
›Open the battery cover in the direction of the arrow 1 or press the interlock on
the side of the battery cover in the direction of the arrow 2 » Fig. 163 , fold the
cover up and remove.
The battery cover is installed in reverse order.
The edge of the polyester battery cover is inserted between the battery and theside wall of the battery cover when working on the battery.
Checking the battery electrolyte level
Fig. 164
Vehicle battery: Electrolyte level
indicator
First read and observe the introductory information and safety warn-
ings on page 207.
On vehicles with a vehicle battery fitted with a colour indicator » Fig. 164 , the
electrolyte level can be determined by looking at the change in colour.
Air bubbles can influence the colour of the indicator. For this reason carefullyknock on the indicator before carrying out the check.
› Black colour - electrolyte level is correct.
› Colourless or light yellow colour - electrolyte level too low, the battery must be
replaced.
Vehicles with a START-STOP system are fitted with a battery control unit for checking the energy level for recurring engine start.
We recommend that you have the acid level checked regularly by a specialist ga-
rage, especially in the following cases.
› High external temperatures.
› Longer day trips.
› After each charge.
Winter time
The vehicle battery only has a proportion of the starting power in lower tempera- tures. A discharged vehicle battery may already freeze at temperatures just be-
low 0 °C .
We therefore recommend that you have the battery checked and, if necessary, re-
charged by a specialist garage before the start of the winter.
CAUTION
For technical reasons, on vehicles with the description “AGM”, the electrolyte lev- el cannot be checked.
Note
The battery acid level is also checked regularly by a specialist garage as part of
the inspection service.
Charging
First read and observe the introductory information and safety warn-ings
on page 207.
A properly charged vehicle battery is essential for reliably starting the engine.
›
Switch off the ignition and all of the electrical components.
›
Only when performing a “quick-charge”, disconnect both battery cables (first
“negative”, then “positive”).
›
Attach the terminal clamps of the charger to the battery terminals (red = “posi- tive”, black = “negative”).
›
Plug the mains cable of the charger into the power socket and switch on thedevice.
›
After charging has been successful: Switch off the charger and remove the
mains cable from the power socket.
›
Only then disconnect the charger's terminal clamps.
›
Reconnect the cables to the battery (first “positive”, then “negative”).
It is not necessary to disconnect the cables of the battery if you recharge the ve-
hicle battery using low amperages (for example from a mini-charger). Refer to the
instructions of the charger manufacturer .
A charging current of 0.1 multiple of the total vehicle battery capacity (or lower) must be used until full charging is achieved.
209Inspecting and replenishing

It is necessary to disconnect both cables before charging the battery with high
amperages, known as “ rapid charging”.
The vent plugs of the vehicle battery should not be opened for charging.WARNING“Quick-charging” the vehicle battery is dangerous and requires a special
charger and specialist knowledge.
CAUTION
On vehicles with the START/STOP system, the pole terminal of the charger must
not be connected directly to the negative terminal of the vehicle battery, but only
to the engine earth » page 228, Jump-starting in vehicles with the START-STOP
system .
Note
We therefore recommend that vehicle batteries be rapid charged by a specialist
garage.
Replacing
First read and observe the introductory information and safety warn-
ings
on page 207.
The new vehicle battery must have the same capacity, voltage, current and the
same size as the original Battery. Suitable vehicle battery types can be purchased
from a specialist garage.
We recommend having the battery replaced by a specialist garage, where the
new vehicle battery will be installed properly and the original battery will be dis-
posed of in accordance with national regulations.
Disconnecting and reconnecting
First read and observe the introductory information and safety warn-
ings
on page 207.
On disconnecting and reconnecting the vehicle battery, the following functions
are initially deactivated or are no longer able to operate fault-free.
OperationOperating measureElectrical power window (operational faults)» page 44Panoramic sliding roof (operational faults)» page 234Enter the radio/navigation system code num-
ber» User manual of the radio
or » user manual of the naviga-
tion systemSetting the clock» page 13Data in the multifunction display are deleted.» page 25
Note
We recommend having the vehicle checked by a specialist garage in order to en-
sure full functionality of all electrical systems.
Automatic load deactivation
First read and observe the introductory information and safety warn-ings
on page 207.
