2012 f150 will stop randomly at stop lights or while driving. Screen says trailer hitch disconnected??? No codes popping up when took to dealership...

 

There are some circumstances when codes are erased when the key is turned off.
This may require you to visit the dealer when the problem presents itself and you need to not shut the engine down before the tech has a chance to check it out.

 

Agreed Hanky. Working for a dealership I have found that duplicating problems can be one of the most difficult things for technicians. Does it do this often or just every now and then?