Air carrier pilot reported the autopilot flew to a dangerously low altitude on approach to MRY. The cause for the deviation is unknown.

Narrative

While flying raceway visual via the FMS loaded procedure; autopilot flew a potentially dangerously low profile with FINAL APP selected; requiring pilot intervention to avoid CFIT with surrounding mountains along final approach course inbound from the southeast. Cause: No GWPWS warnings but approach did call to see if we had the surrounding terrain in sight. I suspect they thought we were low. Even with interactions with the gatekeepers; we cannot determine why the aircraft wanted to seek such a low profile inbound from the IAF (CHRLE) with the autopilot flying. At roughly 5-6 nm I was not sure the jet would clear the final set of downsloping ridges and I climbed to gain sufficient clearance and set a proper descent angle to land. Afterwards I compared the FMS visual procedure with the LOC procedure and then plotted our altitudes that the FMS had us at and we were low at every one of them for the LOC approach with its associated step downs. It is my opinion that we have a potentially unsafe FMS procedure in the database when coming in from the southeast to MRY. If there are step downs on the LOC for 28L for terrain clearance; I think we should also have them for this visual procedure as well.