Nissan immobilizer system 4

https://getnissankeynotrecognizedspark.cavandoragh.org/how-to-fix-a-nissan-key-not-recognized-warning-on-your-dashboard

The Nissan immobilizer system uses a microchip in the key to match a code with one in the car, preventing ignition if the codes don't align. This quiet layer of security helps deter theft by stopping the engine from starting without the correct key, hidden until needed.