UP SD40T-2 Won't run in command control

If you're comfortable taking the shell off, try jumpering the RUN/PGM switch, it may simply be defective.  The switch closed selects program mode.

Also, you can program the R2LC in another locomotive and see if it works there, then just drop it into this one.  The programming won't change by moving it to another locomotive.

I like GRJ's suggestion to swap the R2LC out to known good runner.  Also may want to check your antenna and antenna wire closely and verify continuity. 

Hi gunrunnerjohn and steims  Thanks for your idea's. This locomotive belongs to friend of mine, but I also own the same 6-28540 4004 so I think I'll take the R2LC board from my 4004 and put it in this one and see if that fix's my troubles. I also have a bunch of switches, so I think I'll just replace the run/pgm switch also to see if that's my trouble with this loco. Gary

It should drop right in without programming and be programmed to the same TMCC ID as the engine you take it out of.  You can simply test the switch with an ohmmeter to see if it's making a connection when switched to PGM.