A removable, stand alone, self contained encoder assembly for a micro-fluidic valve actuator assembly operably mounted between a drive motor and a multi-position micro-fluidic valve device, said valve device having a valve shaft rotating about a valve axis thereof between a plurality of discrete fluid distribution positions, said actuator assembly having a housing with an interior wall defining an interior through-chamber having a chamber axis, said encoder assembly comprising: a support structure including a relatively rigid bracket member having a first bracket wall and a generally opposed second bracket wall, said bracket member being sized and dimensioned for insertion into the through-chamber of the housing to a mounting position in the interior through-chamber; an encoder shaft rotatably mounted to said bracket member such that a proximal portion thereof extends outwardly from the first bracket wall, and a distal portion of the encoder shaft extends outwardly from the second bracket wall, said encoder shaft being oriented relative to said bracket member such that an encoder shaft axis of rotation will be generally co-axial with the chamber axis when the encoder assembly is positioned substantially at the mounting position in the interior through-chamber of the actuator housing, enabling rotational coupling of the proximal portion of the encoder shaft to the drive motor, and enabling rotational coupling of the distal portion of the encoder shaft to the valve shaft of the multi-position fluid valve device, the support structure being free of rigid coupling directly to the actuator assembly housing; an encoder wheel mounted to said encoder shaft for rotation about the encoder shaft axis; an encoder module mounted to said bracket member, and configured to cooperate with the encoder wheel, as a preset unit, to determine the rotational position of the encoder shaft about the encoder shaft axis; arid an alignment device (71,71',72) mounted to said bracket member in a manner cooperating with the actuator housing to facilitate guidance of the encoder assembly toward the mounting position and into the interior through-chamber. a support structure including a relatively rigid bracket member having a first bracket wall and a generally opposed second bracket wall, said bracket member being sized and dimensioned for insertion into the through-chamber of the housing to a mounting position in the interior through-chamber; an encoder shaft rotatably mounted to said bracket member such that a proximal portion thereof extends outwardly from the first bracket wall, and a distal portion of the encoder shaft extends outwardly from the second bracket wall, said encoder shaft being oriented relative to said bracket member such that an encoder shaft axis of rotation will be generally co-axial with the chamber axis when the encoder assembly is positioned substantially at the mounting position in the interior through-chamber of the actuator housing, enabling rotational coupling of the proximal portion of the encoder shaft to the drive motor, and enabling rotational coupling of the distal portion of the encoder shaft to the valve shaft of the multi-position fluid valve device, the support structure being free of rigid coupling directly to the actuator assembly housing; an encoder wheel mounted to said encoder shaft for rotation about the encoder shaft axis; an encoder module mounted to said bracket member, and configured to cooperate with the encoder wheel, as a preset unit, to determine the rotational position of the encoder shaft about the encoder shaft axis; arid an alignment device (71,71',72) mounted to said bracket member in a manner cooperating with the actuator housing to facilitate guidance of the encoder assembly toward the mounting position and into the interior through-chamber.