Patent ID: 7551064

Claim:
Method for securing a vehicle against theft, characterized in that at least one essential operational element of the vehicle can be switched between three operating states A, B and C and is switched between these operating states according to the following steps: a. the essential operational elements are switched into a substantially unrestricted operation-ready operating state A by an external usage authorization device independent of the vehicle over means for transmitting the authorization data, b. at least one essential operational element is switched into an operation-ready operating state B by an event-dependent circuit through at least one event for a period of time, the period of time depending on predefined operating parameters, c. either at least one essential operational element of the vehicle is switched after the passage of time for putting out of operation the vehicle into a non-operation-ready or restrictively operation-ready operating state C or the essential operational elements are switched before the passage of the time period into operation-ready operating state A according to method step a) by means of the usage authorization device via means for transmitting the authorization data, and wherein, as the means for transmitting the authorization data from the usage authorization device, a vehicle key is employed, through which the authorization data, being encrypted, are transmitted to a switching device, which, in the case of authorization, switches the essential operational element of the vehicle into operating state A and that subsequently the authorization data is deleted from the vehicle key.