Mercedes-Benz GLA 180 Owner's Manual page 219

Towing a trailer
216
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.
To switch the connected power supply on
X
or off: turn the key to position 2 or 0 respec-
tively ( page 144).
Y
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.
Both can be obtained at a qualified specialist
workshop.
Fitting the adapter
!
Make sure that there is sufficient cable play
so that the cable cannot become detached
when cornering.
!
Remove the installed adapter cable before
folding in the ball coupling. Otherwise, dam-
age may occur to the rear bumper and the
adapter cable.
Open the socket cover.
X
Insert the plug connector with lug : into
X
groove = on the socket.
Turn bayonet connection ; clockwise to the
X
stop.
Let the cover engage.
X
If you are using an adapter cable, secure the
X
cable to the trailer with cable ties.