2008 AUDI A4 technical data

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)131
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with adaptive cruise controlSwitching the system on and off– Pull the control lever to position ⇒fig. 138 to switch
on the system.
– Press the control lever to position (click stop engaged)
to switch the system off.Applies to vehicles: with adaptive cruise controlSetting the speedImportant: The system must be switched on.– Drive at the desired speed. The speed must be in the
range between 30 and 200 km/h.
– Press the button -arrow- ⇒fig. 139 to confirm the
target speed you wish to store.
When the button is released, the current speed is stored in the
memory and the vehicle will then maintain this speed.
One or two red diodes will light up in the speedometer dial
⇒page 134 to mark the speed which is currently stored in the
system. At the same time, the speed will briefly be displayed in the
system status indicator ⇒page 136.
Note
For safety reasons, the speed setting will be deleted when the igni-
tion is switched off.Applies to vehicles: with adaptive cruise controlSetting a new speed
The speed can be altered without touching the acceler-
ator or the brake.
Fig. 138 Control lever
for: Switching the
system on and off
A1A2
Fig. 139 Control lever
for: Setting speed
SET
SET
Fig. 140 Control lever
for: Setting a new
speed
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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)135
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data Target speed
The target speed set by the driver is indicated by a red diode in the
speedometer.
If the speed setting is between two graduations on the speedom-
eter dial, the two closest diodes will both light up ⇒fig. 143.
It is only possible to set target speeds ranging from 30 to 200 km/h.
This speed range is illuminated slightly by the diodes on the speed-
ometer dial.
Indicator lamp (symbol)
•
No vehicle in front: The green indicator lamp ⇒page 134,
fig. 144 shows that the adaptive cruise control system is in cruise
mode and that there is no vehicle in front. It maintains the stored
target speed.
•
Vehicle in front: The green indicator lamp shows that the
system has detected a vehicle in front. The speed is adapted to the
vehicle in front. The adaptive cruise control system accelerates and
brakes the vehicle automatically.
•
Driver intervention prompt: When the red indicator lamp
flashes , this is a warning for the driver to intervene. The driver
has to brake the vehicle with the foot brake. This warning lamp will
always appear when the adaptive cruise control system alone is not
able to brake the vehicle sufficiently to maintain a safe distance to
a vehicle in front. An audible alarm (warning tone) will also sound
when the lamp starts to flash. For further information on the driver
intervention prompt ⇒page 138.Note
•
If you exceed the target speed by using the accelerator, the
driver intervention prompt will not be accompanied by a warning
tone. The indicator lamp shown in the speedometer will also switch
off if the target speed is exceeded.
•
You can change the volume of the warning tone on the sound
system or MMI* ⇒page 139, “Setting the warning tone volume and
driving program”.
Applies to vehicles: with adaptive cruise controlInstrument cluster displayRepeatedly press the button on the windscreen wiper lever
to select whether you wish to display information regarding the on-
board computer, the navigation system* or the adaptive cruise
control in this section of the display screen.
Vehicle image
Distance
System status
Vehicle image
The vehicle image will show you whether the system has detected a
vehicle in front.•
Vehicle outlined: No vehicle in front
•
Vehicle in white: A vehicle in front has been detected
•
Vehicle in red: Driver intervention prompt
Distance
The arrows and scale indicate the distance to the vehicle in front.
•
No vehicle in front: If there is no vehicle in front, no arrows will
be shown.
AA
AA
AB
AB
AC
AC
Fig. 145 Instrument
cluster: Display
RESET
AAABACAAAB
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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)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)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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