ESP AUDI A4 2008 B8 / 4.G Service Manual

adaptive cruise control (ACC) 142Applies to vehicles: with adaptive cruise controlStationary vehiclesIf a vehicle detected by the ACC system turns off or changes lane
and another stationary vehicle is located in front of that vehicle, the
ACC system will not react to the stationary vehicle ⇒fig. 154 and
⇒fig. 155.
Audi braking guardApplies to vehicles: with adaptive cruise controlDescription
Audi braking guard warns you in case of an impending
collision with a vehicle in front.Audi braking guard is active at speeds above approximately 30 km/h
and operates within the system limitations ⇒page 140 even when
the adaptive cruise control is deactivated.
The radar sensor is fitted at the front of the vehicle ⇒page 130,
fig. 137. The system requires reflecting surfaces in order to be able
to measure the distance. If the ACC is unable to measure the
distance it will not respond.
Once the system has measured the distance, it can assess a
dangerous situation where a vehicle in front brakes suddenly or you
are driving fast and approach a vehicle travelling at a much slower
speed. The system warns you as soon as it anticipates that a poten-
tial collision with the vehicle in front can only be avoided by hard
braking or by taking evasive action.
The system has a preset response time so that it can warn you in
time. In certain situations, the system response time will be reduced
dynamically, e.g. when you are accelerating onto a motorway.
Braking, lateral acceleration and steering angle are other factors
Fig. 154 Vehicle
turning off and vehicle
stationaryFig. 155 Vehicle
changing lane and
vehicle stationary
Fig. 156 Instrument
cluster: Display
document_0900452a81b1b9de.book Seite 142 Donnerstag, 26. Juli 2007 9:16 09

adaptive cruise control (ACC)143
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data which can shorten the system response time. The warning will be
deactivated if you press the accelerator pedal right down in order to
overtake.
The system draws the driver's attention to two different hazardous
situations:
Distance !
A distance warning will be given if you travel too close to the vehicle
in front for longer than 5 seconds. For example, if the distance is
less than 9 m at 80 km/h, a message will appear in the instrument
cluster display ⇒page 142, fig. 156.
If the vehicle in front were to brake hard, a collision would no longer
be avoidable, even if you reacted immediately. In this case, you
should leave more room between your car and the vehicle in front.
Speed
If the vehicle in front of you is travelling in the same lane at a much
slower speed or if it brakes hard, the Audi braking guard will calcu-
late the time at which a collision can be avoided only by emergency
braking or evasive action. When the system warns you, it is possible
to avoid a potential collision with the vehicle in front by braking or
changing lane. There are two warning levels:
•
Early warning: A message will appear in the instrument cluster
display and you will also hear a warning tone.
•
Acute warning: The second (acute) warning will be triggered if
you do not react to the advance warning. There will automatically be
a short dab of the brakes to remind you to concentrate on the traffic.
If you brake hard, the brake assist system ⇒page 222 helps you to
achieve the optimum braking effect.
WARNING
Please always direct your full attention to the road, even when the
Audi braking guard is activated. It is always you who is responsible for determining your speed and for keeping a safe distance to the
other vehicles on the road.
•
Always maintain the statutory minimum safety distance to the
vehicle in front (risk of accident).
•
Due to the system limitations, the Audi braking guard will not
react in certain situations, for example when approaching a
stationary obstacle (such as the end of a traffic jam or a broken-
down vehicle).
•
Please note that the Audi braking guard is subject to limita-
tions in tight bends on account of the radar sensor's field of vision.
This means that obstacles may not be detected in certain situa-
tions.
•
The radar sensor's "field of vision" can be impaired by rain,
snow or a lot of water on the road. This results in vehicles not
being reliably recognised or, in some circumstances, not being
detected at all. Always keep the road ahead within your field of
vision.
•
Reflecting objects, such as crash barriers or the entrance to a
tunnel, could impair the function of the radar sensor.
Applies to vehicles: with adaptive cruise controlStatus messages in the instrument cluster displaybraking guard brake jolt
This driver message appears when the brakes are dabbed due to an
acute warning.
braking guard off
This driver message appears when the system is switched off in the
MMI. The message also appears briefly after you begin driving if the
system is switched off.
WARNING (continued)
document_0900452a81b1b9de.book Seite 143 Donnerstag, 26. Juli 2007 9:16 09

