The ECM gives both Air flow gm/sec & MAF gm/sec.

I am wondering what other inputs if any influence the "air flow" data?
At first glance airflow just looks like a duplicate of MAF data , but I am realizing they are different.

Are both of these coming solely from output from the MAF sensor? Or is it a combination of info on the airflow reading?

Is this the dynamic calculation from the ECU's learned A/F tables?

 

It appears it has nothing to with learned A/F ratios like I was guessing above. .

I just dropped power to the ECU to reset, & still had the same type of data.

 

Hi

Assuming you have a '7165 with $6E mask, TPI system

The MAF sends a voltage to the ECM B12 (0-5volts). The ECM looks-up the voltage in a series of MAF tables. The g/sec returned data was human programed by GM. The g/sec data is used by the ecm to calculate injector base pulse width (INJ BPW) before correction and other adjustments.

INJ BPW = (((((MAF/8)/(RPM/60))*2)/AFR)/(INJ Flow Rate/60/60)*1000/2.20462)*1000/2

RPM is read by ECM from distributor
AFR is programmed data, usually 14.73 in closed loop
INJ Flow Rate is programmed data, usually 22.36 (for 5.7TPI L98)

The ECM has a provisions to return g/sec data in case of MAF failure. Unplug the MAF and try scanning. You should still see g/sec but will get a SES code.

I would not know why your scanner returns 2 sets of data for airflow.