Page 358 of 474
356 Practical hintsWhat to do if …?Display
Possible cause
Possible solution
#
BATTERY CHARGE
VISIT WORKSHOP
The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be oper-
ating with restricted capability.
Considerably greater brake pedal force is
required and the stopping distance is
longer.
Stop immediately and check the
poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the
engine will overheat due to an inoperative
water pump which may result in damage
to the engine. Notify an authorized
Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest autho-
rized Mercedes-Benz Center. Adjust driv-
ing to be consistent with reduced braking
responsiveness.
;(USA only)!(Canada only)
RELEASE
PARKING BRAKE
You are driving with the parking brake en-
gaged.
Release the parking brake (
page 48).
Page 366 of 474

364 Practical hintsWhat to do if …?Display
Possible cause
Possible solution
_
ENTRY POSITION
DO NOT DRIVE
Seat, exterior mirrors and steering wheel
have not yet moved to their preset driving
positions.
Wait until the seat, exterior mirrors and
steering wheel have moved to their driv-
ing positions.
The message will disappear.
Y
HOOD OPEN!
You are driving with the hood open.
Close the hood (
page 287).
I
REMOVE KEY!
You have forgotten to remove the
SmartKey.
Remove the SmartKey from the ignition.
REPLACE KEY!
DRIVE TO WORKSHOP
The SmartKey is malfunctioning.
Visit an authorized Mercedes-Benz Cen-
ter as soon as possible.
AUTOMATIC LIGHT ON
REMOVE KEY!
SmartKey in starter switch position 1
or2.
Remove the SmartKey from the starter
switch.
KEY
CHECK BATTERY
The battery in the KEYLESS-GO* key is
discharged.
Replace the battery (
page 387).
KEY
NOT RECOGNIZED
SmartKey with KEYLESS-GO* is not rec-
ognized while the engine is running be-
cause
the SmartKey is not in the vehicle
there is strong radio-frequency inter-
ference
Stop the vehicle as soon as it is safe to do
so.
Search for the SmartKey.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again
after it has been stopped.
Page 372 of 474

370 Practical hintsWhat to do if …?Display
Possible cause
Possible solution
<
SEAT BELT SYSTEM
DRIVE TO WORKSHOP
The seat belt system is malfunctioning.
Visit an authorized Mercedes-Benz
Center as soon as possible.
K
CLOSE
SUNROOF!
You have opened the driver’s door with
the SmartKey removed from the starter
switch and the tilt/sliding sunroof open.
Close the tilt/sliding sunroof
(page 211).
J
CLOSE
SUNROOF!
You have opened the driver’s door with
the SmartKey removed from the starter
switch and the tilt/sliding sunroof open.
Close the tilt/sliding sunroof
(page 211).
L
TELE AID
DRIVE TO WORKSHOP
One or more main functions of the Tele
Aid system are malfunctioning.
Have the Tele Aid system checked by an
authorized Mercedes-Benz Center.
TELE AID BATTERY
DRIVE TO WORKSHOP
The emergency power battery for the Tele
Aid system is malfunctioning. If the vehi-
cle battery is also discharged, Tele Aid
will not be operational.
Have the Tele Aid system checked by an
authorized Mercedes-Benz Center.
t
FUNCTION
UNAVAILABLE
This display appears if button t or
s on the multifunction steering wheel
is pressed and the vehicle is not equipped
with a telephone.
Page 389 of 474

387 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.
SmartKey
Remove mechanical key out of the
SmartKey (
page 383).1Mechanical key
2Battery compartment
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Insert the mechanical key1 in side
opening and push gray slide.
The battery compartment2 is un-
latched.
Pull battery compartment2 out of the
housing in direction of arrow.
Remove the batteries.
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.
iWhen inserting the batteries, make
sure they are clean and free of lint.iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any authorized
Mercedes-Benz Center.
Page 390 of 474

388 Practical hintsReplacing SmartKey batteries3Battery
4Contact spring
Using a lint-free cloth, insert new
batteries3 under the contact
spring4 with the plus (+) side facing
up.
Return battery compartment2 into
housing until it locks into place.
Slide mechanical key1 back into the
SmartKey.
Check the operation of the SmartKey.
SmartKey with KEYLESS-GO*
1Battery
2Tilt battery up
3Mechanical key
Remove mechanical key out of the
SmartKey (
page 383).
Replacement battery: Lithium, type
CR 2025 or equivalent.
Insert the mechanical key3 in side
opening and push gray slide.
The battery compartment is unlatched.
Pull the battery compartment out of the
SmartKey housing.
Using mechanical key3, apply pres-
sure to position2.
Battery1 tilts up slightly.
Pull out battery1 in direction of ar-
row.
Using a lint-free cloth, insert the new
battery with the plus (+) side facing up.
Return battery compartment into hous-
ing until it locks into place.
Slide mechanical key1 back into the
SmartKey.
Check the operation of KEYLESS-GO*.
iWhen inserting the battery, make sure
they are clean and free of lint.iThe required replacement battery is
available at any authorized
Mercedes-Benz Center.
Page 405 of 474

403 Practical hints
Battery
Battery
The battery is located on the right side of
the trunk under the battery cover.
1Battery cover
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.
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.!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
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 (
page 35) on the gear selector
lever will have no effect
the gear selector lever will remain
locked in positionP
Page 406 of 474
404 Practical hintsBattery
Pull on the outer, right-hand side of
cover1 and remove it in the direction
of the arrow.
2Positive terminal
3Negative terminal
Disconnecting the battery
Turn off all electrical consumers.
Open the trunk lid (
page 103).
Remove the battery cover1.
Use a 10 mm open-end wrench to dis-
connect the battery negative lead3.
Remove cover from the positive
terminal2.
Disconnect the battery positive
lead2.
Removing the battery
Remove the screw securing the bat-
tery.
Remove the battery support and
bracket.
Take out the battery.
Charging and reinstalling the battery
Charge battery in accordance with the
instructions of the battery charger
manufacturer.
Reinstall the charged battery. Follow
the previously described steps in re-
verse order.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.
Page 407 of 474
405 Practical hints
Battery
Reconnecting the battery
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover2.
Connect negative lead3.Batteries contain materials that can harm
the environment if disposed of improperly.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.!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.
iThe following procedures must be car-
ried out following any interruption of
battery power (e.g. due to reconnect-
ing):
Set the clock (see COMAND opera-
tor’s manual).
Synchronize the ESP (
page 352).
Synchronize side windows
(page 209).
Synchronize tilt/sliding sunroof
(page 213).