Audi A4 Owner's Manual page 132

document_0900452a81b1b9de.book Seite 130 Donnerstag, 26. Juli 2007 9:16 09
130 adaptive cruise control (ACC)
Applies to vehicles: with adaptive cruise control
How 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 ⇒
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
Fig. 137 Area covered speed and then maintain it.
by radar sensor
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.
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".
in "Description" on page 128.
Note