2008 AUDI A4 sensor

adaptive cruise control (ACC) 140Setting the driving program
In the Driving program menu you can select either dynamic,
standard or comfort according to your personal preferences.
Note
•
We recommend you to leave the warning tone switched on. Even
when the warning tone is switched off, not every warning tone will
be deactivated.
•
When you pass the key on to somebody else please remember to
make the other driver aware of the ACC settings.
•
We recommend a minimum distance setting of DISTANCE 3
(factory default setting).
•
When the ignition is switched off, the distance setting reverts to
the factory default DISTANCE 3. A qualified workshop can cancel
this function. In this case a default distance setting defined on the
sound system or MMI* is applied each time the engine is started.
System limitationsApplies to vehicles: with adaptive cruise controlGeneral notes
The following situations could impair the function of the
radar sensor.The adaptive cruise control is subject to given physical limits and
also has certain limits determined by the system itself. Under
certain circumstances the driver may feel that the ACC system is
responding unexpectedly or belatedly. For this reason, please
always give your full attention to road traffic and if necessary take
action yourself:•
When driving through bends ⇒page 140.
•
When vehicles in front are not in line with your vehicle
⇒page 141.
•
When other vehicles change lanes ⇒page 141.
•
When other vehicles are not clearly discernible ⇒page 141
•
When vehicles are stationary ⇒page 142.
WARNING
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 in front not
being properly recognised or, in some circumstances, not being
detected at all. If necessary, take action yourself!Applies to vehicles: with adaptive cruise controlWhen driving through bends
Fig. 149 Driving into a
bendFig. 150 Driving out of
a bend
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adaptive cruise control (ACC)141
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data Driving into a bend
When you are driving into a bend, the ACC system may react to a
vehicle travelling in the other lane and therefore brake the vehicle
⇒page 140, fig. 149. You can override the braking effect by pressing
the accelerator.
Driving out of a bend
When you are driving out of a long bend, the ACC system may - in
the course of its calculation of the lane ahead - react to a vehicle
travelling in the other lane and therefore brake the vehicle
⇒page 140, fig. 150. You can override the braking effect by pressing
the accelerator.
Applies to vehicles: with adaptive cruise controlVehicles in front travelling out of lineVehicles in front which are not in line with your vehicle cannot be
detected by the ACC system until they are within the range of the
sensor.
Applies to vehicles: with adaptive cruise controlOther vehicles changing lanesVehicles which are very close to you when they move onto your lane
cannot be detected by the radar sensor until they move into its
range.Applies to vehicles: with adaptive cruise controlNot clearly discernible vehiclesVehicles that are not clearly discernible, e.g. a motorcycle travelling
in front of you and vehicles with a large amount of ground clearance
or protruding freight, are often identified late or may not be
detected at all.
Fig. 151 The vehicle in
front is outside the
range of the radar
sensor
Fig. 152 A vehicle is
changing lanesFig. 153 Motorcycle in
front
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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
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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)
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Audi lane assist147
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
Unfilled lines: The lane assist is switched on but not ready for
warning ⇒page 146, fig. 161,
Version : High-resolution display
•
Solid white lines: The lane assist is switched on and ready to
warn.
•
Solid red line (left or right): The lane assist warns you before you
cross the lane demarcation ⇒page 146, fig. 160.
•
Unfilled lines: The lane assist is switched on but not ready for
warning ⇒page 146, fig. 161.
Messages in the instrument cluster display
Should the lane assist be deactivated automatically, the indicator
lamp in the instrument cluster will go out and one of the following
messages will appear in the instrument cluster display:
Audi lane assist not available: currently no sensor vision
This message is displayed when the camera is no longer functional
after the system has continuously failed to detect the lane mark-
ings. This can have the following causes:
•
The outside of the camera window ⇒page 145, fig. 159 is dirty
or frosted. Please remove dirt or ice from this area of the wind-
screen.
•
The inside of the camera window is misted up. In this case,
please wait for the camera window to demist before switching on
the lane assist system again.
•
Due to the conditions (e.g. snow-covered road) the system has
not been able to detect the lane markings for a long period. Do not
switch the lane assist system on again before the lane markings are
discernible.
Audi lane assist currently not available
A temporary error is preventing the lane assist system from fully
functioning. Try switching on the lane assist system again later.
Audi lane assist: system faultThe system should be checked by an Audi dealership or other qual-
ified workshop.
Applies to vehicles: with lane assistSetting the warning time and steering vibration
You can change the lane assist settings on the sound
system or MMI* to suit your individual preferences.– Select: Function selector button > Audi lane assist.Setting time of warning
early: In this setting, the driver will be warned before a wheel
crosses a lane marking. The warning depends on the angle with
which the vehicle is approaching the lane marking. The larger the
angle with which you are driving towards the marking, the earlier
you will receive the warning, i.e. the distance between the vehicle
and the marking might still be still relatively long. If you are driving
toward the marking at a very narrow angle, you will receive the
warning later, i.e. shortly before one of the wheels touches the
marking.
adaptive: In this setting, the time of warning is adapted to the road
layout and the vehicle's speed. The warning will be received later
when you are driving through a bend, and earlier when you are
AA
AB
Fig. 162 Display:
Setting time of
warning and steering
vibration
CAR
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Audi side assist149
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Audi side assistLane change assist featureApplies to vehicles: with side assistDescription
The side assist function assists the driver when changing
lanes.The side assist function employs radar sensors ⇒fig. 163 to assist
the driver in monitoring following traffic and the blind spots on both
sides of the car ⇒page 151, fig. 166.Warning lamps are incorporated in the two exterior mirrors
⇒fig. 164. The warning lamp on the left-hand mirror assists the
driver when changing lane towards the left and the warning lamp
on the right-hand mirror assists the driver when changing lane
towards the right.
When one of these lamps lights up, this is to inform you that the
side assist has detected a vehicle on that side and calculates that a
lane change would be critical. This is the first stage of the warning,
referred to as the information mode ⇒page 151. This stage of the
warning is designed to be visible only when you look in the exterior
mirror.
If you operate the turn signal when the side assist has registered
what it judges to be a critical vehicle, the lamp on the exterior mirror
will then flash several times with greater intensity. This is the
warning mode ⇒page 151.
Applies to vehicles: with side assistSwitching on and off
Fig. 163 Rear bumper:
Position of radar
sensors (not externally
visible)Fig. 164 Warning lamp
on exterior mirror
(driver's side)
Fig. 165 Driver's door:
Button for side assist
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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.
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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
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