2012 MERCEDES-BENZ A CLASS key battery

ATA (anti-theft alarm system)
Activating/deactivating ...................69
ATA (Anti-Theft Alarm system)
Function ........................................... 69
Interior motion sensor .....................70
Switching off the alarm .................... 69
Tow-away protection ........................ 70
ATTENTION ASSIST
Activating/deactivating ................. 219
Display message ............................ 245
Function/notes ............................. 195
Audio menu (on-board computer) .... 214
AUTO lights Display message ............................ 242
see Lights
Automatic engine start (ECO start/
stop function) .................................... 147
Automatic engine switch-off (ECO
start/stop function) .......................... 146
Automatic headlamp mode ..............105
Automatic transmission Accelerator pedal position .............154
Automatic drive program ............... 156
Changing gear ............................... 154
DIRECT SELECT lever .....................151
Display message ............................ 252
Drive program display ....................152
Driving tips .................................... 154
Emergency running mode ..............159
Engaging drive position .................. 153
Engaging neutral ............................ 153
Engaging park position (AMG vehi-
cles) ............................................... 153
Engaging reverse gear ................... 153
Engaging the park position ............ 152
Holding the vehicle stationary on
uphill gradients .............................. 154
Kickdown ....................................... 154
Manual drive program ....................156
Overview ........................................ 151
Problem (fault) ............................... 159
Program selector button ................155
Pulling away ................................... 144
Selector lever ................................ 153
Starting the engine ........................ 144
Steering wheel gearshift paddles ...156
Trailer towing ................................. 155Transmission position display 152, 153
Transmission positions ..................
153
Automatic transmission emer-
gency running mode .........................159
Auxiliary heating Activating/deactivating
.................134
Activating/deactivating (on the
centre console) .............................. 135
Display message ............................ 255
Important safety notes .................. 134
Problem (display message) ............138
Remote control .............................. 135
Setting ........................................... 224
Setting the departure time ............. 136
Auxiliary ventilation
Activating/deactivating ................. 134
Activating/deactivating (on the
centre console) .............................. 135
Problem (display message) ............138
Remote control .............................. 135
Axle load, permissible (trailer tow-
ing) ...................................................... 349 B
Bag hook ............................................ 273
Ball coupling Folding in ....................................... 205
Folding out .....................................

203
BAS (Brake Assist System) ................. 62
Battery (key) Checking .......................................... 76
Important safety notes .................... 76
Replacing ......................................... 76
Battery (vehicle)
Charging ........................................ 306
Display message ............................ 244
Important safety notes .................. 304
Jump starting ................................. 308
Belt force limiter
Activation ......................................... 49
Function ........................................... 49
Belt tensioner
Activation ......................................... 41
Function ........................................... 49
Blind Spot Assist
Activating/deactivating ................. 219
Display message ............................ 247 Index
5

Reading lamp
................................. 111
Setting the ambient lighting
brightness (on-board computer) .... 222
Interior motion sensor ........................70
ISOFIX child seat securing system ....53 J
Jack Storage location ............................ 299
Using ............................................. 326
Jump starting (engine) ...................... 308K
Key Changing the battery ....................... 76
Checking the battery ....................... 76
Convenience closing feature ............ 85
Convenience opening feature .......... 85
Display message
............................ 256
Door central locking/unlocking ....... 75
Emergency key element ................... 75
Important safety notes .................... 74
Loss ................................................. 78
Modifying the programming .............75
Positions (ignition lock) ................. 143
Problem (malfunction) .....................78
Starting the engine ........................ 144
Key positions (ignition lock) ............143
Kickdown Driving tips .................................... 154
Manual drive program ....................158
Kneebag ............................................... 44L
Lamps see Warning and indicator lamps


Lane Keeping Assist
Activating/deactivating ................. 219
Display message ............................ 247
Function/information .................... 199
Lane package ..................................... 197
Lap time (RACETIMER) ......................226
Lashing eyelets ................................. 273
Licence plate lamp (display mes-
sage) ................................................... 241Lighting
see Lights

