Page 93 of 506

91 Safety and Security
Driving safety systems
The SBC brake system is automatically ac-
tivated when you
unlock the vehicle with the SmartKey
or the KEYLESS-GO*
open the driver’s or passenger door
turn the SmartKey in the starter switch
to position1
in vehicles with KEYLESS-GO*, press
the start/stop button on the gear se-
lector lever once
depress the brake pedal
release the parking brake
Warning!
G
The SBC brake system requires electrical
power to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 358) and
warning messages in the instrument cluster
(
page 367) come on while driving. To
brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected braking effect. If necessary, apply
full pressure to the brake pedal. Brakes may
only be applied to the front wheels. Stop-
ping distance is increased!
If there is a malfunction in the SBC brake
system, we recommend that the vehicle be
transported with all wheels off the ground
using flatbed or appropriate wheel lift/dolly
equipment.
A tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
u p t o 3 0 m i l e s ( 5 0 k m ) a n d a t a s p e e d n o t t o
exceed 30 mph (50 km/h). For more infor-
mation, refer to “Towing the vehicle”
(page 439).
iIf the SBC brake system is activated as
the brake pedal is first depressed, you
may feel a reduced pedal resistance
and longer pedal travel than normal.
When releasing the pedal, you may also
feel the brake pedal pulsate and you
may hear a sound which is caused by
the activation of the SBC brake system
pump. This is normal and not an indica-
tion of a malfunction. Pedal travel re-
turns to normal when you release the
brake pedal and the sound soon ceas-
es.
If you experience the above while driv-
ing and the red brake warning lamp
(page 358) illuminates and/or warn-
ing messages appear in the instrument
cluster (
page 367), the brake system
is malfunctioning. Follow the instruc-
tions of the warning message(s) and
have the brake system checked imme-
diately.
Page 95 of 506

93 Safety and Security
Driving safety systems
Four wheel electronic traction system (4MATIC) with the ESP
Models with all-wheel-drive only.
The 4MATIC improves vehicle’s ability to
use available traction, e.g. during winter
operation in mountains under snowy
conditions, by applying power to all four
wheels.Warning!
G
If you see the ESP warning lampv flash-
ing in the speedometer, proceed as follows:
While driving off, apply as little throttle
as possible
While driving, ease up on the accelera-
tor
Adapt your speed and driving style to
the prevailing road conditions
Failure to observe these guidelines could
cause the vehicle to skid.
The ESP cannot prevent accidents resulting
from excessive speed.
!Do not tow with one axle raised.
Otherwise the transfer case can be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.!Performance testing must only be con-
ducted on a two-axle dynamometer.
Otherwise the transfer case can be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.
!Because of the ESP’s automatic opera-
tion, the engine and the ignition must
be shut off (SmartKey in starter switch
position0 or1 or KEYLESS-GO
start/stop button* in position0 or1)
when the parking brake is being tested
on a brake test dynamometer.
Active braking action through ESP may
otherwise seriously damage the front
or rear axle brake system.
Operational tests with the engine
running can only be conducted on a
two-axle dynamometer.
Page 107 of 506

105 Controls in detail
Locking and unlocking
function and the vehicle’s electrical
system will operate according to the
position of the SmartKey in the starter
switch, even stopping the engine.
If the SmartKey with KEYLESS-GO is
positioned farther away from the vehi-
cle, the system may no longer recog-
nize the SmartKey with KEYLESS-GO.
The vehicle cannot be locked or the en-
gine started via the KEYLESS-GO sys-
tem.
If the SmartKey with KEYLESS-GO is re-
moved from the vehicle while the igni-
tion is switched on (e.g. if passenger
exits the vehicle with the SmartKey
with KEYLESS-GO), the message
Key
not recognized
will appear in the mul-
tifunction display while driving off.
Find the SmartKey or change its
present location immediately (e.g.
place it on the front passenger seat or
insert it in shirt pocket).
Remember that the engine can be
started by anyone with a SmartKey
with KEYLESS-GO that is left inside the
vehicle. If you leave the SmartKey with
KEYLESS-GO behind when exiting and
locking the vehicle, the message
Key
still in vehicle
will appear in the
multifunction display.
Factory setting
Global unlocking
Grasp the outside door handle.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The anti-theft alarm system is dis-
armed.
The vehicle will lock again automatically
and reactivate the anti-theft alarm system
within approximately 40 seconds if:
neither door nor trunk is opened
the central locking switch is not acti-
vated.Global locking
Press lock button at the outside door
handle (
page 58) or trunk lid
(
page 107).
All turn signal lamps flash three times.
The locking knobs in the doors move
down. The anti-theft alarm system is
armed.
iThe vehicle could be inadvertently un-
locked if the SmartKey with
KEYLESS-GO is within 3 ft (1 m) of the
vehicle and
the outside door handle is splashed
with water, or
you attempt to clean the outside
door handle.
Page 111 of 506

