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Old 05-21-2007, 07:13 PM
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Trevor Trevor is offline
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Join Date: Feb 2002
Location: Auckland, New Zealand
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Originally Posted by ItsPeteReally
You can take things a little too far in the search for accuracy

Without knowing anything at all about the ECU I think we can safely surmise that the TPS voltage read by the ECU is unlikely to be used to access a myriad of subtly different lookup tables. I'd be very surprised if the TPS output was interpreted as being any more than the equivalent of none, a little, some, a lot, and maximum, which would call for five different mappings (and I suspect that this is too many!).

Similarly, I would venture that other voltages are only significant to the CPU when they cross certain threshold values.

Most inputs can be categorised as rich/lean, cold/hot, etc.

I don't dispute that the input values are readable to quite high degrees of apparent accuracy but I have my doubts as to the dependability of the calibration behind them.
I am confident that set points or calibration to a known value/figure will not be involved, and as you state there will be no apparent accuracy based on any specified criteria.

I think Phil has it right in considering the reading/indication/signal, always in terms of a percentage. As you say a percentage of between none and maximum and not as a specific measurement of a quantity/value/'position/whatever.
Trevor, New Zealand.

As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit!
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