Method for heating a housing containing at least one functional body

A method for heating a housing containing at least one functional member including at least one of a temperature sensor, a pressure sensor, and a level sensor, said housing including at least one wall shared with a reservoir configured to receive a liquid, the housing overlapping an interior volume of the reservoir, and at least one wall provided with an orifice leading to the outside and closed by a pressure equalizing membrane porous to water vapor and impermeable to liquid water, the method comprising:

• heating humid air inside an interior volume of said housing overlapping the interior volume of the reservoir including the at least one wall shared with the reservoir and the at least one wall provided with the orifice in at least one of the following situations, the heating of the interior volume of the housing being triggered based on information supplied by at least one of the temperature sensor, the pressure sensor, and the level sensor inside the housing:
• (i) when the information supplied by the temperature sensor indicates that said reservoir is subjected to a drop in temperature other than a drop in temperature that causes said liquid to freeze,
• (ii) each time a vehicle equipped with the housing is started, and
• (iii) when thermal conditions that produce condensates are detected in the interior volume of said housing, closed by said membrane, indicated by the information supplied by one of the temperature sensor and the level sensor.