Intermittently, when driving in light to moderate precipitation (rain or snow), the adaptive cruise control will not sense a car in front of it yet it will not default to "off/adaptive cruise not available". if my cruise control is set at a speed greater than the car in front, mine will continue to close the gap until a crash is imminent and i manually have to disengage by pressing the brake or turning the cruise control off. this has now occurred 6 times. the dealer suggested changing the module behind the sensor ($1,200) but, could not assure that this was the problem.