Peugeot 4007 Rain Sensor Fault

Sounds like a dodgy rain sensor. Have you checked the gel pad on the windshield? They're notorious for getting bubbles which messes with the sensor readings. Those bubbles act like tiny prisms, scattering light and giving the sensor bad data. Is the windshield original, or has it been replaced? Aftermarket windshields can sometimes cause issues too, if they're not perfectly aligned with the sensor.

Thanks. Can I visually inspect the gel pad without taking the sensor housing apart? The windshield is original to my knowledge. How can I confirm your suspicion and check the windshield's alignment?

You can usually spot the bubbles just by looking closely at the sensor area from outside the car. If you see distortions or cloudiness under that gel, that's probably it. If it's the original windshield and you've got bubbles, you're probably looking at a new sensor or a fiddly repair job with new gel. Alignment is harder to check yourself. A workshop with diagnostic tools can tell you for sure. Might be worth getting it scanned.

I inspected the gel pad and found bubbles. I had the rain sensor replaced by a workshop for 62€. The issue is now resolved. Thanks for the help.