Patent ID: 7855470

Claim:
An immobilizer device comprising: a transponder a key which incorporates the transponder; an engine ECU; and an immobilizer ECU which receives a first identification information transmitted from the key and inputs the first identification information to the engine ECU; wherein the immobilizer ECU includes a second identification information transmitting device which inputs a second identification information to the engine ECU, the engine ECU includes a first identification information authentication device which authenticates the first identification information based on a first comparison data set in the engine ECU corresponding to the first identification information, and a second identification information authentication device which authenticates the second identification information based on a second comparison data set in the engine ECU corresponding to the second identification information, and the engine ECU is configured to allow an engine to start when the first identification information is authenticated as agreeing with the first comparison data and the second identification information authenticated by the second identification information is authenticated as agreeing with the second comparison data.