The vehicle voltage control unit automatically prevents the battery from discharg-
ing when the battery is put under high levels of strain. This manifests itself by the
following.
› The idling speed is raised to allow the generator to deliver more electricity to
the electrical system.
› Where necessary, large convenience consumers such as seat heaters and rear
window heaters have their power limited or are shut off completely in the event
of an emergency.
CAUTION
■ Despite such intervention by the vehicle electric system management, the vehi-
cle battery may be drained. For example, when the ignition is switched on a long
time with the engine turned off or the side or parking lights are turned on during longer parking.■
Consumers that are supplied via a 12-V power socket can cause the vehicle bat-
tery to discharge when the ignition is switched off.
210General Maintenance

WARNING■When the warning light illuminates, immediately reduce the speed and
avoid sudden steering and brake manoeuvres. Stop the vehicle as soon as
possible and inspect the tyres and their inflation pressure.■
Under certain circumstances (e.g. sporty style of driving, wintry or unpaved
roads) the warning light can be delayed or does not light up at all.
CAUTION
■
The tyre control display does therefore not replace the regular tyre inflation
pressure control, as the system cannot detect an even loss of pressure.■
The system cannot warn in case of very rapid tyre inflation pressure loss, e.g. in
case of sudden tyre damage. In this case carefully bring the vehicle to a standstill
without sudden steering movements or sharp braking.
■
To ensure a proper functioning of the tyre control display, it is necessary to re-
peat the basic setting every 10000 km or once a year.
Spare wheel
Fig. 168
Boot: Spare wheel
First read and observe the introductory information and safety warn-
ings on page 212.
The spare wheel is located in a well under the floor covering in the boot and is
fixed in place with a securing bolt » Fig. 168.
Take out wheel
›
Open the boot lid.
›
Lift up the floor in the luggage compartment.
›
Remove the box with the tool kit.
›
Unscrew the bolt » Fig. 168 in an anti-cloockwise direction.
›Remove the wheel.
Store wheel away›
Place the wheel into the spare wheel well with the wheel rim pointing down- ward.
›
Screw the securing bolt » Fig. 168 in a clockwise direction until the wheel is se-
curely attached.
›
Replace the box with the tool kit.
›
Fold back the floor in the luggage compartment.
›
Shut the boot lid.
Fit a wheel in the appropriate dimensions and design as soon as possible.
If the dimensions or design of the spare wheel differ from the tyres fitted to the
vehicle (e.g. winter tyres or low-profile tyres), it must only be used briefly in the
event of a puncture and if an appropriately cautious style of driving is adop-
ted »
.
Temporary spare wheel
A warning label is displayed on the rim of the temporary spare wheel.
Please note the following if you intend to use the temporary spare wheel. › The warning label must not be covered after installing the wheel.
› Be particularly observant when driving.
› The inflation pressure for the temporary spare wheel is identical to the maxi-
mum inflation pressure for the standard tyres.
› Only use this temporary spare wheel to reach the nearest specialist garage, as it
is not intended for long-term use.
› The tyre inflation pressure of the spare wheel R 16 is 420 kPa.
WARNING■
Never drive with more than one spare wheel mounted!■Never use the temporary spare wheel if it is damaged.■
If the dimensions or design of the temporary spare wheel differ from the fit-
ted tyres, never drive faster than 80 km/h (or 50 mph).
■
Avoid accelerating at full throttle, sharp braking and fast cornering.
CAUTION
Observe instructions on the warning sign of the emergency wheel.
216General Maintenance

Full wheel trimFirst read and observe the introductory information and safety warn-
ings
on page 212.
Extracting
›
Hook the clamp found in the vehicle tool kit » page 220 into the reinforced edge
of the wheel trim.
›
Push the wheel wrench through the clamp, support on the tyre and pull off the
wheel trim.
Install
›
Press the wheel trim onto the wheel rim at the designated valve opening.
›
Then press the trim into the wheel rim until its entire circumference locks cor- rectly in place.
CAUTION
■ Use the pressure of your hand only, do not strike the full wheel trim. Avoid
heavy impacts when the trim has not yet been inserted into the wheel rim. This
could cause damage to the guide and centring elements of the trim.■
When using the anti-theft wheel bolt, ensure that it is in the hole in the valve
area » page 224 , Securing wheels against theft .
