427 Practical hints
Battery
Battery
The battery is located in the engine
compartment on the right hand side.
1Clamps
Removing filter box:
Release clamps1.
Remove filter box.
Installing filter box:
Insert filter box properly.
Secure it with clamps1.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and
precautions when handling automotive
batteries (
page 311).
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 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 battery only to avoid the risk
of acid burns in the event of an accident.
428 Practical hintsBattery2Negative terminal
3Positive terminal cover
Disconnecting the battery
Turn off the engine (
page 56).
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 305).
Remove the filter box (
page 427).
Read and observe safety instructions
and precautions (
page 427).
Disconnect the battery negative lead
from negative terminal2.
Remove cover3 from the positive ter-
minal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw securing the
battery.
Remove the battery support and
bracket.
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
reverse 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
429 Practical hints
Battery
Reconnecting the battery
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.
Connect the battery positive lead and
fasten its cover3.
Connect the battery negative lead2.
Reinstall the filter box (
page 427).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.
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*.
!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 147) (vehi-
cles with COMAND*: see COMAND
operator’s manual).
Resynchronize the side windows
(page 243).
432 Practical hintsTowing the vehicleTowing the vehicle
Mercedes-Benz recommends that the vehi-
cle be transported with all wheels off the
ground using flatbed or appropriate wheel
lift/dolly equipment.When circumstances do not permit the
recommended towing methods, the vehi-
cle may be towed with all wheels on the
ground or front wheels raised only so far as
necessary to have the vehicle moved to a
safe location where the recommended
towing methods can be employed.
!Use flatbed or wheel lift/dolly equip-
ment with SmartKey in starter switch
turned to position0.
Do not tow with sling-type equipment.
Towing with sling-type equipment over
bumpy roads will damage radiator and
supports.
To prevent damage during transport,
do not tie down vehicle by its chassis or
suspension parts.
Switch off the tow-away alarm
(page 91) and the automatic central
locking (
page 155).
!If the vehicle is towed with the front
axle raised, the engine must be shut off
(SmartKey in starter switch position0
or1). Otherwise, the ESP will immedi-
ately be engaged and will apply the rear
wheel brakes.
When towing the vehicle with all wheels
on the ground, the selector lever must
be in positionN and the SmartKey
must be in starter switch position2.
When towing the vehicle with all wheels
on the ground or the front axle raised,
the vehicle may be towed only for dis-
tances up to 30 miles (50 km) and at a
speed not to exceed 30 mph
(50 km/h).
!To be certain to avoid a possibility of
damage to the transmission, however,
we recommend the drive shaft be dis-
connected at the rear axle drive flange
for any towing beyond a short tow to a
nearby garage.
433 Practical hints
Towing the vehicle
Warning!
G
Prior to towing the vehicle with all wheels on
the ground, make certain that the SmartKey
is in starter switch position
2.
If the SmartKey is left in starter switch posi-
tion
0 for an extended period of time, it can
no longer be turned in the switch. In this
case, the steering is locked. To unlock, re-
move SmartKey from starter switch and re-
insert.
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:
the engine will not run
there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
as that will be necessary to adequately con-
trol the towed vehicle.
Warning!
G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle. Adapt your driving accordingly.iTo signal turns while being towed with
the hazard warning flasher in use,
switch on the ignition and activate the
combination switch for the left or right
turn signal in the usual manner – only
the selected turn signal will operate.
Upon canceling the turn signal, the haz-
ard warning flasher will operate again.
!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 91).
To prevent the vehicle door locks from
locking, deactivate the automatic cen-
tral locking (
page 155).
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.
434 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.
iIf the battery is disconnected or
discharged
the SmartKey will not turn in the
starter switch. For more informa-
tion, see “Battery” (
page 427)
and “Jump starting” (page 430).
the gear selector lever will remain
locked in positionP. For informa-
tion on manually unlocking the
transmission gear selector lever,
see (
page 400).
463 Technical terms
Head-thorax air bag
Installed in the driver and the front pas-
senger seat, these air bags protect oc-
cupants during side impact collisions
exceeding a preset threshold. Unlike
normal side impact air bags,
head-thorax air bags are also designed
to provide protection for the head area.
Instrument cluster
The displays and indicator/warning
lamps in the driver’s field of vision, in-
cluding the tachometer, speedometer,
coolant temperature indicator and fuel
display.
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.Kilopascal (kPa)
(
page 336)
Lock button
Button on the door which indicates
whether the door is locked or un-
locked. Pushing the lock button down
on an individual door from inside will
lock that door.
Maintenance System (U.S. vehicles)
Maintenance service indicator in the
multifunction display that informs the
driver when the next vehicle mainte-
nance service is due. The Maintenance
System in your vehicle tracks distance
driven and the time elapsed since your
last maintenance service, and calls for
the next maintenance service
accordingly.
Maximum load rating
(page 337)
Maximum loaded vehicle weight
(page 337)
Maximum tire inflation pressure
(page 337)Memory function*
Used to store three individual seat,
steering wheel and mirror positions for
each SmartKey or, if so equipped,
KEYLESS-GO* feature.
Menu
The control system displays are ar-
ranged in menus. Each menu contains
a number of commands for particular
systems.
MON
(M
otor O
ctane N
umber)
The Motor Octane Number for gasoline
as determined by a standardized meth-
od. It is an indication of a gasoline's
ability to resist undesired detonation
(knocking). The average of both the
MON (Motor Octane Number) and
->RON (Research Octane Number) is
posted at the pump, also known as
ANTI-KNOCK INDEX.
Multifunction display
Display field in the speedometer used
to present information provided by the
control system.
465 Technical terms
Restraint systems
Seat belts, child restraints, lower an-
chors and tethers for children (LATCH).
As independent systems, their protec-
tive functions complement one anoth-
er.
Rim
(
page 337)
Roll bars
Occupant protection system which
consists of tubular steel, integrated in
the rear head restraints. The roll bars
are lowered into the car body during
normal driving conditions and raised
automatically in an accident or in a crit-
ical driving situation.RON
(R
esearch O
ctane N
umber)
The Research Octane Number for gaso-
line as determined by a standardized
method. It is an indication of a gaso-
line's ability to resist undesired detona-
tion (knocking). The average of both
the ->MON (Motor Octane Number)
and RON (Research Octane Number) is
posted at the pump, also known as
ANTI-KNOCK INDEX.
Shift lock
When the vehicle is parked, this lock
prevents the gear selector lever from
being inadvertently moved out of
positionP without SmartKey turned
and brake pedal depressed.
Sidewall
(
page 337)Soft top
Soft top roof that can be opened by
pulling and closed by pressing a switch
and stored in the soft top compartment
in the trunk area.
Speedshift (CLK 500, CLK 55 AMG)
Steering wheel gearshift control. You
can change the gears yourself with the
steering wheel gearshift buttons.
SRS
(S
upplemental R
estraint S
ystem)
Air bags, air bag control unit (with
crash sensor), emergency tensioning
device. Though independent systems,
they are closely interfaced to provide
effective occupant protection.