Rogue start up

Do the involved locos have different loco IDs?  They must for decent operations.  Rogue startups can also occur if there is a brief short circuit spark on the tracks; maybe the Challenger had a wheel off the tracks.

Some years ago I did have a loco that would respond to commands sent to a different loco which had a different ID.  Never figured out the cause, but it went away when I changed the loco ID of the rogue, and its successor in that ID# has had not problems.

Well now it is possible that a wheel on the Challenger may have been off.  I'll tell you the truth, it caused a big mess because the ES44AC took off, and I don't mean a slow roll.

the ES44AC took off, and I don't mean a slow roll.

That's most likely because the ES44AC was in conventional mode and received full track voltage.

Further, it's possible that the ES44AC is locked in forward in conventional mode. Then, if the Challenger caused a short and woke the ES44AC up in conventional mode, you'd get exactly what you experienced. I suggest that you subject the ES44AC to atransformer, conventional reset to possibly get it out of being locked in forward.

Is the ES44AC a PS3 engine? If so, there have been several reported instances of PS3 engines being locked in a direction, in conventional mode, directly from the factory.

Yes, it is a PS3 locomotive and it has alway run flawlessly.  Perhaps it was just a freak rare occurrence.

Clint,

In that case, is it possible that there were 2 shorts, with a second or less between them? If so, the first short would have started the engine in neutral in conventional mode and the second would have started it moving forward at high speed.

From RJR....

 Rogue startups can also occur if there is a brief short circuit spark on the tracks; maybe the Challenger had a wheel off the tracks.

My experience as well , it may never happen again.   Weird thing is... It doesn't always take off a full speed.

Having experieced this, I would note that it sometimes takes a long time for this to show up.  If you have a toggle switched siding, try this.  put loco on siding, toggle off.  Apply power to that channel input on tiu. Wait at least 10 seconds. Turn on toggle.  If loco moves, do the conventional reset from a transformer.

Robert,

Wait at least 10 seconds.

I'd suggest other issuing an engine command to some other engine or waiting a minute or so before turning on the siding. According to a recent discussion with MTH, the watchdog signal persists for the lesser of 44 seconds or until a command is issued on that TIU channel.

Hadn't heard the 44 second bit before, Barry.  Thought I had read somewhere it was briefer.  So raise the 10 seconds to a minute.

If an engine immediately moves as voltage comes up, it is either a shorted motor lead to chassis (normally white), or a shorted motor fet.  If it takes a second or 2 to start moving it may be locked in a direction state, or some how is confused and thinks it is in a direction state.  IF it misses watch dog it will take off as if in conventional.  PS-3 seems to be more sensitive to these issues and easier to get locked in a conventional state that normally does not effect DCS operations, nor get cleared with a DCS Factory reset. 

Believe it or not I have had a number of PS-3 engines I first test in conventional start moving in reverse instead of fwd with a direction change.  I have to do a reset to get it to start in fwd.  Seen this enough I have noticed it.   G

I had a rogue startup a few days ago.  # locos were on the tracks at a turntable, tracks being powered awaiting calls to service but engines not yet started up.*  Out on the main line (same TIU channel), a truck derailed on a newly laid section of track (since fixed) and as the train went along, it made two distinct bursts of sparks.  The first burst started up the 3 locos.  The second burst sent them moving forwarded, and all 3 fell into the pit.  SO my guess above, seconded by Gregg, was a sound guess.

*When using wifi, this enables the initial read when starting the app to have the locos you'll be using in active status.  It's a nuisance when running a layout, to lose control while the app is doing a read to activate more locos.  The remote definitley has an advantage in this regard.