A system includes a handheld tool for executing steps of a sequence within a work cell. An electromagnetic marker connected to the tool emits a magnetic field within the cell. A receptor detects the magnetic field and generates a raw position signal in response thereto. A control unit updates an assembly setting of the tool. The host executes a control action when a position determined using the raw data is not equal to an expected position in the sequence. A method calculates the present position of a torque wrench using magnetic fields generated by the marker and measured by a receptor array, and calculates a present position of the tool or a fastener. The present position of the fastener may be compared to an expected position in the calibrated sequence, and the torque wrench may be disabled when the fastener position is not equal to the expected position.