Get Operation -> Trailer towing* Guide for Mercedes A Class 4 Door Second Generation (2004-2011)

Operation

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-

Vehicles without ECO start/stop function

Vehicles with ECO start/stop function

erly when it is attached, the vehicle/trailer

1 Ball coupling

combination is not secured and could

2 Retainer strap

2 Ball coupling recess

become detached. You could therefore

X Undo retainer strap 2.

X Remove ball coupling 1 from the ball cou-

cause an accident. Attach the ball coupling

pling recess.2

carefully and make sure that it engages.

X Remove ball coupling 1 from the ball cou-

pling recess.

Vehicles without ECO start/stop func-

Vehicles with ECO start/stop function*:

tion: the attachable ball coupling is on the

the attachable ball coupling is in the ball cou-

right of the stowage compartment in the lug-

pling recess in the stowage well underneath

gage compartment ( Y page 161).

the luggage compartment floor

X Open the stowage compartment on the

( Y page 201).

right-hand side of the luggage compart-

X Open the luggage compartment floor.

ment.

X Fold the trim downwards.

1 Protective cap

* optional

186

Operation

Trailer towing*

X Pull protective cap 1 down in the direction

of the arrow out of the ball coupling recess.

X Place protective cap 1 into the ball cou-

pling recess.

3 Ball coupling recess

1 Key

4 Handwheel

2 Protective cap

5 Green mark on the handwheel

X Pull handwheel 4 away from the ball cou-

6 Green area on the ball coupling

pling and turn it clockwise until it engages.

1 Key

The green area on the ball coupling is

X Turn key 1 to the stop in the direction of

aligned with the red mark on the hand-

2 Protective cap

the arrow to lock.

wheel.

X Remove key 1.

X Pull protective cap 2 off the lock in the

X Insert the ball coupling in the direction of

X Press protective cap 2 onto the lock.

handwheel.

the arrow into ball coupling recess 3 until

X Insert key 1 into the ignition lock.

it engages.

i You can store the key in the ball coupling

The red mark on the handwheel must be

Handwheel 4 turns so that green mark

stowage compartment in the luggage com-

aligned with the green area on the ball cou-

5 on the handwheel is aligned with green

partment.

pling (fitting position). If this is not the case:

area 6 on the ball coupling.

X Turn key 1 in the direction of the arrow.

The key is released.

* optional

187

Operation

Trailer towing*

If the ball coupling can still not be fitted

R the permissible trailer drawbar nose-

(locked) after it has been cleaned, remove

weight

the ball coupling. The trailer coupling must

R the permissible trailer load

then not be used to tow a trailer, as safe

R the permissible rear axle load of the tow-

operation is not guaranteed.

ing vehicle

Have the entire trailer coupling checked at

R the maximum permissible gross vehicle

a qualified specialist workshop. Mercedes-

weight of both the towing vehicle and the

Benz recommends that you use a

trailer

Mercedes-Benz Service Centre for this pur-

pose. In particular, work relevant to safety

You will find the applicable permissible val-

or on safety-related systems must be car-

ues, which must not be exceeded, in the

1 Trailer power socket

ried out at a qualified specialist workshop.

vehicle documents.

X Fold trailer power socket 1 down.

You will find the values approved by the

G Risk of accident

manufacturer on the vehicle identification

Notes on towing a trailer

plates and those for the towing vehicle in

The ball coupling is only securely mounted

G Risk of accident

the "Technical data" section.

when the green mark on the handwheel is

aligned with the green area on the ball cou-

When reversing the vehicle towards the

You will find installation dimensions and loads

pling and the key can be removed. If the ball

trailer, make sure there is nobody between

in the "Technical data" section

coupling is not securely mounted, it may

the trailer and the vehicle.

( Y page 290).

come loose.

Couple and uncouple the trailer carefully. If

The maximum permissible trailer drawbar

The ball coupling must be locked and the

you do not couple the trailer to the towing

noseweight on the ball coupling is 75 kg.

key must be removed when towing a trailer.

vehicle correctly, the trailer could become

However, the actual drawbar load must not

This is the only way to guarantee that the

detached.

exceed the value given on the trailer coupling

ball coupling is secured and cannot come

Make sure that the following values are not

and trailer identification plates. The lowest

loose while the vehicle is in motion. If the

exceeded:

weight applies.

ball coupling cannot be locked and the key

cannot be removed, remove the ball cou-

! Use a noseweight as close as possible to

pling and clean it.

the maximum permissible noseweight. Do

* optional

188

Operation

Trailer towing*

Driving tips

not use a noseweight of less than 50 kg,

i This also applies if you have activated

otherwise the trailer may come loose.

cruise control* or Speedtronic*.

