability of a co l­
lision . With in the lim its of the system, an im­
pending co llision with vehicles can be detected
in both urba n and rural speed ranges. In t his
case, the system warns the driver visua lly,
acoust ica lly and w ith a jerk on the brakes if nec­
essary. If needed, i t can in itiate a partia l o r fu ll
dece lerat ion to reduce the collision speed or to
avoid the collision under certa in circumstances.
I n conjunction with pre sense basic/rear, the
front safety belts are a lso reve rsibly tens ioned
when needed . The pre sense front is a lso active
when adaptive cruise control* is sw itched off.
- Pre sense rear contains pre sense basic func­
tions. It uses the data from the side assist* ra ­
dar sensors and ca lculates within the limits of
the system the probability of a rear end colli­
sion with t he vehicle behind you. Pre sense rear
is also act ive when side assist* is sw itched off .
- Within the limits of the system,
pre sense city
uses the camera data and can detect an im­
pe nding collision with vehicles and pedestrians.
I n th is case , the system warns the driver visua l­
ly , acous tic ally and wit h a jerk on the b rakes if
necessary. If needed, it c an initi ate a full dece l­
erat io n to reduce the collis io n speed or to avoid
the collision under certain circumstances . In
conjunction with pre sense basic/rear, the front
safety belts are a lso reversibly tens ioned when
needed .
A WARNING
-
Read the genera l information on¢.&. in Gen -
eral information on page
97, c::> .&. in General
information on page 117 .
@ Tips
-Certa in pre sense funct ions sw itch off when
dr iving in reverse.
- The pre sense funct ions may not be availa­
ble if there is a malfunct ion in the ESC sys­
tem or t he a irbag control module .
107

<( a, .... N ,....
N .... 0 0
3 a,
increasing force within the limits of the
system
l)_ This reduces the vehicle speed in the
event of a collision. At low vehicle speeds, pre
sense front can initiate a complete deceleration
shortly before a collision with a vehicle driving
ahead
1>. If pre sense front determines that you
are not braking strongly enough when a collision
is imminent, it can increase the braking force .
The following functions trigger in conjunction
with pre sense basic/rear at corresponding vehi ­
cle speeds :
- Reversible tensioning of the front safety belts.
- Closing the windows and sunroof*.
- Inflating the side bolsters* in the seat backrest
and seat surface.
Audi drive select*: the reversible belt tensioner,
the closing of the windows and sunroof* as well
as the inflating of the side bolste rs* on the seat
backrest and seat surface are not active depend­
ing on the mode selected .
Collision avoidance assist
Collision avoidance assist helps you to steer the
vehicle around an obstacle in a critical situation.
If you avoid an obstacle after the acute warning,
then the collision avoidance supports you by ap­ plying slight steering adjustment to correct your
steering wheel angle as long as you are actively
steering. Collision avoidance assist is available at
speeds between approximately 20 mph (30 km/
h) and 90 mph (150 km/h).
Turn assist
When starting to drive and up to speeds of maxi­
mum 6 mph (10 km/h), the turn assist uses a
braking intervention to prevent your vehicle from
colliding with an oncoming vehicle when turning left or right (available in certain countries) . The
braking intervention causes your vehicle to stay
in its lane.
.8, WARNING
-Pre sense front cannot overcome the laws of
physics.
It is a system designed to assist and
1) This is not availa ble in some co untries.
Assist
it cannot prevent a collision in every circum­
stance. The driver must always intervene.
The driver is always responsible for braking
at the correct time. Do not let the increased
safety provided tempt you into taking risks .
This could increase your risk of a collis ion.
- The system can deploy incorrectly due to
system-specific limits.
- Please note that the sensors and the camera
do not always detect all objects or lane
markings . This increases the risk of an acci­
dent.
- Pre sense front does not react to people, an­
imals or objects that are crossing the vehi­
cle 's path or that are difficult to detect
c> &..
in General information on page 97.
-Reflective objects such as guard rails or the
entrance to a tunnel, heavy rain and ice can
affect the function of the radar sensors and
the system's ability to detect a collision risk.
(D Note
The sensors can be displaced by impacts or
damage to the bumper, wheel housing and
underbody. Pre sense front can be impaired
by this. Have an authorized Audi dealer or au­
thorized Audi Service Facility check their func­
tion.
