Determining misfire?

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GJBETZEL
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2001 Silverado 2500, 6.0

How does the computer determine which cylinder is missing? What sensors are involved?

As an in-shop test, I unhooked the knock sensors and a coil primary. Sure enough the CPU picked up the misfire. How??
Jan 5, 2007 at 10:26 PM
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SERVICE WRITER
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  • ASE Certified Mechanic
Different ones determine it different ways. One of them anyways, will measure the difference between firings of the cylinders by the crankshaft or camshaft sensor. When it sees a delay or the slight slowndown of rotation, it identifies which one should have fired and points it out in the way of po 300 to po306 codes (6 cyls).
Jan 5, 2007 at 10:31 PM
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