Page 25 of 273

Keys, doors and windows23
1. Remove the back cover from theremote control.
2. Extract the flat battery from its location.
3. Replace battery with a battery of the same type. Pay attention to
the installation position.
4. Clip the back cover in place.
Fault
If the central locking system cannot
be operated with the radio remote
control, the cause may be one of the
following:
● Fault in radio remote control.● Electronic key is out of reception range.
● The battery voltage is too low.
● Overload of the central locking system by operating at frequentintervals, the power supply is
interrupted for a short time.
● Interference from higher-power radio waves from other sources.
Manual unlocking 3 24.Electronic key system
Enables a keyless operation of the
following functions:
● central locking system 3 24
● power tailgate 3 30
● ignition switching on and starting the engine 3 133
The electronic key simply needs to be on the driver's person.
Additionally, the electronic key
includes the functionality of the radio
remote control 3 22.
Handle with care, protect from
moisture and high temperatures and
avoid unnecessary operation.
Page 26 of 273

24Keys, doors and windowsReplacing battery in electronic
key
Replace the battery as soon as the
system no longer operates properly
or the range is reduced. The need for battery replacement is indicated by a
message in the Driver Information
Centre 3 103.
Batteries do not belong in household
waste. They must be disposed of at
an appropriate recycling collection
point.
1. Remove the cover.
2. Extract the flat battery from its location.
3. Replace battery with a battery of the same type. Pay attention to
the installation position.
4. Clip the cover in place.
Fault
If the central locking cannot be
operated or the engine cannot be
started, the cause may be one of the
following:
● Fault in electronic key.
● Electronic key is out of reception range.
● The battery voltage is too low.
● Overload of the central locking system by operating at frequent
intervals, the power supply is
interrupted for a short time.
● Interference from higher-power radio waves from other sources.
To rectify the cause of the fault,
change the position of the electronic
key.
Manual unlocking 3 24.
Central locking system Unlocks and locks doors, load
compartment and fuel filler flap.
A pull on an interior door handle
unlocks the respective door. Pulling
the handle once more opens the door.
Note
In the event of an accident in which
airbags or belt pretensioners are
deployed, the vehicle is
automatically unlocked.
Note
A short time after unlocking with the
remote control the doors are locked
automatically if no door has been
Page 110 of 273

108Instruments and controlsA minimum set of data including
vehicle and location information will
be sent to the PSAP.
Note
Establishing an emergency call may
not be possible in areas without
sufficient network availability or due
to hardware damage during an
accident.
Automatic crash notification
In case of an accident with airbag
deployment, an automatic
emergency call is established and an automatic crash notification will be
transmitted to the next public safety
answering point.
Emergency assistance
In case of an emergency you can also
manually place an emergency call by pressing the red SOS button for more
than two seconds. The LED flashes to confirm that a connection to the
nearest PSAP is being established.
The LED illuminates steadily as long
as the call is active.
Pressing the SOS button immediately
a second time will terminate the call.
The LED switches off.Status LED
Illuminates green and red and
extinguishes after a short time, when
the ignition is switched on: the system works properly.
Illuminates red: fault in the system.
Contact a workshop.
Flashes red: backup battery needs
replacement.
Breakdown call function
Pressing . for more than two
seconds connects you to a roadside
assistance service provider.
For information about coverage and
scope of services of the roadside
assistance, please refer to the
Service and warranty booklet.
Page 268 of 273

266IndexAAccessories and vehicle modifications .......................... 197
Active emergency braking ....99, 166
Adaptive cruise control .........98, 158
AdBlue .................................. 96, 139
Adjustable air vents ...................127
Advanced parking assist ............173
Airbag and belt tensioners ...........93
Airbag deactivation ................60, 93
Airbag label................................... 55 Airbag system .............................. 55
Air conditioning regular operation ................................ 129
Air conditioning system .............. 120
Air intake .................................... 128
Air vents...................................... 127
Antilock brake system ................ 146
Antilock brake system (ABS) .......95
Anti-theft alarm system ................35
Anti-theft locking system .............. 35
Appearance care ........................233
Armrest ................................... 51, 52
Ashtrays ....................................... 88
Automatic anti-dazzle ..................39
Automatic crash notification (ACN) ...................................... 107
Automatic light control ...............110
Automatic locking ........................28
Automatic transmission .............143Autostop............................... 97, 135
Auxiliary heater ........................... 127
B Battery discharge protection ......118
BlueInjection ............................... 139
Bonnet ....................................... 200
Brake and clutch fluid .................242
Brake and clutch system .............94
Brake assist ............................... 149
Brake fluid .................................. 203
Brakes ............................... 146, 203
Breakdown.................................. 231
Bulb replacement ....................... 206
C Capacities .................................. 252
Catalytic converter .....................139
Central locking system ................24
Centre console lighting ..............118
Centre console storage ...............70
Changing tyre and wheel size ...221
Charging system .......................... 93
Child locks ................................... 29
Child restraint installation locations ................................... 65
Child restraints.............................. 62
Child restraint systems ................62
Cigarette lighter ........................... 87
Climate control ............................. 16
Climate control systems .............119