2012 MERCEDES-BENZ C-Class SEDAN Anti theft alarm system

1, 2, 3 ...
115 V socket ...................................... 263
12 V socket see Sockets
4ETS
see ETS/4ETS (Electronic
Traction System)
4MATIC (permanent four-wheel
drive) .................................................. 175
4MATIC off-road system ................... 175
A
ABS (Anti-lock Braking System) Display message ............................ 214
Function/notes ................................ 59
Important safety notes ....................59
Warning lamp ................................. 242
Activating/deactivating cooling
with air dehumidification ................. 126
Active Blind Spot Assist Activating/deactivating (on-
board computer) ............................ 205
Function/information ....................187
Active Driving Assistance package . 187
Active Lane Keeping Assist Activating/deactivating (on-
board computer) ............................ 205
Display message ............................ 229
Function/information ....................190
Active light function ......................... 110
Active Light System Display message ............................ 224
Active service system PLUS
see ASSYST PLUS service interval
display
ADAPTIVE BRAKE ................................. 64
Adaptive Highbeam Assist Display message ............................ 225
Function/notes ............................. 110
Switching on/off (on-board
computer) ...................................... 207
Additives (engine oil) ........................ 349
Air bags Display message ............................ 221
Front air bag (driver, front
passenger) ....................................... 39
Important safety notes ....................38
Knee bag .......................................... 40
PASSENGER AIR BAG OFF
indicator lamp .................................. 42
Pelvis air bag ................................... 41
Safety guidelines ............................. 37
Side impact air bag ..........................40
Window curtain air bag ....................42
Air-conditioning system
see Climate control
AIR FLOW ........................................... 127
Air pressure see Tire pressure
Air vents
Glove box ....................................... 132
Important safety notes ..................131
Rear ............................................... 133
Setting ........................................... 131
Setting the center air vents ...........132
Setting the side air vents ...............132
Alarm system
see ATA (Anti-Theft Alarm system)
Alertness Assistant
see ATTENTION ASSIST
AMG menu (on-board computer) ..... 210
Anti-lock Braking System see ABS (Anti-lock Braking System)
Anti-Theft Alarm system
see ATA (Anti-Theft Alarm system)
Ashtray ............................................... 262
Assistance menu (on-board
computer) .......................................... 204
ASSYST PLUS see ASSYST PLUS service interval
display
ATA (Anti-Theft Alarm system)
Activating/deactivating ...................67
Function ........................................... 67
Switching off the alarm ....................67
ATTENTION ASSIST
Activating/deactivating .................205
Display message ............................ 228
Function/notes ............................. 182
Audio menu (on-board computer) .... 201
Audio system see separate operating instructions 4Index

Stowage well beneath the trunk
floor .................................................... 258
Summer opening see Convenience opening feature
Summer tires ..................................... 312
Sun visor ............................................ 260
Supplemental Restraint System see SRS (Supplemental Restraint
System)
Surround lighting (on-board
computer) .......................................... 207
Switching air-recirculation mode
on/off ................................................. 130
Switching off the alarm (ATA) ............ 67
T
Tachometer ........................................ 195
Tail lamps Display message ............................ 223
Tank
see Fuel tank
Tank content
Fuel gauge ....................................... 29
Technical data
Notes ............................................. 342
Tires/wheels ................................. 335
Vehicle data ................................... 351
TELEAID
Call priority .................................... 268
Display message ............................ 218
Downloading destinations
(COMAND) ..................................... 269
Emergency call .............................. 266
Important safety notes ..................264
Locating a stolen vehicle ...............270
MB info call button ........................268
Remote vehicle locking ..................270
Roadside Assistance button ..........267
Search & Send ............................... 269
Self-test ......................................... 265
System .......................................... 265
Vehicle remote unlocking ..............269
Telephone
Accepting a call ............................. 203
Display message ............................ 237
Menu (on-board computer) ............202
Number from the phone book ........ 203
Redialing ........................................ 203
Rejecting/ending a call .................203
Temperature
Coolant .......................................... 194
Coolant (on-board computer) ......... 210
Engine oil (on-board computer) ...... 210
Outside temperature ...................... 195
Setting (climate control) ................128
Theft deterrent systems
ATA (Anti-Theft Alarm system) .........67
Immobilizer ...................................... 66
Through-loading feature ................... 256
Tilt/sliding sunroof see Sliding sunroof
Timing (RACETIMER) ......................... 211
Tiredness assistant see ATTENTION ASSIST
Tire pressure
Calling up (on-board computer) .....319
Checking manually ........................317
Display message ............................ 233
Maximum ....................................... 316
Notes ............................................. 315
Pressure loss warning ....................317
Recommended ............................... 313
Tire pressure monitoring system
Function/notes ............................. 319
Restarting ...................................... 321
Warning lamp ................................. 250
Tires
Aspect ratio (definition) .................333
Average weight of the vehicle
occupants (definition) ....................331
Bar (definition) ............................... 331
Characteristics .............................. 331
Checking ........................................ 311
Definition of terms .........................331
Direction of rotation ......................334
Display message ............................ 233
Distribution of the vehicle
occupants (definition) ....................334
DOT, Tire Identification Number
(TIN) ............................................... 330
DOT (Department of
Transportation) (definition) ............331
GAWR (Gross Axle Weight Rating)
(definition) ..................................... 332Index17