109 Controls in detail
Locking and unlocking
Opening the doors from the inside
You can open a locked door from the in-
side. Open door only when conditions are
safe to do so.
1Locking knob
2Inside door handleFront doors
Pull on door handle2 on the respec-
tive front or rear door to open door.
If door was locked, locking knob1 will
move up.
Rear doors
Pull up locking knob1 on the
respective rear door to unlock door.
Pull on door handle2 on the
respective rear door to open door.
iIf the vehicle has previously been
locked from the outside with the
SmartKey, opening a door from the in-
side will trigger the anti-theft alarm sys-
tem.
To cancel the alarm, do one of the fol-
lowing:
Press button Œ or ‹ on the
SmartKey.
Insert the SmartKey in the starter
switch.
In vehicles with KEYLESS-GO*
Press the KEYLESS-GO* start/stop
button (
page 35).
The SmartKey with KEYLESS-GO
must be inside the vehicle.
Grasp the outside door handle.
The SmartKey with KEYLESS-GO
must be within 3 ft (1 m) of the ve-
hicle.
Page 122 of 506
120 Controls in detailLocking and unlockingUnlocking
Press lower half2 of the central lock-
ing switch.
The vehicle unlocks.iYou can open a locked door from the
inside. Open door only when conditions
are safe to do so.
If the vehicle was previously centrally
locked using the SmartKey, it will not
unlock using the central locking switch.
If the vehicle was previously locked
with the central locking switch
while in the selective remote con-
trol mode, only the front door
opened from the inside is unlocked.
while in the global remote control
mode, the vehicle is unlocked com-
pletely when a front door is opened
from the inside.
Page 125 of 506

123 Controls in detailSeats
Removing and installing front seat head restraints
For more information on head restraint ad-
justment, see the “Getting started” section
(page 39).
Front seat head restraints
Removing front head restraints
Press switch1upwards and hold until
the head restraint is fully extended.
Pull out head restraint.Installing front head restraints:
Press switch1upwards and hold for
about five seconds.
Push the head restraint down until it
engages.
Adjust head restraint to desired posi-
tion (
page 39).
Warning!
G
For your protection, drive only with properly
positioned head restraints.
Adjust head restraint so that the center of
the head restraint supports the back of the
head at eye level. This will reduce the poten-
tial for injury to the head and neck in the
event of an accident or similar situation.
Do not drive the vehicle without the seat
head restraints. Head restraints are intend-
ed to help reduce injuries during an acci-
dent.
iTilt the backrest to the rear for easier
removal and installation of the head re-
straints.
Page 127 of 506

125 Controls in detailSeats
Removing and installing rear seat head
restraints
1Release catch
Removing rear seat head restraints
Fold the backrest forward
(page 257).
Fold back head restraint (
page 124).
Press head restraint release catch1
and pull the head restraints out of the
guides.
Fold the backrest back to its original
position.Installing rear seat head restraints
Warning!
G
For your protection, drive only with properly
positioned head restraints.
Adjust head restraint so that the head re-
straint supports the back of the head at eye
level. This will reduce the potential for injury
to the head and neck in the event of an ac-
cident or similar situation.
Do not drive the vehicle without the seat
head restraints. Head restraints are intend-
ed to help reduce injuries during an acci-
dent.
Do not interchange head restraints from
front and rear seat.
iWhen installing the head restraints,
make sure that:
you place the correct head restraint
on the middle seat. It is marked
with the letter “M” on the outside of
the metal bars.
the head restraints engage fully.
Page 129 of 506

127 Controls in detailSeats
Drive-dynamic features
Activating
Press button4 (
page 126).
The indicator lamp in the button comes
on for five seconds and the following
display appears in the multi-function
display for about five seconds.
Deactivating
Press button4 (
page 126) again.
The indicator lamp in the button goes
out.Massage function (PULSE)
The massage function can help prevent
muscle tension during long drives.
Press button6 (
page 126).
The indicator lamp in button2 comes
on. The air cushions in the lumbar area
pulsate.
Seat heating*
Both switches for the front seats are locat-
ed in the center console. The red indicator
lamps in the switch come on to show
which heating level you have selected.
iYou can adjust the characteristics of
the Drive - Dynamic seat using the con-
trol system (
page 169).
iWhen the engine is turned off, the last
cushion setting is retained in memory.
The cushion is automatically adjusted
to this setting when the engine is re-
started.iThe massage function turns off auto-
matically after approximately five min-
utes.
Leveloff
No indicator lamps on
1
One indicator lamp on
2
Two indicator lamps onThe seat heater automatically
switches to level 1 after approxi-
mately ten minutes.
3
Three indicator lamps onThe seat heater automatically
switches to level 2 after approxi-
mately five minutes.