Does it actually lose air? If so, it may be that you have a nail in the tread or maybe it's leaking through the valve, in which case a new Schrader valve insert will stop it. The system can be deactivated by using a Lexia. If the sensor fails, a new sensor can be bought online, but then after fitting, an exciter has to be used on it, and then the Lexia to programme it to the car.