2008 AUDI A4 ESP

adaptive cruise control (ACC) 128adaptive cruise control (ACC)Speed and distance control systemApplies to vehicles: with adaptive cruise controlDescription
The adaptive cruise control is a combined speed and
distance control system to assist the driver.Adaptive cruise control allows you to maintain any desired constant
speed between 30 and 200 km/h. In addition, the system controls
the distance maintained to the vehicle in front (subject to certain
limitations as described below).
The system can be used to greatest effect on long motorway jour-
neys or on other main roads with long straight sections.
How is the system operated?
The adaptive cruise control system is operated via a control lever on
the steering wheel ⇒page 131, “Setting the speed” and
⇒page 133, “Setting the distance”.Driver messages
When the system is being used, important information is displayed
in the speedometer and on the instrument cluster display screen
⇒page 134, “Driver messages”.
Please note the following points:
The adaptive cruise control has certain limits determined by the
system itself. This means that the driver may in some situations
have to intervene and control the speed and distance to the vehicle
in front himself ⇒page 138, “Driver intervention prompt” and
⇒page 140, “System limitations”.
WARNING
Please always direct your full attention to the road, even when you
are using adaptive cruise control. It is always the driver who is
responsible for determining the speed and for keeping a safe
distance to the other vehicles on the road.•
For safety reasons, the adaptive cruise control must not be
used in city traffic, stop-go traffic, roads with a lot of bends or in
difficult driving conditions (such as ice, fog, loose grit or gravel,
heavy rain, aquaplaning) - this could cause an accident!
•
When you take a turn-off, drive along a motorway exit lane or
pass through roadwork sections, please temporarily switch off the
adaptive cruise control in order to avoid the vehicle accelerating to
the selected speed.
•
The adaptive cruise control can only control the distance to
vehicles in front. As a rule, it cannot recognize vehicles travelling
in other lanes. For this reason, please temporarily switch off the
system if you are travelling in the inside lane and vehicles in the
overtaking lane are travelling at a slower speed than you are.
Otherwise, you would overtake these vehicles on the inside.
Fig. 136 Trim grille
(front right): Position of
radar sensor
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adaptive cruise control (ACC)129
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
Adaptive cruise control will not react when approaching a
stationary obstacle, e.g. the end of a traffic jam or a broken-down
vehicle, or if a vehicle should come towards you in the same lane.
•
Please make sure you do not unintentionally rest your foot on
the accelerator - this will override the adaptive cruise control
system which, as a result, will not automatically brake the vehicle.Note
•
For safety reasons, the speed setting will be deleted when the
ignition is switched off.
•
Switching on the adaptive cruise control automatically activates
the Electronic Stabilisation Program (ESP) and the traction control
system (ASR). These two systems cannot be deactivated while the
adaptive cruise control is switched on.
•
Damage caused by impacts (e.g. if the vehicle is damaged when
parking) can affect the radar sensor settings. This can cause the
system to malfunction or switch off completely.
•
The radar sensor is heated. However, in winter conditions, you
should make sure that the radar sensor is free of ice and snow
before you set off. If necessary, carefully clean the cover of the radar
sensor and the surrounding area ⇒page 128, fig. 136.
•
To make sure that the radar sensor is fully operative, do not
attach any objects (e.g. stickers, add-on parts or other accessories)
to the area surrounding the radar sensor. Do not paint the area
surrounding the radar sensor.
Applies to vehicles: with adaptive cruise control and manual gearboxVehicles with manual gearbox
The driver of a vehicle with a manual gearbox of course
has to change gears as appropriate, even when the adap-
tive cruise control is activated.The adaptive cruise control is available from the second to the sixth
gear (when driven in normal engine speed range).
