2008 MERCEDES-BENZ A-CLASS HATCHBACK towing

Trailer towing*
186 Trailer towing*
Fitting the ball coupling
X Make a note of the ball coupling key num-
ber.
i You can use this number to obtain a
replacement key from a Mercedes-Benz
Service Centre. G
Risk of injury
If the ball coupling does not engage prop-
erly when it is attached, the vehicle/trailer
combination is not secured and could
become detached. You could therefore
cause an accident. Attach the ball coupling
carefully and make sure that it engages.
Vehicles without ECO start/stop func-
tion: the attachable ball coupling is on the
right of the stowage compartment in the lug-
gage compartment (Y page 161).
X Open the stowage compartment on the
right-hand side of the luggage compart-
ment.
X Fold the trim downwards. Vehicles without ECO start/stop function
1
Ball coupling
2 Retainer strap
X Undo retainer strap 2.
X Remove ball coupling 1from the ball cou-
pling recess.
Vehicles with ECO start/stop function*:
the attachable ball coupling is in the ball cou-
pling recess in the stowage well underneath
the luggage compartment floor
(Y page 201).
X Open the luggage compartment floor. Vehicles with ECO start/stop function
1
Ball coupling
2 Ball coupling recess
X Remove ball coupling 1from the ball cou-
pling recess.2 1
Protective cap Operation
* optional
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Trailer towing*
187
X
Pull protective cap 1down in the direction
of the arrow out of the ball coupling recess.
X Place protective cap 1into the ball cou-
pling recess. 1
Key
2 Protective cap
X Pull protective cap 2off the lock in the
handwheel.
X Insert key 1into the ignition lock.
The red mark on the handwheel must be
aligned with the green area on the ball cou-
pling (fitting position). If this is not the case:
X Turn key 1in the direction of the arrow.
The key is released. 3
Ball coupling recess
4 Handwheel
X Pull handwheel 4away from the ball cou-
pling and turn it clockwise until it engages.
The green area on the ball coupling is
aligned with the red mark on the hand-
wheel.
X Insert the ball coupling in the direction of
the arrow into ball coupling recess 3until
it engages.
Handwheel 4turns so that green mark
5 on the handwheel is aligned with green
area 6on the ball coupling. 1
Key
2 Protective cap
5 Green mark on the handwheel
6 Green area on the ball coupling
X Turn key 1to the stop in the direction of
the arrow to lock.
X Remove key 1.
X Press protective cap 2onto the lock.
i You can store the key in the ball coupling
stowage compartment in the luggage com-
partment. Operation
* optional
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Trailer towing*
1881
Trailer power socket
X Fold trailer power socket 1down. G
Risk of accident
The ball coupling is only securely mounted
when the green mark on the handwheel is
aligned with the green area on the ball cou-
pling and the key can be removed. If the ball
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 coupling must
then not be used to tow a trailer, as safe
operation is not guaranteed.
Have the entire trailer coupling checked at
a qualified specialist workshop. Mercedes-
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.
Notes on towing a trailer
G
Risk of accident
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 nose-
weight
R the permissible trailer load
R the permissible rear axle load of the tow-
ing vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
You will find the applicable permissible val-
ues, which must not be exceeded, in the
vehicle documents.
You will find the values approved by the
manufacturer on the vehicle identification
plates and those for the towing vehicle in
the "Technical data" section.
You will find installation dimensions and loads
in the "Technical data" section
(Y page 290).
The maximum permissible trailer drawbar
noseweight on the ball coupling is 75 kg.
However, the actual drawbar load must not
exceed the value given on the trailer coupling
and trailer identification plates. The lowest
weight applies.
! Use a noseweight as close as possible to
the maximum permissible noseweight. Do Operation
* optional
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Trailer towing*
189
not use a noseweight of less than 50 kg,
otherwise the trailer may come loose.
Bear in mind that the payload and the rear
axle load are reduced by the actual nose-
weight.
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.
Coupling up a trailer G
Risk of injury
Do not connect a trailer with an engaged
overrun brake. Otherwise, your hand could
become trapped between the bumper and
drawbar.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise your
vehicle could be damaged by the spring
action of the overrun brake.
X Position the trailer level behind the vehicle.
X Couple up the trailer.
X Establish the electrical connection
between the vehicle and the trailer. Driving tips In Germany, the maximum permitted speed
for vehicle/trailer combinations is 80 km/h.
G
Risk of accident
A maximum speed of 80 km/h should not
be exceeded, even in countries where
higher speeds are permitted for vehicle/
trailer combinations. This lowers the risk of
an accident.
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 consumes more fuel
On long and steep downhill gradients, you
must select a lower gear in good time, or in
vehicles with AUTOTRONIC*, select shift
range 1,2or 3. i
This also applies if you have activated
cruise control* or Speedtronic*.
This will use the braking effect of the engine,
so less braking will be required to maintain
the speed. This relieves the load on the brake
system and prevents the brakes from over-
heating and wearing too quickly. If you need
additional braking, depress the brake pedal
repeatedly rather than continuously. G
Risk of accident
Never depress the brake pedal continu-
ously while the vehicle is in motion, e.g.
never cause the brakes to rub by applying
constant slight pedal pressure. This causes
the brake system to overheat, increases
the braking distance and can lead to the
brakes failing completely.
Driving tips
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, Operation
* optional
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Trailer towing*
190note that the power output of the engine,
and consequently the vehicle's gradient-
climbing capability, decrease with increas-
ing altitude.