adaptive cruise control (ACC) 144The message will also appear if the system is unavailable due to an
error or if you switch the ESP off ⇒page 222. In this state, the
system no longer warns you about an impending collision.Applies to vehicles: with adaptive cruise controlSettings for Audi braking guard
The system and warning settings can be adjusted via the
sound system or MMI*.– Select: Function selector button > Audi braking
guard.•
System - The Audi braking guard system can be switched on and
off.
•
Early warning - The acoustic signals and display messages can
be switched on and off.Note
The settings are stored on the remote control key in use. When you
pass the key on to somebody else please remember to make the
other driver aware of the Audi braking guard settings ⇒page 43.
Fig. 157 Display: Audi
braking guard
CAR
document_0900452a81b1b9de.book Seite 144 Donnerstag, 26. Juli 2007 9:16 09

Audi lane assist145
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Audi lane assistAudi lane assistApplies to vehicles: with lane assistDescription
The lane assist system assists the driver in keeping the
vehicle in the right lane.The system uses a camera to detect the markings of the lane you are
driving in. If the vehicle approaches one of the detected lane mark-
ings, the steering wheel vibrates to warn the driver that the vehicle
might be about to cross one of the markings. The lane assist system
is functional when it has detected lane markings on both sides of
the lane you are driving in. The green lamp
 in the instrument
cluster indicates that the function is activated and fully functional.
If you operate the turn signal before crossing one of the lane mark-
ings (while the lane assist system is functional), the system will
detect that the lane change is intended and will not warn the driver.
As the system is designed for driving on motorways and other major
roads, it is only active above a speed of about 65 km/h.
WARNING
•
The lane assist system does not keep the vehicle in its lane. It
merely warns the driver when the vehicle is in danger of crossing
the markings of the lane. As the driver you are always responsible
for staying in your own lane.
•
The camera cannot detect all lane markings. Therefore it is
possible that variations in the road surface or objects might be
detected as lane markings, which can lead to false warnings, or
warnings not being given.
•
The camera's view might be obstructed, for example by vehi-
cles travelling in front, rain, snow, a lot of water on the road or adverse light. This can result in the system not detecting the lane
markings correctly.
Applies to vehicles: with lane assistSwitching on and off– Press the button ⇒fig. 158 -arrow- to switch the system
on and off. The indicator lamp

in the instrument
cluster will light up or go out.
WARNING (continued)
Fig. 158 Turn signal
lever: Pushbutton for
Audi lane assistFig. 159 Windscreen:
Camera window for
Audi lane assist
document_0900452a81b1b9de.book Seite 145 Donnerstag, 26. Juli 2007 9:16 09

Audi side assist 150
Switching on
– Press the button ⇒page 149, fig. 165. The red indicator
lamp in the button will light up.
Switching off
– Press the button again. The indicator lamp in the button
will go out.The system is designed to provide assistance on motorways and
other out-of-town roads, so it only operates at speeds above about
60 km/h.
WARNING
•
Please note that the sensors are not always able to detect all
vehicles which may represent a potential hazard (accident risk).
•
Please note that the side assist is not able to give adequate
warning of vehicles approaching very fast from behind, or vehicles
that you are overtaking rapidly.
•
The radar sensor's "field of vision" can be impaired by rain,
snow or a lot of water on the road. This results in vehicles not
being reliably recognised or, in some circumstances, not being
detected at all by the side assist. Always give your full attention to
the position of your vehicle on the road and other nearby traffic.
•
The side assist only gives a warning of approaching vehicles
and vehicles in the blind spots when road speed is above 60 km/h.
•
Please note that the side assist does not operate in tight bends
(with a radius of less than 200 metres).
•
The side assist feature is not a substitute for the full concentra-
tion of the driver. The driver is always responsible for the safety of
lane changes and other manoeuvres. Always give your full atten-
tion to the position of your vehicle on the road and other nearby
traffic.
Caution
•
To avoid impairing the function of the side assist, do not attach
any objects (e.g. stickers or bicycle carriers) in such a way that they
might interfere with the radar sensors in the rear bumper.
•
Make sure that the warning lamps on the exterior mirrors are not
obscured by stickers or other objects.Note
•
To ensure that the side assist function works properly, do not
allow snow and ice to accumulate on the rear bumper near the radar
sensors. Please observe the additional notes on ⇒page 157.
•
The side assist function will be switched off automatically when
the electrical connector for the trailer socket is plugged in on vehi-
cles with a factory-fitted towing bracket.
•
The side assist should be switched off manually when towing a
trailer if the vehicle is equipped with a towing bracket which was not
factory-fitted.
•
The side assist system will switch off automatically if it detects
an obstruction that impairs the function of the radar sensors.
•
The warning lamps on the exterior mirrors may not be properly
visible if tinted foil is affixed to the side windows on the driver's or
passenger's side.
document_0900452a81b1b9de.book Seite 150 Donnerstag, 26. Juli 2007 9:16 09

