Hyundai Repair: 2005 elantra remote keyless entry, hyundai elantra, remote keyless entry

Question
I just purchased my 2005 hyundai elantra. It had a remote keyless entry system where when you press unlock, the parking lights flash and when you press the lock, it does nothing but lock the doors. Sometimes (if I'm lucky, because it doesn't always do this), if I hold the lock button down it will flash the parking lights, and if I press and hold it again, it will flash and chirp. Does it need a new battery and is that why it only does that sometimes?

Answer
You'll only receive the lamp flash and siren answerback if the system thinks the doors and hood are shut.  You could have a problem with one of the door switches or with the hood switch.  In most cases, the problem is with the hood switch, its adjustment, or a missing rubber bumper from the hood.  

To check the hood switch, open the hood and lock the car with the remote.  Then depress the hood switch button with your finger.  It'll be on the passenger side near the front of the fender.  If the lamps flash when you depress the switch, then the issue is with the switch's adjustment, or the bumper that contacts the switch is missing from the hood.