i need your help. i built the box from corbins FTSAFC mod. same sensor and all...i built it to read boost on my wideband.

would you mind double checking my wiring for me becaue i not getting correct readings? if the connections are correct, then it has to be messed up in the wideband software for reading the signal.
i have 3 wires from the sensor; red=5v power, black=ground, green input signal to wideband.

my stock map sensor has this color scheme:
black/green = ground
green/yellow = 5v power to MAP ( iahd a steady 5.1v at idle)
yellow/black = map signal to ECU

i have:

red -> green/yellow
black -> black/green
and green to the input cable for my wideband.


however... i now have a 14 CEL (MAP voltage too high/too low), and im getting a trace on my wideband graph of boost into the 25psi range. i have reviewed the pdf file for the sensor charactoristis and have it set to 2.9psi = 0v and 36.3 psi = 5v... so any idea what could be wrong? does the wiring sound alright? am i all screwed up somewhere?

heres the pdf (i think)
http://www.2gnt.com/www/corbin/MPX4250A.pdf

Originally posted by tim97rs
i need your help. i built the box from corbins FTSAFC mod. same sensor and all...i built it to read boost on my wideband. would you mind double checking my wiring for me becaue i not getting correct readings? if the connections are correct, then it has to be messed up in the wideband software for reading the signal. i have 3 wires from the sensor; red=5v power, black=ground, green input signal to wideband. my stock map sensor has this color scheme: black/green = ground green/yellow = 5v power to MAP ( iahd a steady 5.1v at idle) yellow/black = map signal to ECU i have: red -> green/yellow black -> black/green and green to the input cable for my wideband. however... i now have a 14 CEL (MAP voltage too high/too low), and im getting a trace on my wideband graph of boost into the 25psi range. i have reviewed the pdf file for the sensor charactoristis and have it set to 2.9psi = 0v and 36.3 psi = 5v... so any idea what could be wrong? does the wiring sound alright? am i all screwed up somewhere? heres the pdf (i think) http://www.2gnt.com/www/corbin/MPX4250A.pdf

You didn't mess with the stock MAP right? How are you getting a MAP CEL now then? Wierd. As for the MAP sensor does it read vacuum? If it is an absolute pressure sender then you might want to subtract 14.7psi from those values as it does look like a 2bar MAP sensor. Just a thought because I know the MS sensor is similar in range but it only useable for 21PSI.

yea...with metaljims help last night we determined thats what the deal is... the sensor is an absolute pressure sensor that starts off at 2.9 psi, not 14.7... so yea the readings im seeing are actual boost + atmosphereic pressure. now i just gota figure out how to program my wideband software so that the correct pressure for XX volts shows up instead of the added 14.7....

as far as the stock map, no, i didnt fiddle with it other than to stick a multimeter probe in the wires to see what was what..i'll glear the ECU today and see if it comes back.