Seat Mii Fog Sensor and Climate Control Issues

Sounds like a dodgy fog sensor. First thing I'd check is the sensor itself and the wiring harness connected to it. Any signs of corrosion or damage? Have you tried running a VCDS scan to pull any specific error codes? That could pinpoint the electrical issue a bit more precisely. And just to confirm, the dashboard warning light is constantly on, right?

Thanks for the quick reply! I did a scan with my OBD reader, and it just gives a generic 'fog sensor malfunction' error. I visually inspected the connector, and it looks okay, but I'll check again for corrosion with a magnifying glass. VCDS scan is a good idea. Is sensor calibration necessary after replacing it, or is it plug and play?

Yeah, a generic code isn't super helpful. Given the symptoms you're describing, and that you've checked the obvious connection points, it does sound like a deeper electrical issue, possibly impacting the CAN bus. Replacing the sensor might not solve the root cause if it's a wiring problem. Honestly, I'd advise taking it to a workshop with the right diagnostic tools to properly troubleshoot the electrical system. They'll be able to check the wiring harness and the sensor itself with proper equipment.

I wanted to let you know the garage confirmed it was a faulty fog sensor connection, like you thought. They cleaned the connector and reset the error memory. Everything's working now! 95€ well spent for proper visibility and a functioning climate control again. Thanks for the help!