If your vehicle is showing key fob buttons do not lock or unlock doors, here are the most likely causes and the parts you'll need to fix each one.
The internal battery in your remote is dead, or the physical button contacts have worn out from daily use.
If the main car battery is completely dead, the vehicle has no power to operate the electronic door locks or receive the fob signal.
The remote has lost its synchronization with the vehicle. This frequently happens after a DIY fob battery replacement or if the vehicle battery dies.
A blown fuse will cut power to the door lock circuit or the keyless entry receiver, preventing the system from responding to the fob.
If the fob causes the lights to flash or horn to honk but the doors physically do not lock or unlock, the electronic motors inside the doors have failed.
The main computer module that receives the key fob signal and commands the locks has failed or experienced a software glitch.