When the adaptive cruise control is activated, the driver must press
the clutch pedal as normal in order to change gear. When changing
gear or pressing the clutch pedal (for up to 20 seconds), the adap-
tive cruise control will remain activated.
When changing gear, the driver does not have to accelerate after
engaging a gear as the engine torque will be coordinated by the
adaptive cruise control.
The following situations may lead to an automatic deactivation of
the adaptive cruise control:•
pressing the clutch pedal too long (longer than approx.
20 seconds)
•
incorrect changing of gears and/or use of the clutch pedalNote
•
The adaptive cruise control cannot be activated while changing
gears.
WARNING (continued)
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adaptive cruise control (ACC) 130Applies to vehicles: with adaptive cruise controlHow does the distance control work?
Vehicles in front are detected by a radar sensor.The adaptive cruise control uses a radar sensor ⇒fig. 137 which is
integrated in the front of the vehicle and is subject to certain system
limitations ⇒page 140. Stationary objects are disregarded. 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.
No vehicle in front
When there is no vehicle in front, the adaptive cruise control works
like a speed control system. It maintains a constant target speed
specified by the driver.
Vehicle in front
If you catch up with a vehicle driving in front, the adaptive cruise
control will reduce the speed accordingly (within the limits set by
the system ⇒page 138, “Driver intervention prompt” and
⇒page 140, “System limitations”) and adapt it to the speed of the
vehicle in front. Then the system will try to adjust the distance to the
car in front according to the settings selected. During the adjust-
ment process the system may temporarily not be able to adhere to
the distance you had specified ⇒ in “Description” on page 128.If the vehicle in front accelerates, the adaptive cruise control will
also accelerate, up to the target speed you have specified.
Driver intervention prompt
In some situations, it is necessary for the driver to brake the vehicle
with the foot brake in order to keep a safe distance to the vehicle in
front or to avoid a collision. In this case, a warning message will
appear in the display and you will also hear a warning tone
⇒page 138.
When overtaking
When you move into the overtaking lane and no vehicle is detected
in front, the adaptive cruise control will accelerate up to the target
speed and then maintain it.
Overriding
You can still use the accelerator pedal at any time to increase speed
in the normal way. The previously programmed speed will be
resumed when the accelerator pedal is released.
Note
•
Please note that acceleration will vary depending on the preset
programme. If you have, for example, selected “Distance 1” and the
driving programme “dynamic”, acceleration will be more "sporty".
However, if you have set the system to “Distance 4” and driving
programme “comfort”, acceleration will be more gradual. For a
detailed description please refer to ⇒page 133, “Setting the
distance”.
•
No vehicle in front, Vehicle in front and a Driver intervention
prompt will be indicated by an indicator lamp ⇒page 134, “Indi-
cator lamp and display in the speedometer”.
Fig. 137 Area covered
by radar sensor
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adaptive cruise control (ACC)133
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with adaptive cruise controlSetting the distance
The distance can be set in 4 different stages.– Briefly press the sliding switch ⇒fig. 142 once towards
or . The display in the instrument cluster will briefly
show the current distance setting.
– Press the sliding switch again towards or to
increase or reduce the distance by one level at a time.Choosing the distance
The adaptive cruise control system determines the distance to the
vehicle in front by time intervals. It defines a time-based distance to
the vehicle in front which is kept at a constant level. This converts
to a distance which depends on the speed - the higher the speed,
the higher the safety distance in metres ⇒.
The actual distance maintained by the adaptive cruise control can
be longer or shorter, depending on the traffic situation and the
driving style of the driver in front.
Distance 1

