Hi stevieturbo, thanks for your reply,

in the mean time, I've checked, a DC voltage is the sensor's output so, you were right. A guy from a scrap yard had sold me a 1C1A-9F479-AA used sensor and it gives approximately 1.6 to 4.4VDC when its piezoelectric sensing bridge is exposed to an absolute pressure of 1 to 2 bar, respectively. So, the sensor in the vehicle in question is fired. Also, I've found 1C1A-9F479-AA isn't the right spare part for this vehicle; at length I took the fired sensor off the vehicle and saw its part number was 4S7Q-9F479-AA. I've ordered a brand new one and it's on its way to my place but it will take some 10 days to arrive.
In my humble opinion, the engine went into the limp mode. That was the reason to investigate. There is no pressure in the intake manifold. The rotary electronic actuator may be at fault too since there are two pending codes shown on my F Super 2 scanner. Those are P132A and P132B. According to info I found, it's all about the electronic actuator which manages the turbine's vanes. So, the ECM was getting wrong signals from at least two electronic devices.
I can't know if the two mentioned sensors have the same or different transfer characteristics, until I get both of them in front of me and test.
I also don't know the part number for the stepper motor in the actuator. I won't take the actuator apart until I see how the engine works with the genuine MAP sensor.