the Formula in the EIO(AUX) section is called a transfer function
it works by you teling it a step value and then telling it an offset from 0
things you eed to know to figure out the formula for you device you are trying to use in the EIO section
A) Voltage Maximum of the Device being used
B) Value Represented by the (Volts=0) of the Device being used
If the device doen not output 0 Volts then you need to used math to figure out what value 0 volts would equal.
C) Value Represented by the Voltage Maximum of the Device being used
then its (A)/(C-B) +B
Example #1
Wideband O2 Sensor (LC1)
0 Volts= 7.35 AFR
5 Volts= 22.39 AFR
Volts Max = 5
AFR represented by 0 Volts = 7.35
AFR Max = 22.39
so 5/(22.39-7.35) +7.35
or in our EIO Formula
Volts/ 0.3324 + 7.35
Example #2
Autometer P255 Fuel Pressure
0.5 Volts= 0 PSI
4.5 Volts= 100 PSI
to get back to 0 since we do not know it yet
(4.5-0.5) / (100-0) = 0.04
0.5/0.04 = 12.5
0 volts = -12.5 PSI
4.5 Volts = 100 PSI
Volts Max = 4.5
Fuel Pressure Represented by 0 volts = -12.5 PSI
Fuel Pressure Max = 100 PSI
(4.5)/(100-(-12.5)) = 0.04
Volts/ 0.04 + (-12.5)