Bob:
Well... engine can also be put to sleep pressing F9 a couple of times puts engine into idle mode F6 will wake it up...
Then there's the suggested check CV19 if not 0 then a consist has been set and it will only respond to the CV19 engine address...
P2 are not happy with programming track reads sometimes... If the engine responds to any function of it normal address try programming on the main to just change things not reading first.
Jim Albanowski