lffll.___A_ d_ a_,_ p_t _i_ v _e _ C_r_ u_ i_ s_ e_ C_ o_ n_ t_ r_ o_ l __________________________________________ _
Applie s to veh icles : wi th Adap tiv e Crui se Con tro l
How does Adaptive Cruise Control work?
Vehicles traveling ahead ore detected with the aid of a
radar sensor.
Fig. 132 Basic prin
ciple diagram: Radar
sensor measurement
range
Adaptive Cruise Control uses a radar sensor in the front of the vehicle
=>
page 138, fig. 132 . The system has limitations=> page 149.
Things that are not moving in your lane and in your direction of travel
w ill not be detected. The sensor measures the distance to reflective
surfaces that must have a certain size. The system responds only
after the distance measurement has been made . If a measurement is
not possible, the system cannot respond and will not react to a
vehicle or someth ing else up ahead.
Open road
When the road is clear, the Adaptive Cru ise Control works like cruise
control. It maintains a constant target speed specified by the driver .
Driving in traffic
If a slower veh icle driv ing ahead is detected, the Adaptive Cruise
Control decelerates (within the limits of the system)=>
page 148,
"Driver intervention prompt" and => page 149, "System limitations"
to its speed and after adjusting, tries to ma inta in the set distance
from the vehicle ahead. The vehicle may temporarily drive slower
than the set speed whi le adjusting=>
& in "Descr iption" on
page 136.
If the vehicle in front accelerates, Adaptive Cruise Control also accel
erates up to the speed that you have set.
If the vehicle ahead slows to a stop, ACC w ill slow your vehicle down
and to a complete stop if this is possible within the system's limits
and capabilities . ACC will not make an emergency stop. The text
message
ACC off: manual control! appears in the instrument cluster
display. Once the vehicle stops, you must depress the brake pedal to
prevent the veh icle from moving forward or "creeping". Depressing
the brake pedal turns off ACC. When the vehicle ahead accelerates
you can reactivate ACC =>
page 141, as soon as your vehicle has
reached a speed of 1 mph (2 km/h) .
Situations requiring driver intervention
In some situations you will have to use the footbrake to slow the
vehicle down in order to keep a safe distance from vehicle in front of
you or to avoid a rear-end collision. In this situation, a symbol
appears and a warning tone sounds=>
page 148.
Passing another vehicle
If you move into the passing lane and no vehicle is detected ahead,
the Adaptive Cruise Control accelerates to the speed you have set and
maintains it.
Overriding ACC
You can increase your speed at any time by stepping on the acceler
ator pedal. After you release the accelerator pedal, the system
adjusts back down to the speed you previously set.
Reduc ing stopping distance
If the radar sensor detects that the distance to the vehicle ahead is
less than defined minimum distance, the brakes are automatically
prepared for emergency braking by the driver. The brake pads are
moved very close to the brake discs withou t actually bra king the
vehicle. This brake assistant feature reacts more quickly to the driver's braking, and also works when Adaptive Cruise Control is off.
The stopping d istance is reduced as a result of this advance brake .,_
