 The Mitsubishi Electric propulsion system was retained , having performed better than expected . The wheelchair space was made available on the end of two mid @-@ train cars , nearest to the lifts in above @-@ ground stations . LED displays that blink to warn passengers of closing doors were introduced in the upper middle section of the door . Additional loudspeakers and advertisement panels were also introduced . Hand grips were moved to the support bars of the seats on the ceiling and <unk> were located near the doors and at both ends of each carriage . The air @-@ conditioning system was modified to match the system used in the C751B cars , with air @-@ conditioning vents and in @-@ flow fans installed . 
