The key turns in both directions in passenger door lock as far as it does in the driver door lock, and yes the key unlocks the driver door just fine.
There is no resistance I can feel when pulling on the inside or outside door open levers.
I suspect the linkage is jammed or bent or a clip has broken causing linkage to be disconnected. But of course I need to get the door open in order to remove the inner door panel to see what is wrong.
Do you have a picture or drawing of the mechanism?
mine aren't electric, but this could help. Do you know if this is a drivers side or passenger side latch? Also, would the interior latch release be located on the opposite side of the picture?