In Germany, the maximum permitted speed

Bear in mind that the payload and the rear

for vehicle/trailer combinations is 80 km/h.

This will use the braking effect of the engine,

axle load are reduced by the actual nose-

so less braking will be required to maintain

G Risk of accident

weight.

the speed. This relieves the load on the brake

A maximum speed of 80 km/h should not

system and prevents the brakes from over-

i The height of the ball coupling changes

be exceeded, even in countries where

heating and wearing too quickly. If you need

with the load of the vehicle. If necessary,

higher speeds are permitted for vehicle/

additional braking, depress the brake pedal

use a trailer with a height-adjustable draw-

trailer combinations. This lowers the risk of

repeatedly rather than continuously.

bar.

an accident.

G Risk of accident

When towing a trailer, your vehicle's handling

Coupling up a trailer

Never depress the brake pedal continu-

characteristics will be different in comparison

ously while the vehicle is in motion, e.g.

G Risk of injury

to when driving without a trailer.

never cause the brakes to rub by applying

The vehicle/trailer combination:

Do not connect a trailer with an engaged

constant slight pedal pressure. This causes

overrun brake. Otherwise, your hand could

R is heavier

the brake system to overheat, increases

become trapped between the bumper and

the braking distance and can lead to the

R is restricted in its acceleration and gradi-

drawbar.

brakes failing completely.

ent-climbing capability

Driving tips

R has an increased braking distance

! Do not disconnect a trailer with an

R Maintain a greater distance from the vehi-

engaged overrun brake. Otherwise your

R is affected more by strong crosswinds

cle in front than when driving without a

vehicle could be damaged by the spring

R demands more sensitive steering

trailer.

action of the overrun brake.

R consumes more fuel

R Avoid braking abruptly. If possible, brake

X Position the trailer level behind the vehicle.

On long and steep downhill gradients, you

gently at first to allow the trailer to run on.

X Couple up the trailer.

must select a lower gear in good time, or in

Then increase the braking force rapidly.

X Establish the electrical connection

vehicles with AUTOTRONIC*, select shift

R The values given for gradient-climbing

between the vehicle and the trailer.

range 1, 2 or 3.

capabilities from a standstill refer to sea

level. When driving in mountainous areas,

* optional

189

Operation

Trailer towing*

note that the power output of the engine,

X Pull out the ball coupling downwards.

R brake sharply

and consequently the vehicle's gradient-

X Clean the ball coupling if it is dirty.

R change direction suddenly

climbing capability, decrease with increas-

X Vehicles without ECO start/stop func-

R have an accident

ing altitude.

tion*: open the stowage compartment on

If the trailer swings from side to side:

the right of the luggage compartment.

X Do not accelerate.

X Fold the trim downwards.

Trailer power supply

X Do not counter-steer.

X Vehicles with start/stop function*:

When it leaves the factory, your vehicle's

open the luggage compartment floor.

X Brake if necessary.

trailer socket outlet is equipped with a per-

X Remove the protective cap from the ball

G Risk of accident

manent power supply and a power supply that

coupling recess.

is switched on via the ignition lock.

On no account should you attempt to draw

X Press the protective cap into the ball cou-

the vehicle/trailer combination out by

The permanent power supply is supplied via

pling recess until it engages.

increasing speed.

trailer socket pin 9.

The power supply that is switched on via the

Storing the ball coupling

ignition lock is supplied via trailer socket pin

Removing the ball coupling

10.

X Store the ball coupling with the key inser-

X Pull the protective cap off the lock in the

ted in the ball coupling recess.

! You can connect consumers with a power

handwheel.

X Vehicle without ECO start/stop func-

rating of up to 240 W to the permanent

X Insert the key into the lock in the hand-

tion: Secure the ball coupling in place using

power supply and up to 180 W to the power

wheel.

the retainer strap.

supply that is switched on via the ignition

X Turn the key clockwise.

lock.

G Risk of accident

The lock is unlocked.

You must not charge a trailer battery using

Never transport an unsecured ball coupling

X Hold the ball coupling. Pull the handwheel

the power supply.

in the interior of the vehicle.

away from the ball coupling and turn it

The trailer's turn signal lamps are only guar-

Otherwise, vehicle occupants could be

clockwise until it engages.

anteed to function when bulbs are used.

injured by the ball coupling being thrown if

The green area on the ball coupling is

you:

You can obtain further information about

aligned with the red mark on the hand-

installing the trailer electrics from a qualified

wheel.

* optional

190

Operation -> Trailer towing* for Your Mercedes A Class 4 Door Second Generation (2004-2011)

Related Topics

Popular Owner Manuals

Latest Owner Manuals