3 digit numbers for identification.
Gm 3 bar map sensor voltage chart.
Formula for the gm 3 bar map sensor is v 8 94 14 53 i have no idea why it s 14 53 and not 14 696 rounds up to 14 7 but it works out on gm s chart every time.
A 2 bar map sensor will read up to 2 bars of atmospheric pressure difference and a 3 bar will read up to 3.
The map sensor manifold absolute pressure has a 5 volt input and then reduces this voltage according to throttle opening altitude etc and sends the signal to the ecu.
Apparently it s a gm cheverolet performance 3 bar sensor which should have an approx.
If i choose the holley it goes to 31 2 psi.
I m betting either a bad map sensor or the wrong part altogether.
It is possible that detroit is.
039 460 883 876 2 bar.
Why doesn t it give me the full 3 bar of resolution.
So in order to accomplish this the output voltage must be scaled accordingly.
Gm map sensor identification how to identify a gm map sensor.
This means the output voltage of a 2 bar map sensor with the key.
Still not 3 bar but a little better.
It is possible that detroit is slightly above sea level and you can use 12 11 in the formula for 1 mile above sea level.
Now at a slightly higher elevation reading flickers between 1 78 and 1 79v giving a reading of 0 9 psig engine load with the car off.
On my fuel table it only goes up to 26 8 psi.
So by supplying a higher or lower voltage the return signal is varied by the same amount.
This is the opposite of what should really happen.
749 861 the logic module uses the manifold absolute pressure map sensor to determine the absolute pressure not the relative to atmospheric pressure of the air inside the intake manifold and the atmosphere barometric pressure.
The op stated the map voltage was high at idle and went down as vacuum decreased.
886 012 539 609 701 3 bar.
Linear output based in this info chart shown is for a 2 bar scaling to 29 4 psi.
I have looked around to try and find the calibration data for the gm so that i can choose custom 3 bar and get it to work up to 31 2.
But all of these sensors must still operate within the same voltage output specs as a 1 bar.
