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.
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659 Practical hints
Batteries
Starter battery
Connect the switched-off charging de-
vice to the terminals of the starter bat-
tery. Observe the operating
instructions in the manual for the
charging device while doing so.
Reinstalling starter battery
Install starter battery in engine com-
partment.
Swing retaining bar down.
Reconnecting starter battery
Make sure that the consumer battery in
the trunk is correctly installed and con-
nected.
Turn SmartKey in starter switch to po-
sition 0 and remove.
Connect the positive lead and fasten its
cover2 (
page 657).
Connect negative lead1
(
page 657).
Attach ventilation tube.
Switch on the ignition (page 336).
Start the engine (page 378).
Check vehicle functions.
!Only use charging devices with a maximum
charging voltage of 14.8 V.
Warning!G
During the charge procedure, there is a risk
of acid burns due to gases escaping from
the battery. Do not bend over the battery
during the charge procedure.
!The battery and the battery ventilation hose
must always be securely installed when the vehi-
cle is in operation.
!Always connect the starter battery in the or-
der described below. Otherwise, the vehicle’s
electronics could be damaged.
Warning!G
Do not drive without a properly installed and
connected consumer battery.
Have any work on the consumer battery car-
ried out by an authorized Mercedes-Benz
Center.
!Never invert the terminal connections.
!Make sure that the battery has a plug where
the ventilation tube is attached to it.
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660 Practical hints
Jump starting
If the starter battery is discharged, the en-
gine 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 use 12-volt battery to jump start
your vehicle. Jump starting with a high-
er voltage battery could damage the ve-
hicle’s electrical system, which will not
be covered by the Mercedes-Benz Lim-
ited Warranty.
Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.
Always make sure that the jumper ca-
bles 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.
!Jump starting should only be performed on
the starter battery installed in the engine com-
partment.
Avoid repeated and lengthy starting attempts.
Do not attempt to start the engine using a bat-
tery quick charge unit.
If engine does not run after several unsuccessful
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 at-
tached to a battery.
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661 Practical hints
Jump starting
Jump starting should only be performed on
the starter battery. The starter battery is
located in the engine compartment on the
passenger side (
page 657).
Make sure the two vehicles do not
touch.
Secure vehicle in place with electronic
parking brake (
page 384).
Shift the automatic transmission toP
(
page 389).
Turn off all electrical consumers, ex-
cept hazard warning flashers or work
lights.
Open the hood (page 512).
Start the engine of the vehicle with the
charged battery and run at idle speed.1Negative clamp
2Negative terminal of charged battery
3Positive terminal of charged battery
4Positive terminal of discharged 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 655).
iVehicles with KEYLESS-GO: remove the
KEYLESS-GO button (
page 337) and use the
SmartKey with KEYLESS-GO like a normal
SmartKey.
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662 Practical hints
Jump starting
Remove red cover from positive
terminal4.
Connect positive terminal3 of the
charged battery with positive
terminal4 of the discharged battery
with the jumper cable. Clamp cable to
charged battery3 first.
Connect negative terminal2 of
charged battery to jumper cables and
attach other end of the jumper cable
with the negative clamp1 to a suit-
able ground point on the vehicle.
Get into vehicle and start engine within
30 seconds.
If the starting attempt does not suc-
ceed:
Turn the SmartKey in starter switch
to position 0.
Take out the SmartKey.
Turn off engine of donor vehicle, re-
start it and let it run at idle speed
for several minutes.
Disconnect the jumper cable during
this time.
Reconnect jumper cable as de-
scribed before.
Restart engine.
While the engine is running, switch off
several electrical consumers such as
the blower.
Disconnect jumper cables first nega-
tive clamp1 from ground point and
negative terminal2, then from posi-
tive terminals4 and3.
Have the battery checked at the near-
est authorized Mercedes-Benz Center.!Never invert the terminal connections.
