Seat Arosa check engine light and low coolant issues

Low coolant can stem from several areas. Have you inspected the coolant reservoir itself for cracks or leaks? Also, check the radiator hoses for any signs of swelling or weeping. Is the cooling fan operating correctly? Finally, examine the radiator cap; a faulty seal there could cause pressure loss and coolant escape. Do you observe any coolant on the ground after the car has been parked?

I checked the reservoir, seems okay. Hoses look fine too. How can I check if the cooling fan is working properly and what does a faulty radiator cap do exactly?

If the reservoir and hoses appear intact, and you are unfamiliar with electrical testing, I recommend consulting a workshop. A faulty radiator cap is like a lid on a pressure cooker; if it does not seal, the system cannot maintain pressure and coolant will be lost as steam. Considering the error message, a professional diagnosis is advisable to pinpoint the defective component and prevent further issues such as a blown head gasket.

Thanks for your help. Took it to the workshop as you suggested. Turns out it was a defective plug connection, like they suspected. 95€ later, and the Arosa is running fine again.