One of the great advancements in automobile technology is the keyless remote--no more fumbling for the keyhole in the dark or trying to dig ice and snow out of the lock. Programming a new keyless remote for your Mazda 3 is something you can do at home. The process is a little involved but does not require anything other than the key fob, the ignition key and the car. Just because you purchased a new key fob at the dealership doesn't mean you have to let them charge you to program it.
Open the driver-side door of your Mazda and leave it open during this process. Lock and unlock the driver's door one time using the power door lock switch on the door, leaving it unlocked.
Insert the ignition key into the ignition, then turn the key to the "On" position. Turn the key back to the "Lock" position. Repeat this cycle three times within 10 seconds, ending with the key in the "Lock" position.
Close and open the driver's door three times, ending with the door in the open position. The car's computer will respond by locking and unlocking the doors once.
Press any button on the remote and the computer will first lock, then unlock, the car doors. Repeat the process to program up to three remotes for your car.
Remove the key from the ignition and the computer will respond with one final series of door locking and unlocking. Programming is now complete.