Had to do a Cadillac STS with sorta the same problem, security light in dash, says something about waiting so long and try again. Basically you have a resistor in the column wired thru the switch, It detects the resistance in the resistor you have on your key. . last i heard there is 16 different resistor values. When you insert the key in key switch, the computer reads the resistance, if its not the same as programmed, security light in dash and or msg ,, cant start. I removed the switch and found one of the thin wires had broken on the switch. The wires snake down the column and plugs into a 2 prong plug in the base of the column somewhere. You need a steering wheel remover to get past the security lock plate. Also follow the precautions for removing the air bag in the steering wheel. Not recommended for a beginner, but very doable if you're good at following directions
. . also you will need to take back to dealer and get a new set of keys, since when you get a new lock switch at your local parts place,, it doesnt have a resistor on it,, it is only there for rekeying purposes.
Let us know how it goes,,,,