I had one of these that needed the CONGEN params modified and there was nothing I could do because of the locked diag port (and no utility supports it yet as Amarbir stated).
The options here are to find a rogue Seagate engineer with access to a Seagate server or send it to Seagate. The first method costs ~$1500. I had my client just send it to Seagate's data recovery center. They charged $700 and it took about 3 weeks but it was a full recovery.
The drive I had was actually the 2TB ST2000LM007.