Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of a positive terminal and an earth point, in the engine compartment.
All vehicles except Mercedes-AMG vehicles: G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Do not breathe in any battery gases. Do not lean over the battery. Keep the batteries out of the reach of children. Immediately rinse off battery acid
thoroughly with plenty of clean water and seek medical attention at once. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jump leads.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case you may neither jump-start the vehicle nor charge
the battery. The service life of a battery that has been thawed may be reduced. The starting
characteristics may be impaired, especially at low temperatures. Have the thawed battery
checked at a qualified specialist workshop.
All vehicles: 366
Jump-startingBreakdown assistance
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R You may only jump-start the vehicle when the engine and exhaust system are cold.
R Keep away from fire and open flames.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R All vehicles except Mercedes-AMG vehicles: do not start the engine if the battery is
frozen. Let the battery thaw first.
R Jump-starting may only be performed using batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R Do not lean over the battery.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Shift the transmission to position P.
X Make sure the ignition is switched off (Y page 161). All indicator lamps in the instrument
cluster must be off. When using the key, turn the key to position 0in the ignition lock and
remove it (Y page 161).
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Earth point cover (example: right-hand drive) Jump-starting
367Breakdown assistance Z
