My Car's Company Fitted Central Locking has following features:
1) It is built in the Car Company Key.
2) It has 1 button which open the locks and also close.
3) When locks close, Indicator Light Blink once ....... When open its blink twice.
4) When any door remain open, it will not open or close locks. (Which indicates that your cars doors are not properly closed)
5) If you are wearing Seat Belts, It will only open the locks and it won't close the locks. (Which indicates that some one is sitting in the car)