Security light blinks while driving

I have the car listed above S model that I purchased recently. Mechanically and physically in superb condition with the exception of one issue. The security light (immobilizer light) blinks constantly even with the vehicle running. Regardless of which key I use. The light does not blink at all when the car is off. I have done a lot of research on the internet. Some articles have stated it is still stuck in programming mode but none of the procedures suggested actually how to fix the blinking security light issue. I took it to a lock smith but he was afraid if he reprogrammed it that it might not start anymore since he had never seen that issue. Is there anyone who has a concrete solution to this other than taking the car to the dealership? Because frankly I don't want to spend two grand to have a new computer put in the vehicle. It still drives fine.