Page 348 of 464
348 Practical hintsUnlocking/locking in an emergency
Unlocking/locking in an emergencyUnlocking the vehicle
If you are unable to unlock the vehicle with
the SmartKey or KEYLESS-GO*, open the
driver’s door and the trunk using the me-
chanical key.
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in direction of ar-
row and slide the mechanical key2
out of the housing.Unlocking the driver’s door
1Unlocking
2Locking
Unlock the door with the mechanical
key. To do so, push the mechanical key
in the lock until it stops and turn it to
the left.
iUnlocking your vehicle with the me-
chanical key will trigger the anti-theft
alarm system. To cancel the alarm, do
one of the following:
Press button Œ or ‹ on the
SmartKey.
Insert the SmartKey in the starter
switch.
Vehicles with KEYLESS-GO*
Pull the outside door handle.
Press the KEYLESS-GO* start/stop
button (
page 33).
Page 350 of 464

350 Practical hintsUnlocking/locking in an emergencyChanging batteries in the SmartKey/ SmartKey with KEYLESS-GO*
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are dis-
charged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized 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
1Mechanical key
2Battery compartment
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key1
(page 348).
Insert the mechanical key in side open-
ing and push gray slide.
The battery compartment is unlatched.
Pull the battery compartment out of the
SmartKey housing in direction of ar-
row.
Remove the batteries.
Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.
Page 351 of 464

351 Practical hints
Unlocking/locking in an emergency
3Battery
4Contact spring
Using a lint-free cloth, insert new bat-
teries under the contact spring with the
plus (+) side facing up.
Return battery compartment into hous-
ing until it locks into place.SmartKey with KEYLESS-GO*
1Battery
2Tilt battery up
3Mechanical key
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key (
page 348).
Insert the mechanical key in side open-
ing and push grey slide.
The battery compartment is unlatched.
Pull the battery compartment out of the
SmartKey housing in direction of ar-
row.
Using mechanical key3, apply pres-
sure to position2.
Battery1 tilts up slightly.
Pull batteries1 out in direction of ar-
row.
Using a lint-free cloth, insert new bat-
teries with the plus (+) side facing up.
Return battery compartment into hous-
ing until it locks into place.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.
Page 359 of 464

359 Practical hints
Opening/closing in an emergency
Place both straps on soft top compart-
ment cover.
Take hex wrench out of trunk.
Close trunk lid.
You will only have access to the trunk
again when the emergency operation
has been completed.
You and your assistant should each
take one of the straps by the handle.
With a strong, simultaneous tug on the
loops, pull soft top compartment cover
upward and out to the rear.
iDo not place the SmartKey in the open
trunk. You may lock yourself out.
Vehicles with KEYLESS-GO*: To pre-
vent a possible inadvertent lockout, the
trunk lid will open automatically if a
SmartKey with KEYLESS-GO* is recog-
nized in the area of the rear shelf or in-
side the trunk.!The trunk lid must remain closed during
the next steps in the procedure. Other-
wise the trunk lid and the soft top com-
partment cover may come into contact
with one another and be damaged.Warning!
G
At this point, the remaining procedure
needs to be done by two people. Otherwise
you could be injured.
Page 367 of 464

367 Practical hints
Opening/closing in an emergency
Place both straps on soft top compart-
ment cover.
Take hex wrench out of trunk.
Close trunk lid.
You will only have access to the trunk
again when the emergency operation
has been completed.
You and your assistant should each
take one of the straps by the handle.
With a strong, simultaneous tug on the
loops, pull soft top compartment cover
upward and out to the rear.
iDo not place the SmartKey in the open
trunk. You may lock yourself out.
Vehicles with KEYLESS-GO*: To pre-
vent a possible inadvertent lockout, the
trunk lid will open automatically if a
SmartKey with KEYLESS-GO* is recog-
nized in the area of the rear shelf or in-
side the trunk.!The trunk lid must remain closed during
the next steps in the procedure. Other-
wise the trunk lid and the soft top com-
partment cover may come into contact
with one another and be damaged.Warning!
G
At this point, the remaining procedure
needs to be done by two people. Otherwise
you could be injured.
Page 386 of 464

