can anyone give me some insight on what to do about the dreaded security light. My car starts but I would like to get it fixed. I have taken it places and they can't seem to find why it's on as the car is not throwing any codes and my car sometimes has a problem where I will go to start the car and when I turn the key it does nothing except dash lights come on and everything works it just doesn't crank or try to crank. Tried replacing the starter and that wasn't it and even have a new ignition. If anyone has any info about these problems it would be much appreciated. It's a 02 Monte Carlo SS

 

When you say you replaced the ignition, do you mean the ignition lock cylinder or ignition switch housing?

 

The ignition lock cylinder

 

Replace the ignition switch housing. As our cars age this has become a common problem.
There are contacts in the switch that get dirty or corroded and prevent the signal from passing through the theft deterrent system. A passcode is shared between the BCM, PCM and the chip in the ignition lock cylinder. The switch is the conduit the code is passed through.

 

Both the ignition switch housing and lock cynlinder were replaced. I didn't know my dad put both in until now

 

Could be a bad ground, or the BCM. BCM problems usually have other symptoms in addition to starting, like wonky dash lights. I would start by checking ignition ground wires.