# Phantom Throttle



## phxpsd (Jul 29, 2013)

Does anyone with Digitrax Super Chief and DT402D throttle ever have locos set at 0 speed suddenly start to move when display still says 0 speed? Also a variation of this is to stop a moving loco to 0 speed then have it suddenly leap forward with indicated speed of 7 or maybe even 20. I have performed the OP39 process as suggested by Digitrax, but issue continues randomly. This happens to Soundtraxx Tsunami and MTH PS3 equiped locos.


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## Locomotive (Jan 2, 2014)

Is it all your locomotives that will do this?

Reason I ask is I had a Digitrax decoder that would just up and take off. with just track power on. it could sit in the yard for 6 hours and not move and then it would go full speed or sometimes crawl. or it could start moving the second the power was turned on. I said it had a ghost in it.

Sad part was the first time it did that it went full speed and went head on with another parked sd70ace.


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## deedub35 (Jan 29, 2014)

I am having something eerily similar happening with my DCS51 and 2 jump throttles. I haven't had time to troubleshoot yet but when I assign a loco to jump throttle 2, that locomotive starts moving on its own even when the jump throttle knob is at zero and even when the jump throttle power switch is off! In order to gain control of the runway loco I have to steal it with the DCS51.


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## JerryH (Nov 18, 2012)

A command station maintains the last known throttle setting in memory and will use that when that loco is placed on the track. Best practice is to set loco to 0 speed and release the loco address prior to powering the command station down. The same thing can occur when using multiple throttles, hence the "stealing" question. Either of these could be occurring as well as the decoders themselves. They also retain the last known throttle setting.


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## phxpsd (Jul 29, 2013)

A few days ago was the first time for a Tsunami loco to do this. MTH PS3 locos have done this for the past several months. Two of the three MTH locos have had their decoders replaced so often that it is difficult to recall who did what when.
Last known throttle settings are always zero. I rarely release locos as I have never had a stack full warning. That is why I did not put much hope in the OP39 reset as suggested by Digitrax.


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## JerryH (Nov 18, 2012)

Are you using more than one throttle? It sounds like a multiple throttle issue. Could also be a bad Loconet panel or connection.


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## phxpsd (Jul 29, 2013)

Yes, I also have a UT4 with a UR92 that I use plugged-in or as infrared wireless. I use it almost exclusively with my BLI ATSF 4-8-4 (Paragon2). No loco has ever creeped on this throttle. The BLI 4-8-4 and the BLI SP AC-4 (Paragon2) have never acted odd on the DT402D.


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