tow MERCEDES-BENZ A CLASS 2012 Service Manual

When driving at speeds below 30 km/h, you
will see parking symbol
; as a status indi-
cator
in the instrument cluster. When a park-
ing space has been detected, an arrow
towards the right or the left also appears.
Active Parking Assist only displays parking
spaces on the front-passenger side as stand-
ard. Parking spaces on the driver's side are
displayed as soon as the turn signal on the
driver's side is activated. When parking on the
driver's side, this must remain switched on
until you acknowledge the use of Active Park-
ing Assist by pressing the a button on the
multifunction steering wheel.
A parking space is displayed while you are
driving past it, and until you are approx-
imately 15 m away from it.
Parking G
WARNING
Active Parking Assist merely aids you by inter-
vening
actively in the steering. There is a risk
of accident if you do not apply the brakes
yourself.
Always apply the brakes yourself when park-
ing and manoeuvring.
Active Parking Assist does not support you
with parking spaces parallel to the direction
of travel if:
R the parking space is on a kerbstone
R the parking space is apparently blocked,
for example by foliage or grass paving
blocks
R the range of movement is too small
R the parking space is bordered by an obsta-
cle which is not clearly defined such as a
tree or a trailer
X Stop the vehicle when the parking symbol
shows the desired parking space in the
instrument cluster.
X Vehicles with manual transmission: shift to
reverse gear. Vehicles with automatic transmission: shift
into position R.
The Start Park Assist? Yes: OK No:
%

message appears in the multifunction
display.
X To cancel the procedure: press the
% button on the multifunction steering
wheel or pull away.
or
X To park using Active Parking Assist:
press

the a button on the multifunction
steering wheel.
The Park Assist active Accelerate
and brake Observe surroundings mes-
sage appears in the multifunction display.
X Release the multifunction steering wheel.
X Reverse the vehicle, being ready to brake
at all times. Do not exceed a maximum
speed of approximately

10 km/h when
reversing. Otherwise, Active Parking Assist
will be cancelled.
i In tight parking spaces, you will achieve
the best parking results by backing up as
far as possible. When doing so, also
observe the PARKTRONIC messages.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.
Manoeuvring

may be required in tight park-
ing spaces.
Vehicles with manual transmission: the Park
Assist active Engage forward gear
Observe

surroundings message appears in
the multifunction display.
Vehicles with automatic transmission: the
Park Assist active Select D Observe
surroundings message appears in the mul-
tifunction display.
X Vehicles with manual transmission: while
the vehicle is stationary, shift to first gear.
Vehicles with automatic transmission:
select transmission position D while the
vehicle is stationary.
Active

Parking Assist immediately steers in
the other direction. 188
Driving systems
Driving and parking

10 km/h when exiting a parking space.
Otherwise, Active Parking Assist will be
cancelled.
X Stop when PARKTRONIC sounds the con-
tinuous warning tone, if not before.
X Vehicles with manual transmission:
shift to first or reverse gear as required
while the vehicle is stationary.
Vehicles with automatic transmission:
shift
to position D or R as required while the
vehicle is stationary.
Active Parking Assist immediately steers in
the other direction. The Park Assist
active Accelerate and brake
Observe surroundings message appears
in the multifunction display.
i You will achieve the best results by wait-
ing

for the steering procedure to complete
before pulling away.
If you reverse after activation, the steering
wheel is moved to the straight-ahead posi-
tion.
X Drive forwards or reverse the vehicle, being
ready to brake at all times.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.
X Drive forwards and reverse as prompted by
the

PARKTRONIC warning displays, several
times if necessary.
Once you have exited the parking space com-
pletely, the steering wheel is moved to the
straight-ahead position. You hear a tone and
the Park Assist switched off message
appears

in the multifunction display. You will
then have to steer and merge into traffic on
your own. PARKTRONIC is still available. Cancelling Active Parking Assist You can cancel Active Parking Assist at any
time.
X
Stop the movement of the multifunction
steering wheel or steer yourself.
Active Parking Assist will be cancelled at
once. The Park Assist cancelled mes-
sage appears in the multifunction display.
or
X Press the PARKTRONIC button on the
centre console