■
If wheel trims are retrofitted it must be ensured that an adequate flow of air is
assured to cool the brake system.
Wheel bolts
Fig. 169
Remove the capFirst read and observe the introductory information and safety warn-
ings on page 212.
Pulling off
›
Push the extraction pliers » page 220 sufficiently far onto the cap until the inner
catches of the pliers are positioned at the collar of the cap.
›
Remove the cover in the direction of the arrow » Fig. 169.
Installing
›
Push the caps onto the wheel bolts up to the stop.
The wheel bolt caps are housed in a plastic box in the spare wheel or in the stor-
age space for the spare wheel.
Wheel bolts
First read and observe the introductory information and safety warn-ings
on page 212.
Wheels and wheel bolts are matched to each other in terms of design. Each time
you fit other wheels rims, e.g. light alloy wheel rims or wheels with winter tyres,
you must also use the matching wheel bolts with the correct length and dome
shape. This is a prerequisite for ensuring that wheels are attached correctly.
Winter operation
Introduction
This chapter contains information on the following subjects:
Winter tyres
218
Snow chains
218
217Wheels

Winter tyresFirst read and observe the introductory information given on page 217.
Fitting winter tyres will significantly improve the handling of your vehicle when
driving in wintry road conditions. Summer tyres have less grip on ice, snow and at
temperatures below 7 °C. This is especially true of vehicles fitted with wide tyres
or high-speed tyres .
In order to achieve the best possible handling properties, winter tyres must be fit-
ted on all 4 wheels, the minimum tread depth must be 4 mm and tyres must be
no older than 4 years.
Winter tyres of a lower speed category can be used provided that the permissible
maximum speed of these tyres is not exceeded even if the possible maximum speed of the vehicle is higher.
The speed limit for winter tyres can be set in the MAXI DOT display in the menu
item Winter tyres » page 29 .
For the sake of the environment
Fit the summer tyres on again in good time as they provide better handling prop-
erties, a shorter braking distance, less tyre noise, and reduced tyre wear on roadswhich are free of snow and ice as well as at temperatures above 7 °C. The fuelconsumption is also lower.
Snow chains
First read and observe the introductory information given on page 217.
When driving in wintry road conditions, snow chains improve not only traction,
but also the braking performance.
The use of snow chains on vehicles with front-wheel drive and on vehicles with
four-wheel drive differs.
Vehicles with front-wheel drive
Snow chains must only be mounted on the front wheels.
For technical reasons, it is only permissible to fit snow chains with the following wheel/tyre combinations.
Wheel sizeDepth (D)Tyre size6J x 1650 mm205/557J x 1645 mm205/556J x 1745 mm205/50
Vehicles with four-wheel drive
Snow chains can be used on the front wheels as on vehicles with front-wheel
drive.
In order to increase the traction (start-up properties), the use of snow chains is
also technically permissible on the rear axle (this means on the front and rear axle
at the same time) for the following wheel/tyre combinations.
Wheel sizeDepth (D)Tyre size6J x 1650 mm205/557J x 1645 mm205/556J x 1745 mm205/50
The use of snow chains is only technically permissible on the rear axle for the fol-
lowing standard wheel/tyre combinations.
Wheel sizeDepth (D)Tyre size7J x 1645 mm215/607J x 1745 mm225/50
When fitting snow chains on the front and rear axle at the same time, the maxi-
mum speed is limited to 50 km/h.
Only fit snow chains with links and locks not larger than 12 mm.
WARNINGObserve the national legal regulations relating to the use of snow chains and
the maximum vehicle speed with snow chains.
CAUTION
■ The chains must be removed when driving on roads which are free of snow.
They adversely affect the handling of your vehicle, damage the tyres and are rap-
idly destroyed.■
Remove the full wheel trims » page 217 before installing the snow chains.
218General Maintenance

Extraction pliers for wheel bolt capsReplacement bulb set
Screw the jack back into its home position after use to allow you to store it in the
box with the toolkit.WARNING■ The factory-supplied lifting jack is only intended for your model of vehicle.
Under no circumstances use it to lift heavier vehicles or other loads – risk of
injury!■
Ensure that the vehicle tool kit is safely secured in the boot.
