I'm pretty sure its the decoder, but I havn't tried any other decoders in the loco as of yet since I have not currently. I suppose it could be the system however we have used a lot of various Digitrax Decoders on the MRC Podigy Advanced2 as well as the Digitrax system. I'll have to try another decoder, I'm new to DCC so its a crash course for me lol. Thanks for the suggestions