(Y page 185).
PARKTRONIC is switched off and Active
Parking Assist is immediately cancelled.
The Park Assist cancelled message
appears in the multifunction display.
Active Parking Assist is cancelled automati-
cally if:
R you engage the electric parking brake.
R parking using Active Parking Assist is no
longer possible.
R you are driving faster than 10 km/h.
R a

wheel spins and ESP ®
intervenes or fails.
The ÷ warning lamp lights up in the
instrument cluster.
A warning tone sounds. The parking space
symbol disappears and the multifunction dis-
play shows the Park Assist cancelled
message.
When Active Parking Assist is cancelled, you
must steer again yourself.
If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the
accelerator again.
Towing a trailer For vehicles with a trailer tow hitch, the min-
imum required length for parking spaces is
slightly increased.
If you have attached a trailer to your vehicle,
you should not use Active Parking Assist.
Once

the electrical connection is established
between your vehicle and the trailer, Active
Parking Assist is no longer available. PARK-
TRONIC is deactivated for the rear area. 190
Driving systems
Driving and parking

Reversing camera
Important safety notes The reversing camera is only an aid. It is not
a substitute for your attention to the imme-
diate
surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that there are no persons, animals
or objects in range while manoeuvring and
parking.
Under the following circumstances, the
reversing camera will not function, or will
function in a limited manner:
R if the tailgate is open
R in heavy rain, snow or fog
R at night or in very dark places
R if the camera is exposed to very bright light
R if the area is lit by fluorescent light or LED
lighting (the display may flicker)
R if there is a sudden change in temperature,
e.g. when driving into a heated garage in
winter
R if the camera lens is dirty or obstructed
R if the rear of your vehicle is damaged. In
this event, have the camera position and
setting checked at a qualified specialist
workshop.
General notes Reversing camera
:
is in the boot lid handle.
The reversing camera extends, when it is acti-
vated.
The reversing camera is an optical parking
and manoeuvring aid. It uses guide lines to show the area behind your vehicle in the
Audio/COMAND display.
The area behind the vehicle is displayed as a
mirror image, as in the rear-view mirror.
i
The text of messages shown in the
COMAND

display depends on the language
setting. The following are examples of
reversing camera messages in the
COMAND display.
Activating/deactivating the reversing
camera X
To activate: make sure that the key is in
position 2 in the ignition lock.
X Make sure that the "Activation by R gear"
setting is active in the audio system/
COMAND Online; see the separate audio
system/COMAND Online operating
instructions.
X Engage reverse gear.
Guide lines are used to show the area
behind the vehicle in the Audio/COMAND
display. Function mode display for vehicles with COMAND
Online and a trailer tow hitch
X
To change the function mode in vehi-
cles with COMAND Online and trailer
tow hitch: using the COMAND controller,
select

symbol : for the "Reverse parking" Driving systems
191
Driving and parking Z

function; see the separate COMAND Online
operating instructions.
or
X Select symbol ; for the coupling up a
trailer
function (see the separate COMAND
Online operating instructions).
The symbol of the selected function is high-
lighted.
To deactivate:
the reversing camera is deac-
tivated if you:
R select transmission position P (vehicles
with automatic transmission)
R drive forward ten metres
R for vehicles with an automatic transmis-
sion, shift the transmission from R to
another position after 15 seconds
R shift out of reverse gear (vehicles with man-
ual transmission) after 15 seconds
R drive forwards at a speed of over
10 km/h
Displays in the Audio/COMAND display The reversing camera may show a distorted
view of obstacles, show them incorrectly or
not at all. Obstacles are not shown by the
reversing camera in the following locations:
R
very close to the rear bumper
R under the rear bumper
R in the area immediately above the tailgate
handle
! Objects

not at ground level may appear to
be further away than they actually are, e.g.:
R the bumper of a parked vehicle
R the drawbar of a trailer
R the ball coupling of a trailer tow hitch
R the rear section of an HGV
R a slanted post
Use the guidelines only for orientation.
Approach objects no further than the bot-
tom-most guideline. Lanes
:
White guide line without turning the steer-
ing wheel, vehicle width including the
exterior mirrors (static)
; Yellow lane marking the course the tyres
will take at the current steering wheel
angle, vehicle width including the outer
edge of the wheel (dynamic)
= Red guide line for the vehicle width includ-
ing

the exterior mirrors, for current steer-
ing wheel angle (dynamic)
? Bumper Guide lines
?
Bumper
A Red guide line at a distance of approx-
imately

0.25 m from the rear of the vehicle
B Yellow guide line at a distance of approx-
imately

4.0 m from the rear of the vehicle
C Vehicle centre axle (marker assistance)
D Yellow guide line at a distance of approx-
imately

1.0 m from the rear of the vehicle
The lanes and guide lines are only displayed
if you have engaged reverse gear. 192
Driving systems
Driving and parking

