Does anyone know the formula that GM uses to calculate the outputs of the PCM?



In essence, there are really only two ouputs that the PCM controls:
1) Timing
2) Fuel (accomplished by triggering the fuel injectors via the pulse width and voltage)

There are a myriad of inputs, some used during Closed-Loop, others during WOT, and some during both.

a crazy example might look like

TIMING = Timing Table * RPM * PE Load divided by ((IAT/Barometric pressure)-(MAF table)/(PE LOAD value) * 2/RPM)) etc., etc.

Who knows where to find GM's secret formulas?

 

What is it your trying to accomplish?

 

I want to know which tables affect the output of the PCM.
During Closed Loop and Open Loop, which tables affect the fuel injectors and which tables affect the timing. Are some tables minor (reduced in value) and/or major (enhanced in value)?

It seems improbable that barometric pressure or Intake Air Temperature are more significant than RPM or MAF Gms/Sec.

There's got to be a basic formula that has variables flipping constantly, massaging the output of timing and or fuel.

 

You might try this site for some answers.