Page 426 of 491

425 Practical hints
Batteries
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
(page 305).
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 main-
tenance intervals or contact an 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.
Warning!
G
The SBC 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. The same applies if
battery is disconnected. 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 may only be applied to
the front wheels. Stopping distance is in-
creased! Adjust your driving style according-
ly. For more information, refer to “SBC brake
system” (
page 92).
Page 429 of 491

428 Practical hintsJump starting
If the battery is discharged, the engine can
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:
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 more powerful battery could
damage the vehicle’s electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.
Use only 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 the 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.
!Jump starting of the main battery must
only be done using the designated
jump start terminals located in the
engine compartment (
page 429).
Avoid repeated and lengthy starting at-
tempts.
Do not attempt to start the engine us-
ing a battery quick charge unit.
If the 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 catalytic converter.
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 430 of 491

429 Practical hints
Jump starting
The jump-start contacts are located in the
engine compartment.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers.
Apply parking brake.
Shift gear selector lever to positionP.1Negative (-) terminal
2Cover of Positive (+) terminal
Open cover 2 of the positive terminal
of both vehicles.
Connect positive terminal 2 and the
positive terminal of the charged battery
with the jumper cable. Clamp cable to
charged battery first.
Start engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminal1 and the
negative terminal of the charged
battery with the jumper cable. Clamp
cable to charged battery first.
Start the engine of the disabled
vehicle.
Now you can again turn on the electrical
consumers. Do not turn on the lights under
any circumstances.
Remove the jumper cables first from
negative terminals1 and then from
the positive terminals2.
Now you can turn on the lights.
Have the battery checked at the near-
est authorized 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 305).!Never invert the terminal connections!
iThe message
Malfunction - electric
consumers switched off
may appear
in the instrument cluster. It will disap-
pear as soon as the battery is suffi-
ciently charged.
!Do not tow-start the vehicle.
Page 433 of 491

432 Practical hintsTowing the vehicle
iTo signal turns while being towed with
the hazard warning flasher in use, turn
SmartKey in starter switch to
position2 and activate the combina-
tion switch for the left or right turn sig-
nal 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 approximately
9mph (15km/h) or more.
Switch off the tow-away alarm
(page 99).
To prevent the vehicle door locks from
locking, deactivate the automatic cen-
tral locking (
page 122).
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 selector lever will remain locked in
positionP and the SmartKey will not
turn in the starter switch if the battery
is disconnected or discharged. For
more information, see “Battery”
(page 424) and “Jump starting”
(page 428).
For information on manual unlocking of
the transmission selector lever, see
(page 405).