Turning the steering wheel
:
Red lane indicating the route the vehicle
will
take with the steering wheel in its cur-
rent position
; Parking space marking
X While the vehicle is at a standstill, turn the
steering

wheel in the direction of the park-
ing space until the red lane reaches parking
space marking ;.
X Keep the steering wheel in that position
and reverse carefully. Reversing with the steering wheel turned
:
Red lane indicating the route the vehicle
will

take with the steering wheel in its cur-
rent position
X Stop the vehicle when it is almost exactly
in front of the parking space.
The

white lane should be as close to parallel
with the parking space marking as possi-
ble. Driving to the final position
:
White lane indicating the route the vehicle
will

take with the steering wheel in its cur-
rent position
; Parking space marking
X Turn the steering wheel to the centre posi-
tion while the vehicle is stationary. :
Red guide line at a distance of approx-
imately

0.25 m from the rear of the vehicle
; White lane indicating the route the vehicle
will take with the steering wheel straight
= End of parking space
X Reverse carefully until you have reached
the end position.
Red guide line :

is then at end of parking
space =. The vehicle is almost parallel in
the parking space.
"Coupling up a trailer" function This function is only available on vehicles with
a trailer tow hitch and COMAND Online.194
Driving systems
Driving and parking

R
the traffic signs are poorly illuminated
R there are ambiguous traffic signs, for
instance near roadworks or on multi-lane
roads
Information
in the multifunction displayBriefly showing detected traffic signs in
the multifunction display
X
Activate the Speed Limit Assist warning
function using the on-board computer
(Y page 218).
A

traffic sign indicating a speed limit or the
end of a speed limit appears in the multi-
function display for around five seconds as
soon as it is detected. Any other informa-
tion in the multifunction display is hidden
for this period. :
Maximum permissible speed (example)
; Maximum permissible speed for vehicles
subject

to the restriction in the additional
sign (example)
= Additional character in fog
? Speed Limit Assist is available and
switched on Permanently showing detected traffic
signs in the multifunction display
X
Display the assistance graphic using the
on-board computer (Y page 217).
A

traffic sign indicating a speed limit or the
end of a speed limit appears in the multi-
function display as soon as it is detected.
The traffic sign indicating a speed limit : is
generally displayed until:
R a

traffic sign indicating the end of the speed
limit is detected.
R you make a turn.
R you leave or enter a town.
R the road type changes (e.g. motorway,
country road).
R you have travelled a certain minimum dis-
tance without the traffic sign being repea-
ted or detected again. Lane Tracking package
General notes The Lane Tracking package consists of Blind
Spot Assist

(Y page 198) and Lane Keeping
Assist (Y page 199).
Blind Spot Assist Important safety notes
G
WARNING
Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R if you overtake these with a difference in
speed in excess of 12 km/h
R or if they approach with a great relative
speed and overtake you
As a result, Blind Spot Assist cannot warn
drivers in these situations. There is a risk of
an accident.
Always

pay careful attention to the traffic sit-
uation and maintain a safe distance at the side
of the vehicle. Driving systems
197
Driving and parking Z

Indicator and warning display
Blind
Spot Assist is not active at speeds below
approximately 30 km/h. Vehicles in the mon-
itoring range are then not indicated. :
Yellow indicator lamp/red warning lamp
If Blind Spot Assist is switched on, indicator
lamp : in the exterior mirrors lights up yel-
low up to a speed of

30 km/h. At speeds
above 30 km/h, the indicator lamp goes out
and Blind Spot Assist is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
30 km/h, warning lamp : on the corre-
sponding side lights up in red. This warning
always occurs when a vehicle enters the blind
spot monitoring range from behind or from
the side. When you overtake a vehicle, the
warning only occurs if the difference in speed
is less than 12 km/h.
The yellow indicator lamp goes out if reverse
gear is engaged. Blind Spot Assist is then
deactivated.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp : flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :. There are no further warning tones. Activating Blind Spot Assist
X
Make sure that the radar sensor system
(Y page 223) and Blind Spot Assist
(Y page

219) are activated in the on-board
computer.
X Turn the key to position 2 in the ignition
lock.
Warning lamps : in the exterior mirrors
light up red for approximately
1.5 seconds

and then turn yellow.
Towing a trailer
If
you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamp lights up yel-
low in the exterior mirrors and the Blind
Spot Assist currently unavailable
See Owner's Manual message appears in
the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist if:
R the key is in position 2 in the ignition
lock.
R the engine is not running.
R the electrical connection to the trailer
has been established.
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front

of your vehicle by means of a camera at
the top of the windscreen. Lane Keeping
Assist detects lane markings on the road and
warns you before you leave your lane unin-
tentionally. Driving systems
199
Driving and parking Z