Lights
Activating/deactivating the Intel-
ligent Light System ........................ 221
Activating/deactivating the inte-
rior lighting delayed switch-off ....... 223
Active light function .......................109
Automatic headlamp mode ............ 105
Cornering light function .................109
Dipped-beam headlamps ............... 105
Display message ............................ 239
Driving abroad ............................... 104
Foglamps ....................................... 106
Foglamps (extended range) ...........109
Hazard warning lamps ................... 108
Headlamp flasher ........................... 108
Headlamp range ............................ 107
Light switch ................................... 105
Main-beam headlamps ................... 107
Motorway mode ............................. 109
Parking lamps ................................ 106
Rear foglamp ................................. 106
Setting the ambient lighting
brightness (on-board computer) .... 222
Side lamps ..................................... 106
Switching Adaptive Highbeam
Assist on/off ................................. 222
Switching the daytime driving
lights on/off (on-board computer) . 221
Switching the daytime driving
lights on/off (switch) ..................... 105
Switching the exterior lighting
delayed switch-off on/off (on-
board computer) ............................ 222
Switching the surround lighting
on/off (on-board computer) ..........222
Turn signals ................................... 107
see Interior lighting
see Replacing bulbs
Light sensor (display message) .......242
LIM indicator lamp Cruise control ................................ 169
DISTRONIC PLUS ........................... 174
Variable SPEEDTRONIC .................171
Limiting the speed
see SPEEDTRONIC
Loading guidelines ............................26812
Index

Key functions
:
& To lock the vehicle
; % To unlock the vehicle
X To unlock centrally: press button ;.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
R the vehicle is locked again.
R the anti-theft system is primed again.
X To lock centrally: press button :.
The key centrally locks/unlocks:
R the doors
R the tailgate
R the fuel filler flap
When unlocking, the turn signals flash once.
When locking, they flash three times.
i When

it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 222).
i You can also set an audible signal to con-
firm that the vehicle has been locked. The
audible signal can be activated and deacti-
vated using the on-board computer
(Y page 223). Changing the settings of the locking
system
You can change the settings of the locking
system.

This means that only the driver's door
and the fuel filler flap are unlocked when the
vehicle is unlocked. This is useful if you fre-
quently travel on your own.
X To change the setting: press and hold
down the % and & buttons simulta-
neously

for approximately six seconds until
battery check lamp (Y page 76) flashes
twice.
i If the setting of the locking system is
changed
within the signal range of the vehi-
cle, pressing the & or % button:
R locks or
R unlocks the vehicle
The key now functions as follows:
X To unlock the driver's door: press the
% button once.
X To unlock centrally: press the % but-
ton twice.
X To lock centrally: press the & button.
X To restore the factory settings: press
and
hold down the % and & buttons
simultaneously for approximately six sec-
onds until the battery check lamp flashes
twice (Y page 76). Emergency key element
General notes If the vehicle can no longer be unlocked with
the key, use the emergency key element.
If you use the emergency key element to
unlock and open the driver's door, the anti-
theft alarm system will be triggered
(Y page 69).
There are several ways to turn off the alarm:
X
Press the % or &
button on the key.
or
X Insert the key into the ignition lock. Key
75
Opening and closing Z

If you unlock the vehicle using the emergency
key element, the fuel filler flap will not be
unlocked automatically.
X
To unlock the fuel filler flap: insert the
key into the ignition lock.
Removing the emergency key element X
Push release catch : in the direction of
the arrow and at the same time, remove
emergency key element ; from the key. Battery of the key
Important safety notes G
WARNING
Batteries contain toxic and corrosive substan-
ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal
injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately. H
Environmental note Batteries contain pollutants.
It

is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an environmentally responsible
recycling system.
Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection

point for used batter-
ies.
Mercedes-Benz recommends that you have
the
batteries replaced at a qualified specialist
workshop.
Checking the battery X
Press the & or % button.
The battery is working properly if battery
check lamp : lights up briefly.
The battery is discharged if battery check
lamp : does not light up briefly.
X Replace the battery ( Y page 76).
i If the key battery is checked within the
signal
reception range of the vehicle, press-
ing the & or % button:
R locks or
R unlocks the vehicle
i You can obtain a battery from any quali-
fied specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.76
Key
Opening and closing

