Removed my headliner to install cab lights and found this in my 2016 regular cab F-350XL .The black electrical part in the middle. What does it do?

 

Compass sensor module? Not sure.

 

Could very well be. Does anybody know for sure?

 

That is your TPMS module. That is one of the known updates from 2015 and prior model year Super Duties to the '16, the relocation of the module from behind the behind the glove box, to the one illustrated in the OP's picture provided.

 

Thanks for the info.

 

I didn't know what TPMS stood for so I googled it; It has something to do with the tire pressure monitor system. Tire Pressure Monitor System? Thanks for the info.

 

That is correct.