I have an HTD-510DV (last year's model?) and was unable to use any of the built-in codes from an RS 15-2104. The 510 uses one of the more complicated Pioneer protocols that requires 2-byte commands, which precludes using Advanced Codes input directly into the remote as well.

Using JP1, I was able to build an upgrade that controls all the features from the OEM remote. My file is in the Device Codes folder at the JP1 group and it probably would work for the 520 unless Pioneer made any drastic changes to the new model.