Mazda RX-8 2009 Service Highlights page 238

! The rain sensor is installed to the lens which is installed to top center area of the windshield.
! The rain sensor is integrated with the auto-ight sensor as a single unit.
RAIN SENSOR
(AUTO LIGHT SENSOR)
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 lens.
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.
WIPER/WASHER SYSTEM
INFRARED LIGHT
EMITTED
LIGHT
LENS
LED
LENS
RAIN SENSOR
RAIN SENSOR DETECTION AREA
AUTO LIGHT SENSOR
DETECTION AREA
WINDSHIELD
RECEIVED
LIGHT
RAIN SENSOR
PHOTODIODE
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RAIN SENSOR
DETECTION AREA
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09-19–5
09-19