iThe immobilizer is always deactivated
when you start the engine.
In the event that the engine cannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Contact an authorized Mercedes-Benz
Center or call 1-800-FOR-MERCedes (in
USA) or 1-800-387-0100 (in Canada).
ATA (Anti-Theft Alarm system)
A visual and audible alarm is triggered if the
alarm system is armed and you open:
R a door
R the vehicle with the mechanical key
R the trunk lid
R the hood
The alarm is not switched off, even if you
close the open door that has triggered it, for
example.
i If the alarm stays on for more than 30
seconds, the emergency call system
mbrace (USA only) or TELE AID (Canada
only) initiates a call to the Customer
Assistance Center automatically. The
emergency call system initiates the call
provided that:
R you have subscribed to the mbrace/
TELE AID service.
R the mbrace/TELE AID service has been
activated properly.
R the required mobile phone, power supply
and GPS are available.
XTo arm: lock the vehicle with the SmartKey
or KEYLESS-GO.
Indicator lamp : flashes. The alarm
system is armed after approximately 15
seconds.XTo deactivate: unlock the vehicle with the
SmartKey or KEYLESS-GO.XTo stop the alarm using the SmartKey:
insert the SmartKey into the ignition lock.
The alarm is switched off.
or
XPress the % or & button on the
SmartKey.
The alarm is switched off.XTo stop the alarm using KEYLESS-GO:
grasp the outside door handle. The
SmartKey must be outside the vehicle.
The alarm is switched off.
or
XPress the Start/Stop button on the
dashboard. The SmartKey must be inside
the vehicle.
The alarm is switched off.Theft deterrent locking systems67SafetyZ

X To unlock the vehicle: touch the inner
surface of the door handle.XTo lock the vehicle: touch sensor
surface :.XConvenience closing feature: touch
recessed sensor surface ; for an
extended period ( Y page 85).
If you pull on the handle of the trunk lid, only
the trunk of the vehicle is unlocked.
Changing the settings of the locking
system
You can change the setting of the locking
system in such a way that only the driver's
door and the fuel filler flap are unlocked. This
is useful if you frequently travel on your own.
XTo change the setting: press and hold
down the % and & buttons
simultaneously for approximately six
seconds until the battery check lamp
( Y page 74) flashes twice.
i
If the setting of the locking system is
changed within the signal range of the
vehicle, pressing the & or % button
locks or unlocks the vehicle.
The SmartKey now functions as follows:
XTo unlock the driver's door: press the
% button once.XTo unlock centrally: press the %
button twice.XTo lock centrally: press the & button.
The KEYLESS-GO function is changed as
follows:
XTo unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.XTo unlock centrally: touch the inner
surface of the door handle on the front-
passenger door or the rear door.XTo lock centrally: touch the outer sensor
surface on one of the door handles.Restoring the factory settingsXPress the % and & buttons
simultaneously for approximately six
seconds until the battery check lamp
flashes twice.
Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey, use the
mechanical key.
If you use the mechanical key to unlock and
open the driver's door or the trunk lid, the
anti-theft alarm system will be triggered
( Y page 67).
There are several ways to turn off the alarm:
XTo turn the alarm off with the
SmartKey: press the % or & button
on the SmartKey.
or
XInsert the SmartKey into the ignition lock.
or
XTo deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the
ignition lock. The SmartKey must be in the
vehicle.
or
XLock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the
vehicle.
If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked
automatically.
XTo unlock the fuel filler flap: insert the
SmartKey in the ignition lock.SmartKey73Opening/closingZ

Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of
R strong braking maneuvers
R sudden changes of direction
R an accident
Unlocking and opening doors from
inside
You can open a door from inside the vehicle
even if it has been locked. You can only open
the rear doors from inside the vehicle if they
are not secured by the child-proof locks
( Y page 57).
Only open the door when the traffic situation
permits.
If the vehicle was previously locked with the
SmartKey or with KEYLESS-GO, opening the
vehicle from the inside will activate the anti-
theft alarm system. Switch off the alarm
( Y page 67).
XPull door handle ;.
If the door is locked, locking knob : pops
up. The door is unlocked and can be
opened.
Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle
from the inside.
The central locking/unlocking button does
not lock or unlock the fuel filler flap.
i You cannot unlock the vehicle centrally
from the inside if the vehicle has been
locked with the SmartKey or KEYLESS-GO.
i It is only possible to lock the vehicle
centrally if the front-passenger door is
closed.XTo unlock: press button :.XTo lock: press button ;.
If the front-passenger door is closed, the
vehicle locks.
You can open a front door from inside the
vehicle even if it has been locked. Only open
the door when the traffic situation permits.
If the vehicle has been locked with the central
locking button:
R and the SmartKey is set to its factory
setting, the entire vehicle is unlocked if a
front door is opened from the inside
R and the SmartKey is set to an individual
setting, only the front door that is opened
from inside the vehicle is unlocked.
If the vehicle has been locked centrally with
the SmartKey or with KEYLESS-GO, it is not
unlocked when the release button for the
central locking is used.
Automatic locking feature
The vehicle locks automatically when the
ignition is switched on and the wheels of the
78DoorsOpening/closing

