| 摘要 |
<p>The improvements relate to: - the provision of a transmitter (9) in the unit (2) installed in the vehicle for sending to the control unit (3) carried by the user a signal which confirms the activation of the system and can be stored by the control unit (3); - the alternating use of two different messages for activating and deactivating the system so that any recording of the activation message by a third party with a view to its possible use as a deactivation message is rendered useless, and - the temporary shut-down of the activated system upon receipt of successive different messages approximating to the valid deactivation message so as to prevent its possible deactivation.</p> |
