Ford Focus Owners Manual: General information on radio frequencies

CAUTION:

The radio frequency used by your remote control can also be used by other short distance radio transmissions (e.g. amateur radios, medical equipment, wireless headphones, remote controls and alarm systems). If the frequencies are jammed, you will not be able to use your remote control. You can lock and unlock the doors with the key.

Note: You could unlock the doors if you press the buttons on the remote control unintentionally.

The operating range between your remote control and your vehicle varies depending on the environment.