Since the year 1995, vehicles were installed with an immobiliser system that requires a transponder key that has an electronic chip. Once an unprogrammed key is inserted to the ignition your cars engine will not start even if the key blade was cut exactly the same as the original. This feature prevents vehicles from getting stolen.
Below are the types of keys and remotes that needs programming:
?Regular car remotes
?Smart key remotes
?Car keys with remote also called remote head key or remote key
?Cars built after 1995 with keys that has an integrated transponder chip
Can a car owner reprogram a programmed remote to another vehicle?
Yes in some cases, but it depends on the year, make and model of the vehicle. Some remotes have an integrated transponder on its circuit board which means they cannot be reused or reprogrammed.
Can you program a remote yourself?
Yes but this also depends on the year, make and model of the vehicle. If that said vehicle is on board programmable, then you can do it yourself by performing some steps provided in the remotes manual however, if the vehicle is not on board programmable then it would need a special tool to get it programmed and you would most likely need to contact a Locksmith or a Dealer.
Some advancements have been made recently, where the old remotes can be cloned which makes it more convenient to car owners that has an old car system while remotes are discontinued.