Systems have been proposed for closing powered vehicle windows (windows including, but not limited to, for example, front and rear door windows, window side vents, sunroofs, moon-roofs, and convertible roofs) in the event of rain. These systems typically use dedicated rain sensors, and perform automatic window close actions based on detected precipitation. These approaches may seem logical, but they are not cost effective in terms of parts cost or in terms of key-off-load (KOL) electrical current budget for a parked vehicle. Adding a sensor solely to monitor for rain proves difficult from a business perspective, as rain entering windows is a relatively unlikely scenario. Thus, while auto-close window features may be welcome for little to no additional cost, customers may be unwilling to pay extra for such a rarely used option.
To address the cost of additional sensors, some systems propose use of existing windshield rain sensors employed to activate or change wiper speed according to windshield wetness. These systems may sample the windshield rain sensor while the vehicle is off, and may provide an auto-close feature upon detection of wet glass. However, such systems are impractical for vehicles lacking smart wiper systems, and are not cost-effective from a KOL perspective, as windshield rain sensors consume considerable KOL while active. To keep additional KOL manageable, the windshield rain sensors may be sampled at long intervals, but this may reduce the effectiveness of such a system below acceptable limits.
As yet a further disadvantage, such systems fail to take into account safety considerations for animals or persons that may be in the vehicle cabin when an auto-close event occurs. For instance, if rain conditions yield to sunny weather, the vehicle cabin may experience a dangerous increase in temperature due to increased sun load.