What Are Car Key Programmers? Car key programmers are devices that can duplicate a transponder within the memory of a car. These are useful for replacing keys that have been stolen or lost. These can be used to reset oil service light, tire pressure warning lights and many other functions. https://carlocksmiths21334.answerblogs.com/29593523/a-an-instructional-guide-to-car-keys-programmed-from-start-to-finish