vehicle are turning at a speed of more than
9 mph (15 km/h).
You could therefore be locked out when:
R the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is being tested on a
dynamometer.XTo deactivate: press and hold button :
for about five seconds until a tone sounds.XTo 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.
You can also switch the automatic locking
function on and off using the on-board
computer ( Y page 208).
Unlocking the driver's door
(mechanical key)
If the vehicle can no longer be 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 67).
XTake the mechanical key out of the
SmartKey ( Y page 73).XInsert the mechanical key into the lock of
the driver's door as far as it will go.XTurn the mechanical key counterclockwise
to position 1.
The door is unlocked.XTurn the mechanical key back and remove
it.XInsert the mechanical key into the
SmartKey.
Locking the vehicle (mechanical key)
If the vehicle can no longer be locked with the
SmartKey, use the mechanical key.
XOpen the driver's door.XClose the front-passenger door, the rear
doors and the trunk lid.XPress the locking button ( Y page 78).XCheck whether the locking knobs on the
front-passenger door and the rear doors
are still visible. Press down the locking
knobs by hand, if necessary.XClose the driver's door.XTake the mechanical key out of the
SmartKey ( Y page 73).XInsert the mechanical key into the lock of
the driver's door as far as it will go.Doors79Opening/closingZ

XTurn the mechanical key clockwise as far
as it will go to position 1.XTurn the mechanical key back and remove
it.XMake sure that the doors and the trunk lid
are locked.XInsert the mechanical key into the
SmartKey.
i If you lock the vehicle as described above,
the fuel filler flap is not locked. The anti-
theft alarm system is not armed.
Trunk
Important safety notes
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
GWARNING
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unsupervised in the
vehicle, even if they are secured in a child
restraint system, and do not give them access
to an unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. They could:
R injure themselves on vehicle parts
R be seriously or fatally injured by extreme
heat or cold
R injure themselves or have an accident with
vehicle equipment that may still be in
operation even after the SmartKey has
been removed from the ignition, such as the
seat adjustment, steering wheel
adjustment or memory function.
If children open a door, they could cause
severe or even fatal injury to other persons; if
they get out of the vehicle, they could injure
themselves when doing so or be seriously or
even fatally injured by any passing traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and a child could be burned on these
parts.GWARNING
Do not carry heavy or hard objects in the
passenger compartment or trunk unless they
are firmly secured in place.
Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of
R strong braking maneuvers
R sudden changes of direction
R an accident
GWARNING
Make sure the trunk lid is closed when the
engine is running and while driving. Among
other dangers, deadly carbon monoxide (CO)
gases may enter the vehicle interior resulting
in unconsciousness and death.
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
To open the trunk lid completely, a minimum
clearance of 5.90 ft (1.80 m) above the
ground is necessary.
The trunk lid can be:
R opened and closed manually from outside
R opened automatically from outside
R opened automatically from inside
R locked separately
80TrunkOpening/closing

gases may enter the vehicle interior resulting
in unconsciousness and death.
You can open the trunk lid from the driver's
seat when the vehicle is stationary and
unlocked.XTo open: press the upper section of remote
operating switch for trunk lid : until the
trunk lid opens.
Locking the trunk separately
You can lock the trunk separately. If you then
unlock the vehicle centrally, the trunk
remains locked and cannot be opened.
XClose the trunk lid.XTake the mechanical key out of the
SmartKey ( Y page 73).XInsert the mechanical key into the trunk lid
lock as far as the stop.XTurn the mechanical key clockwise from
position 1 to position 2.XRemove the mechanical key.XInsert the mechanical key into the
SmartKey.
Unlocking the trunk (mechanical key)
! The trunk lid swings upwards when
opened. Therefore, make sure that there is
sufficient clearance above the trunk lid.
If the trunk cannot be unlocked with the
SmartKey or KEYLESS-GO, use the
mechanical key.
If you use the mechanical key to unlock and
open the trunk lid, the anti-theft alarm system
will be triggered ( Y page 67).
XTake the mechanical key out of the
SmartKey ( Y page 73).XInsert the mechanical key into the trunk lid
lock as far as the stop.XTurn the mechanical key counter-clockwise
from position 1 as far as it will go to
position 2.
The trunk is unlocked.XTurn the mechanical key back to position
1 and remove it.XInsert the mechanical key into the
SmartKey.
Trunk emergency release
You can open the trunk lid from inside the
vehicle with the emergency release button.
82TrunkOpening/closing