X
Take the emergency key element out of the
key ( Y page 75). X
Press emergency key element ; into the
opening in the key in the direction of the
arrow until battery tray cover : opens.
When
doing so, do not hold cover : shut.
X Remove battery tray cover :.X
Repeatedly tap the key against your palm
until battery = falls out.
X Insert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth
to do so.
X Make sure that the surface of the battery is
free

from lint, grease and all other forms of
contamination.
X Insert the front tabs of battery tray
cover : and then press to close it.
X Insert the emergency key element into the
key.
X Check the function of all key buttons on the
vehicle. Key
77
Opening and closing Z

Problems with the key
Problem Possible causes/consequences and
M SolutionsYou cannot lock or
unlock the vehicle
using the key. The key battery is discharged or nearly discharged.
X
Try again to lock/unlock the vehicle using the remote control
function of the key. Point the tip of the key at the driver's door
handle from close range and press the % / & button.
If this does not work:
X Check the key battery and replace it if necessary ( Y page 76).
X Lock ( Y page 81) or unlock ( Y page 81) the vehicle using
the emergency key element. There is interference from a powerful source of radio waves.
X
Try again to lock/unlock the vehicle using the remote control
function of the key. Point the tip of the key at the driver's door
handle from close range and press the % / & button.The key is faulty.
X
Lock ( Y page 81) or unlock ( Y page 81) the vehicle using
the emergency key element.
X Have the key checked at a qualified specialist workshop. You have lost a key. X
Have the key deactivated at a qualified specialist workshop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the emer-
gency key element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well.78
KeyOpening and closing

Problem Possible causes/consequences and
M SolutionsThe engine cannot be
started using the key. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 304).
or
X Jump-start the vehicle (Y page 308).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the key. The steering lock is mechanically blocked.
X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the automatic transmission out of
parking position P.
R shift the manual transmission into neutral.
R start the engine.
There is a risk of an accident and injury.
When
leaving the vehicle, always take the key
with you and lock the vehicle. Never leave
children or animals unattended in the vehicle.
Always keep the key out of reach of children. G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there
is

a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside.

People in the vehicle can no longer get
out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked with the key,
then the double lock function is activated as
standard. You can deactivate the double lock
function by deactivating the interior motion
sensor (Y page 70). The doors can then be
opened from the inside after the vehicle has
been locked from the outside. The anti-theft Doors
79
Opening and closing Z

even suffer burn-like injuries. There is a risk
of injury.
Therefore, do not switch on the seat heating
repeatedly.
The three red indicator lamps in the button
indicate the heating level you have selected.
The system automatically switches down
from level 3 to level 2 after approximately
eight minutes.
The system automatically switches down
from
level 2 to level 1 after approximately ten
minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
X Make sure that the key is in position 1 or
2 in the ignition lock.
X To switch on: press button : repeatedly
until the desired heating level is set.
X To switch off: press button : repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off. Problems with the seat heating The seat heating has switched off prema-
turely

or cannot be switched on. The vehicle's
electrical system voltage is too low because
too many electrical consumers are switched
on.
X Switch off electrical consumers that you do
not

need, such as the rear window heating
or interior lighting. AMG Performance Seat
To adjust the contour of the seat and for
improved

lateral support, you can individually
adjust the front seats. Adjusting the seat cushion length
X
To extend the seat cushion: press but-
ton :.
X To retract the seat cushion: press but-
ton ;.
Adjusting the side bolsters of the seat
cushion X
To set the side bolsters of the seat
cushion narrower: press button =.
X To set the side bolsters of the seat
cushion wider: press button ?. Seats
97
Seats, steering wheel and mirrors Z