A flip-over ramp assembly is normally stowed in a horizontal position in a recess in a vehicle floor, and can be pivoted upward and outwards to a downward sloping deployed position, after the vehicle door has been opened. The flip-over ramp assembly comprises a mounting enclosure and a ramp which are pivotably connected at their adjacent edges by a hinge which provides a horizontal axis for movement of the ramp between deployed and stowed positions. A driving mechanism comprises an actuator and a driving shaft which is rotatably connected to the actuator. A pair of linkage assemblies are connected to the driving shaft, where the actuator drives the driving shaft which in turn moves the linkage assemblies to lift the ramp to the stowed or deployed position. A positioning cam rotates with the driving shaft for indicating the position of the ramp. A pair of sensors are used with the positioning cam for sensing the position of the ramp, where the sensors transmit a signal to a controller to cut off power to the actuator when the ramp has raised past its vertical position, thereby allowing the ramp to gravity down to the stowed or deployed position.