226Driving and operatingThe permissible gross train weight
must not be exceeded. This weight is
specified on the identification plate
3 281.
Vertical coupling load The vertical coupling load is the load
exerted by the trailer on the coupling
ball. It can be varied by changing the
weight distribution when loading the
trailer.
The maximum permissible vertical
coupling load of:
● 60 kg (Grand Sport with all engines except B20DTH /
B20NFT / D20DTR)
● 75 kg (Sports Tourer, Country Tourer with all engines except
B20DTH / B20NFT / D20DTR)
● 90 kg (All bodystyles with engines B20DTH / B20NFT /
D20DTR)
is specified on the towing equipment
identification plate and in the vehicle
documents. Always aim for the
maximum load, especially in the case
of heavy trailers. The vertical coupling
load should never fall below 25 kg.Rear axle load
When the trailer is coupled and the
towing vehicle fully loaded, the
permissible rear axle load (see
identification plate or vehicle
documents) may be exceeded by
70 kg (engines B20DTH: 80 kg), the
gross vehicle weight rating must not
be exceeded. If the permissible rear
axle load is exceeded, a maximum
speed of 100 km/h applies.
Towing equipmentCaution
The folding coupling ball bar
cannot be removed from the
vehicle. When driving without a
trailer, fold in the coupling ball bar.
9 Warning
Make sure that no one is in the
pivot zone of the coupling ball bar. Risk of body injury.
When releasing the stowed
coupling ball bar, make sure to
stand left of the grip.
Release stowed coupling ball bar
Pull the grip located left to the number
plate under the rear bumper fascia at an angle of approx. 45° to the ground.
Driving and operating227
A buzzing tone sounds as a warning
when the release handle is pulled out and the ball neck is disengaged.
Take the released coupling ball bar
and raise it up until it engages.
Ensure the coupling ball bar is
correctly engaged and the released
handle is guided back to its hidden
initial position, otherwise the buzzing
tone will not stop.
Stow / hide coupling ball bar
Pull the grip located left of the number
plate under the rear bumper fascia at an angle of approx. 45° to the ground.
A buzzing tone sounds as a warning
when the release handle is pulled out and the ball neck is disengaged.
With the flat of the hand, swivel the
released coupling ball bar to the right
until it engages under the floor. Make sure that the release handle is back inits hidden initial position, otherwise
the buzzing tone will not stop.
9 Warning
Towing a trailer is permitted only
when the coupling ball bar is fitted correctly. If the coupling ball bar
does not engage correctly or if the
Vehicle care231Vehicle checks
Performing work9 Warning
Only perform engine compartment
checks when the ignition is off.
The cooling fan may start
operating even if the ignition is off.
9 Danger
The ignition system uses
extremely high voltage. Do not
touch.
Bonnet
Opening
Pull the release lever and return it to
its original position.
Move the safety catch sideways to the left vehicle side and open the bonnet.
The bonnet is held open
automatically.
If the bonnet is opened during an
Autostop, the engine will be restarted automatically for safety reasons.
Stop-start system 3 157.
Closing Lower the bonnet and let it fall into the
latch from a low height (20-25 cm).
Check that the bonnet is engaged.
234Vehicle careDepending on the engine, the
position of the coolant container may be different.9 Warning
Allow the engine to cool before
opening the cap. Carefully open
the cap, relieving the pressure
slowly.
To top up, use a 1:1 mixture of
released coolant concentrate mixed
with clean tap water. If no coolant
concentrate is available, use clean
tap water. Install the cap tightly. Have the coolant concentration checked
and have the cause of the coolant
loss remedied by a workshop.
Washer fluid
Fill with clean water mixed with a
suitable quantity of approved
windscreen washer fluid which
contains antifreeze.
Caution
Only washer fluid with a sufficient
antifreeze concentration provides
protection at low temperatures or
a sudden drop in temperature.
Washer fluid 3 279.
Brakes
In the event of minimum thickness of
the brake lining, a squealing noise
sounds during braking.
Continued driving is possible but
have the brake lining replaced as
soon as possible.
Once new brake linings are installed,
do not brake unnecessarily hard for
the first few journeys.
Brake fluid9 Warning
Brake fluid is poisonous and
corrosive. Avoid contact with eyes, skin, fabrics and painted surfaces.
236Vehicle careReplacing the vehicle batteryNote
Any deviation from the instructions
given in this section may lead to
temporary deactivation or
disturbance of the stop-start system.
When the vehicle battery is being
replaced, please ensure that there
are no open ventilation holes in the
vicinity of the positive terminal. If a
ventilation hole is open in this area, it
must be closed off with a dummy cap, and the ventilation in the vicinity of the negative terminal must be opened.
Ensure that the battery is always
replaced by the same type of battery.
We recommend that you have the
vehicle battery replaced by a
workshop.
Stop-start system 3 157.Charging the vehicle battery9 Warning
On vehicles with stop-start
system, ensure that the charging potential does not exceed 14.6 V
when using a battery charger.
Otherwise the vehicle battery may be damaged.
Jump starting 3 269.
Discharge protection Battery voltage
When the vehicle battery voltage is
running low, a warning message will
appear in the Driver Information
Centre.
1. Switch off any electrical consumers which are not requiredfor a safe ride, e.g. seat heating,
heated rear window or other main consumers.
2. Charge the vehicle battery by driving continuously for a while or
by using a charging device.
The warning message will disappear
after the engine has been started
twice without a voltage drop.
