Lexus GS Overheating Check Engine Light

I have a GS too, and I had similar symptoms. Overheating and the check engine light could point to that active air flap. Is it stuck open or closed, perhaps?

I haven't checked the flap directly. Where exactly is it located, and is it easy to access and inspect?

It's behind the grille, controlling airflow to the radiator. If it's the flap motor electromechanism, you might be best off taking it to a workshop. It cost me 590€ to fix.

Thank you for the insight! I will take it to a mechanic to have the active air flap checked. Sounds like it's the most likely culprit.