X
Position the trailer horizontally behind the
vehicle.
X
Couple up the trailer.
X
Establish the electrical connection between
the vehicle and the trailer.
X
Check that the trailer lighting system is work-
ing.
X
Push the combination switch upwards/down-
wards
X
Check whether the corresponding turn signal
on the trailer is flashing.
A connected trailer is only detected when the
electrical connection is established correctly
and when the lighting system is working prop-
erly. The function of other systems, such as
ESP
®
, PARKTRONIC, Active Parking Assist,
Active Blind Spot Assist or Lane Keeping
Assist also depends on this.
Uncoupling a trailer
G
WARNING
If you uncouple a trailer with an engaged over-
run brake, you could trap your hand between
the vehicle and the trailer drawbar. This poses
a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake.
G
WARNING
Vehicles with level control:
If you disconnect the trailer cable, the vehicle
is lowered. This can cause you or others to
become trapped between the vehicle body
and tyres, or underneath the vehicle. This
poses a risk of injury.
Make sure that no-one is in the immediate
vicinity of the wheel arch or underneath the
vehicle when disconnecting the trailer cable.
!
Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun
brake.
!
Remove the installed adapter cable before
folding in the ball coupling. Otherwise, dam-
age may occur to the rear bumper and the
adapter cable.
X
Make sure that the transmission is in position
P.
X
Apply the electric parking brake.
X
Secure the trailer against rolling away.
X
Remove the trailer cable and decouple the
trailer.
Trailer power supply
!
You can connect accessories to the perma-
nent power supply up to a maximum of 240 W.
You cannot charge a trailer battery using the
power supply.
When it leaves the factory, your vehicle's trailer
socket is equipped with a permanent power
supply and a power supply that is switched on
via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin 10.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about fitting the
trailer electrics at a qualified specialist work-
shop.
X
To switch the connected power supply on
or off: turn the key to position 2 or 0 respec-
tively (
Y
page 145).
Failure check for LEDs
If LED lamps are fitted in the trailer, a malfunc-
tion message may appear in the multifunction
display even if there is no fault. The reason for
the error message may be that the current has
fallen below the minimum of 50 mA.
To ensure reliable operation of the failure indi-
cator, each LED chain in the trailer lighting must
be guaranteed a minimum current of 50 mA.
Trailer with 7-pin connector
General notes
Trailer with 7-pin connector: you can connect
to the 13-pin socket on the ball coupling using
an adapter or, if necessary, an adapter cable.
Towing a trailer
229
Driving
and
parking
Z