Charge pressure sensor voltage too low

Hello together. I’ve been screwing on a sprinter for days by a friend, he always spits out voltage too low as an error charging pressure sensor. Is already a new sensor of the Bosch brand built in. A no name part was installed from the workshop. The error persists. AGR is clean, all other things have been done. There is a new differential pressure sensor in it, we have checked the charging pressure hoses for leakage, everything is fine. Mistakes read through all the forums, in one there was something that you took from another sensor the voltage to the charging pressure sensor that this would have worked. What do you think about it? If this really works then I would try it out, but I don’t know which sensor I can use, and which cable I then take for the 5 volts. Nevertheless, the problem is passed on, I have the MSG in suspicion that something is wrong. Sometimes I can’t use this one. It’s a Sprinter 906 2.2 liters more I don’t know anything about the car from my head now. Lg