What Are Car Key Programmers? Car key programmers are devices that can replicate a transponder into the memory of a car. They are useful to replace keys that are stolen or lost. They can also be used to reset oil service lights, tire pressure warning light and many other functions. https://autolocksmiths59211.ampedpages.com/a-an-instructional-guide-to-car-keys-programmed-from-beginning-to-end-56714941