2003 Mazda MPV KEY PROGRAMMING

Electrical problem
2003 Mazda MPV 6 cyl Front Wheel Drive Automatic

lost all keys, mazda mpv 2003 model.
aready bought another transponder key(8C). And also have the 8 digits security code. The instruction I got about programming is that, before I start the security light must be flashing while ignition is off. But in the case of this car, the security light only flashes when ignition is on. How do I go about it? HELP!