GWARNING
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.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connect-
ing and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnect-
ing the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
GWARNING
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 explo-
sion.
Allow the frozen battery to thaw out before charging it or jump-starting.
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could bedamaged by the non-combusted fuel.
If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it isvery likely that the discharged battery has frozen. In this case you may neither jump-start thevehicle nor charge the battery. Let the battery thaw first. The service life of a thawed-out batterymay be shorter. The starting characteristics can be impaired, particularly at low temperatures.Have the thawed-out battery checked at a qualified specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, theengine can be jump-started from another vehicle or from a second battery using jumper cables.Observe the following points:
RThe 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.
RYou may only jump-start the vehicle when the engine and exhaust system are cold.
RDo not start the engine if the battery is frozen. Let the battery thaw first.
ROnly jump-start from batteries with a 12 V voltage rating.
ROnly use jumper cables that are not damaged and have a sufficient cross-section and insula-ted terminal clamps.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RNon-insulated parts of the terminal clamps do not come into contact with other metal partswhile the jumper cables are connected to the battery.
RThe jumper cables cannot come into contact with parts that can move when the engine is run-ning, such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position ].
XTurn the SmartKey to position Zin the ignition lock and remove it.
296Jump-starting
Roadside Assistance
Towing and tow-starting
Important safety notes
GWARNING
Functions relevant to safety are restricted or
no longer available if:
Rthe engine is not running
Rthe brake system or the power steering is
malfunctioning
Rthere is a malfunction in the power supply
or the vehicle's electrical system
When your vehicle is towed away or towed
started, you may require considerably more
effort to steer and brake. There is a risk of
an accident.
In such cases, use a tow bar. Before being
towed away or tow started, make sure the
steering moves freely.
GWARNING
You can no longer steer the vehicle if the
steering wheel lock has been engaged.
There is a risk of an accident.
Always switch off the ignition when towing
the vehicle with a tow cable or a tow bar.
GWARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissi-
ble gross weight of your vehicle, the:
Rthe towing eye could detach itself
Rthe vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehi-
cle, its weight should not be greater than
the permissible gross weight of your vehicle.
Details on the permissible gross vehicle weightof your vehicle can be found on the vehicleidentification plate (Ypage 333).
!When Active Brake Assist, Active DistanceAssist DISTRONIC or the HOLD function isactivated, the vehicle brakes automaticallyin certain situations.
To avoid damage to the vehicle, deactivatethese systems in the following or similar sit-uations:
Rwhen towing the vehicle
Rin the car wash
!Make sure that the electric parking brakeis released. If the electric parking brake isfaulty, visit a qualified specialist workshop.
!Only secure the tow rope or tow bar at thetowing eyes. Otherwise, the vehicle could bedamaged.
!Do not use the towing eyes for recoverypurposes as this could damage the vehicle.If in doubt, recover the vehicle with a crane.
!When towing, pull away slowly andsmoothly. If the tractive power is too high,the vehicles could be damaged.
!The vehicle can be towed a maximum of30 miles (50km). The towing speed of30 mph (50km/h) must not be exceeded.
If the vehicle has to be towed more than30 miles (50km), the front axle must beraised or the entire vehicle raised and trans-ported.
!Do not tow with sling-type equipment. Thiscould damage the vehicle.
!When towing away vehicles with KEYLESS-GO, use the key instead of the Start/Stopbutton. The automatic transmission mayotherwise shift to position ]when youopen the driver's or front-passenger door,which could damage the transmission.
!Vehicles with automatic transmission mustnot be started by tow-starting. This couldotherwise damage the transmission.
It is better to have the vehicle transportedthan to have it towed away.
If the vehicle can no longer be driven becauseof an accident or breakdown, you have the fol-lowing options:
RTransporting the vehicle.
As a rule, you should have the vehicle trans-ported.
RTowing the vehicle with a tow rope or towbar.
Only tow the vehicle in exceptional cases.
298Towing and tow-starting
Roadside Assistance