636 Practical hints
Unlocking/locking in an emergency
Unlocking the trunk
A minimum height clearance of 5.78 ft
(1.76 m) is required to open the trunk lid.
Insert the mechanical key2 into the
trunk lid lock until it stops.
Turn mechanical key2 all the way
counterclockwise to position 1.
The trunk opens.
Turn the mechanical key2 back and
remove it from the trunk lid lock.
Locking the vehicle
If you cannot lock the vehicle with the
SmartKey or KEYLESS-GO*, do the
following:
Open the passenger door.
Close the driver’s door and the trunk.
Check whether the trunk is locked.
If necessary, lock the trunk with the
mechanical key (
page 465).
Press down the locking knob of the
driver’s door manually.
Press down the locking knob of the
passenger door.
Exit the vehicle.
Close the passenger door.
The vehicle is locked.
1Unlocking in an emergency
2Mechanical key
!The trunk lid swings open upwards automat-
ically. Always make sure that there is sufficient
overhead clearance.
iIf you cannot close the trunk with the re-
mote trunk opening/closing switch, lower the
trunk lid manually and close it with hands placed
flat on the trunk lid until it is engaged in its lock.
!To prevent inadvertent lockout, make sure
to have the SmartKey or SmartKey with
KEYLESS-GO* with you before proceeding with
the next step. The next step will lock the vehicle.
iThis procedure does not arm the anti-theft
alarm system nor does it lock the fuel filler flap.
639 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey/SmartKey
with KEYLESS-GO* are discharged, the ve-
hicle can no longer be locked or unlocked.
It is recommended to have the batteries re-
placed at an authorized Mercedes-Benz
Center.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.SmartKey/SmartKey with
KEYLESS-GO*
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key out of the
SmartKey/SmartKey with
KEYLESS-GO* (
page 635).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
Warning!G
Batteries contain poisonous and corrosive
substances. Therefore keep the batteries
out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen inserting the batteries, make sure
they are clean and free of lint.
iWhen changing batteries, always replace
both batteries.
The required replacement batteries are available
at any authorized Mercedes-Benz Center.
640 Practical hints
Replacing SmartKey batteries
Pull battery compartment 2 out of the
housing.
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2
(
page 639) into housing until it locks
into place.
Slide the mechanical key back into the
SmartKey/SmartKey with
KEYLESS-GO*.
Check the operation of the SmartKey/
SmartKey with KEYLESS-GO*.
647 Practical hints
Replacing wiper blades
Replacing wiper blades
Placing wiper arms in vertical position
Wiper blades in vertical position
Make sure the hood is fully closed.
Vehicles with SmartKey
Turn SmartKey in starter switch
position1.
Turn combination switch to wiper
settingu (
page 372).
With wiper arm in vertical position, turn
the SmartKey in starter switch to
position0.
Warning!G
For safety reasons, switch off wipers and re-
move SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the
vehicle’s on-board electronics have
status0) before replacing a wiper blade.
Otherwise, the wiper motor could suddenly
turn on and cause injury.
Warning!G
Wiper blades are components that are sub-
ject to wear and tear. Replace the wiper
blades twice a year, preferably in the spring
and fall. Otherwise the windows will not be
properly wiped. As a result, you may not be
able to observe surrounding traffic condi-
tions and could cause an accident.
!To avoid damage to the hood:
The wiper arms should only be folded for-
ward when in the vertical position.
Never open the hood when the wiper arm is
folded forward.
!Hold on to the wiper when folding the wiper
arm back. If released, the force of the impact
from the tensioning spring could crack the wind-
shield.
Do not allow the wiper arms to contact the wind-
shield glass without a wiper blade inserted.
For your convenience, we recommend that you
have this work carried out by an authorized
Mercedes-Benz Center.
648 Practical hints
Replacing wiper blades
Vehicles with KEYLESS-GO*
Make sure the vehicle’s on-board elec-
tronics have status 1 (
page 337).
Turn combination switch to wiper
settingu (
page 372).
Press KEYLESS-GO start/stop button
repeatedly until windshield wipers
start.
Press KEYLESS-GO start/stop button
when the wiper arms are in a vertical
position.
Removing wiper blades
Fold the wiper arm forward until it
snaps into place.
Turn the wiper blade at a right angle to
wiper arm (arrow 1).
Slide the wiper blade sideways out of
the retainer in the direction of
arrow2.
Installing wiper blades
Slide the wiper blade onto wiper arm
until it locks in place.
Rotate the wiper blade into position
parallel to wiper arm.
