How do you reprogram your 2003 Honda civic keyless remote?

You can't reprogram a 2003 Honda Civic keyless remote yourself in the same way you might with some newer cars. Honda Civics from that year don't have a user-programmable system for the key fob. If your key fob is malfunctioning or no longer works, you'll need to have a new key fob programmed by a Honda dealership or a qualified locksmith experienced with Honda vehicles. They have the specialized equipment to program the new remote to your car's system.