Service trailer brake error

[4elements21]

While towing my boat which does not have electric brakes I eventually get the service trailer brake error after driving for about 10-15 minutes and after I disconnect and turn the truck off and back on the error is gone. Didn’t know if anyone knew if this is an actual error or just what message you get if the system sees a trailer hooked up in tow mode without an electric brake system on the trailer? Just trying to avoid a service call possibly at the dealership.

 

[Boston]

Four or seven way electrics?

 

[4elements21]

5-way flat plug from the trailer. Truck of course has the 7-way. This is my first trailer brake control to BTW.