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The highly flammable gas mixture forms when
charging the battery as well as when jump-start-
ing.
Always make sure that neither you nor the bat-
tery is electrostatically charged. A build-up of
electrostatic charge can be caused, for exam-
ple:
Rby wearing clothing made from synthetic
fibers
Rdue to friction between clothing and seats
Rif you push or pull the battery across the car-
pet or other synthetic materials
Rif you wipe the battery with a cloth
GWARNING
During the charging process, a battery produ-
ces 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 con- tact with vehicle parts.
RNever place metal objects or tools on a bat-
tery.
RIt is important that you observe the descri-
bed order of the battery terminals when
connecting 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 dis-
connecting the jumper cables.
RNever connect or disconnect the battery
terminals while the engine is running.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
HEnvironmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
!Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist
workshop for more information.
!Always have work on batteries carried out at
a qualified specialist workshop. Should it, in
exceptional circumstances, be absolutely
necessary to disconnect the 12-volt battery
yourself, observe the following:
Rsecure the vehicle to prevent it from rolling
away.
Rswitch off the ignition.
Ralways disconnect the negative terminal
clamp first, followed by the positive termi-
nal clamp.
After the battery has been disconnected, the
transmission is locked in position P.
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
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Battery acid is caustic. Avoid contact
with skin, eyes or clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Rinse any acid spills immediately
with clear water. Contact a physician
if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.
In this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus conserving battery power.
PLUG-IN HYBRID vehicles: if the battery
charge is sufficient, the high-voltage battery can
also supply the 12 V battery. This only happens
if the condition of charge of the 12 V battery
requ
ires this, e.g. after using electrical consum-
ers for an extended period with the engine switched off. As the on-board voltage is contin-
uously monitored this can also be performed
when the engine is switched off. The condition of
charge of the 12 V battery and the on-board
voltage are thereby kept stable for a longer
period.
If the power supply has been interrupted, e.g. if
you reconnect the battery, you will have to:
Rset the clock. Information on setting the clock
can be found in the Digital Operator's Manual.
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally.
Rreset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (
Ypage 111).
High-voltage battery – important
safety notes
Only PLUG-IN HYBRID vehicles are equipped
with a high-voltage battery.
GDANGER
The vehicle's high-voltage electrical system is under high voltage. If you modify components
in the vehicle's high-voltage electrical system
or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may be
damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Following an accident, do not touch any high-
voltage components and never modify the
vehicle's high-voltage electrical system. Have
the vehicle towed away after an accident and
the vehicle's high-voltage electrical system
checked by a qualified specialist workshop.
GWARNING
In the event of a vehicle fire, the internal pres- sure of the high-voltage battery can exceed a
critical value. In this case flammable gas
escapes through a ventilation valve on the
underbody. The gas can ignite. There is a risk
of injury.
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Leave the danger zone immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements.
GWARNING
If the housing of the high-voltage battery has
been damaged, electrolyte and gases may
leak out. These are poisonous and caustic.
There is a risk of injury.
Avoid contact with skin, eyes or clothing.
Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
!Exhaustive discharge caused by the vehicle
standing idle for lengthy periods can damage
the high-voltage battery. If the vehicle is idle
for lengthy periods leave the high-voltage bat-
tery connected to a charging station.
Consult an authorized Mercedes-Benz Center if
you wish to leave your vehicle parked for a long
period of time.
Charging the 12 V battery
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing 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.
!Only use battery chargers with a maximum
charging voltage of 14.8 V.
!Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (
Ypage 379).
XOpen the hood.
XConnect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (
Ypage 379).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do not
light up, it is highly 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 thawed-out battery may be
shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified
specialist workshop.
PLUG-IN HYBRID vehicles: if the battery
charge is sufficient, the high-voltage battery can
also supply the 12 V battery. This only happens if the battery charge of the 12 V battery requires
this, e.g. after using electrical consumers for an
extended period with the engine switched off.
As the on-board voltage is continuously moni-
tored this can also be performed when the
engine is switched off. The condition of charge
of the 12 V battery and the on-board voltage are
thereby kept stable for a longer period.
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Charging the high-voltage battery
when stationary (hybrid vehicles)
Only PLUG-IN HYBRID vehicles are equipped
with a high-voltage battery.
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation.
!Only charge the high-voltage battery in the
"Charging when stationary" mode. Do not
connect any battery chargers to the high-volt- age battery. This could damage the vehicle’s
high-voltage electrical system.
XBring the vehicle to a stop with the engine
running.
The engine powers the electric motor. The
electric motor operates as a generator. The
high-voltage battery is being charged.
If the high-voltage battery has been discharged
excessively, charge the high-voltage battery to
at least 60%. In "Charging while stationary"
mode, you can monitor the condition of charge
of the high-voltage battery up to a maximum of
70% in the COMAND display and the multifunc-
tion display (
Ypage 248).
