Page 334 of 440

334 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
L
defective
Visit 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
Visit workshop!
The 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.
1
Restraint system
defective
Visit workshop!
The 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 visit 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 345 of 440

345 Practical hints
Unlocking/locking in an emergency
Changing batteries in the SmartKey/ SmartKey with KEYLESS-GO*
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
1Mechanical key
2Battery compartment
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key1
(page 343).
Insert the mechanical key in side open-
ing and push gray slide.
The battery compartment is unlatched.
Pull the battery compartment out of the
SmartKey housing in direction of ar-
row.
Remove the batteries.
Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.
Page 346 of 440

346 Practical hintsUnlocking/locking in an emergency3Battery
4Contact spring
Using a lint-free cloth, insert new bat-
teries under the contact spring with the
plus (+) side facing up.
Return battery compartment into hous-
ing until it locks into place.SmartKey with KEYLESS-GO*
1Battery
2Tilt battery up
3Mechanical key
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key (
page 343).
Insert the mechanical key in side open-
ing and push grey slide.
The battery compartment is unlatched.
Pull the battery compartment out of the
SmartKey housing in direction of ar-
row.
Using mechanical key3 apply pres-
sure to position2.
Battery1 tilts up slightly.
Pull out batteries1 in direction of ar-
row.
Using a lint-free cloth, insert new bat-
teries with the plus (+) side facing up.
Return battery compartment into hous-
ing until it locks into place.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.
Page 363 of 440

363 Practical hints
Battery
Battery
The battery is located on the right side of
the engine compartment.
Removal of filter box:
Release the three clamps1.
Remove filter box.
Installation of filter box:
Insert filter box properly.
Secure it with the three clamps1.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries,
see “Battery” (
page 288).
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 battery checked regularly 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 battery only to avoid the risk
of acid burns in the event of an accident.
Page 364 of 440

364 Practical hintsBatteryDisconnecting the battery
1Negative terminal
2Positive terminal cover
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 hood (
page 281).
Remove the filter box.
Disconnect the battery negative lead.
Remove cover2 from the positive ter-
minal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw securing the bat-
tery.
Remove the battery support and brack-
et.
Take out the battery.
Charging and reinstalling 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
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
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 365 of 440
365 Practical hints
Battery
Reconnecting the battery
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover 2.
Connect the negative lead 1.
Reinstall the filter box (
page 363).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 (
page 144) (vehi-
cles with COMAND*: see COMAND
operator’s manual).
Resynchronize side windows
(page 213).
Resynchronize sliding/pop-up
roof* (
page 217).
Page 366 of 440

366 Practical hintsJump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:
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 other
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.
!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 367 of 440

367 Practical hints
Jump starting
The battery is located on the right side of
the engine compartment. For jump start-
ing use the terminals in front of the bat-
tery.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers.
Apply parking brake.
Shift gear selector lever to positionP.
Open the hood.1Positive terminal of charged battery
2Positive under hood terminal in front of
discharged battery
3Negative under hood terminal in front
of discharged battery
4Negative terminal of charged battery
Connect the positive terminal1 of the
charged battery with the positive under
hood terminal 2 in front of the dis-
charged battery with the jumper cable.
Clamp cable to charged battery1
first.
Start engine of the vehicle with the
charged battery and run at idle speed.
Connect the negative terminal4 of
the charged battery with the negative
under hood terminal 3 in front of the
discharged battery with the jumper ca-
ble. Clamp cable to charged battery4
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
the negative terminals3 and4 and
then from the positive terminals1
and2.
You can now turn on the lights.
Have the battery checked at the near-
est authorized 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 288).
!Never invert the terminal connections.
!Do not tow-start the vehicle.