Keyless entry is a standard feature on most vehicles produced today, including the 2002 Hyundai Sonata. The remote, powered by a small battery and synced to your vehicle, allows you to unlock or lock the car, arm the alarm and pop the trunk from a distance. However, if your remote is lost and you need to program a replacement--or if your remote is no longer synced with your vehicle--you will need to follow specific steps to reprogram it.
Sit inside your 2002 Sonata and close all of the doors on the vehicle.
Find the control module for the alarm system, which is located just below the fuse panel on the driver's side of the vehicle. Remove the cover.
Locate the memory switch inside the module. Turn it off.
Insert the key into the ignition and turn it to the "on" position. Leave it in this position for 60 seconds.
Turn the switch inside the control module to the "set" position.
Locate the keyless entry remote. Hold down the "lock" button for 60 seconds to sync the remote.
Release the lock button and turn the switch to the "off" position.
Turn the key in the ignition to "off."
Confirm the keyless entry worked properly by pressing the lock, unlock and trunk buttons on the remote.
