A pump assembly includes an electric motor and different selectable pump covers, and is suitable for mounting within a transmission fluid reservoir for transferring automatic transmission fluid. The pump assembly includes a stator housing having a cylindrical cavity for receiving ATF contained in the transmission fluid reservoir. A rotor is rotatably coupled within the cylindrical cavity and has a plurality of magnets arranged about a rotational axis thereof. A flux collector is coupled with the stator housing adjacent to the cylindrical cavity for transferring magnetic flux from one of the plurality of magnets from a first portion to a second portion thereof. A hall sensor is disposed proximate the second portion for sensing magnetic flux in the flux collector, such that the magnetic flux is used to determine a rotated position of the rotor.