(D Tips
- You can cancel the braking with increasing
force that is initiated by the system by brak­
ing yourself, by accelerating noticeably or
by swerving.
- Keep in mind that pre sense front can brake
unexpectedly. Always secure any cargo or
objects that you are transporting to reduce
the risk of damage or injury.
- Certain pre sense front functions are switch­
ed off when the ESC is limited or switched
off
c> page 135 .
109

Assist
Audi pre sense rear
Description
App lies to: ve hicles w ith Audi side assist
If the risk of a collision is detected, the following
functions can trigger:
- Reversible tensioning of the front safety belts
at the corresponding speeds .
- Closing the windows and sunroof*.
- Inflating the side bolsters* in the seat backrest
and seat surface.
- Switching on the emergency flashers with in-
creased frequency
l ).
The message Audi pre sense. ~ page 108,
fig. 104 will warn you about the danger.
Aud i drive select*: the function is not active de­
pending on the mode selected.
A WARNING
- To reduce the risk of an accident, please
note that the side assist* radar sensors do
not always detect every object.
- Pre sense rear does not react to people, ani­
mals or objects that are crossing the vehi­
cle's path or that are difficult to detect.
- Reflective objects such as guard rails, heavy
rain and ice can impair the function of the
radar sensors and the ability to detect a col­
lision risk .
(D Note
The radar sensors can be displaced by impacts
or damage to the bumper, wheel housing and
underbody. Pre sense rear can be impaired by
this . Have an authorized Audi dealer or au­
thorized Audi Service Facil ity check their func­
tion.
(0 Tips
- The pre sense rear functions switch off
when towing a trailer.
- The pre sense rear functions may also
switch off if there is a malfunction in the
side assist* system.
1> This is not ava ilab le in some co untri es.
110
Audi pre sense city
' Description
App lies to : vehicles wit h Audi pre sense city
Within the limits of the system, pre sense city
can warn you of impending collisions with
vehicles and pedestrians and initiate the applica­
ble braking maneuver if needed. Pre sense city is
active at a speed of 6 mph (9 km/h) and higher.
A pedestrian warning can occur at speeds up to 50 mph (85 km/h), and vehicle warnings can oc­
cur at speeds up to 155 mph (250 km/h). A pre
sense city braking maneuver is possible at speeds
up to 50 mph (85 km/h).
Warnings
App lies to: vehicles wit h Aud i pre sense city
The system recognizes various dangerous situa­
tions. The
early warning occurs when:
- a vehicle driving ahead brakes sudden ly,
- your own vehicle approaches a sign ificantly
slower vehicle or stationary vehicle in the direc­
tion of travel.
- a pedestrian is standing in the lane or is moving
into the lane.
When this warning occurs, it may only be possi­
ble to avo id a collision by swerving or braking
strongly. The message
Audi pre sense.
~ page 108, fig. 104 and a warning tone will
warn you about the danger.
Additionally, a jerk on the brakes may occur as an
acute warning when there is an impend ing colli­
sion . If you do not react to the acute warning, pre
sense city can brake to the point of complete de­
ce leration within the limits of the system. This
reduces the vehicle speed in the event of a colli­
sion. The message
Audi pre sense. also ap­
pears.
The following functions are triggered in conjunc­
tion with pre sense basic/rear:
- Reversible tensioning of the front safety belts .
- Closing the windows and sunroof*. ..,

<( a, .... N ,....
N .... 0 0
3 a,
-Inflating the side bolsters* in the seat backrest
and s eat surfac e.
Aud i drive select*: the function is not active de ­
pending on the mode selected.
A WARNING -,..___
-Pre sense city cannot overcome the laws of
physics. It is a system designed to assist and
it cannot prevent a collision in every circum­
stance. The driver must always intervene.
The driver is always responsible for braking at the correct time . Do not let the increased
safety provided tempt you into taking risks.
This could increase your risk of a collision .
- The system can deploy incorrectly due to
system-specific limits.
- To reduce the risk of an accident, please
note that the camera does not always detect
every object .
- Pre sense city does not react to animals,
crossing or oncoming vehicles, objects such
as bars, railings or railcars, and objects that
are difficult to detect~&.
in General infor­
mation on page 97.
