Mercedes-Benz E-Class 2011 Owner's Manual page 229

Towing a trailer
226
Grasp release wheel ; with your hand
X
such that the thumb is in the thumb rest
and turn it anti-clockwise.
The ball coupling unlocks and lowers. Indi-
cator lamp : flashes.
Press the ball coupling in the direction of
X
the arrow until it engages behind the
bumper.
Indicator lamp : goes out and the mes-
sage in the multifunction display disap-
pears.
Trailer 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.
! You can connect accessories with a
power rating of up to 240 W to the perma-
nent power supply and with a power rating
of up to 180 W to the power supply that is
switched on via the ignition lock.
The trailer battery may not be charged from
the power supply.
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 instal-
ling the trailer electrics at a qualified special-
ist workshop.
To switch the connected power supply
X
on or off: turn the key in the ignition lock
to position 2 or 0 respectively.
Bulb failure indicator for LED lamps
i
If LED lamps are fitted in the trailer, an
error message may appear in the multi-
function 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 bulb failure
indicator, each LED chain in the trailer lighting
must be guaranteed a minimum current of
50 mA.
Trailer with 7-pin connector
General notes
If your trailer has a 7-pin connector, you can
connect it to the 13-pin socket on the ball
coupling using an adapter or, if necessary, an
adapter cable. Both can be obtained in a
qualified specialist workshop.