We left Chicago about an hour and a half late because 29 came in late. Then we waited a few minutes because 6 came in really late too, and they held for connecting passengers. After that, we made pretty good time through the night until we were a mile from the Pittsburgh station. Stopped dead on the tracks because of a diagnostic code involving brake faults. After some back and forth, NS sending a freight locomotive to pull us. Should be here soon, but who knows when we'll get into DC.