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663 Practical hints
Towing the vehicle
Towing the vehicle
Mercedes-Benz recommends that the
vehicle be transported with all wheels off
the ground using flatbed or appropriate
wheel lift/dolly equipment. This method is
preferable to other types of towing.
When circumstances do not permit the
recommended towing methods, the
vehicle may be towed with all wheels on
the ground or front axle 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 or SmartKey with KEYLESS-GO*
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.
Towing of the vehicle should only be done using
the properly installed towing eye bolt. Never at-
tach tow cable, tow rope, or tow rod, to vehicle
chassis, frame, or suspension parts.
Switch off the ESP
® (page 71), the tow-away
alarm (
page 78) and the automatic central
locking (
page 334).
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
supply or in the vehicle’s electrical
system
as that will be necessary to adequately
control the towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the SmartKey or
SmartKey with KEYLESS-GO* is in starter
switch position 2.
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664 Practical hints
Towing the 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
vehicle. Adapt your driving accordingly.
!When towing the vehicle with all wheels on
the ground or with the front axle raised, the start-
er battery must be connected and charged. Oth-
erwise:
you will not be able to switch on the ignition
you will not be able to engage the automatic
transmission in positionN (
page 394)
you cannot release the electronic parking
brake
For information on charging the starter battery
see “Batteries” (
page 655) or see “Jump start-
ing” (
page 660).
!Make sure that the electronic parking brake
is released. If the electronic parking brake is
malfunctioning, release it mechanically
(
page 637).
!If the vehicle is towed with the front axle
raised, the automatic transmission must be in
positionN and the engine must be shut off
(SmartKey or SmartKey with KEYLESS-GO* 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 automatic transmission must be
shifted to positionN and the SmartKey or
SmartKey with KEYLESS-GO* 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).
!If the vehicle is towed with all wheels on the
ground or with the front axle raised, the trans-
mission must be in positionN.
If you turn off the engine using
the SmartKey and
remove the SmartKey from the starter
switch
or
open a door
the KEYLESS-GO* start/stop button and
open a door
the transmission will shift to park position P
automatically.
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667 Practical hints
Fuses
Fuses
The electrical fuses in your vehicle serve to
switch off malfunctioning power circuits.
If a fuse is blown, the component(s) and
systems secured by that fuse will stop op-
erating.
If a newly inserted fuse blows again, have
the cause determined and rectified by an
authorized Mercedes-Benz Center.
The following aids are available to help you
replace fuses. They are located in the trunk
with the vehicle tool kit (
page 632):
Fuse chart
The fuse chart explains the fuse alloca-
tion and fuse amperages.
Spare fuses
Special fuse extractor
The electrical fuses are located in different
fuse boxes:
in the dashboard on the passenger side
(
page 669)
in the dashboard on the driver’s side
(
page 669)
behind the rear center armrest
(
page 669)
on the driver’s side of the engine com-
partment (
page 668)
on the passenger side of the engine
compartment (
page 668)
Before replacing fuses:
Engage the electronic parking brake
(
page 384).
Make sure the automatic transmission
is set to P (
page 389).
The gear position indicator in the ta-
chometer display should be on P.
Turn off all electrical consumers.
Turn off the engine (page 387).
Switch off the vehicle’s internal electri-
cal functions (
page 658).
Warning!G
Only use fuses approved by Mercedes-Benz
with the specified amperage for the system
in question and do not attempt to repair or
bridge a blown fuse. Using other than ap-
proved fuses or using repaired or bridged
fuses may cause an overload leading to a
fire, and/or cause damage to electrical
components and/or systems. Have the
cause determined and remedied by an
authorized Mercedes-Benz Center.
!Switch off the vehicle’s internal electrical
functions (
page 658) when you are working on
the fuses.
iA blown fuse must be replaced by an appro-
priate spare fuse (recognizable by its color or the
fuse rating given on the fuse) of the amperage
recommended in the fuse chart.
Any Mercedes-Benz Center will be glad to advise
you on this subject.
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