Kia Optima: System Function

Basic Principle

Emitted Beam from luminosity diode is reflected entirely against the windshield exterior, and then turn into photo diode.

If there is water on the windshield exterior, beam separates optically, and the degree of remained beam is measured in the photo diode.

What there is water in the windshield, it means beam is not reflected all, so the degree of lost beam indicates the degree of glass surface wet.

Rain sensor consist of two luminosity diode, two photo diode, optic fiber and coupling pad.

Operation Control

Wiper ECU transmits the signal as a rain sensor, and then the rain sensor perceives the rainwater to transmit to the wiping order wiper ECU, wiper ECU controls the wiper motor according to the signal.

Contact Influence

The rain sensor can malfunction due to following condition

•	Contamination of the measurement surface.

•	Air bubbles between the windshield and the coupling pad contact surface.

•	The movement of coupling pad by vibration.

•	Damaged wiper blade.

Operation Condition

In case that engine starts under wiper switch AUTO, rain sensor activates after once wiper operation to inform the driver that the system is under AUTO.

In case that the rain sensor doesn't work or malfunction, it is needed manual wiper switch operation by the driver.