386 Practical hintsBatteryDisconnecting the battery
1Negative terminal
2Positive terminal cover
Depress parking brake firmly or move
gear selector lever to positionP.
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO*:
Press the start / stop button until
the engine shuts off.
Open the driver’s door.
Open the hood (
page 287).
Remove the filter box.
Disconnect the battery negative lead.
Remove cover2 from the positive ter-
minal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw securing the bat-
tery.
Remove the battery support and brack-
et.
Take out the battery.
Charging and reinstalling battery
Charge battery in accordance with the
instructions of the battery charger
manufacturer.
Reinstall the charged battery. Follow
the previously described steps in re-
verse order.
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 position
P
Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
Page 392 of 464

392 Practical hintsTowing the vehicle
Installing towing eye bolt
Towing eye bolt CLK 320/CLK 500
1Cover on right side of front bumper2Cover on right side of rear bumper
To remove cover:
Press mark on cover in direction of ar-
row.
Lift cover off to reveal threaded hole for
towing eye bolt.
The towing eye bolt is supplied with the
tool kit (located in the compartment under-
neath the trunk floor).
Screw towing eye bolt to its stop and
tighten with lug wrench.
To reinstall cover:
Fit cover and snap into place.
!When towing the vehicle with all wheels
on the ground, please note the follow-
ing:
With the automatic central locking acti-
vated and the SmartKey in starter
switch position2, or KEYLESS-GO*
start/stop button in position2, the ve-
hicle doors lock if the left front wheel
as well as the right rear wheel are turn-
ing at vehicle speeds of approx. 9 mph
(15 km / h) or more.
Switch off the tow-away alarm
(page 84).
To prevent the vehicle door locks from
locking, deactivate the automatic cen-
tral locking (
page 149).
Towing of the vehicle should only be
done using the properly installed tow-
ing eye bolt. Never attach tow cable,
tow rope or tow rod to the vehicle chas-
sis, frame or suspension parts.
iThe gear selector lever will remain
locked in positionP and the SmartKey
will not turn in the starter switch if the
battery is disconnected or discharged.
See notes on the battery (
page 385)
or on jump starting (
page 388).
Manually unlocking gear selector lever
(
page 352)
Page 421 of 464

421 Technical terms
Engine number
The number set by the manufacturer
and placed on the cylinder block to
uniquely identify each engine pro-
duced.
Engine oil viscosity
Measurement for the inner friction (vis-
cosity) of the oil at different tempera-
tures. The higher the temperature an
oil can tolerate without becoming thin,
or the lower the temperature it can tol-
erate without becoming viscous, the
better the viscosity.
ESP
(E
lectronic S
tability Pr
ogram)
Improves vehicle handling and direc-
tional stability.
ETD
(E
mergency T
ensioning D
evice)
Device which deploys in certain frontal
and rear collisions exceeding the sys-
tem's threshold to tighten the seat
belts.
->SRSFSS
(F
lexible S
ervice S
ystem)
Service indicator in the multifunction
display that informs the driver when
the next vehicle maintenance service is
due.
Gear range
Number of gears which are available to
the automatic transmission for shifting.
The automatic gear shifting process
can be adapted to specific operating
conditions using the gear selector le-
ver.
GPS
(G
lobal P
ositioning S
ystem)
Satellite-based system for relaying
geographic location information to and
from vehicles equipped with special re-
ceivers. Employs CD digital maps for
navigation.Head-thorax airbag
Installed in the driver and the front pas-
senger seat, these airbags protect oc-
cupants during side impact collisions
exceeding a preset threshold. Unlike
normal side airbags, head-thorax air-
bags are also designed to provide pro-
tection for the head area.
Instrument cluster
The displays and indicator/warning
lamps in the driver’s field of vision, in-
cluding the tachometer, speedometer,
engine temperature and fuel gauge.
KEYLESS-GO*
System for entering and operating the
vehicle without the use of a SmartKey.
Kickdown
Depressing the accelerator past the
point of resistance shifts the transmis-
sion down to the lowest possible gear.
This very quickly accelerates the vehi-
cle and should not be used for normal
acceleration needs.