Page 359 of 434
358 Practical hintsBatteries
BatteriesYour vehicle is equipped with two
batteries:
The starter battery (located in the en-
gine compartment)
The battery for electrical consumers
(located in the trunk)
Starter battery in the engine compartment1Positive terminal
2Negative terminal
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
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 starter battery checked regu-
larly by an authorized Mercedes-Benz
Center.
Refer to Service Booklet for mainte-
nance intervals or contact an autho-
rized Mercedes-Benz Center for further
information.
Page 360 of 434
359 Practical hints
Batteries
Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof batteries only to avoid the
risk of acid burns in the event of an acci-
dent.
Warning!
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. 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 are only applied to the
front wheels. Stopping distance is in-
creased! Adjust your driving style according-
ly. For more information, see “SBC brake
system” (
page 81).
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
Page 361 of 434
360 Practical hintsBatteriesDisconnecting the batteries Disconnecting the battery for electrical
consumers
Unhook the luggage cover in the trunk.
Remove the trunk floor.
The battery for electrical consumers is
located in the right hand area of the
trunk (
page 323).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
battery negative lead.
Remove the cover from the positive ter-
minal.
Disconnect the battery positive lead.Disconnecting the starter battery
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
battery negative lead.
Remove the cover from the positive ter-
minal.
Disconnect the battery positive lead.
!To avoid damage to electrical compo-
nents, always disconnect the battery
for electrical consumers (in trunk) first.
This applies even if you only wish to
charge the starter battery. Otherwise
the electronics of the vehicle can be
damaged.
Page 362 of 434
361 Practical hints
Batteries
Removing the batteries
Removing the battery for electrical con-
sumers
Remove the screws securing the bat-
tery in the trunk.
Remove the battery support and brack-
et. Take out the battery.
Removing the starter battery
Remove the screws securing the start-
er battery in the engine compartment.
Lift the retaining bracket and remove
the battery.
Charging and reinstalling batteries
Charge batteries in accordance with
the instructions of the battery charger
manufacturer.
Reinstall the charged battery. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Reconnecting the starter battery
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover.
Connect the negative lead.
Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
!To avoid damage to electrical compo-
nents, always reconnect the starter
battery (in engine compartment) first. !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.
Page 363 of 434
362 Practical hintsBatteriesReconnecting the battery for electrical
consumers
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover.
Connect the negative lead.
Reinstall the trunk floor.
Rehook trunk luggage cover into hold-
ers.
!Never invert the terminal connections!iThe following procedures must be car-
ried out following any interruption of
battery power (e.g. due to reconnec-
tion):
Resynchronize the ESP
(page 295).
Resynchronize side windows
(page 183).
Page 364 of 434
363 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 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.
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 oth-
er 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.
!Jump starting may only be performed
on the battery installed in the engine
compartment.
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 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 365 of 434
364 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 parking brake.
Shift gear selector lever to positionP.
Remove the red cover from positive ter-
minal on both vehicles (
page 358).1Negative terminal of charged battery
2Negative terminal of discharged
battery
3Positive terminal of discharged battery
4Positive terminal of charged battery
Connect positive terminals 3 and 4
of the batteries with the jumper cables.
Clamp cable to charged battery 4
first.
Start the engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminals 1 and 2
of the batteries with the jumper cables.
Clamp cable to charged battery 1
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 1 and 2 and then
from positive terminals 3 and 4.
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 260).
!Never invert the terminal connections.
!Do not tow-start the vehicle.
Page 367 of 434
366 Practical hintsTowing the vehicle
!
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.
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 SBC 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.
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.
