This is uncanny. I was scheduled to get the Sheffield to Piccadilly service at 20:11 last night (Friday).
The 185 got to Sheffield but the engine sounded very rough. I know they are loud ones but even I was surprised at just how loud it was. Got on, a few calls for staff on the intercom, station staff frantically running on the platform, engine turn off & 20 minutes later - staff recommended we catch another service.
They said it was a technical fault. So yeah, another 185 out of service it seems. As I left Sheffield it was still stranded on platform 6. I checked train refunds and it shows the train was cancelled.
Sorry I didn't catch what unit it was, I'm noob & not that geeky - YET anyway. But yes, the fact I came across this thread suggests everything is not right at the moment in regards to maintanence & reliablity at TPE.