■
Ensure that the box is always secured with the strap.
Changing a wheel
Introduction
This chapter contains information on the following subjects:
Preparation
222
Changing a wheel
222
Follow-up tasks
222
Loosening/tightening wheel bolts
223
Raising the vehicle
223
Securing wheels against theft
224WARNING■ If you are in flowing traffic, switch on the hazard warning light system and
set up the warning triangle at the prescribed distance! The national legal re-
quirements must be observed.■
Park the vehicle as far away as possible from the flow of traffic. Park on as
flat and firm a surface as possible.
■
If the vehicle is subsequently fitted with tyres which are different from
those it was fitted with at the works, follow these guidelines » page 214, New
tyres .
89WARNINGNotes for vehicle lifting■If the wheel has to be changed on a slope, first of all block the opposite
wheel with a stone or similar object to prevent the vehicle from unexpectedly
rolling away.■
Secure the base plate of the lifting jack with suitable means to prevent pos-
sible moving. A soft and slippery ground under the base plate may move the lifting jack, causing the vehicle to fall down. It is therefore always necessary to
place the lifting jack on a solid surface or use a wide and stable base. Use a non-slip base (e.g. a rubber foot mat) if the surface is smooth, such as cobbled
stones, tiled floor, etc.
■
Only attach the lifting jack to the attachment points provided for this pur-
pose.
■
Always raise the vehicle with the doors closed.
■
Never position any body parts, such as arms or legs under the vehicle, while
the vehicle is raised with a lifting jack.
■
Never start the engine with the vehicle sitting on the raised jack – risk of in-
jury.
WARNINGInformation on the wheel bolts■The wheel bolts must be clean and must turn easily. Never treat them with
grease or oil.■
The prescribed tightening torque of the wheel bolts for steel and light alloy
wheels is 120 Nm.
■
If the wheel bolts are tightened to a too low tightening torque, the rim can
come loose when the car is moving – risk of accident! A tightening torque
which is too high can damage the bolts and threads and this can result in per-
manent deformation of the contact surfaces on the rim.
■
In case of incorrect treatment of the wheel bolts, the wheel can loosen
when the car is moving – risk of accident!
Note
The national legal requirements must be observed when changing a wheel.
221Emergency equipment and self-help

Sealing and inflating the tyreFirst read and observe the introductory information and safety warn-
ings
on page 224.
Sealing
›
Forcefully shake the tyre inflator bottle
10
» Fig. 178 on page 225 several times.
›
Firmly screw the inflation hose
3
onto the tyre inflator bottle
10
in a clockwise
direction. The film on the cap is pierced automatically.
›
Remove the plug from the inflation hose
3
and plug the open end fully onto
the tyre valve.
›
Hold the bottle
10
with the bottom facing upwards and fill all of the sealing
agent from the tyre inflator bottle into the tyre.
›
Remove the empty tyre inflator bottle from the valve.
›
Screw the valve core back into the tyre valve using the valve remover
2
.
Inflating
›
Screw the air compressor tyre inflation hose
7
» Fig. 178 on page 225 firmly on-
to the tyre valve.
›
Start the engine and run it in idle.
›
Plug the connector
6
into 12 Volt socket » page 75.
›
Switch on the air compressor with the ON and OFF switch
9
.
›
Allow the air compressor to run until a pressure of 2.0 - 2.5 bar is achieved. Max-
imum run time of 8 minutes » !
›
Switch off the air compressor.
›
If you cannot reach an air pressure of 2.0 – 2.5 bar, unscrew the tyre inflation
hose
7
from the tyre valve.
›
Drive the vehicle 10 metres forwards or backwards to allow the sealing agent to
“distribute” in the tyre.
›
Firmly screw the tyre inflation hose
7
back onto the tyre valve and repeat the
inflation process.
›
If you cannot reach the required tyre inflation pressure here either, this means
the tyre has sustained too much damage. You cannot seal with tyre with the breakdown kit »
.
›
Switch off the air compressor.
›
Remove the tyre inflation hose
7
from the tyre valve.
Once a tyre inflation pressure of 2.0 – 2.5 bar is achieved, continue the journey at
a maximum speed of 80 km/h (50 mph).
