I have a 2017 Lariat Supercrew with the Sync 3 overhead console. What are these 4 holes (see finger) ?

 

pretty sure those are cabin lights

 

Do you have this console? If not, no offense, I need somebody to reply that does. The map lights are ahead of these closer to the windshield.

 

Those are perimeter sensors. Turn the perimeter sensing alarm on, leave the windows down, without the fob in your hand, stick your arm in the window and see what happens. That is the reason there are 4 sensor, one for each window.

 

This is the reason it ask you if you want to turn perimeter sensors on when you turn the truck off. You have the option to enable or disable the sensors.

 

Thanks, Coyote, I'll check it out.

 

Actually, only 3 of the 4 are sensors. The particular one the OP is pointing to is a blank....that is the one that isn’t actually a sensor.
I drilled that one out and installed a recessed dim red LED to give a tiny amount of ambient light in my cab.