WARNING■It is prohibited to work with naked flames or lights.■It is prohibited to smoke or carry out any activities that produce sparks.■
Never use a damaged vehicle battery – risk of explosion!
■
Never charge a frozen or thawed vehicle battery – risk of explosion and
chemical burns!
■
Replace a frozen vehicle battery.
■
Never jump-start vehicle batteries with insufficient acid levels – risk of ex-
plosion and chemical burns.
WARNING■ When you charge a battery, hydrogen is released, and a highly explosive gas
mixture is also produced. An explosion can be caused through sparkling over during unclamping or loosening of the cable plug while the ignition is on.■
Creating a bridge between the poles on the battery (e.g. with a metal object
or cable) creates a short circuit - risk of melting the lead bars, and risk of ex-
plosion, battery fire and acid splashes.
■
Avoid creating sparks when working with cables and electrical devices.
Strong sparking represents a risk of injury.
■
Before carrying out any work on the electrical system, switch off the engine,
the ignition and all electrical components and disconnect the negative termi-
nal (-) on the battery.
CAUTION
Improper handling of the battery can lead to damage. We recommend having all
work on the vehicle battery carried out by a specialist garage.
CAUTION
■ The vehicle battery must only be disconnected if the ignition is switched off,
otherwise the vehicle's electrical system (electronic components) can be dam-
aged. When disconnecting the battery from the electrical system, first of all dis-
connect the negative terminal (-) of the battery, followed by the positive terminal
(+).■
When connecting the battery to the electrical system, first of all connect the
positive terminal (+) of the battery, followed by the negative terminal (-). Under no
circumstances must the battery cables be connected incorrectly – risk of a cable fire.
■ Ensure that battery acid does not come into contact with the bodywork – risk of
damage to the paintwork.■
Do not place the battery in direct daylight in order to protect the vehicle battery
housing from the effects of ultra-violet light.
■
If the vehicle has not been driven for more than 3 to 4 weeks, the battery will
discharge. This is because certain electrical components consume electricity (e. g.
control units) also in idle state. Prevent the battery from discharging by discon- necting the battery's negative terminal (-) or continuously charging the battery
with a very low charging current.
■
If the vehicle is frequently used for making short trips, the vehicle battery will
not have time to charge up sufficiently and may discharge.
For the sake of the environment
A vehicle battery that has been removed is a special type of hazardous waste.
These must be disposed of in accordance with national legal regulations.
Note
You should replace batteries older than 5 years.
Opening the cover
Fig. 163
Engine compartment: Polyester cover of the vehicle battery/plastic
cover of the vehicle battery
First read and observe the introductory information and safety warn-ings
on page 207.
The battery is located in the engine compartment in a polyester cover or in a plas-
tic cover » Fig. 163 .
208General Maintenance
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■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
Negative cable - colour coding in the majority of cases is black.
Jump-starting in vehicles with the START-STOP system
Fig. 180
Engine earth: START-STOP sys-
tem
First read and observe the introductory information and safety warn- ings on page 226.
On vehicles with the START-STOP system, the jump-start cable of the charger
must never be connected directly to the negative pole of the vehicle battery, but
only to the engine earth » Fig. 180.
Towing the vehicle
Introduction
This chapter contains information on the following subjects:
Front towing eye
229
Rear towing eye
229
Vehicles with a tow hitch
230
Vehicles with manual transmission may be towed in with a tow bar or a tow rope
or with the front or rear wheels raised.
Vehicles with automatic transmission may be towed in with a tow bar or a tow
rope or with the front wheels raised. If the vehicle is raised at rear, the automatic
gearbox is damaged!
A tow bar is the safest way of towing a vehicle and also minimises any shocks.
Only use a tow rope if a suitable tow bar is not available.
When towing, the following guidelines must be observed.
Driver of the tow vehicle›
Release the clutch particularly gently when starting off or depress the accelera-
tor particularly gently if the vehicle is fitted with an automatic gearbox.
›
On vehicles with a manual transmission, only push down on the accelerator pedal once the rope is taught.
The maximum towing speed is 50 km/h.
Driver of the towed vehicle
›
Switch on the ignition so that the steering wheel is not blocked and so that the
turn signal lights, horn, windscreen wipers and windscreen washer system can be used.
›
Take the vehicle out of gear or move the selector lever into position N if the ve-
hicle is fitted with an automatic gearbox.
Please note that the brake servo unit and power steering only operate if the en-
gine is running. If the engine is not running, significantly more physical force is re- quired to depress the brake pedal and steer the vehicle.
If using a tow rope, ensure that it is always kept taught.
CAUTION
■ Do not tow start the engine – there is a risk of damaging the engine and the
catalytic converter! The battery from another vehicle can be used as a jump-start aid » page 226 , Jump-starting .■
If the gearbox no longer contains any oil because of a defect, your vehicle must
only be towed with the driven wheels raised clear of the ground or on a special
breakdown vehicle or trailer.
■
The vehicle must be transported on a special breakdown vehicle or trailer if it is
not possible to tow in the vehicle in the way described or if the towing distance is
greater than 50 km.
■
To protect both vehicles when tow-starting or towing, the tow rope should be
elastic. Thus one should only use plastic fibre rope or a rope made out of a simi-
larly elastic material.
■
While towing, take care to avoid impermissibly high tensile forces or jerky loads.
There is always a risk of excessive stresses and damage resulting at the points to which you attach the tow rope or tow bar when you attempt to tow a vehicle
which is not standing on a paved road.
■
Attach the tow rope or the tow bar to the towing eyes » page 229
or » page 229 to the detachable ball head of the towing device » page 152 .
228Do-it-yourself