Rain Sensor - Function - GF82.30-P-4103-02GH
How it works
An infrared transmitter (2)sends infrared light to a lens (1) which directs the beam to the windshield (4) . The intensity of the light reflected by the windshield is measured by an IR receiver (3)located at the opposite end of the lens.
- Dry windshield (Fig. A)
When the area around the rain sensor (B38) is dry nearly all of the light is reflected and the IR receiver (3) measures a high level of light intensity.
- Wet windshield (Fig. B)
When the reflection area is wet, some of the light is scattered away from the glass of the windshield. This reduces the intensity of the reflected light and the IR receiver (3) measures a lower level of light intensity.
The light intensity measured by the IR receiver (3) provides a measure of the rain intensity on the windshield. Lower light intensities indicate higher levels of rain intensity on the windshield.
Rain sensor data flow
The rain sensor (B38) networks with the All Activity Module (AAM, N10) via the engine compartment CAN.
More than just a "rain sensor," the unit also comprises integrated light sensors
for the vehicle lighting system
. Data from the light sensors is also sent to the All Activity Module (AAM, N10)
via the engine compartment CAN.
Power supply
Power is supplied to the rain sensor (B38) via KI. 15 so that these functions are available only when the ignition is on.