Page 31 of 464

31 Getting started
Unlocking
Starter switch positionsStarter switch0For removing SmartKey
1Power supplies to some electrical con-
sumers, such as seat adjustment
2Ignition (power supply for all electrical
consumers) and driving position
3Starting position
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take the
SmartKey with KEYLESS-GO* with you and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Unsupervised use of vehi-
cle equipment may cause an accident
and/or serious personal injury.iThe SmartKey can only be removed
from the starter switch with the gear
selector lever in position P.
!If the SmartKey cannot be turned in the
starter switch, the battery may not be
sufficiently charged.
Check the battery and charge it
if necessary (
page 385).
Get a jump start (
page 388).
To prevent accelerated battery dis-
charge and a possible dead battery, al-
ways remove the SmartKey from the
starter switch when the engine is not in
operation.
ProCarManuals.com
Page 385 of 464

385 Practical hints
Battery
Battery
The battery is located on the right side of
the engine compartment.
Removal of filter box:
Release the three clamps1.
Remove filter box.
Installation of filter box:
Insert filter box properly.
Secure it with the three clamps1.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(For more information, see “Battery”
(page 294)
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 termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized 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 battery only to avoid the risk
of acid burns in the event of an accident.
ProCarManuals.com
Page 387 of 464
387 Practical hints
Battery
Reconnecting the battery
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover 2.
Connect the negative lead 1.
Reinstall the filter box (
page 385).Batteries contain materials that can harm
the environment if disposed of improperly.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!Never invert the terminal connections.!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.
iThe following procedures must be car-
ried out following any interruption of
battery power (e.g. due to reconnect-
ing):
Set the clock (
page 144) (vehi-
cles with COMAND*: see COMAND
operator’s manual).
Resynchronize side windows
(page 214).
ProCarManuals.com
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)
ProCarManuals.com