If the vehicle battery cannot be
recharged, have the cause of the fault
remedied by a workshop.
Vehicle battery state of charge
function
The function guarantees longest vehicle battery life via a generator
with controllable power output and
optimised power distribution.
To prevent discharge of the vehicle
battery when driving, the following
systems are reduced automatically in two stages and finally switched off:
● auxiliary heater
● heated rear and front window
● heated steering wheel
● heated mirrors
● heated seats
● fan
In the second stage, a message
which confirms the activation of the
vehicle battery discharge protection
will be displayed in the Driver
Information Centre.
Vehicle care237Idle boost
If charging of the vehicle battery is
required due to battery condition, the
power output of the generator must
be increased. This will be achieved by
an idle boost which may be audible.
A message appears in the Driver
Information Centre.
Power outlet
The power outlets are deactivated in
the event of low vehicle battery
voltage.
Warning labelMeaning of symbols: ● No sparks, naked flames or smoking.
● Always shield eyes. Explosive gases can cause blindness or
injury.
● Keep the vehicle battery out of reach of children.
● The vehicle battery contains sulphuric acid which could cause
blindness or serious burn
injuries.
● See the Owner's Manual for further information.
● Explosive gas may be present in the vicinity of the vehicle battery.
Diesel fuel system bleeding If the tank has been run dry, the diesel
fuel system must be bled. Switch on
the ignition three times for
15 seconds at a time. Then crank the
engine for a maximum of 40 seconds. Repeat this process after
no less than 5 seconds. If the engine fails to start, seek the assistance of a
workshop.Wiper blade replacement
Windscreen
Lift the wiper arm until it stays in the
raised position. Lift retaining clip to
disengage the wiper blade and
remove.
Attach the wiper blade slightly angled
to the wiper arm and push until it
engages.
Lower wiper arm carefully.
256Vehicle careIncorrect tyre pressures will impair
safety, vehicle handling, comfort and
fuel economy and will increase tyre
wear.
Tyre pressures differ depending on
various options. For the correct tyre
pressure value, follow the procedure
below:
1. Identify drive axle and body style.
2. Identify the engine identifier code.
Engine data 3 286.
3. Identify the respective tyre.
The tyre pressure tables show all possible tyre combinations 3 293.
For the tyres approved for your
vehicle, refer to the EEC Certificate of
Conformity provided with your vehicle or other national registration
documents.
The driver is responsible for correct
adjustment of tyre pressure.9 Warning
If the pressure is too low, this can
result in considerable tyre warm-
up and internal damage, leading to tread separation and even to tyre
blow-out at high speeds.
9 Warning
For specific tyres the
recommended tyre pressure as
shown in the tyre pressure table may exceed the maximum tyre
pressure as indicated on the tyre.
Never exceed the maximum tyre
pressure as indicated on the tyre.
After adjusting tyre pressure, select
the according tyre loading setting on
the page Tyre load in the Driver
Information Centre 3 111.
Temperature dependency The tyre pressure depends on the
temperature of the tyre. During
driving, tyre temperature and
pressure increase. Tyre pressure
values provided on the tyre
information label and tyre pressure
chart are valid for cold tyres, which means at 20 °C.
The pressure increases by nearly
10 kPa for a 10 °C temperature
increase. This must be considered
when warm tyres are checked.
The tyre pressure value displayed in
the Driver Information Centre shows
the real tyre pressure. A cooled down tyre will show a decreased value,
which does not indicate an air leak.
Tyre pressure monitoring system
The tyre pressure monitoring system
checks the pressure of all four wheels once a minute when vehicle speed
exceeds a certain limit.Caution
Tyre pressure monitoring system
warns just about low tyre pressure condition and does not replace
regular tyre maintenance by the
driver.
Vehicle care257All wheels must be equipped with
pressure sensors and the tyres must have the prescribed pressure.
Note
In countries where the tyre pressure
monitoring system is legally
required, the use of wheels without
pressure sensors will invalidate the
vehicle operating permit.
Select the Tyre pressure monitoring
page under the Info Menu in the
Driver Information Centre 3 111.
System status and pressure warnings
are displayed by a message
indicating the corresponding tyre in the Driver Information Centre.
The system considers the tyre
temperature and the tyre loading
setting for the warnings.
Tyre loading setting, see below in this chapter.
Temperature dependency 3 255.
Baselevel display: If the pressure of a
tyre decreases significantly, the
respective tyre pressure value is displayed inverted.
Uplevel display: Tyre pressure values in normal range are shown in greenletters. If the pressure of a tyre
decreases significantly, the
respective value will turn its colour to
amber.
A detected low tyre pressure
condition is indicated by the control
indicator w 3 109.
If
w illuminates, stop as soon as
possible and inflate the tyres as
recommended 3 293.
Ensure that vehicle loading status
matches selected tyre pressure.
Vehicle loading status, see below in
this chapter.
After inflating, some driving may be
required to update the tyre pressure
values in the Driver Information
Centre. During this time w may
continue to illuminate.
If w illuminates at lower temperatures
and extinguishes after some driving,
this could be an indicator for
approaching a low tyre pressure
condition. Check tyre pressure.
Vehicle messages 3 122.
Only mount wheels with pressure
sensors, otherwise the tyre pressure
will not be displayed and w
illuminates continuously.
A spare wheel or temporary spare
wheel is not equipped with pressure
sensors. The tyre pressure
monitoring system is not operational
for these wheels. Control indicator w