See also:

Centrally locking and unlocking thevehicle 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. The buttons are located on both front doors. ...

Additives
Do not use any additives in the engine oil. This could damage the engine. ...

Locking and unlocking centrally
The SmartKey centrally locks/unlocks: the doors the tailgate the fuel filler flap 1 Locks the vehicle 2 Opens/closes the tailgate 3 Unlocks the vehicle When unlocking, the turn sign ...