Boost Pressure Intermittent at 1500 mbar

Golf3 Estate MBK ALE 1.9 TDI, 200,000 km.
(AFN Nozzles, MSW, Boost Pressure 1900 mbar)

Hello,
My Golf has been experiencing boost pressure problems lately. It intermittently only shows 0.5 bar above atmospheric pressure, especially when the engine is warm or after a hot start.
Everything is normal again when the engine is cool.
After unsuccessfully checking the intercooler, mass airflow sensor, N75 valve, and relay 109, the solution suddenly became clear.
In group 10, the ambient pressure is approximately 680 mbar, which is about 300 mbar lower than the pressure sensed by the charge pressure sensor.
At 11 (presumably referring to a temperature or pressure reading), the actual pressure (IST) reaches the target pressure (Soll), but unfortunately, it then reaches 1500 mbar.
Can the Motorola 60-120 kPa sensor be purchased separately, or do I need a new control unit?
Is it possible to simulate a signal using a potentiometer or a resistor?

Problem solved, I bought a new control unit.

Thank you for the good advice.

Best regards,
Michael.