Mike,
It's been a while since I set up my keyboard for MIDI pedals but here is what I remember.
If you want to play the keyboard as an organ you have to go into the midi preset page and select *Bass Pedals without APC* and set the rear midi switch to *Pedals*.
In this condition the keyboard uses midi channel 4 as the pedal input so you must set your pedal unit to transmit on channel 4.
Give it a try and see if this works.
Walt