Skoda Fabia Diesel Transmission Issue

A slipping gearbox and grinding noises definitely point to transmission issues. Is the error message specifically referencing the transmission oil pressure sensor? It could be a faulty pressure switch, but low oil level is a plausible cause given the symptoms. Have you checked the transmission oil level? If so, what did you find?

I haven't personally checked the transmission oil level. I'm not entirely sure how to do it on this Fabia model. Where is the dipstick or check plug located? Could a failing transmission sensor cause those grinding noises, even if the oil level is ok?

It does sound like the low oil level is the most likely culprit, especially given the grinding noises. While a failing transmission sensor could theoretically cause some shifting issues, it usually wouldn't lead to grinding. Checking the oil level on your Fabia can be tricky depending on the specific transmission. Some have a dipstick, others only a check plug. I'd recommend taking it to a workshop to have them check the level and top it off. It's probably the simplest and cheapest thing to try first.

It was the transmission oil level, lower than expected. A workshop topped it off, and the pressure sensor fault is gone. The total cost was 365€, including oil and labor. Thanks for the advice!