A WARNING
Pre sense city may be restricted or not availa­
ble in the following example situations:
- in heavy fog, rain, spray or snow.
- when there are visual obstructions, such as
glare, reflections or var iations in light.
- when it is dark .
- if the camera window or the windshield is
dirty, iced over, damaged or covered .
- when driving on snow, ice or loose ground .
- on sharp curves.
- if the ESC was restricted or switched off .
- when towing a trailer.
- when the driver's seat belt is unfastened.
- up to ten seconds after sw itching on the ig-
nition.
1 ) Thi s is no t avail able in some c oun tries.
Assist
(D Note
Impacts or damage to the camera mount on
the windshield can displace the sensor . Pre
sense city can be impaired by this. Have an au­
thorized Audi dealer or authorized Audi Serv­
ice Facility check their function .
(i) Tips
-You can cancel the system braking interven­
tion if you accelerate considerably or swerve
away .
- Keep in mind that pre sense city can brake
unexpectedly. Always secure any cargo or
objects that you are transporting to reduce
the risk of damage or injury.
- When there is a malfunction in the camera,
the pre sense city functions also switch off.
Settings in the
Infotainment system
Applies to: vehicles with Aud i pre sense
.,. Select in the Infotainment system: I MEN U! but­
ton
> Vehicle > left control button > Driver as­
s ist > Audi pre sense.
Audi pre sense-
switch On/Off. You can switch
the pre sense functions on and off with th is.
If the system is switched off, it switches on again
automatically once the ignition is switched on
again
l ).
Early warning1
) -the early warning can be
switched off or the pre sense city/front warning
point
( Early /Mediu m/La te) can be set .
Driver messages
Applies to: vehicles with Aud i pre sense
fll Audi pre sense currently restricted. Restrict­
ed sensor vision due to surroundings. See own­
er's manual
This message appears if the radar sensor and
camera view is obstructed, for example by leaves,
snow, heavy spray or dirt . If necessary , clean the .,..
111

_& WARNING
The exit warning system is subject to limita­
tions and cannot warn you before every im­
pending collision:
- If the vehicle is too wide for the parking
space and covered by the neighboring
vehicles.
- Approaching objects or people such as cy­
cl ists o r skateboarders may not be detected
under certain circumstances.
- The system does not react to stationary ob­
jects.
- The view of the radar sensors may be im­
paired by leaves, snow, heavy spray or d irt.
Clean the area in front of the sensors
r:!vpage 116, fig. 112.
(D Note
Also read this information ¢0 in General in­
formation on page 117.
@ Tips
- The ex it warning system is switched on and
off through the side assist¢
page 117.
-The display brightness for the exit warning
system cannot be adjusted.
- The system is not available when towing a
trailer.
Rear cross-traffic assist
A ppl ies to: vehicl es with rear cross-traffic assist
Fig. 115 Example display
Assist
Fig. 116 Infotainment system: rear c ross -tra ffic assist dis­
play
The rear cross-traffic ass ist can warn the driver of
a potential collision with approach ing cross-traf­
fic when driving in reve rse. Within its limits, the
system monitors the areas behind and next to
the vehicle using the radar sensors when leaving
a parking space
r:!vpage 116, fig. 112. Moving ob­
j ects that are approaching, such as cars, are de­
tected
¢ fig. 115.
If the system detects critical cross traffic when
backing out of a parking space, it wi ll react as fol­
lows:
- Visual indicator : an indicator appears in the In­
fotainment system disp lay with a red arrow
symbo l. The arrow points in the direction from
which the object is approaching
¢fig. 116.
-Audible warning signal: a continuous tone may
sound as an additional indicator when driving in
reverse.
- Automatic brake activation : a brief activation
of the brakes may also warn you of a potent ial
collision with an approaching object.
Requirements for using the rear cross-traffic
assist :
-The parking aid m ust be switched on
¢page 124.
-Reverse gear m ust be engaged.
- The speed must not be higher than approxi-
mate ly 9 mph (15 km/h).
A WARNING
- The rear cross-traffic assist is an assist sys­
tem and cannot prevent a co llision by itself.
The driver must always intervene. The driver
is always responsible for braking at the cor-
rect time .
~
119