Prius oil sludge warning light

I had a similar issue with my Prius. Those are classic symptoms of oil contamination. Is the engine noisier than usual, especially at startup? It's worth checking for oil leaks, but if the oil itself is sludgy, you might be dealing with a maintenance interval that was exceeded, and resulting oil degradation.

Thanks for the quick response! Noisier at startup, yes, now that you mention it. I'll check for leaks, but assuming it is sludge, what's the worst-case scenario? And how urgent is this? Can I still drive it?

Continuing to drive with contaminated oil could lead to serious engine damage due to reduced lubrication. The worst-case is complete engine failure, requiring a rebuild or replacement. I suggest taking it to a trusted workshop ASAP for an oil change and engine flush. They can also assess any potential long-term damage. An engine flush involves circulating a cleaning solvent through the engine to dissolve and remove sludge buildup.

Took your advice and brought it in. Turns out I was overdue for an oil change, which caused the issue. New oil and filter, plus an engine flush, and the lights are gone. Total cost was 165€ Thanks for the help!