2015 AUDI A4 brake sensor

14 Instruments and warning/indicator lights
TPMS
smsoR
Electronic Stabilization Control
( ES C) ./
¢page 18
Electronic Stabilization Control
(ESC)
¢ page 185
USA models:
Anti-lock braking system (ABS)
defective ./
¢ page 19
Canada models:
Anti-lock braking system (ABS)
defective ./
¢ page 19
USA models:
Safety systems ./
¢page20
Canada models:
Safety systems ./
¢ page20
Worn brake pads
¢ page 20
E lectromechanical parking brake
¢ page 16
T ire pressu re monitoring
system ./
¢ page258
Tire pressure monitoring system
¢page258
E lectronic power control./
¢ page20
Malfunction indicator Lamp
(MIL) ./
¢ page 20
Engine speed limitation
¢ page20
Engine oil leve l
¢ page 17
Engine oil sensor
¢page 21
Battery
¢ page 16
Tank system
¢ page 21 Warm
up eng ine*
¢ page208
Windshield washer fl uid leve l
¢page21
Windshield wipers
¢page 21
Remote control key
¢page85
Battery in remote control key
¢page33
Defective light bulb warning
¢ page21
Fog lights
¢page 21
Rear fog light(s)*
¢page21
Headligh t range control*
¢page21
Adaptive light*
¢page22
Light-/rain sensor *
¢ page22
Adaptive dampers*
¢page22
Sport differential*
¢page22
I gnition lock
¢page 22
Steering column lock
¢page 18
Electromechanical steering, dy­
namic steering *./
¢pag e 190
Transmission
- mult itronic, t iptron ic
¢page99
- S tronic
¢ page 99
Transmission
- S tronic
¢ page 99

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Audi adaptive cruise control and braking guard 101
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 . This he lps to make driv­
ing more comfortable on long highway
stretches.
The braking guard system can warn you about
an impending collision and initiate braking
maneuvers
c::;, page 107.
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. 113 Front of the vehicle: Position of radar sensor
The area that contains the radar sensor
c::;, fig. 113 must never be covered by stickers
or other objects or obstructed with dirt, in­
sects, snow or ice that will interfere with the
adaptive cruise control system and braking
guard. For information on cleaning, refer to
c::;, page 202. The same applies for any modifi­
cations made in the front area . The
function of the adaptive cruise control
system and braking guard is limited under
some cond itions:
- Objects can only be detected when they are
within sensor range
.:!>page 103 , fig. 116.
-The system has a limited ability to detect
objects that are a short distance ahead, off
to the side of your vehicle or moving into
your lane.
- Some kinds of vehicles 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 all.
- When driving through curves
c::;, page 102.
-Stationary objects c::;, page 102.
A WARNING
-Always pay attention to traffic when adap-
tive cruise control is switched on and brak­ ing guard is active. As the dr iver, you are
still respons ible for start ing and for main­
tain ing speed and distance to other ob­
jects. Braking guard is used to assist you.
The driver must always take action to avoid
a collision. The driver is always responsible
for braking at the correct time.
- Improper use of adaptive cruise con trol
can cause collisions, other accidents and
serious personal injury .
- Never let the comfort and convenience
that adaptive cruise control and braking
guard offer d istract you from the need to
be alert to traffic conditions and the
need to remain in fullcontrolofyourve­
hicle at all times,
- Always remember that the adaptive
cru ise contro l and braking guard have
limits -they will not slow 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
moving, such as vehicles stopped in a
traffic jam, a stalled or disabled vehicle.
If registered by the radar sensor, vehicles
or obstacles that are not moving can
trigger a collision warning and if .,.

102 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 . 114 Examp le: driv ing into a curve
When driving into a curve ~ fig. 114 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. 115 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 examp le,
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.

