Welcome to Just Answer. My name is XXXXX XXXXX X will be glad to assist you.
Start by checking the 15A room fuse. Replace if blown. #4 in diagram.
If the fuse is good, check to see if the power locks will lock/unlock from inside the car using the drivers master switch.If your concern is still present, let me know and I will get you the next diagnosis steps. Simply hit the reply button.ThanksDrew
Since the power locks operate from the master switch, that indicates the system is operational. Your next step will be to replace the battery in the transmitters.
Let me know if this does not resolve your concern and I will give you the next step.
For your next reply I will need to know if you have factory keyless entry (switch blade key) or advanced keyless entry (smart card)
Also is there is any aftermarket alarm/remote start system installed, REMOVE it.
Now that I know you have the switch blade key, I suspect that you have a faulty BCM (body control module)
This module is located in the left front foot kick panel area. Check to see if there is any sign of water or wet carpet on the drivers side. I have seen water leak into the BCM module and cause this concern. (#4 in diagram)
Next remove all connections the the BCM and check for corrosion, water or damage to the module.
If all looks good, I want you to try to program the transmitter key fob. Here is the procedure. Try several times.
Verify that door locks cycle to the lock/unlock position when entering the programming procedure.
Let me know.ThanksDrew
BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION
Key transmitter programming.
TRANSMITTER ID CODE REGISTRATION [KEYLESS ENTRY SYSTEM]