Keyless entry stopped working

I have a 2004 Malibu LT and the other night both of my remotes quit working at the same time. The batteries are good and when I put the volt meter across the terminals on the little circuit board inside the remotes it's sending signals to the car but not activating anything. Did the remotes just all of sudden lose their programing or is this a computer thing in the car thats the issue? Do I need to take the remotes to the dealer to have them reprogramed?

Thanks.

Are any tests I can perform or parts I can check before I take the car to the dealer and pay a bunch of money to diagnose?

Thanks