Page 425 of 489

424 Practical hints
Flat tire
Detach the electric air pump.
Stow the electrical plug and the air
hose behind the flap and place the air
pump back in the trunk.
Lowering the vehicle
Lower vehicle by turning crank coun-
terclockwise until the full weight of the
vehicle is resting on the ground.
Pull the jack out of the jack support
tube.1 - 5 Wheel bolts
Tighten the five wheel bolts evenly,
following the diagonal sequence
illustrated (1 to 5), until all bolts
are tight. Observe a tightening torque
of 96 lb-ft (130 Nm).
Warning!G
Follow recommend inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver’s door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
iThe flat tire may be transported in the trunk
when the retractable hardtop is raised. If avail-
able, use a protective sheet on the spare wheel.
Vehicles with TPMS or Advanced TPMS*:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.
Warning!G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
96 lb-ft (130 Nm).
Page 426 of 489

425 Practical hints
Flat tire
Before storing the jack in the trunk,
crank back to storage position and fold
in the arm.Replacing jack support tube cover
Slide tongue of cover under the upper
edge of the tube opening.
Applying even pressure, press cover
until it snaps into place.
Be careful not to damage the locking
tabs or clamp the plastic retaining
strap.
MOExtended system*
The MOExtended system allows you to
continue driving your vehicle even if there
is a total loss of pressure in one or more
tires.
You may only use the MOExtended system
in conjunction with the Run Flat Indicator*
(Canada vehicles) (
page 303), TPMS
(U.S. vehicles) (
page 305), or Advanced
TPMS* (Canada vehicles) (
page 308).
Warning!G
When turning the wheel wrench to tighten
the wheel bolts, make sure you position
hands on the wrench in such a way that you
avoid injury to yourself, such as scraping
your hands against the wheel. Make sure
turning the wheel wrench will not scratch or
damage the wheel rim.
iFor information on storing the spare wheel
back into the trunk, see “Storing the spare wheel
after use” (
page 402).
!The maximum distance in emergency
mode depends on the vehicle’s load. It is
30 miles (50 km) if the vehicle is partially
loaded and 18 miles (30 km) if the vehicle is
fully loaded.
The point at which the maximum driving distance
begins in emergency mode is when the warning
message appears in the multifunction display
indicating that there is a loss of tire inflation
pressure.
Do not exceed the maximum speed of
50 mph (80 km/h).
Page 427 of 489

426 Practical hints
Flat tire
Warning!G
In emergency mode, your vehicle’s driving
characteristics are diminished in such situa-
tions as:
driving around curves
while braking
while accelerating rapidly
Therefore, your driving style must be adapt-
ed accordingly. Avoid abrupt steering and
driving maneuvers, as well as driving over
obstacles (road curbs, potholes, or off-road
areas). This is especially important if the ve-
hicle is heavily loaded.
The emergency driving distance that can be
achieved greatly depends on the demands
placed on the vehicle. Depending on speed,
load, driving maneuvers, road conditions,
outside temperature, etc., the distance can
be significantly shorter or, if the vehicle is
driven cautiously, somewhat longer.
Do not continue driving in emergency mode
if
you notice knocking sounds
the vehicle starts to shake
smoke develops and you smell rubber
ESP® is intervening continuously
you notice tears on the tire sidewalls
After driving in emergency mode, you must
have the rims inspected by an authorized
Mercedes-Benz Center to check if they are
suitable for further use. The failed tire must
be replaced in any case.
iWhen replacing individual or all tires on the
vehicle, make sure only matching tires marked
with “MOExtended” are mounted in the size
specified for your vehicle (
page 449).
Page 428 of 489

427 Practical hints
Batteries
Batteries
For more information on batteries, see
“Battery” (
page 290).
Your vehicle is equipped with two
batteries:
The starter battery
The battery for electrical consumers
(consumer battery), located in the
trunk
The starter battery is located on the
right-hand side of the engine compart-
ment.
1Positive terminal
2Negative terminal
3Battery ventilationThe consumer battery is located on the
right-hand side of the trunk.
4Positive terminal
5Negative terminal
!The starter battery, its filler caps, and the
ventilation hose must always be securely
installed when the vehicle is in operation.!The consumer battery located in the trunk is
a valve-regulated lead acid (VRLA) battery, also
referred to as “fleece” battery. Such batteries do
not require topping-up of the electrolyte level.
VRLA batteries therefore do not have cell caps
and the battery cover is non-removable. Do not
attempt to open the consumer battery as other-
wise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, disconnect the con-
sumer battery if you do not intend to operate
your vehicle for an extended period of time to
prevent battery discharge or connect an acces-
sory battery charge unit expressly approved by
Mercedes-Benz for your vehicle model to main-
tain the battery charge. Contact an authorized
Mercedes-Benz Center for further information.
Page 429 of 489

