Page 366 of 473
365 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
#Battery Alternator
Visit workshopThe battery is no longer charging.
Possible causes:
broken poly-V-belt
alternator malfunctioning
Stop immediately and check the
poly-V-belt in a safe location or as
soon as it is safe to do so.
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
authorized Mercedes-Benz Center.
Low voltage
Charge batteryThe battery has insufficient voltage.Start the engine (page 45).
Low voltage
Consumers offThe battery has insufficient voltage.Turn off unnecessary electrical
consumers.
Page 393 of 473
392 Practical hints
Replacing SmartKey batteries
If the batteries in the SmartKey are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced 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.
Warning!G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
i
When inserting the batteries, make
sure they are clean and free of lint.
i
When replacing batteries, always
replace both batteries of both
SmartKeys.
The required replacement batteries are
available at any Mercedes-Benz
Center.
Page 394 of 473
393 Practical hints
Replacing SmartKey batteries
SmartKey
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key
(
page 386).
1Mechanical key
2Slide
3Battery compartment
Insert the mechanical key1 in direc-
tion of arrow in side opening.
Using mechanical key1, push gray
slide 2 to unlatch battery compart-
ment 3.
Pull battery compartment3 out of the
housing in direction of arrow.
4Battery
5Contact spring
Remove the batteries4 in direction of
arrow.
Using a lint-free cloth, insert new
batteries4 under the contact
spring5 with the positive terminal (+)
side facing up.
Return battery compartment3 into
housing until it locks into place.
Slide mechanical key1 back into the
SmartKey.
Check the operation of the SmartKey.
Page 412 of 473

411 Practical hints
Battery
Battery
The battery is located in the engine
compartment on the right hand side.
1Clamps
Removing filter box:
Release clamps1.
Remove filter box.
Installing filter box:
Insert filter box properly.
Secure it with clamps1.
Warning!G
Failure to follow these instructions can
result in severe injury or death.
Observe all safety instructions and
precautions when handling automotive
batteries (
page 303).
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
maintenance intervals or contact an
authorized Mercedes-Benz Center for
further information.
Page 413 of 473

412 Practical hints
Battery
1Negative terminal
2Positive terminal cover
Disconnecting the battery
Depress the parking brake pedal.
Make sure the gear selector lever is set
to positionP.
Turn off all electrical consumers.
Turn off the engine (page 56).
Remove SmartKey from starter switch.
Open the hood (page 297).
Remove the filter box (page 411).
Disconnect the battery negative lead
from negative terminal1.
Remove cover2 from the positive
terminal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw-nuts securing the
battery.
Remove the battery bracket.
Pull out the battery ventilation hose
from the battery (depending on battery
arrangement in your vehicle model, the
ventilation hose is located either on the
left or right side of the battery).
Take out the battery.
Warning!G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch
the gear selector lever will remain
locked in positionP
!
Always disconnect the battery in the
order described below. Otherwise the
vehicle’s electronics can be damaged.
Page 414 of 473

413 Practical hints
Battery
Charging and reinstalling the batteryCharge battery in accordance with the
instructions of the battery charger
manufacturer.
Reinstall the charged battery. Follow
the previously described steps in
reverse order.
Reconnecting the battery
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Connect the battery positive lead and
fasten its cover2.
Connect the battery negative lead.
Reinstall the filter box (page 411).
Warning!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.
!
The battery, its filler caps and the bat-
tery ventilation hose must always be
securely installed when the vehicle is in
operation.
!
Always connect the battery in the order
described below. Otherwise the
vehicle’s electronics can be damaged.
!
Never invert the terminal connections!
Page 415 of 473
414 Practical hints
Battery
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.i
The following procedures must be
carried out following any interruption of
battery power (e.g. due to reconnec-
tion):
Set the clock (page 140).
Vehicles with COMAND*:
See COMAND operator’s manual.
Synchronize side windows
(
page 240).
Synchronize tilt/sliding sunroof
(
page 244).
Page 416 of 473

415 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the
battery of another vehicle. Observe the
following:
Jump starting should only be performed
when the engine and catalytic con-
verter 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
starting 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 oth-
er 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.
!
Do not tow-start the vehicle.
!
Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine
using a battery quick charge unit.
If 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.