Collision Warning System* - Limitations - Volvo V40 Cross Country Owner's Manual

Collision warning system* - limitations

The function has certain limitations - for
example, it is not active until approx. 4 km/h.
The collision warning system's visual warning
signal may be difficult to notice in the event of
strong sunlight, reflections, when sunglasses
are being worn or if the driver is not looking
straight ahead. The warning sound should
therefore always be activated.
On slippery road surfaces the braking dis-
tance is extended, which may reduce the
capacity to avoid a collision. In such situa-
tions the ABS and ESC (p. 183) systems will
provide best possible braking force with
maintained stability.
NOTE
The visual warning signal can be temporar-
ily disengaged in the event of high passen-
ger compartment temperature caused by
strong sunlight for example. If this occurs
then the warning sound is activated even if
it is deactivated in the menu system.
•
Warnings may not appear if the dis-
tance to the vehicle in front is small or
if steering wheel and pedal move-
ments are large, e.g. a very active driv-
ing style.
For cyclists, the warning and full brake intervention may come very late or simultaneously.
26
WARNING
Warnings and brake interventions could be
implemented late or not at all if the traffic
situation or external influences mean that
the radar or camera sensor cannot detect
a pedestrian, a vehicle or a cyclist in front
correctly.
The sensor system has a limited range for
26
pedestrians and cyclists - the system
can provide effective warnings and brake
interventions for them at vehicle speeds up
to 50 km/h. For stationary or slow-moving
vehicles, warnings and brake interventions
are effective at vehicle speeds up to
70 km/h.
Warnings for stationary or slow-moving
vehicles could be disengaged due to dark-
ness or poor visibility.
Warnings and brake interventions for
pedestrians and cyclists are deactivated at
vehicle speeds exceeding 80 km/h.
The collision warning system uses the same
radar sensors as the adaptive cruise control
(p. 198).
If warnings are perceived as being too fre-
quent or disturbing then the warning distance
can be reduced. This then leads to the sys-
tem providing a warning at a later stage,
which reduces the total number of warnings;
see Collision warning system - operation
(p. 227).
07 Driver support
Collision Warning with Auto Brake is tempo-
rarily deactivated with reverse gear engaged.
Collision Warning with Auto Brake is not acti-
vated at low speeds - under 4 km/h, which is
why the system does not intervene in situa-
tions where the car is approaching a vehicle
in front very slowly, e.g. when parking.
In situations where the driver demonstrates
active, aware driving behaviour, a collision
warning may be postponed slightly in order to
keep unnecessary warnings to a minimum.
When Auto Brake has prevented a collision
with a stationary object the car remains sta-
tionary for a maximum of 1.5 seconds. If the
car is braked for a vehicle in front that is mov-
ing, then speed is reduced to the same speed
as that maintained by the vehicle in front.
On a car with manual gearbox the engine
stops when Auto Brake has stopped the car,
unless the driver manages to depress the
clutch pedal beforehand.
Related information
•
Collision warning system* (p. 223)
*
Option/accessory, for more information, see Introduction.
07
229