Contact Influence

WARNING: This page is about a different car, the 2008 Hyundai Azera. However, it is still accessible from the selected car via links, so may be relevant.

Rain sensor can misoperate according to behind condition

Measurement signal gets weak by the dust of measurement surface or all beam way surface (the surface of luminosity and photo diode, optic fiber, coupling pad, windshield copula glass surface).
The bubble on the windshield and the coupling pad contact surface.
The movement of coupling pad by vibration.
Damaged wiper blade.