JPH0587415B

PURPOSE:To prevent engine starting due to picking or a wrong key by setting the load of a starter, an engine controller and the like to be in a ready condition for operation only when a light receiving element signal of a steering lock coincides with the code signal set beforehand. CONSTITUTION:A key body 1 is provided with an electrode 1b connected to the terminal 2a of a steering lock 2 for power supply, and also to light emitting element 1d for emitting light based on the code set beforehand when power is supplied. Meanwhile, the steering lock 2 is provided with a light receiving element 2c in order to receive light from the emitting element 1d. And, when a groove 1a of the key body 1 coincides with the key hole 2a of the steering lock 2 for swinging the key body 1, a signal from said light receiving element 2c is input to a light emitting circuit 3. Thereby, whether or not the signal coincides with the set code in a memory circuit 3c, and when it does not, operation of a starter, an engine controller and the like is set to be in an inoperative condition. Consequently, malfeasance by picking or a wrong key can be prevented.