Yeah I know where it connects to the ecu, "IT DOSEN'T"
It is only connected to the boost gauge in the dash, thats it.
It is not shown on that ecu diag you posted i will find the circuit wiring for it and post it up.
To me this seem to be a waste of money because as you stated most of the nissan sensors work between 0-5volts or 0-12volts to aquire the data in 0-4volt range you would be missing the most important part (when everything is at full load) just my 2 cents,
I will oneday however buy one of these devices but not for use in my car.
With the tacho frequency why wouldnt you just feed this straight into your laptop? I mean seem's a little silly to convert to voltage and then analog to digital. the accuracy goes out the window.
Btw there is a tacho voltage output somewhere behind the dash.