S4 Cooling Issue Points to Faulty Air Flap System

The symptoms you describe match what I encountered with an Audi S6 2008. The fault code pointed to the flap motor malfunction in the air intake system. The active grille shutter was stuck in a closed position, significantly reducing airflow to the engine. The thermal management system relies heavily on proper air intake control. When the flap motor fails, it typically causes engine overheating and triggers the check engine light, exactly as you describe. This required specialized diagnostic equipment to properly identify. The mechanic found that the electromechanism controlling the flaps had failed completely. The repair involved replacing the entire flap motor assembly and recalibrating the system. While not immediately dangerous if addressed promptly, this issue can lead to serious engine damage if left unattended. The repair was complex due to the location of the components and the need for specific diagnostic tools. Consider getting a second opinion from an Audi specialist who can properly diagnose the fault code. The symptoms strongly suggest air intake control issues rather than a conventional cooling system problem.

Thanks for sharing your S6 experience. That sounds exactly like my issue with those same overheating problems and check engine warnings. Getting it diagnosed by an Audi specialist sounds like the right move. Could you remember roughly how much you paid for the flap motor assembly replacement? Also, has the thermal management system worked properly since the repair, or have you noticed any other issues popping up?

After getting it fixed at the specialist dealership, I can confirm the active air flap system works perfectly now. The total repair cost came to 590 Euro, which covered replacing the defective electromechanism and system recalibration. The car runs at normal temperature since the repair, with no check engine lights or cooling system issues. The thermal management operates exactly as it should. It was definitely worth addressing the flap motor problem properly rather than trying temporary fixes. The mechanic explained that the fault code indicated a complete failure of the air intake control unit. Getting this diagnosed and repaired by specialists who understand these systems proved to be the right choice. They had the proper diagnostic equipment to pinpoint the exact issue with the active air flaps. For anyone else facing similar symptoms, having the fault code properly read by qualified technicians can save time and prevent potential engine damage from chronic overheating.

After following your advice, I took my S4 to an Audi specialist last week. They ran a diagnostic scan which confirmed the flap motor failure. The repair cost was higher than expected at 780 Euro, but the mechanic showed me the damaged components and explained everything thoroughly. The car is running perfectly now. No more overheating issues and the check engine light has stayed off. The thermal management system is working as it should. Glad I addressed this before it caused more serious problems. The specialist also gave my car a thorough inspection and found no other issues. While it was expensive, having a proper diagnosis and repair from someone who knows these systems was worth every cent. Much better than my previous repair shop experience where they just kept guessing at the problem.