2012 MERCEDES-BENZ A-CLASS HATCHBACK tow

prescribed maximum speed in the relevant
country.
For certain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing a trailer. Refer to the "Technical
data" section to find out whether this applies to your vehicle. If you utilise any of the added
maximum rear axle load when towing a trailer, the vehicle/trailer combination may not
exceed a maximum speed of 100 km/ hfor
reasons concerning the operating permit.
This also applies in countries in which the
permissible maximum speed for vehicle/
trailer combinations is above 100 km/h.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer and it will
consume more fuel.
Change into a lower gear in good time on long
and steep downhill gradients. For vehicles
with automatic transmission, you need to
have selected manual drive program
M(Y page 156).
i This also applies if you have activated
cruise control, SPEEDTRONIC or DIS-
TRONIC PLUS.
This will use the braking effect of the engine,
so less braking will be required to maintain
vehicle speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly. If you
need additional braking, depress the brake
pedal repeatedly rather than continuously.
i Briefly depressing the accelerator pedal
on downhill gradients while the manual
drive program Mis temporarily activated
(vehicles with automatic transmission): the automatic transmission may switch back to
the last active automatic drive program Eor
S. The automatic transmission may shift to a higher gear. This can reduce the engine'sbraking effect. Driving tips If the trailer swings from side to side:
X Do not accelerate.
X Do not countersteer.
X Brake if necessary.
R Maintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine,
and consequently the vehicle's gradient-
climbing capability, decrease with increas-
ing altitude. Folding out the ball coupling
G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that the ball coupling engages when folding in.
Before you can tow a trailer with your vehicle, you must fold out the ball coupling.
The release wheel is located behind the left-
hand side trim panel in the boot. Towing a trailer
203Driving and parking Z

X
To open the cover: turn handle:anti-
clockwise and fold down cover ;and
remove it. X
Pull out release wheel =.
X Turn release wheel =anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator lamp ?
flashes. G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is a risk of an
accident. Always engage the ball coupling as described.
X Pull the ball coupling in the direction of the
arrow until it engages in a vertical position.
Indicator lamp ?goes out. The power
socket folds down automatically.
The multifunction display shows the
Check Check trailer
trailer hitch
hitchlock
lockdisplay mes-
sage until the ball coupling is engaged.
X Remove the protective covering from the
ball coupling and store it in a safe place.
X Make sure that the ball of the ball coupling
is clean and that it is either greased or dry
(grease free), depending on the instruc-
tions for the trailer. Coupling up a trailer
X Make sure that the transmission is in posi-
tion P.
X Apply the electric parking brake.
X Position the trailer level behind the vehicle.
X Couple up the trailer.
X Establish the electric connection between
the vehicle and the trailer.
X Check that the trailer lighting system is
working.
A trailer that is connected is recognised
only when the electrical connection is
established correctly and when the lighting system is working properly. The function of
other systems, such as ESP ®
or PARK-
TRONIC 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. 204
Towing a trailerDriving an
d parking

!
Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable.
X Make sure that the transmission is in posi-
tion P.
X Apply the electric parking brake.
X Secure the trailer against rolling away.
X Remove the trailer cable and decouple the
trailer. Folding in the ball coupling
G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that the ball coupling engages when folding in.
X Fold the ball coupling back in if you are not
using the trailer tow hitch.
X Place the protective covering on the ball
coupling.
The release wheel is located behind the left-
hand side trim panel in the boot. X
To open the cover: turn handle:anti-
clockwise and fold down cover ;and
remove it. X
Pull out release wheel =.
X Turn release wheel =anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator lamp ?
flashes. X
Press the ball coupling in the direction of
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
! 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. Towing a trailer
205Driving and parking Z

The trailer battery may not be charged from
the power supply.
X To switch the connected power supply
on or off: turn the key in the ignition lock to
position 2or 0respectively.
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 instal-
ling the trailer electrics at a qualified special- ist workshop. 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 could 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 Trailer with 7-pin connector:
you can con-
nect 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. Other-
wise, damage may occur to the rear
bumper and the adapter cable. X
Open the socket cover.
X Insert the plug connector with lug :into
groove =on the socket. Turn bayonet con-
nection ;clockwise to the stop.
X Let the cover engage.
X If you are using an adapter cable, secure
the cable to the trailer with cable ties. 206
Towing a trailerDriving and parking

