Trailer Brake Controller Issue

That's good my friend but has nothing to do with the TBC. The TBC has one wire control. My Chevy will not tell me when a 4 pole trailer is connected but will show in the turn signals if a trailer tail light is not functioning. Sure new trucks have better light technology, granted. The TBC looks for a load on the one wire associated with brakes and uses that load sense to determine a trailer connection - ONLY FOR THE TBC. It is designed to NOT be associated with lights and is a safety factor. I can send you pics of how your Pod is wired and connected or you can do it yourself, just find a 7 pin flat standard RV connection diagram, you will see one wire is used from the TBC to the wheel backing plate. It doesn't matter about light technology the vehicle system has to work with the existing RV technology, end of the day the RV brakes have nothing to do with lights and the RV lights have nothing to do with brakes. I can have a disconnected TT plug and energize the brakes with a jumper and not have a single lit light.

Quote from OP: As I reentered the Interstate, I noticed a message on the dash display stating the trailer was disconnected. I stopped at the next safe place and found all physical connections were good, trailer lights worked properly, but the trailer brake controller would not sense the presence of the trailer.

So bottom line is he has no light problem, he has a TBC issue. And the TBC uses the blue Brake Control signal right to the trailer magnetic brakes to see if there is a power draw, which indicates the brakes are at least receiving a control signal. The blue wire into the brake backing plates. Some trucks know when the lights are connected but they also know when the electronic brake is too, they have too when a braked trailer is being pulled. Two different circuits.

Why would a four pin connector need to interact with the TV.  I have never noticed my F150 indicate anything when I pull my boat.  When I have the Pod behind if not connected it tells me if I manually try to apply the trailer brakes.  unless I initiate an action there is no response from the truck.

Thanks for all the helpful information.  I needed some ideas to point me in the right direction.  We are working on this and will have the trailer checked out at the dealer's service center next week.  I have heard of others with similar problems, and there does not seem to be a common cause.  I'm betting that this has something to do with the backing plates that were replaced earlier.  I will keep you all informed of what we find.