This setting is suitable for brisk driving in a line of traffic. The time
interval is 1 second. This is equivalent to (for instance):•
A distance of 14 metres at a speed of 50 km/h
•
A distance of 36 metres at a speed of 130 km/h
Distance 2

This setting is suitable for relaxed “moving with the flow” in a line
of traffic. The time interval is 1.3 seconds. This is equivalent to (for
instance):•
A distance of 18 metres at a speed of 50 km/h
•
A distance of 47 metres at a speed of 130 km/h
Distance 3

This (recommended) setting is suitable for relaxed “moving with the
flow” in a line of traffic. The time interval is 1.8 seconds. This is
equivalent to (for instance):•
A distance of 25 metres at a speed of 50 km/h
•
A distance of 65 metres at a speed of 130 km/h
Distance 4

This setting is suitable for single-carriageway roads. The time
interval is 2.3 seconds. This is equivalent to (for instance):•
A distance of 32 metres at a speed of 50 km/h
•
A distance of 83 metres at a speed of 130 km/h
You can control the acceleration and braking response of your
vehicle in adaptive cruise control mode by adjusting the settings on
the sound system or MMI* ⇒page 139. Depending on the driving
program and distance selected, acceleration and braking response
will range from dynamic (1) to relaxed (5).
Fig. 142 Control lever
for: Setting the
distance
A+
A-
A+
A-
Driving pro-
gram
dynamic
standard
comfort
Distance 1
1
2
3
Distance 2
2
3
4
Distance 3
2
3
4
Distance 4
3
4
5
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adaptive cruise control (ACC) 134
WARNING
When setting the distance, the driver is responsible for adhering
to the laws and regulations which apply in the country he is trav-
elling in.Driver messagesApplies to vehicles: with adaptive cruise controlMessages in the instrument cluster
The instrument cluster displays various driver messages.Fig. 143 Overview of instrument cluster
Indicator lamp and speedometer display
Instrument cluster display
System status indicator Indicator lamp and speedometer display
Section of the display shows important information regarding
the use of the adaptive cruise control system. The target speed you
have set is marked by diodes in the speedometer.
The indicator lamp shows whether the system has detected a
vehicle in front.
Instrument cluster display
You can call up the display for the adaptive cruise control by repeat-
edly pressing the button on the windscreen wiper lever. For
more details refer to ⇒page 27.
System status indicator
The information in section of the display is not shown perma-
nently. It only appears if you, for example, set or change the speed
setting, change the time interval, when messages are displayed, or
if the adaptive cruise control is switched off for safety reasons.
Applies to vehicles: with adaptive cruise controlIndicator lamp and display in the speedometer
AAABAC
AA
AA
AB
RESET
AC
AC
Fig. 144 Instrument
cluster: Indicator lamp
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adaptive cruise control (ACC)137
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
The control lever has been pushed up / down to increase / reduce
the speed, but the resulting speed would be outside the range of 30
to 200 km/h.
ACC deactivation
The message ACC deactivation sometimes appears on vehicles with
a manual gearbox. If you press the clutch pedal for longer than
about 20 seconds, the adaptive cruise control will be automatically
deactivated and a warning tone will sound.
ACC not available
The text message ACC not available will appear if, for example, the
brakes are overheated. The adaptive cruise control will then tempo-
rarily not be available. This is indicated by a warning tone.
ACC not available!
The text message ACC not available! appears if a malfunction
should occur. The adaptive cruise control will then be switched off.
This is indicated by a warning tone. Have the system checked by a
qualified workshop.
ACC sensor blocked!
The text message ACC sensor blocked! appears if the ACC system
can no longer detect objects reliably. The adaptive cruise control
will then be switched off. This is indicated by a warning tone.
The ACC sensor is obstructed by dirt or foreign objects (e.g. leaves
or snow). Clean the sensor to restore the function ⇒page 128,
fig. 136.
Engine speed !
On vehicles with manual gearbox, the text message Engine speed !
will appear if the driver does not change gear in time when the
adaptive cruise control accelerates or brakes the vehicle. The adap-
tive cruise control will automatically be deactivated if the engine
speed is not maintained within the permissible range. This is indi-
cated by a warning tone.ESP activation
The text message ESP activation appears if the Electronic Stabilisa-
tion Programme (ESP) has intervened. In this case, the adaptive
cruise control will automatically be switched off. This is indicated by
a warning tone.
Speed (in km/h)
The target speed (in km/h) will appear in the display whenever it is
stored or changed ⇒page 131, “Setting the speed” and
⇒page 131, “Setting a new speed”.
Speed range
The text message speed range appears if the current speed is too
low to set or to maintain the target speed.
To set a target speed, the speed of the vehicle must be at least
30 km/h. The cruise control system switches off if the speed falls
below 20 km/h.
If the speed exceeds 200 km/h (OVERRIDE), the system will remain
active and will reduce the speed to 200 km/h once the driver stops
accelerating.
ACC functionality limited
The text message ACC functionality limited appears if the ACC
system does not detect any objects for an extended period. The
distance to vehicles in front is not being controlled while the
message is displayed. The ACC system is not deactivated, and so
extra care should be taken! The text message ACC functionality
limited can appear for the following reasons:
•
The ACC sensor is dirty. The ACC system is not responding or is
not responding correctly to the vehicles in front!
•
You may be driving on a country road with no traffic and no clear
roadside demarcation (e.g. safety barriers, traffic signs, trees). As
soon as the system detects a vehicle, distance control is resumed
and the text message disappears.
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adaptive cruise control (ACC)139
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
An acoustic warning will also sound (unless it has been deacti-
vated in the sound system or MMI* settings).Note
•
Pressing the brake pedal will switch off the adaptive cruise
control system. The speed set at that point will, however, remain
stored until the adaptive cruise control is activated again.
•
To resume the programmed cruising speed, release the brake
pedal and pull the control lever towards you ⇒page 132,
“Switching off the system (with speed memory function) and reacti-
vating it”.
•
If you exceed the target speed by pressing the accelerator, the
driver intervention prompt will not be accompanied by a warning
tone. The indicator lamp shown in the display will also switch off
when the target speed is exceeded.
•
If the adaptive cruise control triggers a braking operation the
hydraulic brake system is under pressure. This is why brake pedal
travel will be shorter and the pedal will feel “harder”.
Applies to vehicles: with adaptive cruise controlSetting the warning tone volume and driving program
You can change the adaptive cruise control settings on
the sound system or MMI* to suit your individual driving
style.– Select: Function selector button > adaptive cruise
control.Setting the volume of the warning tone
If the adaptive cruise control system switches off (e.g. when the ESP
intervenes) or a driver intervention prompt appears, a warning tone
will sound.
You can set the volume of the warning tone to low, medium, or high.
The new volume will sound briefly after making any adjustment. If
you do not want a tone to sound, select off.
Adjusting the basic settings
You can set the distance (time interval) you want the adaptive cruise
control system to keep to the vehicle in front by selecting distance
1, distance 2, distance 3 or distance 4.
Fig. 148 Display: adap-
tive cruise control
CAR
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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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