Coolant Temperature Sensor Location?

Hi All. First post here. I got the the red flashing coolant warning. It only happens an freeway speeds. At low speed it's OK. I pulled the ODB2 code an saw the P1117 thrown which indicated the coolant temperature sensor. I purchased one as well as a thermostat. My question is where is the coolant temperature sensor located? Google searching only gave results for the regular Prius, but not the C. Maybe I'm not searching well enough, but could use some help here. Thanks in advance.