428 Practical hints
Batteries
!The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation and the
lateral plug must always be securely installed
when the vehicle is in operation.
Warning!G
Failure to follow these instructions can
result in severe injury or death.
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the starter battery checked regularly by an
authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
Mercedes-Benz Center for further information.
Warning!G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof batteries only to avoid the
risk of acid burns in the event of an acci-
dent.
Warning!G
The brake system requires electrical power
to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. The same applies if
battery is disconnected. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels.
Stopping distance is increased! Adjust your
driving style accordingly. For more informa-
tion, see “Electro-hydraulic brake system”
(
page 94).
Page 430 of 489

429 Practical hints
Batteries
Disconnecting the batteries
Apply the parking brake (page 63).
Make sure the gear selector lever is set
to position P (
page 172).
Close the retractable hardtop
(
page 204).
Turn off all electrical consumers.
Turn off the engine (page 64).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*: Open
the driver’s door.
Open the trunk.
Read and observe safety instructions
and precautions (
page 290).
Open the luggage cover in the trunk
(
page 211).
Remove the trunk floor.
The battery for electrical consumers is
located in the right hand area of the
trunk (
page 400).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal5 of the consumer battery
(
page 427).
Warning!G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button on the gear selector lever will
have no effect
the gear selector lever will remain
locked in positionP
!Always disconnect the batteries in the order
described below, even if you only want to charge
the starter battery, for example. Otherwise the
vehicle’s electronics can be damaged.
Page 431 of 489

430 Practical hints
Batteries
Open the hood (page 282).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal2 of the starter battery
(
page 427).
Remove the covers from the positive
terminals 1 and 4 (
page 427).
Disconnect the positive lead from pos-
itive terminal 4 of the consumer bat-
tery (
page 427).
Disconnect the positive lead from pos-
itive terminal 1 of the starter battery
(
page 427).
Removing the batteries
Removing the consumer battery
Remove the screws securing the bat-
tery in the trunk.
Remove the battery support and
bracket.
Pull out the battery ventilation hose
from the battery.
Depending on battery arrangement in
your vehicle model, the ventilation tube
is located either on the left or right side
of the battery.
Take out the battery.
Removing the starter battery
Remove the screws securing the start-
er battery in the engine compartment.
Pull battery ventilation 3
(
page 427) out of the battery.
Lift the retaining bracket.
Remove the battery.
Charging and reinstalling batteries
Warning!G
Never charge a battery while still installed in
the vehicle unless the accessory battery
charge unit approved by Mercedes-Benz is
being used. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
An accessory battery charge unit specially
adapted for Mercedes-Benz vehicles and
tested and approved by Mercedes-Benz is
available, permitting the charging of the
battery in its installed position. Contact an
authorized Mercedes-Benz Center for infor-
mation and availability. Charge battery in
accordance with the separate instructions
for the accessory battery charger.
Page 432 of 489

431 Practical hints
Batteries
Charge batteries in accordance with
the instructions of the battery charger
manufacturer.
Reinstall the charged batteries. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.
Install starter battery in the designated
location in the engine compartment.
Install consumer battery in the desig-
nated location in the trunk.
Attach supports and brackets.
Tighten support and bracket screws.
Connect positive lead 4 (page 427)
of the consumer battery and positive
lead 1 (
page 427) of the starter bat-
tery and fasten covers.
Connect negative lead 2
(
page 427) of the starter battery.
Connect negative lead 5
(
page 427) of the consumer battery.
Reinstall the trunk floor.
Close trunk luggage cover
(
page 211).
!Always connect the batteries in the order
described below. Otherwise the vehicle’s elec-
tronics can be damaged.
!Never invert the terminal connections!
iThe following procedures must be carried
out following any interruption of battery power
(e.g. due to reconnection):
Synchronize the ESP® (page 367).
Synchronize side windows (page 203).