:Vehicle centre point on the yellow guide
line at a distance of approximately 1.0 m
from the rear of the vehicle;Trailer drawbar=Ball couplingXSet the height of trailer drawbar ; so that
it is slightly higher than ball coupling =.XPosition the vehicle centrally in front of
trailer drawbar ;.:Ball coupling;Red guide line at a distance of approx-
imately 0.25 m from the ball coupling=Trailer drawbar locating aid?Trailer drawbarASymbol for the "Coupling up a trailer"
functionXSelect symbol A with the Audio/COMAND
controller; see the separate operating
instructions for the audio system/
COMAND Online.
The "Coupling up a trailer" function is selec-
ted. The distance specifications now onlyapply to objects that are at the same level
as the ball coupling.XReverse carefully, making sure that trailer
drawbar locating aid = points approx-
imately in the direction of trailer draw-
bar ?.XReverse carefully until trailer drawbar ?
touches red guide line ;.XCouple up the trailer ( Y page 201).
ATTENTION ASSIST
General notes
ATTENTION ASSIST helps you during long,
monotonous journeys such as on motorways
and trunk roads. It is active in the 80 km/h
to 180 km/h range.
If ATTENTION ASSIST detects typical indica-
tors of fatigue or increasing lapses in con-
centration on the part of the driver, it sug-
gests taking a break.
Important safety notes
ATTENTION ASSIST is only an aid. It cannot
always detect fatigue or lapses in concentra-
tion until too late or not at all. The system is
not a substitute for a well-rested and atten-
tive driver.
ATTENTION ASSIST assesses your level of
fatigue or lapses in concentration by taking
the following criteria into account:
R your personal driving style, e.g. steering
characteristics
R journey-related parameters, e.g. time of
day, length of journey
The functionality of ATTENTION ASSIST is
restricted, and warnings may be delayed or
not occur at all:
R if the road condition is poor, e.g. if the sur-
face is uneven or if there are potholes
R if there is a strong side wind
Driving systems195Driving and parkingZ
sion surrounding the possible health risk
posed by electromagnetic fields.
Observe the notes on operating mobile
phones ( Y page 278).
The following aerial positions may be used for
the correct installation of RF transmitters:
Approved aerial positions
:Front roof area;Rear roof area=Rear wing?Boot lid
i On vehicles with panorama sliding sun-
roof, fitting an aerial to the front roof area
is not permitted.
On the rear wing, it is recommended that
you position the aerial on the side of the
vehicle closest to the centre of the road.
Use Technical Specification ISO/TS 21609
(Road Vehicles – "EMC guidelines for fitting
aftermarket radio frequency transmitting
equipment") when retrofitting RF (radio fre-
quency) transmitters. Comply with the legal
requirements for add-on parts.
If your vehicle has fittings for two-way radio
equipment, use the power supply or aerial
connections intended for use with the basic
wiring. Be sure to observe the manufacturer's
additional instructions when installing.
Deviations with respect to wavebands, maxi-
mum transmission outputs or aerial positions
must be approved by Mercedes-Benz.
The maximum transmission output (PEAK) at
the base of the aerial must not exceed the
following values:WavebandMaximum
transmission outputShort wave
3 - 54 MHz100 W4 m waveband
74 - 78 MHz30 W2 m waveband
144 - 174 MHz50 WTrunked radio/Tetra
380 - 460 MHz10 W70 cm waveband
400 - 460 MHz35 WGSM/DCS/PCS
850/900/1800/190010 WUMTS/LTE10 W
The following can be used in the vehicle with-
out restrictions:
R RF transmitters with a maximum transmis-
sion output of up to 100 mW
R mobile phones (GSM/DCS/PCS/UMTS/
LTE)
There are no restrictions when positioning the
aerial on the outside of the vehicle for the fol-
lowing wavebands:
R Trunked radio/Tetra
R 70 cm waveband
R GSM/DCS/PCS
R UMTS/LTE
Vehicle electronics335Technical dataZ
