Sensor and method for determining operating states associated with one or more tires. The operating state of the tire can be determined based on one or more measures environmental conditions of the tire(s). For example, a controller can be configured to determine a change in one or more environmental conditions, including determining, for example, a rate-of-change value, a variance value, a standard deviation, or the like. The rate-of-change, variance, and/or standard deviation values can be compared to one or more threshold values to determine the operating state(s) associated with the tire(s). The environmental condition can include, for example, acceleration of the tire, pressure of the tire, and/or temperature of the tire. The operating state can be, for example, a filling state indicative of the tire being inflating, and/or a drive state indicative of the tire rotating about its axle.