Page 304 of 399
304 Practical hintsWhat to do if …#
Undervoltage
Switch off
consumers
The battery has insufficient voltage.
Turn off unnecessary electrical con-
sumers.
–
Battery/Alternator
Visit workshop!
The battery was charged with a battery
charger or jump started.
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 operat-
ing with restricted capability. Considerably
greater brake pedal force is required and
the stopping distance is increased.
Have the battery checked at a ser-
vice station.
Stop immediately and check the
poly-V-belt.
If it is broken:
Do not continue to drive. Notify
an authorized Mercedes-Benz
Center.
If it is in order:
Drive immediately to the nearest
authorized Mercedes-Benz Cen-
ter. Adjust driving to be consis-
tent with reduced braking
responsiveness.
Display
Possible cause
Suggested solution
Page 309 of 399
309 Practical hints
What to do if …
Display
Possible cause
Suggested solution
F
Key
Check battery!
The batteries in the KEYLESS-GO*
key are discharged.
Change the batteries (
page 328).
Key
not recognized!
The KEYLESS-GO* key is not recog-
nized while the engine is running be-
cause
the card is not in the vehicle
there is strong radio-frequency
interference
Stop the vehicle as soon as it is safe to do
so.
Search for the card or continue to operate
the vehicle with the key.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again
after the engine is stopped.
The KEYLESS-GO* key is momen-
tarily not recognized.
Change the position of the card in the vehi-
cle.
Operate the vehicle with the key if neces-
sary.
ì
Function
Not available!
This display appears if button ì
or í on the multifunction steer-
ing wheel is pressed and the vehicle
is not equipped with a telephone.
Page 328 of 399

328 Practical hintsUnlocking/locking in an emergencyUnlocking the trunk
The trunk can no longer be locked with the
key.
Lock and unlock the trunk with the me-
chanical key as follows:Trunk lid lock1Unlocking
2Locking
Insert the mechanical key in the trunk
lid lock.
Turn the key to the left in position1
and hold it in this position.
Pull on the trunk lid handle and lift the
trunk lid.
Locking the vehicle
If you are unable to lock the vehicle with
the SmartKey, lock it with the mechanical
key as follows:
Close the passenger doors and the
trunk.
Press the central locking switch in the
cockpit (
page 100).
Check to see whether the locking
knobs on the passenger doors are still
visible. If necessary, push them down
manually.
Lock the driver’s door with the me-
chanical key (
page 327).
Check if the trunk is locked. If neces-
sary lock the trunk with the mechanical
key (
page 98).
Changing batteries
If the batteries in the SmartKey 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.Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
Page 344 of 399

344 Practical hintsBatteries
Disconnecting the battery
Depress the parking brake firmly or
move the gear selector lever to
positionP.
Open the trunk (
page 261).
Disconnect battery negative lead1.
Remove cover2 from the positive ter-
minal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw-nuts securing the
battery.
Remove the battery 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.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the key is in the starter switch. Oth-
erwise the alternator and other elec-
tronic components could be severely
damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Contact your authorized
Mercedes-Benz Center for further infor-
mation.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
With a disconnected battery
the brake boosting effect is not avail-
able.
You need more power to brake and
brake pedal travel is increased. If neces-
sary, you must depress the brake pedal
with full power.
you can no longer turn the ignition key
or, in cars with KEYLESS-GO*, pressing
the KEY-LESS-GO button* on the gear
selector lever has no effect.
the gear selector lever is locked in
position P.
Page 345 of 399

345 Practical hints
Batteries
Reconnecting the batteries
Turn off all electrical consumers.
Connect the positive lead and fasten its
cover.
Connect the negative lead.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.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.!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 reconnec-
tion):
Set the clock (
page 136) (vehi-
cles with COMAND*: see COMAND
operator’s manual).
Resynchronize the front seat head
restraints (
page 104).
Resynchronize the ESP
(page 75).
Re-enter the radio code (see radio
operating instructions).
Resynchronize the side windows
(page 186).
Resynchronize the sliding/pop-up
roof* (
page 189).
Page 346 of 399

346 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.
Use only jumper cables with sufficient
cross-section, insulated terminal
clamps and polarity reversal protec-
tion.
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.
Read all instructions before proceeding.
iJumper cables with polarity reversal
protection are available at any autho-
rized Mercedes-Benz Center.
!Jump starting may only be performed
on the main battery installed in the
trunk.
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.
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 347 of 399

347 Practical hints
Jump starting
The battery is located in the trunk on the
right hand side underneath the luggage
box (
page 325). Only jump start the ve-
hicle from the battery in the trunk.
Make sure that the two vehicles do not
touch.
Turn off all electrical consumers.
Apply parking brake.
Shift selector lever to positionP.1Positive terminal of charged battery
2Positive terminal of discharged battery
3Vehicle ground
4Negative terminal of charged battery
Connect positive terminals1 and2 of
the batteries with the jumper cables.
Clamp cable to charged battery1 first.
Start engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminal4 of the
charged battery and vehicle ground3
(lock ring of the trunk lid lock) in the
trunk with the jumper cable. Clamp ca-
ble to charged battery4 first.
Start the engine of the disabled vehi-
cle.
Now you can again turn on the electrical
consumers. Do not turn on the lights under
any circumstances.
Remove the jumper cables first from
vehicle ground3 and negative
terminal4 and then from positive
terminals1 and2.
Have the battery checked at the next
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 266).
iThe message
Malfunction - electric
consumers switched off
may appear
in the instrument cluster. It will disap-
pear as soon as the battery is suffi-
ciently charged.
!Vehicles with automatic transmission:
Do not tow-start the vehicle.
Page 350 of 399

350 Practical hintsTowing the vehicle
Installing towing eye bolt
Front of vehicle
1Cover on right side of front bumperTo remove cover:
Press mark on cover in direction of ar-
row.
Lift cover off to reveal threaded hole for
towing eye bolt.
The towing eye bolt is supplied with the
tool kit (located in the storage compart-
ment under the trunk floor).
Screw towing eye bolt in to its stop and
tighten with lug wrench.
To reinstall cover:
Fit cover and snap into place.
!When towing the vehicle with all wheels
on the ground, please note the follow-
ing:
With the automatic central locking acti-
vated and the key in starter switch
position2, or KEYLESS-GO* start/stop
button (if so equipped) in position2,
the vehicle doors lock if the left front
wheel as well as the right rear wheel
are turning at vehicle speeds of approx.
9 mph (15 km / h) or more.
To prevent the vehicle door locks from
locking, deactivate the automatic cen-
tral locking (
page 99).
Towing of the vehicle should only be
done using the properly installed tow-
ing eye bolt. Never attach tow cable,
tow rope or tow rod to the vehicle chas-
sis, frame or suspension parts.
iThe selector lever will remain locked in
positionP and the key will not turn in
the starter switch if the battery is dis-
connected or discharged. See notes on
the battery (
page 343) or on jump
starting (
page 346).