Automatic locking feature
:
To deactivate
; To activate
X To deactivate: press and hold button :
for about five seconds until a tone sounds.
X To activate: press and hold button ;for
about five seconds until a tone sounds.
i If you press one of the two buttons and do
not hear a tone, the relevant setting has
already been selected.
The vehicle is locked automatically when the
ignition is switched on and the vehicle's
wheels are moving at a speed in excess of
9 mph (15 km/h).
You could therefore be locked out if:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is being tested on a dynamom-
eter.
You can also switch the automatic locking
function on and off using the on-board com-
puter (Y page 208). Unlocking the driver's door (mechan-
ical key)
If the vehicle can no longer be centrally
unlocked with the SmartKey, use the
mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm
system will be triggered (Y page 66).Take the mechanical key out of the SmartKey
(Y page 70). X
Insert the mechanical key into the lock of
the driver's door as far as it will go.
X Turn the mechanical key counter-clockwise
to position 1.
The door is unlocked.
X Turn the mechanical key back and remove
it.
X Insert the mechanical key into the Smart-
Key. Locking the vehicle
If the vehicle can no longer be centrally
locked with the SmartKey, use the mechani-
cal key. X Close the front-passenger door, the rear
doors and the tailgate.
X Press the locking button (Y page 74).
X Make sure that the locking knobs on the
doors are still visible. Press down the lock-
ing knobs by hand, if necessary.
X Close the driver's door from the outside. Doors
75Opening and closing Z 
Switching the ZONE function on/off
X To switch on: press theábutton.
The indicator lamp in the ábutton lights
up.
i The temperature setting for the driver's
side is not adopted for the front-passenger side and the rear compartment. The tem-
perature for the front-passenger side and
the rear compartment must be set sepa-
rately.
X To switch off: press buttoná.
The indicator lamp in the ábutton goes
out.
i The temperature setting for the driver's
side is adopted for the front-passenger side and the rear compartment. Defrosting the windshield
You can use this function to defrost the wind-
shield or to defrost the inside of the wind-
shield and the side windows.
i You should only select the defrosting
function until the windshield is clear again.
X Turn the SmartKey to position
2(Y page 133) in the ignition lock.
X To activate: press the¬button.
The indicator lamp in the ¬button lights
up.
The climate control system switches to the
following functions:
R cooling with air dehumidification (only
with engine running)
R high airflow (depending on the outside
temperature)
R high temperature (depending on the out-
side temperature)
R air distribution to the windshield and
front side windows
R air-recirculation mode off
X To deactivate: press the¬button.
The indicator lamp in the ¬button goes
out. The previously selected settings are restored. The cooling with air dehumidifi-
cation function remains on. Air-recircula-
tion mode remains deactivated.
or
X Press the Ãbutton.
The indicator lamp in the ¬button goes
out. Airflow and air distribution are set to
automatic mode.
or X Turn controls :orB clockwise or coun-
ter-clockwise (Y page 119).
or
X Press the KorI button. Activating/deactivating MAX COOL
maximum cooling
The MAX COOL function is only available in
vehicles for the USA. MAX COOL is only operational when the
engine is running.
X To activate: press theÙbutton.
The indicator lamp in the button lights up.
X To activate: press off-road button Ù
again.
The indicator lamp goes out. The previously
selected settings are restored.
When you activate MAX COOL, climate con-
trol switches to the following functions:
R maximum cooling
R maximum airflow
R air-recirculation mode on Operating the climate control systems
125Climate control Z 
little energy, thus conserving battery
power.
i If the power supply has been interrupted,
e.g. due to a discharged battery, you will
have to:
R set the clock. Information on setting the
clock can be found in the separate oper-
ating instructions.
On vehicles with COMAND and a naviga-
tion system, the clock is set automati-
cally.
R reset the head restraints on the front
seats (Y page 87)
R reset the function for folding the exterior
mirrors in/out automatically, by folding
the mirrors out once (Y page 93).Charging the battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten- tion. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion. Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only charge the battery using the jump-
starting connection point.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz. These battery
chargers allow the battery to be charged
while still installed in the vehicle.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do
not light up, it is highly likely that the dis-
charged battery has frozen. In this case you
may neither jump-start the vehicle nor charge the battery. The service life of a thawed-out
battery may be shorter. The starting charac-
teristics can be impaired, particularly at low
temperatures. Have the thawed-out battery
checked at a qualified specialist workshop.
A battery charger unit specially adapted for
Mercedes-Benz vehicles and tested and
approved by Mercedes-Benz is available as an
accessory. Contact an authorized Mercedes-
Benz Center for information and availability.
Charge the battery in accordance with the
operating instructions for the battery
charger.
The jump-starting connection point is in the
engine compartment (Y page 296).
X Read the operating instructions for the bat-
tery charger.
X Open the hood (Y page 275).
X Connect the battery charger to the positive
terminal and ground point in the same
order as when connecting the donor bat-
tery in the jump-starting procedure
(Y page 296). Battery (vehicle)
295Roadside Assistance Z