Vehicle care237Vehicle 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 3 162.
Closing Lower the bonnet and let it fall into the
latch from a low height (20-25 cm).
Check that the bonnet is engaged.
240Vehicle 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 3 284.
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.
242Vehicle 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 3 162.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 3 275.
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 care243Idle 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.
262Vehicle 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 3 291.
3. Identify the respective tyre.
The tyre pressure tables show all possible tyre combinations 3 298.
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 3 112.
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 care263All 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 3 112.
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 3 261.
Baselevel display: If the pressure of a
tyre decreases significantly, the
respective tyre pressure value is displayed inverted.
Midlevel and uplevel display: Tyre
pressure values in normal range are
shown in green letters. 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 3 298.
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 3 123.
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
264Vehicle careilluminates. For the further three
wheels the system remains
operational.
The use of commercially available
liquid tyre repair kits can impair the
function of the system. Factory-
approved repair kits can be used.
Operating electronic devices or being close to facilities using similar wave
frequencies could disrupt the tyre
pressure monitoring system.
Each time the tyres are replaced, tyre
pressure monitoring system sensors
must be dismounted and serviced. For the screwed sensor, replace
valve core and sealing ring. For the
clipped sensor, replace complete
valve stem.
Vehicle loading status
Adjust tyre pressure to load condition according tyre information label or
tyre pressure chart 3 298, and select
the appropriate setting in Tyre Load
within the vehicle information menu
3 112. This setting determines the
reference pressures for the tyre
pressure warnings.The Tyre Load menu only appears
when the vehicle is at a standstill and the parking brake is applied. On
vehicles with automatic transmission
the selector lever must be in P.
Select:
● Light for comfort pressure up to
3 people.
● Eco for Eco pressure up to
3 people.
● Max for full loading.
Auto learn function After changing wheels or wheel
positions the vehicle must be
stationary for approx. 20 minutes,
before the system recalculates. The
following relearn process takes up to
10 minutes of driving in a speed range
of 40 to 100 km/h. Avoid to drive
outside of this range for a longer time.
If possible, use a country road or
similar which allows continuous
driving. During relearn process $
can be displayed or pressure values can swap in the Driver Information
Centre.
If problems occur during the relearn
process, a failure message is
displayed in the Driver Information
Centre. w will flash for 60 seconds
and then illuminate continuously.
If this happens, repeat learning
process. Keep your vehicle stationary for approx. 20 minutes and then drive
again for 10 minutes as described
above.
Tread depth
Check tread depth at regular
intervals.
Tyres should be replaced for safety
reasons at a tread depth of 2-3 mm
(4 mm for winter tyres).
Vehicle care265For safety reasons, it is
recommended that the tread depth of
the tyres on one axle should not vary
by more than 2 mm.
The legally permissible minimum
tread depth (1.6 mm) has been
reached when the tread has worn
down as far as one of the tread wear
indicators (TWI). Their position is
indicated by markings on the
sidewall.
If there is more wear at the front than
the rear, swap round front wheels and rear wheels periodically. Ensure that
the direction of rotation of the wheels
remains the same.
Tyres age, even if they are not used.
We recommend tyre replacement
every 6 years.
Changing tyre and wheel
size
If tyres of a different size than those
fitted at the factory are used, it may be necessary to reprogramme the
nominal tyre pressure and make
other vehicle modifications.
After converting to a different tyre
size, have the label with tyre
pressures replaced and the tyre
pressure monitoring system
reinitialised 3 262.9 Warning
The use of unsuitable tyres or
wheels may lead to accidents and will invalidate the vehicle
operating permit.
Wheel covers
Wheel covers and tyres that are
factory approved for the respective
vehicle and comply with all of the
relevant wheel and tyre combination
requirements must be used.
If the wheel covers and tyres used are
not factory approved, the tyres must
not have a rim protection ridge.
Wheel covers must not impair brake
cooling.9 Warning
Use of unsuitable tyres or wheel
covers could lead to sudden
pressure loss and thereby
accidents.
Vehicles with steel wheels: When
using locking wheel nuts, do not
attach wheel covers.