A fluid infusion device includes a pump mechanism having a rotor and a stator. The rotor includes a reference surface and a cam element rising from the reference surface. The stator includes a cam element with a stator cam surface. The cam elements cooperate to axially displace the rotor as it rotates. A drive motor is coupled to actuate the rotor to pump medication fluid from a fluid cartridge module to a body, via a subcutaneous conduit. A sensor contact element resides on the reference surface in an area unoccupied by the rotor cam element. A sensing element terminates at the stator cam surface, and cooperates with a detection circuit to detect when the stator cam surface contacts the sensor contact element. The circuit monitors a detection signal obtained from the sensing element to determine an operating condition of the pump mechanism.
