Wanted to turn off the automatic door lock function and enable the lock at 17 mph. Had to actually do both steps (in sequence). 1. Disable automatic door lock when shifting out of park. 2. Enable automatic door lock based on speed. Took a bit of trial and error, but it works!
You are right, the EU manual doesn't mention this procedure anyway. When I tried to setup it up with techstream/tactrix the lock settings are empty.
You might try setting up Techstream in North American mode. I think some of the menus are different. Just because Techstream can't do something it doesn't mean the car can't.
I know this is an old thread. Hope you all can help me. Even I cannot get this worked on my Prius III gen. Mine was imported from Japan & the option is there on the manual. The doors won't lock when exceeding the speed limit, wont unlock when i put it to P, or wont lock when I put it to D from P. Any help would be much appreciated.