It wont start jus sayin security and engine light comes on

Since your car says SECURITY, It can only be one thing. You have a failing antitheft system.

This is how it works.

Your key has a little black chip in the shaft. It is actually an ohms resistor.
It has a certain resistence. 1 of 15 different possibilities designated by GM

Your ignition lock cylinder not only works with the key, but also reads the resistence of that chip.

It then sends this reading to the TDM (theft deterrent module). If the ohms are right, and the ignition reads it right, and the TDM does its job, the car will start like normal. But if any of these things fail to do their job, the car goes into antitheft mode and you get the SECURITY light.

So you have a few options, try to find the failing parts, take it to the dealer to get fixed, or bypass the system.

Here is a link with some info to help you out http://vatspasslockpasskeysecurityhelp.yolasite.com/