Seat Inca diesel rain sensor issues

Sounds like the rain sensor is definitely the prime suspect. Does the error code specifically point to the rain/light sensor unit? Have you checked the sensor's connection? Sometimes a loose connector can cause weird issues. Also, is the windshield original or has it been replaced?

The error code does mention the rain/light sensor. I checked the connection, seems secure. The windshield was replaced a few years ago, I'm not sure about the brand. Do you think a generic windshield could cause problems with the auto sensor's calibration or functionality?

A non-original windshield could be the issue, especially if it's not designed for the rain/light sensor. However, the bubbles forming under the gel pad are a well-known problem with these sensors and could impact car electronics in general. Since you've checked the connection and the error points to the sensor, I'd recommend getting it checked by a workshop that can properly diagnose and potentially recalibrate or replace the rain sensor. The auto sensor functionality will be back after the sensor calibration.

Took it to a workshop, and they confirmed the rain sensor was the culprit, bubbles formed under the gel pad of the windshield as suspected. They replaced it and calibrated the new one. Cost me 62€, but now everything's working again! Thanks for your help!