why when temp is below 80 will turn over start then die for about 15-20 minutes

Both messages require a tech to use a scan tool to diagnose what is causing the problem. Both issues may be related to one cause, or could have more than one issue causing the problems. The issue of starting then stalling out could be related to the throttle body or any number of sensors on the engine. The security message could be caused by a key, or a module. Bottom line, a tech will need time to diagnose the problems.