R
"From reset" trip computer
R ECO display
X Press the =or; button on the steer-
ing wheel to select the Trip
Tripmenu.
X Press the 9or: button to select the
function that you wish to reset.
X Press the abutton.
X Press the :button to select Yes
Yesand
press ato confirm.
i If you reset the values in the ECO display,
the values in the "From start" trip computer
are also reset. If you reset the values in the "From start" trip computer, the values in
the ECO display are also reset. Navigation menu
Displaying navigation instructions X
Switch on the audio system or COMAND
Online; see the separate operating instruc-
tions.
X Press the =or; button on the steer-
ing wheel to select the Navi
Navi menu.
In the Navi
Navi menu, the multifunction display
shows navigation instructions. For more
information, see the separate operating
instructions.
Route guidance not active :
Direction of travel
; Current road Activating route guidance No change of direction announced
:
Distance to the destination
; Distance to the next change of direction
= Current road
? Symbol indicating "follow the road's
course"
Change of direction announced without a lane recommendation :
Road to which the change of direction
leads
; Distance to change of direction and visual
distance display
= Change-of-direction symbol
When a change of direction is announced, you
will see symbol =for the change of direction
and distance graphic ;. This shortens
towards the top of the display as you
approach the point of the announced change
of direction. Menus and submenus
213On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions The red
!indicator lamp flashes and the yellow !warning
lamp is lit.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
To apply:
X Switch off the ignition and turn it back on.
X Apply the electric parking brake manually.
If the red !indicator lamp continues to flash:
X Do not drive on.
X Secure the vehicle against rolling away (Y page 325).
X Vehicles with manual transmission: engage first gear.
X Vehicles with automatic transmission: shift the transmission
to P.
X Turn the front wheels towards the kerb.
X Consult a qualified specialist workshop. The yellow
!warning lamp lights up. The red !indicator
lamp flashes for about ten seconds after the electric parking brake
has been applied or released. It then goes out or remains lit.
The electric parking brake is malfunctioning.
X Switch off the ignition and turn it back on.
X Apply the electric parking brake.
If it is not possible to apply the electric parking brake:
X Vehicles with manual transmission: engage first gear.
X Vehicles with automatic transmission: shift the transmission
to P.
X Visit a qualified specialist workshop.
If it is not possible to release the electric parking brake:
X Vehicles with manual transmission (automatic emergency
release): insert the seat belt in the belt buckle and accelerate
slightly more when pulling away.
X Vehicles with automatic transmission: release the electric
parking brake automatically (Y page 163).
If the electric parking brake still cannot be released:
X Consult a qualified specialist workshop. 234
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions b
Left tail lamp Left tail lamp
or
Right tail lamp
Right tail lamp The left or right-hand tail lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Left daytime driv‐ Left daytime driv‐
ing lamp ing lamp
orRight
Right
daytime driving
daytime driving
lamp lamp The left-hand or right-hand daytime driving lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 112).
or
X Visit a qualified specialist workshop. b
Intell. Light Sys‐ Intell. Light Sys‐
tem inoperative tem inoperative The Intelligent Light System is faulty. The lights remain available
without the Intelligent Light System.
X Visit a qualified specialist workshop. b
Malfunction See Malfunction See
Owner's Manual Owner's Manual The exterior lighting is faulty.
X Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X Check the fuses (Y page 314).
X If necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed: X Visit a qualified specialist workshop. b
AUTO AUTO
lights
lights inoper‐
inoper‐
ative
ative The light sensor is faulty.
X Visit a qualified specialist workshop. b
Switch off lights Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã.242
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is not
connected, the radar sensor system is deactivated automatically.
Blind Spot Assist is not available.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Lane Keeping
Lane Keeping
Assist currently Assist currently
unavailable See unavailable See
Owner's Manual Owner's Manual Lane Keeping Assist is deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for a longer period.
R the lane markings are worn, dark or covered, e.g. by dirt or snow.
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 162).
X Clean the windscreen. Lane Keeping Lane Keeping
Assist inoperative Assist inoperative Lane Keeping Assist is faulty.
X Visit a qualified specialist workshop. Blind Spot Assist
Blind Spot Assist
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual Blind Spot Assist is temporarily inoperative.
You have established the electrical connection between the trailer
and your vehicle.
X Press aon the steering wheel to confirm the display mes-
sage.
Blind Spot Assist is deactivated while towing a trailer. Display
messages
247On-board computer and displays Z