Mercedes Rain Sensor Learning
Supported coding features by StarCOM diagnostic tool https://www.obdtester.com/starcom
What it does
- Calibrates the rain/light sensor for automatic wiper and lighting control
- Learns sensor sensitivity and response thresholds
- Ensures correct detection of rain intensity and ambient light
When it is required
- After replacing the rain sensor or windshield
- After cleaning or repairing sensor optics
- When wipers operate incorrectly or too late/early
- When headlight automatic control is inaccurate
Conditions that must be met
- Windshield clean and free of obstructions
- Ignition ON, engine OFF (or as instructed)
- Stable battery voltage
- No active wiper or lighting fault codes
What happens during learning
- Sensor is exposed to ambient light and simulated water drops
- Control unit adjusts sensitivity and thresholds
- Sensor data is stored for:
- Automatic wiper speed
- Intermittent intervals
- Automatic headlight activation
If learning is not performed
- Wipers may react too slowly or too quickly
- Headlight automatic control may fail
- Fault codes or warnings may remain active
After learning
- Test wiper automatic function in light and rain
- Verify headlight automatic activation
- Confirm smooth and correct operation
- Clear any related fault codes