My keyless entry battery seemed to die. I replaced the battery and after several times I finally got the alarm to reset with the key fob. But now when im driving the alarm is arming itself, locking doors..but the car will still run. After I turn the car off I have to use the disarm button on the remote otherwise the alarm will go off. Any ideas on why this is happening.

SOURCE: '03 Hyundai Elantra - Keyless entry remote not working

It wouldn't be the car battery, but since you just purchased the car, the dealership should correct the problem. Bring it to their attention right away. Did you get any kind of warranty? Most dealers have at least a 30 day warranty for things like this.

SOURCE: disarm alarm on a 2004 sonata

If you use your keyfob to lock the doors, it will activate the alarm, and you will need to unlock with the keyfob. If you lock the doors with the lock button on the inside of the door, it should not activate the alarm.

SOURCE: keyless entry didnt work on 2003 tiburon unlocked

you should be able to do this on the driver door key lock by turning to open position holding it there for a second then turning it oposite direction.

SOURCE: WHEN I PUSH TO BUTTON TO UNLOCK MY 2007 HYUNDAI

the car has two codes one is fixed the other is a rolling code which changes each time you press the unlock button,the first is allowing you to unlock the car but when you open the door it thinks your trying to steal it and the alarm goes off,then when you put in key it is recognising the key and switching off the alarm....NOW if you follow the instructions in the book you can reset the alarm(as i worked for hyundai over 5 years ago i cant remember the sequence,sorry)

SOURCE: my car alarm will not

Here's how you fix this:
- Open the remote, and take a piece of paper (something small, I used a crushed straw wrapper) and put it on top of the battery. It needs to make the remote somewhat difficult to close, but it needs to close.
- Make sure the red light flashes EVERY time you press unlock/lock. Your car might lock/unlock now. If it doesn't, move on.
- Get into the car somehow. Yes, the alarm might go off. Ignore it, put the key in the ignition and turn it to ACC. Then and hold both buttons for a few seconds. The light should continuously flash.
- Turn the key off, and wait for the alarm to stop. Then press unlock. If it works, congrats! No more issue! If not, you may need to take it to the dealer for service.
I just fixed my remotes this way. The contacts wear out, and the battery box literally fell off of one of the remotes. Forcing the battery box against the circuit board is the free way to fix it. Remotes aren't too cheap! Good luck!