Hello and welcome to Just Answer!
When you put your key in the ignition and turn it on, does the alarm shut off and are you able to start your engine?
It sounds like you just have a faulty remote in the key. We know the the key part is working because it disables the security system once you turn the key on.
All you should need is a new key and you should be good to go. The dealer will have to program the key.
I would double check the battery connections in the remote and make sure the connections aren't broke off or don't put enough pressure on the battery.
I hope this helps, anymore questions feel free!
The key(part # XXXXX) retails for $204.00 cad, so if you live in the U.S. the price may vary a little.
It only takes 10 minutes to program the key.