Mercedes GLS diesel car overheating issue

Active air flaps are important for cooling system efficiency. If they don't work, car overheating is common. Did the scan give a specific fault code? I had a similar issue with my GLS, also with a fault code for the active air flap. Was the car overheating all the time, or only in certain situations, like city driving?

Yes, there was a fault code, but I don't remember it. The car overheating seems worse during city driving, like you said. Can you explain how the active air flap affects cooling, and what fixed your issue?

The active air flaps manage airflow to the radiator, which helps keep the engine at the right temperature and improves aerodynamics. If they break, airflow can be limited, leading to car overheating, especially at lower speeds when there's less natural airflow. Based on what you're seeing and the fault code, it sounds like the flap's electromechanism is the problem. I'd suggest having a technician check it out carefully. Driving with car overheating could damage the engine further.

Thanks for the explanation and advice. I took it to a workshop, and they confirmed the electromechanism controlling the active air flap was defective. The repair was 590€. The car overheating problem is now solved.