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Audi adaptive cruise control and braking guard 107
Setting the driving mode for vehicles with
Audi drive select*
Refer to <=> page 116.
(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. 122 Inst rumen 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<=>
fig. 122:
- 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. 123 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
r=.> fig. 123. 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. ~

108 Audi adapti ve cruise control and br aking guard
- If a co llision is imminent, the system will
first provide an
acute wa rning 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 collis ion.
- 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 function s can be contr oll ed ?
You can switch braking g uard and the dis­
tance/approach warning on or off in the radio
or MM I c> poge 108, Settings in the radio/
MMI.
A WARNING
Lack of attention can cause col lisions, oth­
er accidents and serious persona l injuries.
The b raking guard is an assist system and
cannot p revent a col lis ion by itself. The
dr iver m ust always in tervene . T he d rive r is
always responsib le for br aking at the cor­
rect time.
- Always pay close attention to traffic,
even when the bra king 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 wo rks 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 109.
- Keep in mind that brak ing 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 > Driver a ssist> Audi brak ­
ing guard .
Or
., Select: !CAR I function button> Audi b raking
gua rd.
S ys tem -
Switch A udi braking guard On and
Off . When you switch the ignition on, the
message
Audi b raking guard 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.

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Audi adaptive cruise control and braking guard 109
-If you restrict or switch off the ESC, the
braking guard also switches itself off
¢page 187.
- Switch braking guard off when you are
loading the vehicle onto a vehicle carrier,
tra in, ship or other type of transporta­
tion. This can prevent undesired warn­ i ngs from the braking guard system.
Messages
App lies to vehicles: with Audi adaptive cruise co ntrol
Braking guard: Off
This driver message appears if the system is
turned off via the radio/MM!*. Otherwise, if
the system is turned off, the information ap­ pears every time shortly after the start of the
tr ip.
The driver message also appears if the system is not avai lab le due to a malfunction or if the
ESC is not switched on¢
page 187. If this is
the case, the system will not provide warnings
about a possible collision.
Braking guard: Activated
This driver message appears if sharp brake
press ure was applied due to an acute warning.
•••
Three wh ite dots appear if a setting cannot be
selected with the operat ing lever . For exam­
p le , this happens if you want to raise/lower
the speed even though there was no previous­
l y saved speed .
ACC: Deactivation
The driver message appears in vehicles with
manual transmission . If the clutch pedal was
pressed down for too long, the adaptive cruise
control turns off . A chime sounds as a rem ind­
er .
ACC: Sensor blocked
This message appears if the sensor view is ob ­
structed, for example by leaves, snow, heavy
spray or dirt. Clean the sensor¢
page 101,
fig. 113.
ACC: not available
The driver message appears if there is a mal­
function . The adaptive cruise contro l turns off .
A chime sounds as a reminder. Have the sys ­
tem checked by an authori zed Aud i dea ler or
authorized Aud i Service Fac ility.
ACC: unavailable
The driver message appears if, for example,
the brake temperat ure is too high. The adap­
tive cruise control is temporarily unavailable .
A chime sounds as a reminder.
Engine speed!
This driver message appears in vehicles with
manua l transmission if the driver had not up­
shifted or downs hifted in time while using
adaptive cruise control braking or accelerat­
ing, caus ing the vehicle to exceed or no t reach
the permitted limit speed. The adaptive cruise
control turns off. A chime sounds as a remind­
er .
Shift lever position!
Vehicles with an automat ic transmission: the
driver message appears if the selecto r lever is
shifted to the N position. Th e adaptive cruise
control is no t available while in this position.
Vehicles with manua l transm ission: the driver
message appears for vehicles with manual
transmission if there is no forward gear en­
gaged, meaning if the reverse gear or the 1st
gear is engaged or if the selector leve r is in
the neutral position . The adaptive cr uise con­
trol is not available while in th is position.
Stabilization control (ESC)
This message appears if the electronic stabili­
z ation control ( ESC) is taking action to stab i­
lize the vehicle. The adaptive cruise contro l
turns off. A chime sounds as a reminder .
Speed too low
This message appears if the current speed is
too low
to set or to maintain the desired
speed .
The speed be ing saved must be at least
20 mph (30 km/h). The cruise control is
turned off for speeds lower than 12 mph

