Loksound Equipped Engine Refuses To Move But Sound Is Fine Updated 2024-12-01

This problem has plagued users for a long while now and is almost constantly an issue brought up on the LokSound groups.io forum. Guaranteed you'll see it brought up about every two or three days.

There are several reasons this could happen and the majority of them are easily remedied. There is a list of things that need to be checked and these are mentioned whenever the problem pops up. 

• Make sure Drive Hold is not on
• Insure the Independent Brake is not on
• Insure the Automatic (Train) Brake is not on
• To learn how to implement the Train brake read this
• Make sure CV19 is set to 0 (not in advanced consist)

If group members think of other things that need to be checked, email the author and he'll add them to this list. 

Recently, the author came across this problem in a couple of his locomotives and it always occurred when initially programming the decoder. It didn't matter if the engine was programmed from scratch or was a copy of a previously programmed engine with just the engine number changed. It happened in both instances and was always for a v5 decoder (that's what the author has) so, both 21 pin and micro decoders developed the problem.

Definition of Terms

Just to be clear, the following was done with a LokProgrammer and not JMRI. Also, with a LokProgrammer there are some terms used in this discussion that may be confusing for those used to JMRI, Panes, Sheets and Driver's Cab. 

• Panes are the columnar selections on the left side of the LokProgrammer window. They start with Driver's Cab at the top and end with Sound at the bottom. Directly to the right of the Panes are the Sheets starting with Address. See figure 1. 
• Sheets give you access to the individual CV settings of the decoder but they can also give you access to other things such as the individual sound slots on the Sound Pane. It depends on which Pane you select. It  takes a little getting used to.
• Driver's Cab is a built in throttle which allows you to immediately test the changes you have made to CVs after Writing Decoder Data. It does not allow you to test any changes you have made to the Sound Pane though. Some changes there have to be burned to the decoder to hear them (the Simulator in the sound pane will allow hearing some changes but not all of them and that is beyond the scope of this discussion).
  
  
  

Fig 1 Panes, Sheets and CV access

Now For The Insidious One
Re-burning the unchanged original downloaded file from ESU (pure factory reset not a reset to previosly programmed values) would clear up the problem so what did the author change that caused this? 

Today it was decided he was going to take the time and trace the cause. One sheet at a time utilizing the Driver's Cab to test if the engine is running or not after changes and then go changed setting by changed setting on the particular sheet if the problem occurred.

This took some time. Brake Settings, Driving Characteristics, the various Function Sheets, all were fine. Motor Settings, WAIT!!! the engine refused to move!!! Now change by change until the author got to Motor Overload Protection. Long story short finally, checking the Enable motor current limiter would prevent the engine from moving!  See figure 2.

 

Fig 2 Motor current limiter

Think! Why? This was an older HO KATO AC4400CW purchased at a swap meet and it had the same changes made to a new one that was working. This makes perfect sense. The older motor needs more current than the new model and the protection wouldn't let it move because it was above the set limit.

Uncheck the Enable motor current limiter box, test, engine moves! Problem solved. Perhaps in the future (when there's time) some experimentation with this setting will show what's going on.

Don't forget this one after checking Drive Hold and all the different brakes don't fix the problem. Also remember that if after all of these checks are done and the engine still does not move, you probably have a blown drive circuit in the decoder and it requires a trip to Colorado for a fix. Remember that the ESU office has moved. It's no longer in Pennsylvania. 

I hope this helps and I know it demonstrates what lengths you sometimes have to go through to isolate problems. Good luck!

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