My wife has a 2002 chevy Malibu. Some times when she goes to start it, the security light will flash and the car will not start. She looked in the owners manual and found that when it comes on you have to leave the switch on for ten minutes until the light goes out, then it will start. But, it doesn't say what causes this to happen. She has had the car for over five years with no problem until now. What would cause this to be randomly happening now.?