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Shift light/buzzer wierdness

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Old Mar 21, 2002 | 03:42 AM
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Default Shift light/buzzer wierdness

I have an LS1, HSV GTS 300 to which HSV fit a shift light/buzzer (at around 6100, redline is around 6500).

Sometimes at low RPM the buzzer will chirp for about 1/10th of a second.

I have a theory - based on other peoples experiences with programming shift lights/buzzers into ECMs. I just wonder if anyone can offer any confirmation on this:

Assuming the RPM is calculated based on spark pulses (I don't know if it is or is not in the LS1 ECM)...
Is it possible for a sudden and large enough change in the spark advance to fool the rpm calculation routine into "thinking" that the "advanced" spark pulse (P2), is close enough to the preceding non-advanced pulse (P1), that the calculation determines the rpm to be above the redline and so fires the shift light/buzzer.
The next pulse (P3), will be the "normal" distance from the pulse (P2) so the shift light/buzzer will be extinguished almost as soon as it is illuminated.

Can anyone confirm or deny this "theory".
If this theory is just plain bogus - does anyone have any other reasons that might make sense as to my "chirping shift light"?

Regards
Paul
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