#
Attach the cable to the trailer with cable ties
(only in the case of adapter cable).
#
Make sure that the cable is always slack for
ease of movement during cornering.
#
Establish all electrical and other connections
to the trailer. In the process, attach the trail‐
er's breakaway cable to the eyelet on the ball
neck.
#
Check that the trailer's lighting system works
properly.
#
Indicate in both directions and check whether
the corresponding turn signal light on the
trailer is flashing.
A trailer is detected only if the electrical con‐
nection is established correctly and the light‐
ing system is in working order. The function
of other systems also depends on this, e.g.
ESP
®
, PARKTRONIC, Active Parking Assist,
Blind Spot Assist or Lane Keeping Assist.
Even if the trailer is connected correctly, a mes‐
sage may nevertheless appear on the multifunc‐
tion display in the following cases:
R
LEDs have been installed in the trailer's light‐
ing system.
R
The current has fallen below the trailer light‐
ing system's minimum current (50 mA)
%
You can connect accessories up to a maxi‐
mum of 240 W to the permanent power sup‐
ply.
#
Remove objects or devices that prevent the
trailer from rolling, e.g. chocks.
#
Release the trailer's parking brake.
Observe the maximum permissible trailer dimen‐
sions (width and length).
Most states and all Canadian provinces pre‐
scribe:
R
Safety chains between the towing vehicle and
the trailer. The chains should be routed in a
criss-cross pattern under the drawbar. They
must be connected to the trailer hitch and not
to the bumper or to the vehicle's axle.
Leave sufficient slack in the chains. This also
allows for sharp cornering.
R
A separate brake system for specific trailers.
R
Safety shutoff for braked trailers. Determine
the specific requirements according to the
relevant laws.
If the trailer becomes detached from the tow‐
ing vehicle, the safety shutoff will activate the
trailer brakes.
Uncoupling a trailer
&
WARNING Risk of being crushed and
becoming trapped when uncoupling a
trailer
When uncoupling a trailer with an engaged
inertia-activated brake, your hand may
become trapped between the vehicle and the
trailer drawbar.
#
Do not uncouple trailers with an
engaged overrun brake.
*
NOTE Damage when uncoupling in a
state of overrun
Uncoupling in a state of overrun can damage
the vehicle.
#
Do not uncouple trailers with an
engaged overrun brake.
#
Shift the transmission to position
j
.
#
Apply the vehicle's parking brake.
#
Close all the doors.
#
Apply the trailer's parking brake.
#
Further secure the trailer against rolling away
with a wheel chock or similar object.
#
Remove the trailer cables and safety chains.
#
Uncouple the trailer.
Information about towing a trailer
Operating a trailer is subject to many statutory
regulations such as speed restrictions.
Many states also require an auxiliary separate
functional braking system when towing a weight
that exceeds a certain limit. For your safety, it is
recommended to use a separate functional brak‐
ing system on any towed vehicle.
Make sure that your trailer combination meets
local regulations. This not only applies to your
place of residence, but also to your destination.
Information on this can be obtained from the
police and local authorities.
Comply with the following when driving with a
trailer:
R
Practice cornering, stopping and backing up
in a traffic-free location. In this way, you will
Driving and parking 133