Audi side assist151
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with side assistArea covered by the radar sensorsThe area covered by the radar sensors ⇒fig. 166 consists of:•
The rearward approach zone (light green area: up to about 50
metres) and
•
Blind spots (dark green area) .
The radar sensors monitor the lanes immediately to the left and
right of your vehicle. Other lanes are not covered by the sensors.Note
The side assist system is programmed for lanes of a fixed width, and
is not able to measure differing lane widths. It monitors a zone
equivalent to one normal lane width on either side. If the lanes are
narrower than this, or if vehicles are not travelling in the centre of
the lanes, the system may register vehicles that are not in fact trav-
elling in an adjacent lane ⇒page 156.Applies to vehicles: with side assistHow the system worksWhen other vehicles are detected, the side assist system registers
their distance and how fast they are approaching. The warning lamp on the relevant exterior mirror will light up whenever the side assist
calculates that the distance and the speed differential of
approaching vehicles would be critical in the event of a lane change.
The warning lamp may light up when you are being overtaken and
when you are overtaking another vehicle.
If you are overtaking slowly, with a speed differential of less than
15 km/h, the warning lamp will light up as soon as the other vehicle
enters your blind spot and is detected by the sensors. If you are
overtaking with a speed differential which is greater than this the
lamp will not give a warning.
Applies to vehicles: with side assistInformation mode and warning modeThe side assist has two modes of operation•
The information mode and
•
The warning mode
The side assist will respond in the appropriate mode, depending on
whether or not you operate the turn signal to indicate an intended
lane change.
Information mode
As long as you do not operate the turn signal, the side assist will
merely inform you of the presence of vehicles that it has detected
and judges to be critical in the event of a lane change. The warning
lamp on the relevant exterior mirror will light up with low intensity
whenever the side assist calculates that the distance and the speed
differential of an approaching vehicle are critical.
The intensity of the warning lamp in this information mode is delib-
erately kept relatively low, so that it does not distract you while you
are looking at the road in front and do not intend to change to a
different lane. The information mode is clearly visible when you look
in the exterior mirror.
Fig. 166 Schematic
diagram: Area covered
by the radar sensors
A1
A2
document_0900452a81b1b9de.book Seite 151 Donnerstag, 26. Juli 2007 9:16 09

