Skoda Citigo Solar Sensor Fault

I had a similar issue with my Skoda Fabia, probably the same sensor. Heating was weak, and VCDS kept throwing a solar sensor fault code. Have you checked the measuring blocks for the sensor? Maybe the voltage is off. Could be a faulty G107 automotive sensor.

Measuring blocks? G107? Could you elaborate? Where exactly is this automotive sensor located, and what voltage should I be seeing?

The G107 daylight sensor is usually behind the rearview mirror, on the dashboard. You access the measuring blocks via diagnostics, with VCDS or similar. You should see voltage fluctuating with daylight intensity. If it's zero or a fixed value, the sensor is likely gone. Since you suspect the wiring, check that first. But honestly, for 95€, just get it checked at a workshop, they'll sort out the sensor calibration too.

Took it to the workshop as suggested. It was indeed the solar sensor, the cable was the problem. 95€ later, the heating is back to normal. Thanks for the tip.