Mercedes-Benz R-Class Owner's Manual page 240

Key
1
2 Protective cap
Green area on the handwheel
5
White dot on the ball coupling
6
Handwheel 4 turns automatically, aligning
X
green area 5 on handwheel
dot 6 on the ball coupling.
Turn key 1 to the stop in the direction of
X
the arrow (lock).
Remove key 1.
X
Press protective cap 2 onto the lock.
X
G Risk of accident
The ball coupling is only securely mounted
when the green area on the handwheel is
aligned with the white dot on the ball cou-
pling and the key can be removed. If the ball
* optional
coupling is not securely mounted, it may
come loose.
The ball coupling must be locked and the
key must be removed when towing a trailer.
This is the only way to guarantee that the
ball coupling is secured and cannot come
loose while the vehicle is in motion. If the
ball coupling cannot be locked and the key
cannot be removed, remove the ball cou-
pling and clean it.
If the ball coupling can still not be fitted
(locked) after it has been cleaned, remove
the ball coupling. The trailer tow hitch must
then not be used to tow a trailer, as safe
operation is not guaranteed.
Have the entire trailer tow hitch checked at
a qualified specialist workshop. Mercedes-
4 with white
Benz recommends that you use a
Mercedes-Benz Service Centre for this pur-
pose. In particular, work relevant to safety
or on safety-related systems must be car-
ried out at a qualified specialist workshop.
Trailer towing*
Socket
1
Coupling up and uncoupling a trailer
Coupling up a trailer
Steel-spring vehicles
Make sure the selector lever is set to P.
X
Depress the parking brake.
X
Position the trailer level behind the vehicle.
X
Couple up the trailer.
X
Establish the electrical connection
X
between the vehicle and the trailer.
Operation
Z
237