Safrane water sensor issue

I also have a Safrane, though I can't remember the year, and I had a similar thing happen a while back. The symptoms you described match my experience almost exactly. Have you checked the wiring harness near the sensor for corrosion or damage? Maybe try cleaning the contacts with some electrical contact cleaner?

Thanks for the tip! Which particular wiring harness are you referring to? The one directly connected to the sensor, or a more central one within the engine bay?

Ah, yes. It was the one directly connected to the sensor. After checking it all it was clear to me that I do not know how to fix it. You should just go to the workshop, it will save you the hassle, and it is usually not too expensive.

Took your advice and brought it in. Turns out it was indeed a faulty connection at the water sensor, as suspected. The cable and plug were replaced, costing around 95€. Engine runs smoothly now, and the check engine light is gone. Thanks again for pointing me in the right direction!