I have a 2010 f150xlt with the 4.6l. It did not come with tow package but I want to put a factory brake controller in and was wondering if it could still get unlocked in the computer to work

 

if it didn't have the factory tow package, there probably isn't wiring for the brake controller.
you'll have to recreate the factory tow package, including 7-pin wiring and aux trans cooler and wiring for the BC.

 

You may be able to use your VIN to determine the capabilities of your truck.