Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged,the engine can be jump-started from another vehicle or from a second battery using jumper
cables. 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 Do not start the engine if the battery is frozen. Let the battery thaw first.
R Only jump-start from batteries with a 12 V voltage rating.
R Only use jump leads that are not damaged and have a sufficient cross-section and insulated
terminal clamps.
R Make sure that the two vehicles do not touch.
Make sure that:
R the jumper cables are not damaged.
R when the jumper cables are connected to the battery, uninsulated sections of the terminal
clamp do not come into contact with other metal sections.
R the jumper cables 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 Turn the SmartKey to position 0in the ignition lock and remove it.
X Switch off all electrical consumers, e.g. rear window defroster, lighting, etc.
X Open the hood.
Position number Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Press together cover :of positive clamp ;and slide it back.
X Connect positive terminal ;on your vehicle to positive terminal =of donor battery B
using the jumper cable, beginning with your own battery.
294Jump-starting
Roadside Assistance
XStart the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ?of donor battery Bto ground point Aof your vehicle using
the jumper cable, connecting the jumper cable to battery of other vehicle Bfirst.
X 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 battery slightly.
X Start the engine.
X Before disconnecting the jumper cables, let the engine run for several minutes.
X First, remove the jumper cables from ground point Aand negative terminal ?, then from
positive clamp ;and positive terminal =. Begin each time at the contacts on your own
vehicle first.
X Close cover :of positive terminal ;after removing the jumper cables.
X Close the hood.
X Have the battery checked at a qualified specialist workshop.
iJump-starting is not considered to be a normal operating condition.
iJumper cables and further information regarding jump-starting can be obtained at any
qualified specialist workshop.
Towing and tow-starting
Important safety notes
GWARNING
Functions relevant to safety are restricted or
no longer available if:
R the engine is not running.
R the brake system or the power steering is
malfunctioning.
R there is a malfunction in the voltage supply
or the vehicle's electrical system.
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that 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 permissible gross weight of your vehicle, the:
R the towing eye could detach itself
R the vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle
weight of your vehicle can be found on the
vehicle identification plate ( Ypage 334).
!When COLLISION PREVENTION ASSIST
PLUS, DISTRONIC PLUS or the HOLD func- tion is activated, the vehicle brakes auto-
matically in certain situations. To avoid
damage to the vehicle, deactivate these
systems in the following or similar situa-
tions:
R when towing the vehicle
R in the car wash
Towing and tow-starting295
Roadside Assistance
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!Make sure that the electric parking brake
is released. If the electric parking brake is
faulty, visit a qualified specialist workshop.
!Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could
be damaged.
!Do not use the towing eyes for recovery
purposes as this could damage the vehicle. If in doubt, recover the vehicle with a crane.
!When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
!The vehicle can be towed a maximum of
30 miles (50km). The towing speed of
30 mph (50km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the front axle must be
raised or the entire vehicle raised andtransported.
!Do not tow with sling-type equipment.
This could damage the vehicle.
!When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop but-
ton. Otherwise, the automatic transmission
may shift to position Pwhen the driver's or
front-passenger door are opened, which
could lead to damage to the transmission.
!Vehicles with automatic transmission
must not be started by tow-starting. This
could otherwise damage the transmission.
It is better to have the vehicle transported
than to have it towed away.
If the vehicle can no longer be driven because of an accident or breakdown, you have the
following options:
R transporting the vehicle
As a rule, you should have the vehicle trans-
ported.
R towing the vehicle with a tow rope or tow bar
Only tow the vehicle in exceptional cases. When towing a vehicle, the transmission must
be in position N.
The battery must be connected and charged. Otherwise, you:
R cannot turn the SmartKey to position 2in
the ignition lock
R cannot release the electric parking brake
R cannot shift the transmission to position N
iThe function of the electric parking brake
and the parking lock is dependent on the
on-board voltage.
If the on-board voltage is low or there is a
system malfunction, it is possible that:
R the electric parking brake may not be
applied in certain circumstances, or
R the transmission may not be shifted to P
iSwitch off non-essential consumers, e.g.
the radio.
iDisarm the automatic locking feature
( Y page 205). You could otherwise be
locked out when pushing or towing the vehicle.
Installing/removing the towing eye
Installing the towing eye
Example: towing eye mounting covers
296Towing and tow-starting
Roadside Assistance
XDepress and hold the brake pedal.
X Shift the automatic transmission to posi-
tion N.
X Leave the SmartKey in position 2in the
ignition lock.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps(Y page 107).
iIn order to signal a change of direction
when towing the vehicle with the hazard
warning lamps switched on, use the com-
bination switch as usual. In this case, only
the indicator lamps for the direction of
travel flash. After resetting the combina-
tion switch, the hazard warning lamp starts
flashing again.
Transporting the vehicle
!
You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise,
the vehicle could be damaged.
X Turn the SmartKey to position 2in the igni-
tion lock ( Ypage 135).
X Shift the transmission to position N.
As soon as the vehicle has been loaded: X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Shift the transmission to position P.
X Turn the SmartKey to position 0in the igni-
tion lock and remove it.
X Secure the vehicle.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting
purposes.
Notes on 4MATIC vehicles
!
Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
Vehicles with 4MATIC may only either be
towed away with both axles on the ground or be loaded up and transported.
If the vehicle's transmission, front, or rear
axle is damaged, have the vehicle transported on a truck or trailer.
In the event of damage to the electrical
system:
If the battery is defective, the automatic
transmission will be locked in position P. To
shift the automatic transmission to positionN , you must provide power to the vehicle's
electrical system in the same way as when
jump-starting ( Ypage 293).
Have the vehicle transported on a transporter
or trailer.
Tow-starting (emergency engine
starting)
!
Vehicles with automatic transmission
must not be tow-started. You could other-
wise damage the automatic transmission.
iYou can find information on "Jump-start-
ing" under ( Ypage 293).
Fuses
Important safety notes
GWARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper-
age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
298Fuses
Roadside Assistance
Curb weight
The weight of a vehicle with standard equip-
ment including the maximum capacity of fuel,oil and coolant. It also includes the air-condi-
tioning system and optional equipment if
these are installed in the vehicle, but does not include passengers or luggage.
Maximum load rating
The maximum load rating is the maximum
permissible weight in kilograms or lbs for
which a tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axleby two.
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's
surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has not been driven further
than 1 mile (1.6 km) Tread
The part of the tire that comes into contact
with the road.
Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the accesso-
ries.
TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identify the purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing
capacity of a tire.
Traction
Traction is the result of friction between the
tires and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are dis-
tributed over the tire tread. If the tire tread is level with the bars, the wear limit of áin
(1.6 mm) has been reached.
All about wheels and tires321
Wheels and tires
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