V90 Oil Level Sensor Faulty

Those symptoms do point to a potential sensor issue. Have you checked the oil level manually with the dipstick to confirm it's actually okay? If the dipstick shows a good level, then I'd lean towards the sensor or its wiring being the culprit. Could be as simple as a corroded connector.

Good call on the dipstick, I checked it and the oil level seems fine, so it's probably not a critical issue. But corroded connector... where exactly should I be looking? Is there a common spot on the V90 where these things tend to go bad, or am I just doomed to trace wires until my eyes cross?

Since the dipstick reads fine and you've checked the level, the oil level sensor is likely the culprit. Given it's intermittent and potentially wiring related, I advise taking it to a workshop. These sensors can be tricky to diagnose without the right tools. A faulty signal can create havoc with your car's computer and potentially cause more extensive damage. Better be safe than sorry!

Thanks for the advice! You were spot on about needing the right tools. Took it to the workshop, and it turned out to be a corroded connector, just like you suspected. They cleaned everything up and replaced a small section of the cable, and the error is gone. Total cost? Only 95€.