Hi Carl.
Pioneer stopped publicly listing information on the 2012 receivers, but you can still download the spreadsheet directly from Pioneer's web site that defines all the commands and responses
here. In the "Functions" tab of that Excel spreadsheet, look for the "*ATF" command for "Sound Delay". The asterisk (*) should be replaced by a 3 digit number from 000 to 100 where 001 represents a delay of 0.1 frames and 100 represents a delay of 10.0 frames. So a command of 025ATF would set an audio delay of 2.5 frames. You can also specify either "DOWN" or "UP" adjustment with 998 and 999 respectively.
The document isn't clear about what "frames" are, whether they're talking about video frames or data frames. My guess would be video frames, but I can't be certain.