My 2004 Impala sometimes doesn't want to start and the word security flashes when you try to start it and it doesn't start.

Then you have to put the switch on for 10 minutes then put it off and count from one to ten and then the vehicle starts normally.

I wonder if the problem is the ignition cylinder that the passlock doesn't recognize when you put the key in and that's why it doesn't start?

 

try a spare key