Compact cable drive power sliding door mechanism

A cable tensioner for tensioning a cable extending between and operatively coupled to a sliding door drive assembly and a sliding door, said cable tensioner comprising:

• a housing defining a cavity;
• a pulley disposed in said cavity and rotatably journaled on a shaft, and wherein the cable is wound around a portion of said pulley between the sliding door drive assembly and the sliding door;
• a pair of end caps receiving opposite ends of said shaft and slidably disposed in opposing grooves formed in said housing and extending longitudinally, and
• a pair of springs extending between said end caps and said housing biasing said pulley longitudinally away from the sliding door drive assembly.

A sliding door drive assembly for a motor vehicle with an electric energy source and a sliding door, said sliding door drive assembly comprising:

• a motor electrically connected to the electric energy source, said motor converting electric energy into a rotating force;
• a door drive transmission operatively connected to said motor for transmitting said rotating force to a door drive transmission output shaft;
• a cable drum fixedly secured to said output shaft for rotating with said door drive transmission output shaft;
• a housing covering a portion of said sliding door drive assembly;
• first and second cables wound about said cable drum in opposite directions, said first cable extending from said cable drum forward along the sliding door, said second cable extending from said cable drum rearward along the sliding door;
• an absolute position encoder including an encoder transmission, a two-pole magnet and a printed circuit board adapted to be mounted to said housing and having four integrated Hall sensors for sensing a rotational position of said magnet, wherein the encoder transmission is driven by the motor and the two-pole magnet is driven by the encoder transmission, and wherein the encoder transmission and the door drive transmission are related such that full travel of the sliding door between a fully open position and a fully close position corresponds to no more than one revolution of said magnet so that said rotational position of said magnet correlates to a position of the sliding door between said fully open and fully close positions.