Just had a no brake situation with my unit 2 weeks ago. Started to get a "wire fault on trailer" message. Tested truck with meter and had 12v at pin. Trailer brakes worked hooked up to a different vehicle but not mine. Long story short, the brake pin in my truck plug and the brake pin in the trailer plug were not making contact. Adjusted the pins and now I have brakes and no wire fault message. Don't ask me how they got out of alignment. Hope this helps.
2013 Ford F250 SD 6.7L
2014 Wildwood Heritage Glen 282RK
Certified Rumble Strip Tester