When
Standard is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this event, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
When Adaptive is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane
marking, the system recognises certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a motor-
way.
R the system recognises solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend. Towing a trailer
Notes on towing a trailer
Important safety notes G
WARNING
The braking system can overheat if you leave
your foot on the brake pedal while driving.
This

increases the braking distance and could even cause the braking system to fail. There
is a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal

and the accelerator pedal while driving. G
WARNING
You could lose control of the vehicle/trailer
combination if it begins to swerve. The vehi-
cle/trailer combination could even overturn.
There is a risk of an accident.
On no account should you attempt to
straighten out the vehicle/trailer combina-
tion by increasing speed. Decrease your
speed and do not countersteer. Brake if nec-
essary. G
WARNING
If the maximum the permissible load for a car-
rier system is exceeded, the carrier could
come loose from the vehicle and endanger
other

road users. There is a risk of an accident
and injury.
Never exceed the permissible noseweight
when using a carrier.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
Trailer towing is not permissible on the fol-
lowing models:
R A 45 AMG 4MATIC
R Vehicles with the AMG Sports package
If you exceed the maximum permissible nose-
weight of the trailer drawbar on the ball cou-
pling, the following may become damaged:
R your vehicle
R the trailer
R the ball coupling
R the trailer tow hitch
The vehicle/trailer combination could
become unstable.
If the noseweight used is lower than the min-
imum permissible noseweight, the vehicle/ Towing a trailer
201
Driving and parking Z

trailer combination could also become unsta-
ble.
To avoid hazardous situations:
R
make
sure to check the noseweight before
each journey.
R use a drawbar noseweight as close as pos-
sible to the maximum noseweight.
R do not exceed the maximum permissible
noseweight.
R do not use a noseweight lower than the
minimum permissible trailer drawbar nose-
weight.
When reversing the vehicle towards the
trailer, make sure there is nobody between
the trailer and the vehicle.
Couple and uncouple the trailer carefully. If
you do not couple the trailer to the towing
vehicle correctly, the trailer could become
detached.
Make sure that the following values are not
exceeded:
R the permissible trailer drawbar noseweight
R the permissible trailer load
R the permissible rear axle load of the towing
vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
The applicable permissible values, which
must not be exceeded, can be found:
R in your vehicle documents
R on the identification plates of the trailer tow
hitch and the trailer
R on the vehicle identification plate
If the values differ, the lowest value applies.
You will find the values approved by the man-
ufacturer on the vehicle identification plates
and those for the towing vehicle under "Tech-
nical data" ( Y page 349).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer. The vehicle/trailer combination:
R
is heavier
R is restricted in its acceleration and gradi-
ent-climbing capability
R has an increased braking distance
R is affected more by strong crosswinds
R demands more sensitive steering
R has a larger turning circle
This can impair the vehicle's handling char-
acteristics.
Adapt your style of driving accord-
ingly. Maintain a safe distance. Drive care-
fully.
When towing a trailer, always adjust your
speed to the current road and weather con-
ditions. Do not exceed the maximum permis-
sible speed for your vehicle/trailer combina-
tion.
General notes X
When towing a trailer, set the tyre pressure
on the rear axle of the towing vehicle for a
maximum

load; see the tyre pressure table
in the fuel filler flap ( Y page 321).
Please note that when towing a trailer, PARK-
TRONIC ( Y page 182) and Blind Spot Assist
(Y

page 197) availability is limited or not avail-
able at all.
i The height of the ball coupling changes
with the load of the vehicle. If necessary,
use a trailer with a height-adjustable draw-
bar.
You will find fitting dimensions and loads
under "Technical data" ( Y page 348).
Driving tips i
Observe the notes on ESP ®
trailer stabi-
lisation ( Y page 68).
The

maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check
the trailer's documents to see what the max-
imum permitted speed is. Observe the legally 202
Towing a trailer
Driving and parking

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/h for
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 M is temporarily activated
(vehicles with automatic transmission): the
automatic transmission may switch back to
the last active automatic drive program E
or S. The automatic transmission may shift
to a higher gear. This can reduce the
engine's braking 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
203
Driving and parking Z