Page 372 of 481

371 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Tire Pressure
Monitor
Inoperative
No Wheel SensorsThere are wheels without appropri-
ate wheel sensors mounted (e.g.
winter tires).Have the TPMS or Advanced TPMS* checked
by an authorized Mercedes-Benz Center.
Have the appropriate wheel sensors installed
by an authorized Mercedes-Benz Center.
Tire Pres. Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more sensors malfunction
(e.g. battery in one or more wheel
sensors is empty).
One or more wheels without appro-
priate wheel sensors mounted (e.g.
spare tire).Have the Advanced TPMS* checked at an au-
thorized Mercedes-Benz Center.
Have the wheel sensors installed at an
authorized Mercedes-Benz Center.
The tire pressure for the respective tire is
shown in the multifunction display.
One or more wheels without appro-
priate wheel sensors mounted (e.g.
spare tire).
The respective tire is indicated by ---
instead of the tire inflation pressure
in the multifunction display.Have the Advanced TPMS* checked at an au-
thorized Mercedes-Benz Center.
Have the appropriate wheel sensors installed
at an authorized Mercedes-Benz Center.
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You may lose control of the vehicle. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.
Page 373 of 481
372 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
V You are driving with one or more doors
open.Close the doors.
YYou are driving with the hood open.Close the hood (page 286).
Ê This message will appear whenever the
trunk is open.Close the trunk.
#The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Considerably greater brake pedal force is
required and the stopping distance is
increased.
Stop immediately in a safe location or
as soon as it is safe to do so 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 re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest
authorized Mercedes-Benz Center.
Adjust driving to be consistent with
reduced braking responsiveness.
Page 374 of 481
373 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
#There is a malfunction in the electronic
system.Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
#Battery/Alternator
Stop VehicleThe battery is malfunctioning.
Considerably greater brake pedal force is
required and the stopping distance is in-
creased.Stop the vehicle as soon as it is safe
to do so. Adjust driving to be consis-
tent with reduced braking responsive-
ness.
Call Roadside Assistance.
Notify an authorized Mercedes-Benz
Center.
#Low Voltage
Start EngineThe battery has insufficient voltage.Start the engine (page 51).
2Brake WearThe brake pads have reached their wear
limit.Have the brake pads replaced as soon
as possible.
!Brake pad thickness must be visually in-
spected by a qualified technician at the intervals
specified in the Maintenance Booklet.
Page 389 of 481

388 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
.Right Mirror
Turn Signal
The turn signal in the right exterior rear
view mirror is malfunctioning. This mes-
sage will only appear if a critical number of
LEDs have stopped working.Contact an authorized Mercedes-Benz
Center as soon as possible.
L Tele Aid
InoperativeOne 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
BatteryThe emergency power battery for the
Tele Aid system is malfunctioning. If the
vehicle battery is also dead, Tele Aid will
not be operational.Have the Tele Aid system checked by
an authorized Mercedes-Benz Center.
1Restraint System
Malfunction
Service RequiredThe system is malfunctioning.Drive with added caution to the near-
est authorized Mercedes-Benz Center.
Warning!G
In the event a malfunction of the SRS is indi-
cated as outlined above, the SRS may not be
operational.
For your safety, we strongly recommend
that you contact an authorized
Mercedes-Benz Center immediately
to have the system checked; otherwise the
SRS may not be activated when needed in
an accident, which could result in serious or
fatal injury, or it might deploy unexpectedly
and unnecessarily which could also result in
injury.
Page 403 of 481

402 Practical hints
Replacing SmartKey batteries
If the batteries in the SmartKey/SmartKey
with KEYLESS-GO* are discharged, the ve-
hicle can no longer be locked or unlocked.
It is recommended to have the batteries re-
placed at an authorized 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.
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key out of the
SmartKey/SmartKey with
KEYLESS-GO* (
page 398).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.
Warning!G
SmartKey batteries contain Perchlorate ma-
terial, which may require special handling
and regard for the environment. Check with
your local government’s disposal guidelines.
California residents, see
http://www.dtsc.ca.gov/HazardousWaste
/Perchlorate/index.cfm.
iWhen inserting the batteries, make sure
they are clean and free of lint.
iWhen changing batteries, always replace
both batteries.
The required replacement batteries are available
at any authorized Mercedes-Benz Center.
Page 404 of 481
403 Practical hints
Replacing SmartKey batteries
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2
(
page 402) into housing until it locks
into place.
Slide the mechanical key back into the
SmartKey/SmartKey with
KEYLESS-GO*.
Check the operation of the SmartKey/
SmartKey with KEYLESS-GO*.
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420 Practical hints
Battery
The battery is located on the right hand
side of the trunk under the luggage box
(
page 397).
1Positive terminal cover
2Negative terminal
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
Failure to follow these instructions can
result in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 291).
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.
!The battery is a Valve-Regulated Lead Acid
(VRLA) battery, also referred to as “fleece” bat-
tery. 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 bat-
tery as otherwise 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.
The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the facto-
ry-equipped battery.
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421 Practical hints
Battery
Disconnecting the battery
Depress parking brake firmly or move
gear selector lever to positionP.
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO*:
Press the start/stop button until
the engine shuts off.
Open the driver’s door.
Open the trunk.
Read and observe safety instructions
and precautions (
page 420).
Remove the luggage box (page 397).
Disconnect battery negative lead2.
Remove cover1 from the positive ter-
minal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw-nuts securing the
battery.
Remove the battery bracket.
Pull out the battery ventilation tube
from the battery (depending on battery
arrangement in your vehicle model, the
battery ventilation tube is located on
the left or right side of the battery).
Take out the battery.
!As with any other battery, disconnect the
battery if you do not intend to operate your vehi-
cle for an extended period of time to prevent bat-
tery discharge or connect an accessory 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.
The battery, the battery ventilation hose and the
lateral plug must always be securely installed
when the vehicle is in operation.
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact your authorized
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 on the gear selector lever will
have no effect
the gear selector lever will remain
locked in positionP