Page 417 of 473

416 Practical hintsBatteries
Disconnecting the batteries
Apply the parking brake (
page 61).
Make sure the gear selector lever is set
to position P (
page 168).
Close the retractable hardtop
(page 199).
Turn off all electrical consumers.
Turn off the engine (
page 62).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*: Open
the driver’s door.
Open the trunk.
Read and observe safety instructions
and precautions (
page 281).
Open the luggage cover in the trunk
(page 206).
Remove the trunk floor.
The battery for electrical consumers is
located in the right hand area of the
trunk (
page 388).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal5 of the consumer battery
(page 414).
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 batteries in the order
described below, even if you only want to charge
the starter battery, for example. Otherwise the
vehicle’s electronics can be damaged.
Page 418 of 473

417 Practical hints
Batteries
Open the hood (
page 274).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal2 of the starter battery
(page 414).
Remove the covers from the positive
terminals 1 and 4 (
page 414).
Disconnect the positive lead from pos-
itive terminal 4 of the consumer bat-
tery (
page 414).
Disconnect the positive lead from pos-
itive terminal 1 of the starter battery
(page 414).
Removing the batteries
Removing the consumer battery
Remove the screws securing the bat-
tery in the trunk.
Remove the battery support and
bracket.
Pull out the battery ventilation hose
from the battery.
Depending on battery arrangement in
your vehicle model, the ventilation tube
is located either on the left or right side
of the battery.
Take out the battery.
Removing the starter battery
Remove the screws securing the start-
er battery in the engine compartment.
Pull battery ventilation 3
(page 414) out of the battery.
Lift the retaining bracket.
Remove the battery.
Charging and reinstalling batteriesWarning!
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.
Page 419 of 473

418 Practical hintsBatteries
Charge batteries in accordance with
the instructions of the battery charger
manufacturer.
Reinstall the charged batteries. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.
Install starter battery in the designated
location in the engine compartment.
Install consumer battery in the desig-
nated location in the trunk.
Attach supports and brackets.
Tighten support and bracket screws.
Connect positive lead 4 (
page 414)
of the consumer battery and positive
lead 1 (
page 414) of the starter bat-
tery and fasten covers.
Connect negative lead 2
(page 414) of the starter battery.
Connect negative lead 5
(page 414) of the consumer battery.
Reinstall the trunk floor.
Close trunk luggage cover
(page 206).
!
Always connect the batteries in the order
described below. Otherwise the vehicle’s elec-
tronics can be damaged.
!
Never invert the terminal connections!
i
The following procedures must be carried
out following any interruption of battery power
(e.g. due to reconnection):
Resynchronize the ESP
® (page 355).
Resynchronize side windows (
page 198).
Page 420 of 473

419 Practical hints
Jump starting
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
converter 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 more powerful 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.
!
Jump starting may only be performed on the
battery installed in the engine compartment.
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
catalytic 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.
Page 421 of 473

420 Practical hintsJump startingThe starter battery is located on the right
side of the engine compartment.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers.
Apply the parking brake (
page 61).
Make sure the gear selector lever is set
to position P (
page 168).
Open the hood (
page 274).
Remove the red cover from positive ter-
minal on both vehicles (
page 414).1Positive terminal of charged battery
2Positive terminal of discharged battery
3Negative terminal of discharged
battery
4Negative terminal of charged battery
Connect positive terminals 1 and 2
of the batteries with the red jumper ca-
ble. Clamp cable to charged battery 1
first.
Start the engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminals 3 and 4
of the batteries with the black jumper
cable. Clamp cable to charged
battery3 first.
Start the engine of the disabled vehi-
cle.
You can now turn on the electrical con-
sumers. Do not turn on the lights under
any circumstances.
Remove the jumper cables first from
negative terminals 4 and 3 and then
from positive terminals 2 and 1.
You can now turn on the lights.
Have the battery checked at the near-
est Mercedes-Benz Center.
Warning!
G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 281).
!
Never invert the terminal connections.
Page 422 of 473

421 Practical hints
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.!
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 tow-away alarm and the automatic
central locking.
!
If the vehicle is towed with the front axle
raised, the gear selector lever must be in
positionN and the engine must be shut off
(SmartKey in starter switch position0 or1).
Otherwise, the ESP
® will immediately be en-
gaged and will apply the rear wheel brakes.
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).
To be certain to avoid a possibility of damage to
the transmission, however, we recommend the
drive shaft be disconnected at the rear axle drive
flange for any towing beyond a short tow to a
nearby garage.
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
electro-hydraulic brake system
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.
Prior to towing the vehicle with all wheels on
the ground, make certain that the SmartKey
is in starter switch position2.
If the SmartKey is left in starter switch
position0 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.
Page 423 of 473

422 Practical hintsTowing the vehicleWarning!
G
The brake system requires electrical power
to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels. Stopping distance is
increased! Adapt your driving style
accordingly. For more information, see
“Electro-hydraulic brake system”
(page 92).
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.
!
When 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 approx. 9 mph (15 km / h) or more.
To prevent the vehicle door locks from locking,
deactivate the automatic central locking
(
page 119).
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.
i
To signal turns while being towed with the
hazard warning flasher in use, turn SmartKey in
starter switch to position2 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 warn-
ing flasher will operate again.
i
If the battery is disconnected or discharged
the SmartKey will not turn in the starter
switch
the gear selector lever will remain locked in
positionP.
For more information, see “Batteries”
(
page 414) and “Jump starting” (
page 419).
Page 424 of 473

423 Practical hints
Towing the vehicle
Installing towing eye bolt
FrontExample illustration (SL 550 and SL 600
without Sport Package)1Cover on passenger side of front
bumper
To remove cover:
Press mark on cover 1 in direction of
arrow.
Lift cover1off to reveal the threaded
hole for towing eye bolt.To reinstall cover:
Fit locking tabs of cover under the
lower edge of the opening in the
bumper.
Apply even pressure on the upper part
of the cover until it snaps into place.
Rear
1Cover on passenger side of rear
bumper
To remove cover:
Insert flat, blunt object as a lever into
upper left or right recess of cover 1.
Loosen cover 1 using the lever.
Fold cover 1 down in direction of ar-
row to reveal the threaded hole for the
towing eye bolt.
To reinstall cover:
Fit cover 1 and snap into place.
Installing towing eye bolt
Take the towing eye bolt and the wheel
wrench from the vehicle tool kit
(page 388).
Screw towing eye bolt into threaded
hole to its stop.
Insert wheel wrench into towing eye
and tighten towing eye bolt by turning
it clockwise.
Removing towing eye bolt
Take the wheel wrench from the
vehicle tool kit (
page 388).
Insert wheel wrench into towing eye
and loosen towing eye bolt by turning it
counterclockwise.
Remove towing eye bolt.