The system is designed to operate in certain
conditions and circumstances. Due to condi‐
tions or other factors, the system may not re‐
spond. There may be a risk of accident or risk
of damage to property. Actively intervene as
warranted. Refer to the information in this Own‐
er’s Manual regarding the scope of the sys‐
tem’s operation and limitations.
Limits of ultrasonic measurement
Ultrasonic measurements might not function in
the following situations:
▷ For small children and animals.
▷ For persons with certain clothing, for instance
▷ With external interference of the ultrasound,
for instance from passing vehicles or loud
▷ When sensors are dirty, iced over, damaged
or out of position.
▷ Under certain weather conditions such as
high relative humidity, wet conditions, snow‐
fall, extreme heat, or strong wind.
▷ With tow bars and trailer couplings of other
▷ With thin or wedge-shaped objects.
▷ With moving objects.
▷ With elevated, protruding objects such as
▷ With objects with corners, edges, and
▷ With objects with a fine surface structure
such as fences.
▷ For objects with porous surfaces.
▷ With small and low objects, for instance
▷ With obstacles and persons at the edge of
▷ With soft obstacles or obstacles covered in
▷ With plants and bushes.
▷ Low objects already displayed, for instance
curbs, can move into the blind area of the
sensors before or after a continuous tone
▷ Cargo that extends beyond the perimeter of
the vehicle is not taken into account by the
The system may issue a warning under the fol‐
lowing conditions even though there is no obsta‐
cle within the detection range:
▷ In heavy rain.
▷ When sensors are very dirty or covered with
▷ When sensors are covered in snow.
▷ On rough road surfaces.
▷ On uneven surfaces, such as speed bumps.
▷ In large buildings with right angles and
smooth walls, for instance in underground ga‐
▷ In automatic vehicle washes.
▷ Due to heavy exhaust.
▷ Due to other ultrasound sources, for instance
sweeping machines, high pressure steam
cleaners or neon lights.
To prevent false alarms, switch off automatic
PDC activation on obstacle detection, refer to
page 191, for instance in automatic vehicle
A Check Control message is displayed.
Driver assistance systems
Online Edition for Part no. 01402779051 - II/19