TPS voltage and ECM interpretation

[James S. Fearn, Jr.]

Hello,

I have a 165 ECM for my TPI F-body and am modifying Craig Moates scanning software code and I have a few questions on how the ECM interpretes the voltage from the TPS.

Since the TPS is supplied with 5v, it scales from 0v to 5v.  The ECM then interprets that scale as 0 to 256 bits accordingly, right?  I know some tables and constants use throttle position to determine actions like EGR and entering PE.  With my TPS set at .54 volts at idle that translates into 27or 28 bits (i don't know if the ECM truncates or rounds up) and 10.8% throttle.  But I don't think that is correct because there would never be 0% throttle and also I know there is an EGR constant on my stock bin set at 6% throttle.  That leaves me asking what does the ECM consider as 0% throttle and 100% throttle?

A somewhat related question:  How does the ECM know when to follow the idling commands?



James

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