Audi side assist 156Applies to vehicles: with side assistWhen driving through bendsThe side assist cannot detect vehicles in tight bends (with a radius
of less than 200 metres).
When driving through a bend, the side assist may react to a vehicle
that is two lanes away and activate the warning lamp in the exterior
mirror.Applies to vehicles: with side assistLane widthsThe side assist system is designed to cover adjacent lanes of normal
width on both sides of your vehicle (left and right), regardless of whether you are driving directly in the centre of your lane or further
to one side.
If the lane widths are reduced, the sensors may also detect vehicles
in additional lanes, especially if you are driving further to one side
of your lane ⇒fig. 173. In such situations the system may react to
vehicles travelling two lanes away, so that the side assist activates
the information or the warning mode.
Similarly, if the lanes are very wide, it is possible that the system
may not detect vehicles in the adjacent lane because they are
outside the area covered by the sensors.
NotesApplies to vehicles: with side assistMessages in the instrument cluster displayShould the side assist be deactivated automatically, the indicator
lamp in the button will go out and a message will appear in the
instrument cluster display:
Audi side assist not available: sensors blocked
The sensors, which are not externally visible, are incorporated on
either side of the rear bumper ⇒page 149, fig. 163. To ensure the
proper function of the side assist system, do not attach any objects
(such as stickers or bicycle carriers, etc.) to the rear bumper in such
a way that they might obstruct these sensors. Should the function
of the system be impaired, the instrument cluster display will show
this message. Please check whether anything is obstructing the
sensors and remove the obstruction if necessary.
Audi side assist currently not available
The side assist is temporarily inoperative and cannot be switched
on (for instance if the battery is not sufficiently charged).
Fig. 172 Lanes of
normal width are
covered by the sensorsFig. 173 Narrow lanes:
side assist may react
to vehicles travelling
two lanes away
document_0900452a81b1b9de.book Seite 156 Donnerstag, 26. Juli 2007 9:16 09

Audi side assist157
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data Audi side assist: system fault
The system should be checked by an Audi dealership or other qual-
ified workshop.
Audi side assist not available when towing
On vehicles with a factory-fitted towing bracket the side assist func-
tion will be switched off automatically when the electrical connector
for the trailer is plugged in, and this message will appear in the
instrument cluster display. The side assist function may not be
switched off automatically if the towing bracket is not of the factory-
fitted type.
Applies to vehicles: with side assistSafety notesThe function of the side assist can be restricted when driving in
tight bends or over crests and in bad weather conditions.
It is possible that the radar sensors may register objects such as
high or offset roadside barriers as well as other vehicles.
The side assist system is programmed for lanes of a fixed width, and
is not able to measure differing lane widths. It monitors a zone
equivalent to one normal lane width on either side. If the lanes are
narrower than this, or if vehicles are not travelling in the centre of
the lanes, the system may give a warning for vehicles which it
judges to be critical, even though they are not in fact travelling in an
adjacent lane.
WARNING
•
Please note that the sensors are not always able to detect all
vehicles which may represent a potential hazard (accident risk).
•
Please note that the side assist is not able to give adequate
warning of vehicles approaching very fast from behind, or vehicles
that you are overtaking rapidly.
•
The radar sensor's "field of vision" can be impaired by rain,
snow or a lot of water on the road. This results in vehicles not
being reliably recognised or, in some circumstances, not being
detected at all by the side assist. Always give your full attention to
the position of your vehicle on the road and other nearby traffic.
•
The side assist only gives a warning of approaching vehicles
and vehicles in the blind spots when road speed is above 60 km/h.
•
Please note that the side assist does not operate in tight bends
(with a radius of less than 200 metres).
•
The side assist feature is not a substitute for the full concentra-
tion of the driver. The driver is always responsible for the safety of
lane changes and other manoeuvres. Always give your full atten-
tion to the position of your vehicle on the road and other nearby
traffic.Caution
To avoid impairing the function of the side assist, do not attach any
objects (e.g. stickers or bicycle carriers) in such a way that they
might interfere with the radar sensors in the rear bumper.
Note
For reasons of safety, the side assist system must be checked by a
qualified workshop if the positions of the radar sensors have been
affected by a rear-end collision, etc.Applies to vehicles: with side assistConformity certificationThe side assist employs radar sensors operating in one of two
frequency bands at 24 GHz. Please note that in some countries only
one of these two frequency bands is permitted. Accordingly, the
frequency band permitted in the country where the vehicle is being
WARNING (continued)
document_0900452a81b1b9de.book Seite 157 Donnerstag, 26. Juli 2007 9:16 09

