Abstract: An apparatus and method for disarming an automobile alarm system uses the ignition switch of the automobile to create a sequential pulse access code. Toward this end, two commonly available electrical circuits in the vehicle's wiring that are switched on and of by the shifting of a vehicle's ignition switch among power-applying switch positions serve to supply a pulse code of sequential electric pulses to the alarm system to perform a selected function, including entering a valet mode or overriding and disarming the system without a remote control transmitter. Because the shifting of the ignition switch generates a two-wire detectable pulse code, previously-programmed pulse codes can be selected to perform different functions in addition to disarming the system, including using pulse codes to trigger entry of the system into a learning mode.