Page 24 of 279
22Keys, doors and windows
Batteries do not belong in household
waste. They must be disposed of at
an appropriate recycling collection
point.
1. Remove the back cover from the remote control.
2. Extract the flat battery from its location.
3. Replace battery with a battery ofthe 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
Page 25 of 279

Keys, doors and windows23Depending on the version, the
electronic key system enables a
keyless operation of the following functions:
● central locking system 3 24
● tailgate unlocking
● ignition switching on and starting the engine 3 145
● headlight activation
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 21.
Handle with care, protect from
moisture and high temperatures and
avoid unnecessary operation.
Notice
To save battery power, the keyless
functions are set to stand-by after 21 days of non-use. To reactivate the
functions, press a button on the
electronic key.Replacing battery in electronic
key
Replace the battery as soon as the
system no longer operates properly
or the range is reduced.
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.
Page 274 of 279

272IndexAAccessories and vehicle modifications .......................... 211
Active emergency braking ..107, 179
Adaptive cruise control .......107, 171
AdBlue ................................ 105, 152
Adjustable air vents ...................140
Advanced parking assist ............187
Airbag and belt tensioners .........101
Airbag deactivation ..............62, 102
Airbag label................................... 57 Airbag system .............................. 57
Air conditioning regular operation ................................ 141
Air conditioning system .............. 131
Air intake .................................... 141
Air vents...................................... 140
Antilock brake system ................ 159
Antilock brake system (ABS) .....104
Anti-theft alarm system ................34
Anti-theft locking system .............. 34 Appearance care ........................247
Armrest ......................................... 49
Ashtrays ....................................... 96
Automatic anti-dazzle ..................39
Automatic crash notification (ACN) ...................................... 119
Automatic light control ...............122
Automatic locking ........................27Automatic transmission .............155
Autostop ............................. 106, 147
B Battery discharge protection ......129
BlueInjection ............................... 152
Bonnet ....................................... 213
Brake and clutch system ...........103
Brake assist ............................... 162
Brake fluid .......................... 216, 254
Brakes ............................... 159, 216
Breakdown.................................. 245
Bulb replacement ....................... 220
C Capacities .................................. 263
Cargo management system ........78
Catalytic converter .....................151
Central locking system ................24
Centre console lighting ..............128
Centre console storage ...............73
Changing tyre and wheel size ...234
Charging system ........................ 102
Child locks ................................... 27
Child restraint installation locations ................................... 66
Child restraints.............................. 63
Child restraint systems ................63
Child surveillance mirror ...............39
Cigarette lighter ........................... 95
Climate control ............................. 15