S40 Overheating Radiator Fan

I had a similar overheating problem with my S40. Engine overheating and the check engine light. Have you checked if the fan motor is getting power? Sometimes, it's a relay or fuse. What does your temperature gauge show when the engine is overheating? Is it gradual or a spike?

The fan motor is receiving power, but the fan isn't moving. The temperature gauge climbs to the red zone quickly. Could it be the thermal switch? Did you replace the fan motor?

Given that the fan motor is getting power but not spinning and the temperature is rising quickly, it sounds like the fan motor itself. Although, the thermal switch could be the problem as well, because it tells the fan when to kick on. In my case, it was the fan motor. Diagnosing electrical problems can be a headache. I'd visit a workshop for a diagnosis. I ended up spending around 250€.

A visit to the workshop was inevitable. A new fan motor did the trick.