Mini One Fog Sensor Malfunction

That sounds incredibly frustrating! I'm no expert, but could a faulty humidity sensor also cause the windshield fogging and air conditioning malfunction? Have you checked the sensor's connections for any corrosion or damage? Is the error memory showing any other related codes besides the fog sensor?

That's a valid point about the humidity sensor. How would I go about checking the sensor's connections and identifying potential corrosion? Also, is there a specific procedure for sensor calibration that I should be aware of?

Well, if the error memory specifically points to the fog sensor, then the humidity sensor is likely related or a consequence. If you're not comfortable probing around with electrical connections and sensor calibration, it's probably best to take it to a workshop. They have the tools and expertise to diagnose the problem correctly and perform the necessary repairs without causing further damage. It sounds like you've already narrowed it down, but I am still uncertain if you can solve the issue by yourself.

I appreciate your input greatly. The diagnosis was spot on. It was indeed the fog sensor. They replaced it, performed a sensor calibration, and everything is functioning as it should. The air conditioning is now blowing cold, and the mirror heating is working. I feel much safer with proper visibility now. The total cost came to 98€ including tax, which is in line with what I was expecting. Thank you once again for your valuable assistance!