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Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
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 connecting
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 disconnecting
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 explosion. Allow the frozen battery to thaw out before charging it or jump-starting.
!Vehicles with a gasoline engine: avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery may be shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have the thawed-out battery checked at a qualified
specialist workshop.
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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:
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.
RVehicles with a gasoline engine: 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 which have a sufficient cross-section and insulated terminal clamps.
RIf 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.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RBare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery.
RThe 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.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position P.
XMake sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position 0in the ignition lock and remove it
(
Ypage 145).
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
Position number Bidentifies the charged battery of the other vehicle or an equivalent jump-starting
device.
XSlide cover :of positive terminal ;in the direction of the arrow.
XConnect positive terminal ;on your vehicle to positive terminal =of donor battery Busing the
jumper cable, always begin with positive terminal ;on your own vehicle first.
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XStart the engine of the donor vehicle and run it at idling speed.
XConnect 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.
XStart the engine.
XBefore disconnecting the jumper cables, let the engine run for several minutes.
XFirst, remove the jumper cables from ground point Aand negative terminal ?, then from pos-
itive clamp ;and positive terminal =. Begin each time at the contacts on your own vehicle first.
XClose cover:of positive terminal ;after removing the jumper cables.
XHave the battery checked at a qualified specialist workshop.
PLUG-IN HYBRID vehicles: if your vehicle has been jump-started, it may not be possible to use the
electric drive for approximately 30 minutes.
Jump-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:
Rthe engine is not running.
Rthe brake system or the power steering is
malfunctioning.
Rthere 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
When towing or tow-starting another vehicle
and its weight is greater than the permissible
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 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 iden-
tification plate (
Ypage 432).
!When COLLISION PREVENTION ASSIST
PLUS, DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automatically
in certain situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations:
Rwhen towing the vehicle
Rin the car wash
!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, or the trailer tow hitch, if availa-
ble. You could otherwise damage the vehicle.
!Do not use the trailer tow hitch for recovery
or towing. Do not use the towing eye for
recovery. this could damage the vehicle. If in
doubt, have the vehicle recovere d u
sing a
crane.
!When towing, pull away slowly and
smoothly. Pull the towed vehicle as straight as
possible and not at an acute angle. Excessive
tractive power could damage the vehicles.
When towing, it is preferable to use a rigid tow-
ing bar as opposed to a tow rope. A rigid towing
bar helps to keep the tractive power low.
!When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop button.
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Otherwise, the automatic transmission may
shift to positionPwhen the driver's or front-
passenger door are opened, which could lead
to damage to the transmission.
!Do not tow with sling-type equipment. This
could damage the vehicle.
!Vehicles with differential locks: make sure
the differential locks are in automatic mode.
When towing, the differential locks must not
be switched on. The transmission may other- wise be damaged.
!The vehicle can be towed a maximum of
30 miles (50km). The towing speed of 30 mph
(50 km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the entire vehicle must be
raised and transported.
It is better to have the vehicle transported than
to have it towed away.
If the vehicle has suffered transmission damage,
have it transported on a transporter or trailer.
The automatic transmission must be in position
N when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
Rcannot turn the SmartKey to position 2in the
ignition lock
Rcannot release the electric parking brake
Rcannot shift the automatic transmission to
position N
Disarm the automatic locking feature before the vehicle is towed (
Ypage 275). You could other-
wise be locked out when pushing or towing the
vehicle.
PLUG-IN HYBRID vehicles:
PLUG-IN HYBRID vehicles may not be towed
away but must instead be transported, if:
Rthe multifunction display is not working or
Rthe á Towing Not Permitted SeeOperator'sManualmessage appears in the
multifunction display.
If the vehicle is in a dangerous area, it can be
towed out of that area with both axles on the
ground. In this case, the towing distance must
not be greater than 165 ft (50 m)and must not
exceed a towing speed of 6 mph (10 km/h). For
longer distances, have the vehicle loaded and
transported.
Installing/removing the towing eye
Installing the towing eye
The brackets for the screw-in towing eye are
located in the bumpers. They are at the front and
rear behind covers :;.
XRemove the towing eye from the vehicle tool
kit (Ypage 369).
XTo open the cover at the front: press the
mark on cover :inwards in the direction of
the arrow.
XTo open the cover at the rear: insert a flat,
blunt object into the cutout and lever
cover ;out of the bumper.
XTake cover :or; off the opening.
XScrew in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye
XUnscrew and remove the towing eye.
XPosition cover :or; in the bumper and
press the cover on until it engages.
XPlace the towing eye in the vehicle tool kit.
Towing a vehicle with both axles on
the ground
The automatic transmission automatically shifts
to position Pwhen you open the driver's or front-
passenger door or when you remove the Smart-
Key from the ignition lock.
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