Why is transponder key programming a requirement for smart keys? All smart keys have chips that are embedded in the plastic fob. This chip contains a code that is read by the car’s engine control unit (ECU) when you insert the key into the ignition. If the code is right, then the car’s immobilizer is deactivated and your vehicle will start. If it’s wrong, then the vehicle won’t start. Programming is required if you want the chip to contain the right code. It’s implemented as a security measure to prevent thieves with key blanks from unlocking and stealing your vehicle.
