Activating/deactivating the automatic locking mechanism
Requirements:
The power supply or the ignition is switched on.
The doors are closed.
When the automatic locking mechanism is activated and the vehicle is travelling at a speed above 15 km/h, the vehicle is locked automatically.
Central locking buttons (vehicles with electrically adjustable front seats)
Central locking buttons (vehicles with manually adjustable front seats)
If the vehicle is being tested on a roller dynamometer or is being tow-started or push-started, there is a risk of being locked out when the function is activated.
To activate:
press and hold button 
until you hear a tone. To deactivate:
press and hold button 
until you hear a tone.