Originally Posted by
fjb2069
Thanks for your response.
I believe 0.4% does cause a difference in the operation of the system because the Throttle Follower Airflow Table typically has lower cells that only activate on 0.0% not 0.4% TPS.
I am also basing this on an expert tuner telling me that this will cause an issue with idle and changing Airflow table to 0.4% to compensate is a bandaid.
I am not an expert tuner, but I do have 30 years experience in embedded systems and I do agree with your statement about A/D converter operation, but assuming the GM ECU has at least a 10 or 12 bit resolution, +/- a couple bits due to ground noise should still vary the TPS reading 0.1, 0.2, 0.3, and not go from 0.0 to 0.4% repeatedly. And the system should show SOME change in voltage in order to change the TPS value regardless if the voltage change is cause by noise or ground path variance.
Was hoping someone from HP would chime in to explain what is going on.