Rain Sensor

The rain sensor uses an infrared beam to optically sense water on the windshield. The intensity of the reflected beam is measured and compared to the intensity of the transmitted beam. If there is water on the surface of the windshield, the beam distorts, reducing the intensity of the beam. If the beam is not reflected completely, it is interpreted as rain on the windshield and the windshield wipers are activated.

A gel-type lens is integral to the rain sensor and acts as the interface between the rain sensor and the windshield. If the lens is missing or damaged, the rain sensing wipers may become inoperative and the sensor must be replaced.