Page 29 of 376

29 Getting started
Unlocking
Starter switch positionsStarter switch0For removing key
1Power supplies to some electrical con-
sumers, such as seat adjustment
2Ignition (power supply for all electrical
consumers) and driving position
3Starting position
Warning!
G
When leaving the vehicle always remove the
key from the starter switch, take the KEY-
LESS-GO
* card (if so equipped) with you
and lock the vehicle. Do not leave children
unattended in the vehicle, or with access to
an unlocked vehicle. Unsupervised use of
vehicle equipment may cause an accident
and/or serious personal injury.
!If the key is left in the starter switch
position0 for an extended period of
time, it can no longer be turned in the
starter switch.
Remove the key from the starter
switch and reinsert.
If the key can still not be turned, the
starter battery may not be sufficiently
charged.
Check the starter battery and
charge it if necessary (
page 319).
Get a jump start (
page 323).
More information can be found in the
“Controls in detail” section
(
page 80).
Page 153 of 376

153 Controls in detail
Automatic climate control
Rear window defroster
The rear window defroster uses a large
amount of power. To keep the battery
drain to a minimum, switch off the defrost-
er as soon as the rear window is clear. The
defroster is automatically deactivated af-
ter approximately 6 to 17 minutes of oper-
ation depending on the outside
temperature.
Activating
Press button
F
(page 148).
The indicator lamp on the button lights
up.Deactivating
Press button
F
(page 148) again.
The indicator lamp on the button goes
out.
Warning!
G
Any accumulation of snow and ice should be
removed from the rear window before driv-
ing. Visibility could otherwise be impaired,
endangering you and others.!The rear window defroster cannot be
switched on when the retractable hard-
top is open. The indicator lamp will
start blinking if the hardtop is open.
Close the retractable hardtop.
The rear window defroster can again be
turned on.
!If the rear window defroster switches
off too soon and the indicator lamp
starts blinking, this means that too
many electrical consumers are operat-
ing simultaneously and there is insuffi-
cient voltage in the battery. The system
responds automatically by deactivating
the rear window defroster.
As soon as the battery has sufficient
voltage, the rear window defroster au-
tomatically turns itself back on.
Page 232 of 376

232 OperationEngine compartmentBattery
Your vehicle is equipped with two batter-
ies:
The starter battery (located in the en-
gine compartment)
The battery for electrical consumers
(located in the trunk)
These batteries should always be suffi-
ciently charged in order to achieve their
rated service life.
If you use your vehicle mostly for short dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing batteries, always use bat-
teries approved by Mercedes-Benz. If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.
Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
G
Observe all safety instructions
and precautions when han-
dling automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.
Page 242 of 376

242 OperationMaintenanceCalling up the service indicator
Switch ignition on.
The standard display of the control sys-
tem appears (
page 110).
Press button
k
or
j
on the
steering wheel until the service symbol
9
or
´
appears in the speedom-
eter display and the service deadline in
the tachometer.
Resetting the service indicator
In the event that the service on your vehi-
cle is not carried out by an authorized
Mercedes-Benz Center, you can reset the
service indicator yourself.
Switch ignition on.
The standard display of the control sys-
tem appears (
page 110).
Press button
k
or
j
on the
steering wheel until the service symbol
9
or
´
appears in the speedom-
eter display and the service deadline in
the tachometer.
Press the reset knob for about four
seconds.
This message appears in the tachome-
ter:Do you want to reset the service
interval?
Confirm by using reset button
To confirm, hold down the reset knob
until you hear a signal.
The service indicator now displays the
reset interval.iOnly reset if the proper service has
been performed. Resetting the system
without performing proper service as
called for by the FSS will cause the FSS
to incorrectly determine the next ser-
vice interval which will result in engine
damage not covered by the Mer-
cedes-Benz Limited Warranty.
If the battery supplying the vehicle’s
electrical consumers is disconnected,
the days of disconnection will not be in-
cluded in the count shown by the ser-
vice indicator. To arrive at the true
service deadline, you will need to sub-
tract these days from the days shown
in the service indicator.
Do not confuse the service indicator
with the engine oil level indicator
:
.
Page 264 of 376

264 Practical hintsWhat to do if …Left display
Right display
Possible cause
Possible solution
#
Electric consumers
offline!
The consumer battery has insuffi-
cient voltage and can no longer sup-
ply the convenience functions such
as seat ventilation*.
The electrical consumers will come back online
as soon as on-board voltage is sufficient.
Battery/Alternator
Stop vehicle!
The battery was charged with a bat-
tery charger or jump started.
The battery is no longer charging.
Possible causes
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake system
requires electrical energy and may
be operating with restricted capabil-
ity. Considerably greater brake ped-
al force is required and the stopping
distance is increased.
Have the battery checked at a service sta-
tion.
Stop immediately and check the poly-V-belt.
If it is broken
Do not continue to drive. Notify an autho-
rized Mercedes-Benz Center.
If it is in order
Drive immediately to the nearest autho-
rized Mercedes-Benz Center. Adjust driv-
ing to be consistent with reduced braking
responsiveness.
Page 289 of 376
289 Practical hints
Where will I find ...?
Vehicles with spare wheel
1Spare wheel
2Electric air pump
3Vehicle tool kit
4Battery for electrical consumers5Jack (under spare wheel)
6Wheel wrench (under spare wheel)Vehicles with TIREFIT kit
1TIREFIT kit
2Electric air pump
3Vehicle tool kit
4Battery for electrical consumers
5Wheel wrench
6Jack
Page 319 of 376

319 Practical hints
Batteries
Batteries
Your vehicle is equipped with two batter-
ies:
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 key is in the starter switch. Oth-
erwise the alternator and other elec-
tronic components could be severely
damaged.
Have the starter battery checked regu-
larly by an authorized Mercedes-Benz
Center
Refer to Service Booklet for mainte-
nance intervals or contact your 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 batteries only to avoid the
risk of acid burns in the event of an acci-
dent.
Page 320 of 376

320 Practical hintsBatteries
Disconnecting the batteriesDisconnecting 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 289).
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.
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
limp-home (emergency operation) mode.
The same applies if battery is disconnected.
To brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected braking effect. If necessary, apply
full pressure to the brake pedal. Brakes are
only applied to the front wheels. Stopping
distance is increased! Adjust your driving
style accordingly. SBC brake system
(page 72).
Warning!
G
With a disconnected battery
y o u w i l l n o l o n g e r b e a b l e t o t u r n t h e k e y
in the starter switch and pressing the
KEYLESS-GO
* start/stop button (if so
equipped) on the selector lever will have
no effect
the selector lever will remain locked in
positionP!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.