Comparison with ordinary remote control
The functions can be controlled by pressing the buttons or via Comfort Access.
Unlocking
Fully grasp a door handle, arrow 1. This corresponds
to pressing the 
button.
Locking
Press the area on the door handle, arrow 2, with your finger for approx. 1 second.
This corresponds to pressing the 
button.
To save battery power, ensure that the ignition and all electronic systems and/or power consumers are switched off before locking the vehicle.
Convenient closing
Press the area, arrow 2, with your finger and hold.
In addition to locking, the windows and the glass sunroof* are closed.
Monitor the closing process
Monitor the closing process to ensure that no one becomes trapped.
Unlocking the trunk lid separately
Press the button on the exterior of the trunk lid.
This corresponds to pressing the 
button.
Do not place the remote control in the
cargo area
Take the remote control with you and do not leave it in the cargo area; otherwise, the remote control may be locked inside the vehicle when the trunk lid is closed.
See also:
BMW X3 iDrive Owners Manual
h1 {color: red;}
h2 {color: green;}
h3 {color: blue;}
h4 {color: #FF00FF;}
...
Emergency unlocking
Pull the handle inside the cargo area.
The trunk lid unlocks. ...
Safety switch for the rear
Press the button on the
driver's door if
children are being transported in the
rear.
This locks various functions so that they cannot
be operated from the rear: safety switch. ...