Audi drive select159
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Audi drive selectAdjusting the vehicle set-upApplies to vehicles: with Audi drive selectIntroductionAudi drive select allows you to use different set-ups on your vehicle.
Using the three modes COMFORT, AUTO and DYNAMIC, you can
change the set-up at the press of a button for a more comfort-
oriented or dynamic drive.
On vehicles with MMI*, you also have the INDIVIDUAL* mode, which
allows you to adapt the vehicle set-up individually to your personal
driving style. For example, you might choose to combine a more
dynamic engine set-up with a lighter steering response.Applies to vehicles: with Audi drive selectDescriptionThe possible vehicle set-up in each mode depends on which equip-
ment is installed on your vehicle. The engine and the servotronic
power steering are basic parts of your vehicle which are always
included in the set-up. In addition, you can change the characteris-
tics of the automatic gearbox*, dynamic steering* and suspension
control*.
The response of the engine and automatic gearbox* to accelerator
pedal movements will be more spontaneous or balanced,
depending on which mode you select.
The servotronic power steering ⇒page 225 will also respond to
different drive set-ups.
The dynamic steering* alters the steering ratio depending on the
road speed to optimise the amount of steering effort required by the
driver at any given time. This enables the sensitivity of the steering to be reduced at higher speeds in order to improve the handling of
the vehicle. The steering is more direct at lower speeds to minimise
the amount of steering effort required by the driver, e.g. when
manoevring in tight spaces. The dynamic steering* also provides a
more agile steering response at low and medium speeds. You can
adjust the basic characteristics of the steering in the Audi drive
select menu.
The suspension control* uses sensors to collect information on
steering movements, braking and acceleration input by the driver,
road surface quality, road speed and vehicle loading. Using this
information, the suspension can be adapted almost instantane-
ously to changing driving conditions. With Audi drive select, the
driver can choose between dynamic and comfort-oriented suspen-
sion set-ups (DYNAMIC and COMFORT modes), or opt for a more
balanced set-up (AUTO mode).
The following table provides an overview of the characteristics in
each driving mode.
If your vehicle is equipped with dynamic steering*, the servotronic
power steering settings are adjusted in the Dynamic steering*
menu.
Systems
COMFORT
AUTO
DYNAMIC
Engine or
engine/gearbox*
Balanced
Balanced
Dynamic
Steering
Comfortable
Balanced
Dynamic
Dynamic steering*
Comfortable
(indirect)
Balanced
(direct)
Dynamic
(direct)
Suspension control*
Comfortable
Balanced
Dynamic
document_0900452a81b1b9de.book Seite 159 Donnerstag, 26. Juli 2007 9:16 09

Audi drive select 160
Note•
You can select the sport program for gear changes on vehicles
with an automatic gearbox* by activating the DYNAMIC mode. There
is no S position on the selector lever.
•
You may hear a noise on vehicles with dynamic steering* when
you start or stop the engine. This is no cause for concern.
Applies to vehicles: with Audi drive selectSelecting the driving mode
You can choose between COMFORT, AUTO, DYNAMIC and
INDIVIDUAL*.
The control is next to the selector gate ⇒fig. 174 on vehi-
cles with sound system, or in the centre console ⇒fig. 175
on vehicles with MMI*.
– Switch on the ignition.
– Press the left or right arrow button until the desired
mode lights up in red.You can change the driving mode while the vehicle is stationary or
moving. If traffic conditions permit, take your foot off the acceler-
ator briefly after you change the mode so that the new mode is also
activated for the engine.
COMFORT
The COMFORT mode alters the vehicle set-up for a more comfort-
able ride. The response of the engine and automatic gearbox* to
accelerator pedal movements is balanced. The steering is light and
indirect* and the suspension control* is set to soft. This setting is
suitable for driving long distances on motorways for example.
AUTO
The overall impression in AUTO mode is of a comfortable but
dynamic ride. This setting is suitable for everyday use.
DYNAMIC
DYNAMIC gives the vehicle a tighter set-up. The engine reacts spon-
taneously to accelerator pedal movements and the steering is
dynamic and direct*. The suspension control* is stiffer and the
automatic gearbox* changes gear at higher engine speeds. This
setting is ideal for performance driving.
INDIVIDUAL*
You can configure this mode on the MMI according to your personal
preferences.
Fig. 174 Selector gate:
Control for Audi drive
selectFig. 175 Centre
console: Control for
Audi drive select
document_0900452a81b1b9de.book Seite 160 Donnerstag, 26. Juli 2007 9:16 09