Try contacting the Grace company?
Years ago they sent me the "wrong" control and when I contacted them, they walked me through taking the cover off, moving some "pieces" that just lifted and clicked into place - the configuration was different for the machine I had, so they "re-configured" it over the phone by having me move piece "A" to position "B" sort of thing.... then it worked. I don't recall at the moment what those pieces were called, and I'm not a techie person!