Seat Alhambra solar sensor fault and heating issue

That sounds very familiar. I have a Seat Alhambra as well, though I don't recall the exact build year, and I experienced something quite similar. The heating wasn't performing as expected, and the car sensor was throwing errors. Have you checked the connection to the daylight sensor? It's like a chain reaction; a small fault can cause bigger problems.

When you mention the connection to the daylight sensor, are you referring to the cable and plug connection specifically? Is there a particular area I should inspect, or a way to test the connection to confirm it's defective?

Yes, I meant the cable and plug connection. While you could try to inspect it yourself, I would advise against it unless you have experience with car electrics. It is best to have a workshop check it. In my case, it was a similar fault, and the workshop confirmed the defective plug connection immediately. It's a relatively inexpensive repair, thankfully.

Thank you for the advice! I took it to the workshop, and you were spot on. It was indeed a defective plug connection on the solar sensor. The repair cost me 95€. Everything is working as it should now.