If the trailer swings from side to side:
X Do not accelerate.
X Do not counter-steer.
X Brake if necessary. G
Risk of accident
On no account should you attempt to draw
the vehicle/trailer combination out by
increasing speed. Removing the ball coupling
X Pull the protective cap off the lock in the
handwheel.
X Insert the key into the lock in the hand-
wheel.
X Turn the key clockwise.
The lock is unlocked.
X Hold the ball coupling. Pull the handwheel
away from the ball coupling and turn it
clockwise until it engages.
The green area on the ball coupling is
aligned with the red mark on the hand-
wheel. X
Pull out the ball coupling downwards.
X Clean the ball coupling if it is dirty.
X Vehicles without ECO start/stop func-
tion*: open the stowage compartment on
the right of the luggage compartment.
X Fold the trim downwards.
X Vehicles with start/stop function*:
open the luggage compartment floor.
X Remove the protective cap from the ball
coupling recess.
X Press the protective cap into the ball cou-
pling recess until it engages.
Storing the ball coupling X
Store the ball coupling with the key inser-
ted in the ball coupling recess.
X Vehicle without ECO start/stop func-
tion: Secure the ball coupling in place using
the retainer strap. G
Risk of accident
Never transport an unsecured ball coupling
in the interior of the vehicle.
Otherwise, vehicle occupants could be
injured by the ball coupling being thrown if
you: R
brake sharply
R change direction suddenly
R have an accident Trailer po
wer supply
When it leaves the factory, your vehicle's
trailer socket outlet is equipped with a per-
manent 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 consumers with a power
rating of up to 240 W to the permanent
power supply and up to 180 W to the power
supply that is switched on via the ignition
lock.
You must not charge a trailer battery using
the power supply.
The trailer's turn signal lamps are only guar-
anteed to function when bulbs are used.
You can obtain further information about
installing the trailer electrics from a qualified Operation
* optional
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199
Where will I find...?
...........................200
Display messages ............................. 202
Troubleshooting ................................ 222
Locking/unlocking in an emer-
gency ................................................. 241
Changing the batteries .....................244
Changing the bulbs ...........................245
Replacing the wiper blades ..............251
Flat tyre ............................................. 253
Battery ............................................... 263
Jump-starting .................................... 266
Towing and tow-starting ..................268
Fuses .................................................. 271 Practical advice
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Troubleshooting
240 Trailer towing
Problem Possible cause/consequence Suggested solutions
The ball coupling cannot be
locked.
The key cannot be removed from
the ball coupling.
G
Risk of accident
The ball coupling is dirty.
The trailer tow hitch is damaged. X
Remove the ball coupling and clean it (Y page 196). Ifthe ball cou-
pling still cannot be locked, remove the ball coupling. It must no
longer be used to tow a trailer, as safe operation is not guaranteed.
X Have the entire trailer tow hitch checked at a qualified specialist
workshop. Parking up the vehicle
Problem Possible cause/consequence Suggested solutions
The vehicle is to be left parked up
for longer than six weeks. Damage resulting from non-use
may occur if the vehicle is parked
up for long periods. X
Visit a qualified specialist workshop and seek advice.
X Disconnect the battery ( Ypage 265). Practical advice
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Towing and tow-starting
268 Towing and tow-starting
Points to remember
G
Risk of accident
If you have the vehicle towed, you must use
a rigid towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the voltage sup-
ply or the vehicle's electrical system.
The electric power steering and the brake
force booster do not work when the engine
is not running. Greater braking force will
then be required and brake pedal travel will
be longer. If necessary, depress the brake
pedal with full force.
Do not tow the vehicle if the key cannot be
turned in the ignition lock. If this is the case,
the steering is locked and the vehicle can-
not be steered.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum per-
missible gross vehicle weight of your vehi-
cle.
It is better to have the vehicle transported
than to have it towed. When towing, observe the legal requirements
in all countries concerned.
!
When towing, pull away slowly and with-
out jerking. If the tractive power is too high,
the vehicles could be damaged.
! Do not use the towing eye for recovery,
as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! You may tow the vehicle for a maximum
of 50 km. A towing speed of 50 km/h must
not be exceeded.
With towing distances over 50 km, the
entire vehicle needs to be lifted up and
transported.
! Only secure the tow cable or towing bar
to the towing eyes. You may otherwise
damage the vehicle.
R Vehicles with AUTOTRONIC* must not be
tow-started.
R If the engine does not start, try jump-start-
ing it (Y page 266).
R If it is not possible to jump-start the vehicle,
have it towed to the nearest qualified spe-
cialist workshop, e.g. a Mercedes-Benz
Service Centre. R
The selector lever must be in position N
when towing a vehicle with AUTO-
TRONIC*.
R If you are towing the vehicle over a consid-
erable distance, this must only be done
with the front axle raised.
R The ignition must be switched off if you are
towing the vehicle with the front/rear axle
raised. Intervention by ESP ®
could other-
wise damage the brake system.
R Before towing the vehicle, make sure that
the battery is connected and charged. Oth-
erwise:
-you cannot switch on the ignition
- you cannot move the selector lever
to N(on vehicles with AUTOTRONIC*)
- you have no support when braking
i Switch off the automatic locking feature
before the vehicle is towed (Y page 111).
You could otherwise be locked out when
pushing or towing the vehicle. Practical advice
* optional
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