Page 465 of 521

464 Practical hints
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 329).
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 battery checked regularly at an autho-
rized 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.
Page 466 of 521

465 Practical hints
Battery
2Negative terminal
3Positive terminal cover
Disconnecting the battery
Apply the parking brake (page 59).
Make sure gear selector lever is set to
positionP (
page 174).
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 323).
Remove the filter box (page 464).
Read and observe safety instructions
and precautions (
page 464).
Disconnect the battery negative lead
from negative terminal2.
Remove cover3 from the positive
terminal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw securing the
battery.
Remove the battery support and
bracket.
Pull out the ventilation hose from the
battery (depending on battery arrange-
ment in your vehicle model, the ventila-
tion hose is located either on the left or
right side of the battery).
Take out the battery.
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 battery in the order
described below. Otherwise the vehicle’s elec-
tronics can be damaged.
Page 467 of 521

466 Practical hints
Battery
Charging and reinstalling the 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.
Reconnecting the battery
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO*:
Open the driver’s door.
Connect the battery positive lead and
fasten its cover3 (
page 465).
Connect the battery negative lead 2
(
page 465).
Reinstall the filter box (page 464).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.
!The battery, its filler caps and the ventilation
hose must always be securely installed when the
vehicle is in operation.
!Always connect the battery in the order
described below. Otherwise the vehicle’s
electronics 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 reconnecting):
Set the clock (page 160). Vehicles with
COMAND*: see COMAND operator’s manu-
al.
Synchronize the side windows
(
page 252).
Synchronize the tilt/sliding sunroof* (CLK
coupe) (
page 258).
Page 468 of 521

467 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the
battery of another vehicle. Observe the
following:
Jump starting should only be performed
when the engine and catalytic convert-
er are cold.
Do not start the engine if the battery is
frozen. Let the battery thaw out first.
Only jump start from batteries with the
same voltage rating (12 V). Jump start-
ing with a higher voltage battery could
damage the vehicle’s electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.
Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.
Always make sure the jumper cables
are not on or near pulleys, fans or other
parts that move when an engine is
started or running.
Warning!G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, 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 very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Do not tow-start the vehicle.
!Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine using a bat-
tery quick charge unit.
If the engine does not run after several unsuc-
cessful starting attempts, have it checked at the
nearest authorized Mercedes-Benz Center.
Excessive unburned fuel generated by repeated
failed starting attempts may damage the catalyt-
ic converter and may present a fire risk.
Make sure the jumper cables do not have loose
or missing insulation.
Make sure the cable clamps do not touch any
other metal part while the other end is still
attached to a battery.
Warning!G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 329).
Page 469 of 521

468 Practical hints
Jump starting
The battery is located on the right side of
the engine compartment. For jump start-
ing, use the terminals in front of the
battery.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers.
Apply the parking brake (page 59).
Make sure the gear selector lever is set
to positionP (
page 174).
Open the hood (page 323).
Flip up cover from positive under hood
terminal2 in front of the filter box
(
page 465).1Positive terminal of charged battery
2Positive under hood terminal in front of
discharged battery
3Negative under hood terminal in front
of discharged battery
4Negative terminal of charged battery
Connect the positive terminal1 of the
charged battery with the positive under
hood terminal 2 in front of the filter
box with the jumper cable. Clamp cable
to charged battery1 first.
Start engine of the vehicle with the
charged battery and run at idle speed.
Connect the negative terminal4 of
the charged battery with the negative
under hood terminal 3 in front of the
filter box with the second jumper cable.
Clamp the cable to the negative
terminal4 of the charged battery
first.
Start the engine of the disabled
vehicle.
You can now turn on the electrical con-
sumers. Do not switch on the headlamps
under any circumstances.
Remove the jumper cables first from
the negative terminals3 and4 and
then from the positive terminals2
and1.
You can now switch on the headlamps.
Have the battery checked at the near-
est authorized Mercedes-Benz Center.
!Never invert the terminal connections.
Page 470 of 521

469 Practical hints
Towing the vehicle
Towing the vehicle
Towing 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.
!Do not tow-start the vehicle.
!Use flatbed or wheel lift/dolly equipment
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 automatic central locking
(
page 166).
Warning!G
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 brake
system
there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
This is necessary to adequately control the
towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the SmartKey is in
starter switch position2.
If the SmartKey is left in starter switch
position 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,
remove SmartKey from starter switch and
reinsert.
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
vehicle. Adapt your driving accordingly.
!If the vehicle is towed with the front axle
raised, the gear selector lever must be in
position N and the engine must be shut off
(SmartKey in starter switch position0 or1).
Active braking action through the ESP
® may
otherwise seriously damage the brake system.
When towing the vehicle with all wheels on the
ground, the gear 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 distances up to 30 miles
(50 km) and at a speed not to exceed 30 mph
(50 km/h).
Page 471 of 521

470 Practical hints
Towing the vehicle
Installing towing eye bolt
Towing eye bolt CLK 350
1Cover on right side of front bumper2Cover on right side of rear bumper
To remove cover:
Press mark on cover 1 or 2.
Lift cover off to reveal the 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 in to its stop and
tighten with wheel wrench.
To reinstall cover:
Fit cover 1 or 2 and snap into place.
!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach tow cable, tow rope or tow rod to
the vehicle chassis, frame or suspension parts.
iWhen towing the vehicle with all wheels on
the ground, please note the following:
With the automatic central locking activated and
the SmartKey in starter switch position2, or
KEYLESS-GO* start/stop button in position2,
the vehicle doors lock if the left front wheel as
well as the right rear wheel are turning at vehicle
speeds of approximately 9 mph (15 km / h) or
more.
To prevent the vehicle door locks from locking,
deactivate the automatic central locking
(
page 166).
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 hazard
warning flasher will operate again.
iIf the battery is disconnected or discharged
the SmartKey will not turn in the starter
switch. For more information, see “Battery”
(
page 464) and “Jump starting”
(
page 467).
the gear selector lever will remain locked in
positionP. For information on manually un-
locking the transmission gear selector lever,
see (
page 429).
Page 472 of 521

471 Practical hints
Towing the vehicle
Towing eye bolt CLK 550/CLK 63 AMG
Towing eye bolt in front bumper
The cover for the towing eye bolt in the
front bumper is identical to the cover on
the CLK 350.
To remove and to reinstall cover, see “Tow-
ing eye bolt CLK 350” (
page 470).
Towing eye bolt in rear bumper
1Cover on right side of rear bumper
2Recess in the coverTo remove cover 1:
Insert flat, blunt object as a lever in
recess 2 on the edge of cover 1.
Loosen cover 1 from the bumper us-
ing lever, to reveal the threaded hole
for towing eye bolt.
The towing eye bolt is supplied with the
tool kit (located in the compartment
underneath the trunk floor).
Screw towing eye bolt in to its stop and
tighten with wheel wrench.To reinstall cover 1:Hook right-hand side of the cover1
into opening.
Slide cover1 as far as it will go in the
direction of the arrow3.
Gently press left-hand side of cover1
in direction of the arrow4.
The hooks on the left-hand side
engage.
iWhen closing the cover1, make sure the
cover’s check strap does not get caught.