Check the tyre inflation pressure after driving for 10 minutes » page 226, Check
after 10 minutes' driving .
WARNING■
During inflation, the tyre inflation hose and air compressor may get hot –
risk of injury!■
Do not place the hot tyre inflation hose or hot air compressor on flammable
materials – risk of fire!
■
If you cannot inflate the tyre to at least 2.0 bar, this means the damage sus-
tained was too serious. The sealing agent cannot be used to seal the tyre.
Do not drive the vehicle! Seek help from a specialist garage.
CAUTION
Switch off the air compressor after running 8 minutes at the latest – risk of over-
heating! Allow the air compressor to cool a few minutes before switching it on
again.
Check after 10 minutes' driving
First read and observe the introductory information and safety warn-ings
on page 224.
Check the tyre inflation pressure after driving for 10 minutes!
If the tyre inflation pressure is 1.3 bar or less
›
Do not drive the vehicle! You cannot properly seal with tyre with the break-
down kit.
If the tyre inflation pressure is 1.3 bar or more
›
Adjust the tyre inflation pressure to the correct value (see inside of fuel filler cap).
›
Continue driving carefully to the nearest specialist garage at a maximum speed
of 80 km/h (50 mph).
Jump-starting
Introduction
This chapter contains information on the following subjects:
Jump-starting using the battery from another vehicle
227
Jump-starting in vehicles with the START-STOP system
228
226Do-it-yourself

WARNING■A discharged vehicle battery may already freeze at temperatures just below
0 °C. If the battery is frozen, do not carry out a jump start with the battery of another vehicle – risk of explosion!■
Pay attention to the warning instructions relating to working in the engine
compartment » page 199.
■
The non-insulated parts of the terminal clamps must never touch each other
– risk of short circuit!
■
The jump-start cable connected to the positive terminal of the battery must
not come into contact with electrically conducting parts of the vehicle – risk of
short circuit!
■
Do not clamp the jump-start cable to the negative terminal of the dis-
charged battery. There is the risk of detonating gas seeping out the battery
being ignited by the strong spark which results from the engine being started.
■
Route the jump-start cables so that they cannot be caught by any rotating
parts in the engine compartment.
■
Do not bend over the battery – risk of caustic burns!
■
The vent screws of the battery cells must be tightened firmly.
■
Keep any sources of ignition (naked flame, smouldering cigarettes, etc.)
away from the battery – risk of explosion!
■
Never jump-start vehicle batteries with an electrolyte level that is too low –
risk of explosion and caustic burns.
CAUTION
■ There must not be any contact between the two vehicles otherwise current
may flow as soon as the negative terminals are connected.■
The discharged battery must be properly connected to the system of the vehi-
cle.
■
We recommend you buy jump-start cables from a car battery specialist.
Jump-starting using the battery from another vehicleFig. 179
Jump-starting: A – flat battery, B
– battery providing current
First read and observe the introductory information and safety warn-
ings on page 226.
The battery of another vehicle can be used to jump-start your vehicle if the en-
gine will not start because the battery is flat. Jump-start cables are required for
this purpose.
The jump-start cables must be attached in the following sequence.
›
Attach clamp
1
to the positive terminal of the discharged battery
A
» Fig. 179 .
›
Attach clamp
2
to the positive terminal of the battery supplying power
B
.
›
Attach clamp
3
to the negative terminal of the battery supplying power
B
.
›
Attach the clamp
4
to a solid metal part which is connected firmly to the en-
gine block or to the engine block itself.
Starting engine
›
Start the engine on the vehicle providing the power and allow it to idle.
›
Start the engine of the vehicle with the discharged battery.
›
If the engine does not start, terminate the attempt to start the engine after 10 seconds and wait for 30 seconds before repeating the process.
›
Disconnect the cables in exactly the reverse order
to the one described above.
Both batteries must have a rated voltage of 12 V. The capacity (Ah) of the battery
supplying the power must not be significantly less than the capacity of the dis-
charged battery in your vehicle.
Jump-start cables
Only use jump-start cables which have an adequately large cross-section and in-
sulated terminal clamps. Observe the instructions of the jumper lead manufactur-
er.
Positive cable - colour coding in the majority of cases is red.
227Emergency equipment and self-help