I have a 2013 Hyundai Sonata that the keyless entry system suddenly stopped working. As usual, I locked my car via the FOB one night and when I tried to use the FOB(as usual) to unlock my car, it wouldn’t work. Changed the battery, same thing. I then I used the key to open my car and the alarm went nuts. It would do this every time and would not start. I towed it to the dealer. They were all baffled until one person there showed everyone a little push button knob under the dashboard you have to hold for a number of seconds to disengage the security system. I’ve been making due with having to disengage the system every few days and still not being able to use any of my three FOB’s. Does anyone know what’s going on?