Ive done extensive work rebuilding the systems on this 3.4 L.....after driving it from Cali to Carolina this last time ive noticed in the past week the security light intermittently comes on at times during driving. Havent had any issues with starting the vehicle as of yet. Is it time to call AC-Delco and order a new tumbler....if so does anyone have the AC part number please. Thanks for the input. Consequently...the starter has 254K on it and its factory of course.

 

if it is the key failing it would be a good idea to find what ohm the key resistor is before it fails. can be a pita after. for part number look in the parts manual in the info sticky a tthe top of general section.

 

You might be getting an intermittent break in contact between the key and reader. Spray some electrical contact cleaner inside your tumbler, you may just have a build up of crud that needs to get cleaned out. And if you have another key, try that one instead to see if that makes a difference.