281 Operation
Engine compartment
Battery
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. Refer to Maintenance
Booklet for battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more frequent-
ly.
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.
Warning!
G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.
316 OperationWinter drivingBefore the onset of winter, have your vehi-
cle winterized at an authorized
Mercedes-Benz Center. This service in-
cludes:
Check of anticorrosion and antifreeze
concentration.
Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a pre-mixed windshield washer
solvent/antifreeze which is formulated
for temperatures below freezing point
(page 451).
Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
that the engine can be started and the
electro-hydraulic brake system will be
fully operational even at low ambient
temperatures.
Tire change.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Not all M+S rated
tires provide special winter performance.
Make sure the tires you use show M+S and
the mountain/snowflake sym-
bol.marking on the tire sidewall.
These tires meet specific snow traction
performance requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC) and
have been designed specifically for use in
snow conditions. Use of winter tires is the
only way to achieve the maximum effec-
tiveness of the ABS and ESP
® in winter op-
eration.
For safe handling, make sure all winter
tires mounted are of the same make and
have the same tread design.
!
When scraping ice or snow from the rear
window, be careful not to damage the sealing
strip or apertures along the side of the window.
334 Practical hintsWhat to do if …Problem
Possible cause/consequence
Suggested solution
-
The yellow ABS indicator lamp
comes on while driving.
The ABS has detected a malfunction and has
switched off. The BAS and the ESP
® are also
switched off (see messages in display).
The electro-hydraulic brake system is still
functioning normally but without ABS avail-
able.
If the ABS control unit is malfunctioning, oth-
er systems such as Parktronic*, Distronic*,
or the automatic transmission may also be
malfunctioning.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
Failure to follow these instructions in-
creases the risk of an accident.
Read and observe messages in the
display (
page 347).
The charging voltage has fallen below
10 volts and the ABS was switched off.
The battery may not be sufficiently charged.
Switch off electrical consumers that
are currently not needed, e.g. seat
heating.
If necessary, have the generator and
battery checked.
When the voltage is above this value
again, the ABS is operational again.
379 Practical hints
What to do if …
Left display
Right display
Possible cause/consequence
Possible solution
F
Key
not detected
The SmartKey with KEYLESS-GO* is
not recognized while the engine is
running because:
The SmartKey with
KEYLESS-GO* is not in the vehi-
cle.
There is strong radio-frequency
interference.
Stop the vehicle in a safe location or as soon
as it is safe to do so.
Search for the SmartKey with KEYLESS-GO*.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again af-
ter the engine is stopped.
Operate the vehicle with the SmartKey with
KEYLESS-GO* in the starter switch
Key
not detected
The SmartKey with KEYLESS-GO* is
not recognized when attempting to
start the engine with the
KEYLESS-GO start/stop button* on
the gear selector lever because:
The SmartKey with
KEYLESS-GO* is not in the vehi-
cle.
The battery in the SmartKey
with KEYLESS-GO* is not insert-
ed properly or completely dis-
charged.
Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.
Make sure the batteries in the SmartKey with
KEYLESS-GO* are properly inserted
(page 395) and are not discharged
(page 110).
Start the engine with the SmartKey with
KEYLESS-GO* in the starter switch if
necessary.
395 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are dis-
charged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized Mercedes-Benz Center.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.
Remove the mechanical key from the
SmartKey or SmartKey with
KEYLESS-GO* (
page 391).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
Pull battery compartment 2 out of the
housing.
Warning!
G
Batteries contain poisonous and corrosive
substances. Therefore keep the batteries
out of reach of children.
If a battery is swallowed, seek medical help
immediately.
i
When inserting batteries, make sure they
are clean and free of lint.
i
When replacing batteries, always replace
both batteries.
The required replacement batteries (Lithium,
type CR 2025 or equivalent) are available at any
authorized Mercedes-Benz Center.
414 Practical hintsBatteriesFor more information on batteries, see
“Battery” (
page 281).
Your vehicle is equipped with two
batteries:
The starter battery
The battery for electrical consumers
(consumer battery), located in the
trunk
The starter battery is located on the
right-hand side of the engine compart-
ment.
1Positive terminal
2Negative terminal
3Battery ventilationThe consumer battery is located on the
right-hand side of the trunk.
4Positive terminal
5Negative terminal
!
The starter battery, its filler caps, and the
ventilation hose must always be securely in-
stalled when the vehicle is in operation.
!
The consumer battery located in the trunk is
a valve-regulated lead acid (VRLA) battery, also
referred to as “fleece” battery. Such batteries do
not require topping-up of the electrolyte level.
VRLA batteries therefore do not have cell caps
and the battery cover is non-removable. Do not
attempt to open the consumer battery as other-
wise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, disconnect the con-
sumer battery if you do not intend to operate
your vehicle for an extended period of time to
prevent battery discharge or connect an acces-
sory battery charge unit expressly approved by
Mercedes-Benz for your vehicle model to main-
tain the battery charge. Contact an authorized
Mercedes-Benz Center for further information.
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.
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.