Fold the wiper arm backward to rest on
the windshield. Make sure you hold
onto the wiper when folding the wiper
arm back.
!Do not pull on the wiper blade inserts. They
could tear.
!Make certain that the wiper blades are prop-
erly installed. Improperly installed wiper blades
may cause windshield damage.
649 Practical hints
Flat tire
Flat tire
Preparing the vehicle
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flashers.
Turn the steering wheel so that the
front wheels are in a straight ahead
position.
Shift the automatic transmission toP
(
page 389).
Turn off the engine (page 387).
Remove the SmartKey from the starter
switch.
Vehicles with SmartKey with
KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 388).
Open the driver’s door (this puts
the starter switch in position0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Mounting the Minispare wheel
iOpen the door only when conditions are safe
to do so.
Warning!G
The dimensions of the Minispare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a Minispare wheel
mounted. Adapt your driving style accord-
ingly.
The Minispare wheel is for temporary use
only. When driving with Minispare wheel
mounted, ensure proper tire inflation
pressure and do not exceed a vehicle speed
of 50 mph (80 km/h).
Contact the nearest Mercedes-Benz Center
as soon as possible to have the Minispare
wheel replaced with a regular road wheel.
Never operate the vehicle with more than
one Minispare wheel mounted.
Do not switch off the ESP
® when a Minis-
pare wheel is mounted.
657 Practical hints
Batteries
Starter battery (example illustration from
CL 550)
1Negative terminal
2Positive terminal
Disconnecting starter battery
Secure vehicle in place with electronic
parking brake (
page 384).
Shift the automatic transmission toP
(
page 389).
Do not rub the battery with rags or cloths.
The battery could explode if touched due to
electrostatic charge or due to spark forma-
tion.
!Switch off the engine and switch off the ve-
hicle’s internal electrical functions (
page 658)
before you disconnect or remove the battery’s
terminal clamps. You could otherwise destroy
electronic assemblies such as the generator.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center. Refer to Mainte-
nance Booklet for maintenance intervals or
contact an authorized Mercedes-Benz Center for
further information.
!Do not connect any consumers directly to
the starter battery. The starter battery will other-
wise be discharged.
iOnly replace a discharged battery with a bat-
tery recommended by Mercedes-Benz. The con-
sumer battery is installed in the trunk in such a
way that it is safeguarded as much as possible
against mechanical destruction in the event of
an accident.
iRemove SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the vehicle’s
on-board electronics have status 0)
(
page 336) when you turn off the engine and
no longer require any electrical consumers. The
vehicle then uses very little power and the con-
sumer battery is spared.
iIf the consumer battery is discharged, you
must use the mechanical key to unlock the vehi-
cle (
page 635). Since the vehicle has a sepa-
rate starter battery, however, you can still start
the vehicle.
!Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle’s electronics.
!Switch off the vehicle’s internal electrical
functions before disconnecting the starter bat-
tery. If the vehicle is stationary for more than one
hour with the SmartKey removed, you do not
need to switch off the vehicle’s internal electrical
functions.
658 Practical hints
Batteries
Switching off vehicle’s internal
electrical functions
Turn off all electrical consumers.
Turn SmartKey in starter switch to po-
sition 0.
Turn SmartKey in starter switch to po-
sition 1.
Wait for 30 seconds.
The vehicle’s internal electrical func-
tions are switched off.
Turn SmartKey in starter switch to po-
sition 0.Disconnecting starter battery
Open the hood (page 512).
Use a 10-mm open-end wrench to dis-
connect the battery negative lead.
Remove cover2 (page 657) from
the positive terminal.
Disconnect the battery positive lead.
Removing starter battery
Pull out the battery ventilation hose
from the battery (depending on battery
arrangement in your vehicle model, the
ventilation hose is located either on the
left or right side of the battery).
Fold bar on starter battery up.
Take out the starter battery.
Charging battery
iVehicles with KEYLESS-GO: remove the
KEYLESS-GO button (
page 337) and use the
SmartKey with KEYLESS-GO like a normal
SmartKey.
!Do not remove the SmartKey!
iFor your convenience, have the starter bat-
tery removed by a Mercedes-Benz Center.
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 bat-
tery in its installed position. Contact an au-
thorized Mercedes-Benz Center for
information and availability. Charge battery
in accordance with the separate instruc-
tions for the accessory battery charger.
iHave the batteries charged by a
Mercedes-Benz Center. If you charge the batter-
ies yourself, follow the operating instructions for
your charging device.