Pressure Relief Valve V71 Problem

"This weekend, while working on my vehicle's diagnostic system (FIS), I read the error codes and received a message from the climate control system indicating that the pressure control valve (V71) is blocked or without power. However, the recirculation function is working properly. Additionally, during the actuator test, the flap in the pollen filter box moves without any issues."

However, I also noticed a second flap there that doesn't seem to move. It's located above the V71. Or is that the V71, and is the lower flap, which opens and closes the airflow to the blower, designated differently?

Hello!

V71 controls both the recirculation valve and the back pressure valve.

Both are powered by the same engine, using a type of belt drive.
Unfortunately, the connection between the two flaps is very fragile and tends to come loose easily.
Then the recirculation flap will still operate correctly, but the back pressure flap will remain closed.

Since the end-of-travel position is determined by the pressure relief valve, the drive mechanism gradually shifts over time, resulting in an error message (the end-of-travel values drift).
During the actuator test, the actuator travels too far, which prevents the pressure relief valve from opening. After the actuator test, the pressure relief valve should be fully open in AUTO mode (in these outside temperatures, it may be necessary to activate the heating mode to prevent recirculation).

Unfortunately, the only solution is Tasch from V71.


BYE
TDI mechanics.

Does only the actuator need to be replaced, or something else?