I called ford dealer< told my 2000 explorer didn t have the theft ignition.

You must purchase a cylinder and keys with a chip inside. Once installed the system must be programmed via a device most locksmiths have which plugs into the PCM under the dash. NOTE: On the 99 model when programming is conducted the doors must be in the closed position and cycled through the unlock/lock for programming to be successful. If a door is left open during the programming steps it will not be successful.

Thanks for info, tried another dealer, they said bring it in for reprogramming.