I have 1 tire that leaks very little just enough to set the senser off once a month or so but only in the winter when the cold air changes the pressure reading in the tires. Just add a little more air then normall 34+ and it should go out. It might take it a little time for it to recalculate, start drive, start drive so on.
When the weather gets cold, the sensor sounds loudly the morning of the first cold snap of the fall. Just put in air until you get a reading of 34-35 psi. Silence the alarm and drive. In about 1-3 miles the sensor goes out.