How to Deactivate the Alarm on a Hyundai Sonataby John Smith
There are three different situations that will trigger the alarm system in your Hyundai Sonata. If someone opens any of the doors but doesn't use the remote or Sonata key to do so, the alarm will go off. Likewise, if you open the trunk or the hood without unlocking the car with the remote or the key, the alarm will also be activated. You will need to deactivate the alarm to stop the horn from honking while the turn signal lights flash. The lights and sounds will continue for 27 seconds, then the process will repeat.
Point the wireless transmitter at the Sonata and click the "Unlock" button, which has an image of an open padlock.
Use the ignition key to unlock the Sonata doors, then open the door and enter the driver's seat.
Put the key into the ignition and turn the ignition cylinder clockwise as far as it will go before cranking the Sonata engine. Leave the key here for 30 seconds to deactivate the system.