Rain And Light Sensor, Basic Function - GF54.21-P-2005A
Model All (4xWD)
Model All (CAR)
Example illustration of rain and light sensor
Overview
This document contains information on:
- General
- Function
- Background light intensity
- Degree of windshield wetting
- Air humidity and temperature on inside of windshield
- Intensity of solar radiation
General
The rain/light sensor (1) is located on the inside of the windshield in the area of the inside rearview mirror.
The following sensors are integrated into the rain/light sensor (1):
- Rain sensor
- Light sensor
- Humidity/temperature sensor
- Head-up Display light sensor (vehicles with Head-up Display)
- Sun sensor
Function
The rain/light sensor (1) is networked with the front signal acquisition and actuation module.
To reference the signals from the integrated sensors, the rain/light sensor (1) evaluates, among others, the following information:
- Terminal status of terminal 15
- Outside temperature
- Vehicle speed
- Windshield wiper, status
- Request for sensitivity of light sensor
- Request for sensitivity of rain sensor
The rain/light sensor (1) also sends the following signals:
- Ambient light intensity (dimness stages)
- "Switch on low beam" request.
- Windshield wiper request
- Dew point temperature, surface temperature of windshield
- Intensity of solar radiation
- Diagnosis information
The rain/light sensor (1) detects the following conditions:
- Background light intensity
- Degree of windshield wetting
- Air humidity and temperature on inside of windshield
- Intensity of solar radiation
Background light intensity
The light sensor records the ambient light intensity.
The Head-up Display light sensor (vehicles with Head-up Display) records the road brightness in the viewing direction.
Degree of windshield wetting
The rain sensor detects the degree of wetting of the windshield. An infrared transmitter unit beams infrared light at a defined angle to the interior of the windshield, which is almost completely reflected when the windshield is dry. If there are water droplets outside on the windshield, a considerable part of the infrared light is diverted. The intensity of the reflected infrared light is correspondingly lower. The lower the measured light intensity, the higher the degree of wetting of the windshield.
Air humidity and temperature on inside of windshield
The humidity and temperature sensor measures the relative air humidity and the temperature directly at the inside of the windshield. The data are used to calculate the dew point temperature and the surface temperature of the windshield. This enables any (imminent) windshield fogging to be detected.
Intensity of solar radiation
The sun sensor records the intensity of the solar radiation in the vehicle. Depending on this, the control of the climate control adapts the vehicle interior temperature and the blower setting.
| Component descriptions | |||
| Rain/light sensor, component description | Model 206 | GF54.21-P-6002C | |
| Model 243 | GF54.21-P-6002B | ||
| Model 295 | GF54.21-P-6002E | ||
| Model 297 | GF54.21-P-6002D | ||
| Model 296 | GF54.21-P-6002G | ||
| Model 254 | GF54.21-P-6002H | ||
| Rain/light sensor with additional functions, component description | Model 223 | GF54.21-P-6005A | |
| Model 232 | GF54.21-P-6005F | ||
| Model 214 | GF54.21-P-6005K | ||
| Model 118 as of model year 2023 Model 177, 247 as of model year 2022 |
GF54.21-P-6005L | ||
| Model 167 as of model year 2023 |
GF54.21-P-6005M | ||
| Model 294 | GF54.21-P-6005N | ||
| Model 192 | GF54.21-P-6005R |