Need Help with TMCC FM

I am thinking that you have a Hall effects sensor and pickup on one of the axles, may be defective or out of adjustment. I have seen these on some of the S gauge locomotives and on the sound cars.

Ray

Nice thought Ray but there are no hall sensors either.  I had dropped both trucks when I lubed the worms for each motor and I saw nothing for speed sensing.  I checked the parts breakdown on Lionel's web site and it also does not list any cherry switch or hall sensors.

The Odyssey DCDS supplies the motion indication, there should be a wire from the 10-pin white connector that supplies the "hey, we're moving" signal to the R2LC.  I believe the wire is on pin 2 of the Odyssey DCDS, that's where the connection is on the ERR Odyssey replacement CC-M module.

Thanks for the tip John.  I ended up re-seating all the connectors on the motor driver board to ensure all was connected properly.  Re-tested the engine.  The rpms and brake squeal now work correctly.  Must have just been a loose connection on the motor driver board.

Locomotives that sit in boxes for years frequently develop oxidation on the contacts, reseating them usually fixes it.

This is a question for gunrunnerjohn.

I'm having the same problem with my Lionel 6-28544 PRR RS11 that you helped Joe Fermani out with back on 5-1-19 (See issue below)

I actually had to replace both the R2LC and DCDS boards, as the locomotive would accept commands and after using a known good R2LC, it would do everything but move, so I replaced both boards with new from Lionel (Bought them from Hennings).

So far, I've tried reseating all the plugs and boards with no success. I've also remove the white 10 pin connector on the DCDS, as well as all the boars from the mother board, then checked continuity on the black wire on pin 2 of the white 10 pin connector on the DCDS all the way through the mother board to the pin going into the railsounds module and it had good continuity. Is there a particular voltage range I should see at the black wire on pin 2 of the white 10 pin connector on the DCDS when the locomotive is running and if so what should I look for? I hate to think the brand new DCDS that I just waited 5 weeks for is defective, but I don't want to just throw another railsounds module in without knowing that's the issue. Since I see nothing burnt on the mother board and have continuity through the circuit from the DCDS all the way to the pin going into the railsounds module on the mother board, do you have any further ideas?

Thanks in advance for your help.

Paul Dube

I'm guessing the same thing is happening, you're not getting the duty cycle signal from the DCDS.  Pin 2 of the DCDS should be connected to pin-17 of the R2LC.  I'd check that connection first.  The duty cycle is a pulse, not a steady voltage.  That being said, you may have difficulty detecting it with a plain meter, I use a 'scope.  FYI, here's the pin-out of the DCDS from the excellent Motherboard document by @Rod Stewart.

@Pauld68,

Did you fix your 28544 PRR RS11?  I'm thinking about buying one NIB, but did a check here for any posts, and this was the only significant one.