Pat, Maybe we are talking over each other. Serial data is internal and not riding on the TMCC signal from the command base. Serial data is the R2LC talking to the motor driver, smoke unit, Rail Sounds etc... Even in conventional mode there is serial data. TMCC signal is talking to the R2LC receiver (one way). Serial data and the TMCC signal don't rely on each other. Chuff is and internal function. There is no chuff TMCC signal. G
Indeed, we are talking over each other, …….you are 100% correct, we know that the R2 or R4LC receives the TMCC signal, that signal is a command that is then sent down the data stream. If the signal is convoluted in any way, odd commands can be sent down the data stream. That is what can cause odd behaviors. Not saying that’s the case here, but I can prove it. I had a broken ground prong on the the cord that plugs into my wall socket on my layout. I had different issues with different engines. Mostly erroneous whistle blasts, or refusing to blow the whistle, or ring the bell, and a few of them would miss chuff. I had no problems running the engines, just odd behavioral issues,……
Pat
The discussion has been interesting, though I don't always follow it. However, I think I am not alone. 
Here is the video I mentioned yesterday with the K-Line Hudson running outdoors on a single loop of track. The sound never cut out during 15 minutes of running whether I had the smoke on or off.
This evening, I placed it on the layout using the level lower loop. The sound cuts out randomly. By that I mean sometimes it cuts out once per lap, sometimes more than once per lap. The cut outs happen at different spots on the loop, never the same place twice. It is obvious to me it has something to do with my layout, which I will work out after I fix the switch that makes the observation car truck derail.
Marc, Try a battery and see what happens. G
@GGG posted:Marc, Try a battery and see what happens. G
George, it’s got the equivalent of a YLB ( Your Last Battery ) installed in it already.
Pat
I had an idea after I left the train room. I’m going to disconnect the outputs of the DCS TIU and the GRJ watchdog circuits from the layout. Then run the TMCC base and power only. Maybe there is an interaction between the two systems. 🤷♂️
Any progress Marc? Also begs the question do other Lionel engines do this on your layout? G
@harmonyards posted:I heard the sound drop outs too, …..I don’t like that either, …..when I test ran the engine on my layout for hours on end, I never once experienced a drop out, or I would’ve never sent it out ….that’s one thing that drives me nutz!…….it ran amazing on my layout,…..here’s a video of how Mark’s smokes, ….it has a wee bitty leak, but the effect is so cool, Mark & I both agreed to leave it, as it’s actually an added feature,…when Mark gets his track work fixed ( I believe he’s got a misbehaving switch or something ) and he runs that locomotive some more, if he’s still got drop outs, I fix it, plain & simple,…..you guys wait long enough for this stuff, so I’ll deliver perfection….
Pat
Once the guys at Lionel see this clip ou can expect another smoke feature in their next production run.
George, I ran it on the upper loop of my layout with the DCS TIU disconnected only running TMCC. The sound still cuts out at random intervals. I Reconnected the TIU. I have one TMCC Pacific, one Legacy GP7, and one Weaver ERR RS3 that I ran last evening. All of them pulled the same train over the same route, and all ran fine without any sound cut outs. I packaged the Hudson last evening and emailed Pat I will send it back. I still have doubts about my layout, since it ran fine for Pat. He can see what happens there. Thank you for your ideas
