RAIN SENSOR CONSTRUCTION/OPERATION

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Warning
•  If vehicle servicing such as car washing is performed with the ignition switch turned to the ON position, and the wiper and washer switch is in the AUTO position, the windshield wipers may operate automatically. Always turn the ignition switch, and the wiper and washer switch off before performing servicing such as the car washing; otherwise a pinched hand or fingers could result in injury or a wiper system malfunction.
Caution
•  In the following cases, the rain sensor cannot detect the rainfall amount correctly which could cause a windshield wiper malfunction:
―  A sticker or label is adhered to the windshield above the rain sensor.
―  The windshield is dirty above the rain sensor.
•  The rain sensor is installed to the lens which is installed to top center area of the windshield.
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•  The rain sensor is integrated with the auto light sensor as a single unit.
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Operation With No Rainfall Contacting Windshield

1.  Infrared light is emitted from the LED in the rain sensor towards the windshield.

2.  The emitted infrared light passes through the lens and is reflected off the windshield.

3.  The infrared light reflected off the windshield is received by the photodiode in the rain sensor.

4.  The photodiode receives the light, the microcomputer in the rain sensor calculates the rainfall amount from the reflection rate, converts this to an electric signal and sends a windshield wiper control signal to the auto light/wiper control module.

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Operation With Rainfall Contacting Windshield

1.  Infrared light is emitted from the LED in the rain sensor towards the windshield.

2.  Emitted infrared light passing through the lens is received by the windshield and diffused by the rainfall contacting the windshield.

3.  The infrared light that is not diffused is reflected by the windshield and received by the photodiode in the rain sensor.

4.  The photodiode receives the light, the microcomputer in the rain sensor calculates the rainfall amount from the reflection rate, converts this to an electric signal and sends a windshield wiper control signal to the auto light/wiper control module.

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