I have the PLX iMFD Sensor Module SM-Vac/Boost. The Vacuum scan reads 10 short.

When scanning with HPTuners if the Pillar Gauge reads a vacuum of 18.0, the Scanner reads a vacuum of 8.0.

The numbers for Boost on the pillar and the scanner however match pretty good.

I would like to fix it on the Vacuum side but need a guru in this area.

This Pic Is The PLX Specs



This Pis Is From HPTuners Enhanced User Defined IO Inputs I presume one needs to tweak- Not sure on the Sensor or the Units to use either. Just exploring it.



This Pic is the PID I currently use that Scans 10 short on the vacuum.

 

I am not too familiar with what you are trying to do, but this is what I came up with and should work. You have the ground going into the hptuners box in the same ground as the plx boost gauge does? if not then it will create an offset in your readings, in order to fix that offset u either have to adjust either up or down the -15 u see in the screen by the amount offset you have. If your unit is internally grounded then ignore the previous statement.





my assumption is that it should work if the data posted above is right.

 

Thanks,

I have my PLX AFR & Boost Modules daisy chained and from there a red and black wire going to the side of my hptuners vcm.

I'll try your formula soon.

 

let me know how it goes

 

I am not math guru but since my Vacuum was 10 short I made the read -25 instead of -15 and the vacuum became very close but.........

The Boost went the other way reading a -6 psi when it was actually a +5 psi.

So perhaps I have a Voltage/Ground issue and can tweak it in the list instead of linear?

 

dont increase by whole numbers increase by like .5, so 15.5, since the offset is in VOLTS, not in actual psi/vacuum, so if you are lets say off by 5 mmhg, and every 1mmhg=.03 volts...then .03 times 5, then the offset would be negative or positive .15 volts, so it would be either-14.75, or -15.15.. this is just an example though, but that is how your offset would work, the -15 is the y intercept so it should be fairly close, 1.66 volts is the root, or x intercept.

 

Thanks, So I should experiment with the volts field in smaller increments and leave the .1111 alone?

 

Correct do not touch the .1111, nd either increments or decrements