The paper presents an application of unscented Kalman filters to an automotive electronic throttle device. The motivation of this study is on estimating the position of the throttle device when measurements of position are inaccessible, e.g., due to failures in the sensor of position. In this case, an external wattmeter is connected in the circuitry to measure the power consumed by the throttle, and this information feeds unscented Kalman filters to produce the estimation for the position. Experimental data support the findings of this paper.