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Vehicl e ca re a nd cl eanin g 203
& WARNING
-Only wash the vehicle when the ignition
is off and follow the instructions from
the car wash operator to reduce the risk
of accidents.
- To reduce the risk of cuts, protect your­
self from sharp meta l components when
washing the underbody or the inside of
the wheel housings.
- After washing the vehicle, the braking ef­
fect may be delayed due to moisture on
the brake rotors or ice in the winter . The
brakes must be dried first with a few
careful brake applicat ions .
{[) Note
-If you wash the vehicle in an automatic
car wash, you must fold the exterior m ir­
rors in to reduce the r isk of damage to
the mirrors . Power folding exterior m ir­
ro rs* must only be folded in and out us­
i ng the power folding function.
- To prevent pa int damage, do not wash
the veh icle in direct sunl ight. -
To reduce the r isk of damage to the sur­
face, do not use insect removing spong­ es, kitchen sponges or similar items.
- Matte finish painted vehicle compo­
nents :
- To reduce the risk of damage to the
surface, do not use polishing agents or hard wax.
- Never use car wash cycles that apply
protective wax.
It can destroy the
matte fi nish effect.
- Do not place any stickers or magnet ic
signs on vehicle parts painted w ith
matte fi nish paint. The paint cou ld be
damaged when the stickers o r magnets
are removed.
@ For the sake of the environment
Only wash the vehi cle in facilities spec ial ly
designed for that purpose . This will red uce
the risk of dirty water contam inated with
oil from entering the sewer system.
Cleaning and care information
When clean ing and caring for individua l vehi­
cle components, refer to the fo llow ing tab les .
The informa tion contained there is s imply rec­
ommendations. For questions or for compo- nents that are not listed
, refer to an author­
ized Audi dea ler or qua lified workshop. A lso
fol low the information fo und in ¢ ,&. .
Cleanin g exte rior
Component Situation Solution
Wiper blade s
Dirty ¢ page 5 6, Cleaning windshield wiper blades
Hea dlight s/ Dirty Soft sponge with a mild soap solution a>
t a il light s
Sen sors /
Dirty Sensors: soft cloth with a so lvent-free cleaning product
came ra lens es Camera lenses: soft cloth with an alcohol-free cleaning
solution
Snow/ice Hand brush/so
lvent-free de-icing spray
Wheels Road sal t Water
Brake d ust Acid-free special cleaning so
lution
Ex haust tail Road sa lt Water, cleaning solut io n suitable for sta inless steel, if
pipe s necessary
•
•

2 70 Fuses and bulbs
No. Consumer Amps No. Consumer Amps
A/C system pressure sensor, Two-door models: rear left
electromechanical parking window regulator; Four-
brake, Homelink, automatic 11 door models: rear
left door
30
3 dimming interior rear view
5 (window regulator, central
m irror, air quality/outside locking, switch, lighting)
air sensor, Electronic Stab ili-
12 Rain
and light sensor
5
zation Control (button)
5 Sound actuator 5
Fuse panel© (red)
6 Headlight
range control/
5/7,5
head light (corner ing light)
No . Consumer Amps
3 Lumbar support 10
7 Headlight (cornering light) 7,5
4 Dynamic steering
35
Contro l modu les (electro-
5 Interior lighting (Cabriolet)
5
8 mechanical parking brake,
5
shock absorber, quattro
sport), DCDC converter
9 Adaptive cruise control 5 6
W
indshield washer system,
35
headlight washer system
7 Vehicle electrical system
20
control module 1
10 Shift gate/clutch sensor
5
11 Side ass ist 5
8
Vehicle electr ica l system
30
control module 1
12 Headlight range control,
5
parking system 9 Left rear window regulator
7,5/20
motor (Cabriolet)/sunroof
13 Airbag 5
14 Rear wiper (allroad) 15 10
Vehicle e
lectrica l system
30
control module 1
15 Auxiliary fuse (instrument
10
pane l) 11 Right
rear window regulator
7,5/20
(Cabriolet)/sun shade motor
16 Aux
iliary fuse terminal 15
40
(engine area) 12 Anti-theft alarm warning
s system
Fuse panel
@ (brown)
No. Consumer Amps
2 Brake light sensor 5
3 Fuel pump 25
4 Clutch sensor 5
5 Left seat heating with/with-
15/30
out seat ventilation
6 Electronic Stabilization
Con-
5
trol (electric)
7 Horn 15
Front left door (window reg-
8 ulator, centra
I locking, mi r-
30
ror, switch, lighting)
9 Windshield wiper motor 30
10 Electronic Stabi
lization Con-
25
trol (valves)