a modular electronic control system for a differential is described . such a control system can contain an actuator and sensor in the differential casing and a connection between these elements in the differential casing and a controller outside the differential . the controller can be in the form of a printed circuit board residing in a control housing attached to the differential casing . in alternative embodiments , the controller may also be more distally located in the vehicle , where the controller housing contains means for conducting electrical signals from the interior of the differential casing to the vehicle without containing a printed circuit board . the controller may also contain a thermally conductive portion for dissipating heat generated by the controller .