340If and when
Starting assistance
Introduction
If the engine fails to start because of a discharged battery, the battery of an-
other vehicle can be used to start the engine. Before starting, check the
magic eye on the battery ⇒ page 291.
For starting assistance, jump lead cables conforming to the standard
DIN 72553 are required (see the cable manufacturer instructions). The jump
lead cable must be at least 25 mm 2
in section (0.038 inches 2
) for petrol en-
gines, and 35 mm 2
(0.054 inches 2
) for diesel engines.
For vehicles whose battery is not in the engine compartment, the jump
leads should only be connected to the starting assistance connection
points in the engine compartment.
Additional information and warnings:
● Starter assist systems (Start-Stop function) ⇒ page 195
● Working in the engine compartment ⇒ page 278
● Selective Catalytic Reduction (AdBlue) ⇒ page 274
● Vehicle battery ⇒ page 291
WARNING
Incorrect use of jump leads and incorrectly jump starting could cause the
battery to explode resulting in serious injury. Please observe the follow-
ing rules to minimise the risk of a battery explosion:
● All work involving the vehicle battery and electrical system can cause
corrosion, fire and serious electric shocks. Always read and take into ac-
count the safety warnings and standards before beginning work on the
battery ⇒ page 291, Vehicle battery.
WARNING (Continued)
● The battery providing current must have the same voltage (12V) and
approximately the same capacity (see markings on battery) as the flat
battery.
● Never charge a frozen or recently thawed battery. A flat battery can al-
so freeze at temperatures close to 0 °C (+32 °F).
● If a battery is frozen and/or has been frozen then it must be replaced.
● A highly explosive mixture of gases is released when the battery is
being charged. Always keep lit cigarettes, open flames, sparks and fire
far from the battery. Never use a mobile telephone when connecting and
removing the jump leads.
● Charge the battery only in well ventilated areas given that when the
battery is charged by outside assistance, it creates a mix of highly explo-
sive gases.
● Jump leads should never enter into contact with moving parts in the
engine compartment.
● Never switch the positive and negative poles or connect the jump
leads incorrectly.
● Note the instruction manual provided by the manufacturer of the jump
leads.
CAUTION
To avoid considerable damage to the vehicle electrical system, note the fol-
lowing carefully:
● If the jump leads are incorrectly connected, this could result in a short
circuit.
● The vehicles must not touch each other, otherwise electricity could flow
as soon as the positive terminals are connected.
343
If and when
WARNING (Continued)
● Observe the instructions provided by the manufacturer of the jump
leads.
● Do not connect the negative cable from the other vehicle directly to
the negative terminal of the flat battery. The gas emitted from the battery
could be ignited by sparks. Danger of explosion.
● Do not attach the negative cable from the other vehicle to parts of the
fuel system or to the brake line.
● The non-insulated parts of the battery clamps must not be allowed to
touch. The jump lead attached to the positive battery terminal must not
touch metal parts of the vehicle, this can cause a short circuit.
● Position the leads in such a way that they cannot come into contact
with any moving parts in the engine compartment.
● Do not lean on the batteries. This could result in chemical burns.
Note
The vehicles must not touch each other, otherwise electricity could flow as
soon as the positive terminals are connected.
Towing and tow starting Introduction
When towing, always respect legal requirements.
For technical reasons, it is not possible to tow a vehicle if the battery is flat.
Additional information and warnings:
● Electronic power control and exhaust gases purification system
⇒ page 231
WARNING
A vehicle with a flat battery should never be towed.
● Never remove the key from the ignition lock. The electronic steering
lock could engage. Then the vehicle will be uncontrollable. You may lose
control of the vehicle and there is a risk of serious accident.
WARNING
When towing the vehicle, the handling and braking efficiency change
considerably. Please observe the following instructions to minimise the
risk of serious accidents and injury:
● As the driver of the vehicle being towed:
– The brake must be depressed must harder as the brake servo does
not operate. Always remain aware to avoid collision with the towing
vehicle.
– More strength is required at the steering wheel as the power steer-
ing does not operate when the engine is switched off.
● As the driver of the towing vehicle:
– Accelerate gently and carefully.
– Avoid sudden braking and manoeuvres.
– Brake well in advance than usual and brake gently.
CAUTION
● Carefully fit and remove the towline anchorage and its cover to avoid
damage to the vehicle (for example, paintwork).
● When towing, fuel could enter the catalytic converter and cause dam-
age!
Safety FirstOperating instructionsPractical tipsTechnical Specifications
