misfire logs.. how does the computer know

[black98V6]

I figured this is pretty in depth for general tech.. though it is related to a post I made there....

how does the computer decide which cylinder is missing?? is there some sort of sensor on each cylinder?? does it compare the crank placment to a loss in power?? any info would be appreciated.. the biggest part of this question is what does the computer do to distinguish between cylinder 5 misfiring and cylinder 3... or something like that.. so.. pcm gurus??

edit.. fixed the miss but I'm still curious how the computer knows which cylinder is misfiring..

[ June 29, 2002: Message edited by: black98V6 ]</p>

[Magnus]

This is definately an advanced tech question. [img]smile.gif[/img]

The computer measures crank speed via the Crank Position Sensor.. If the crank speed slows down on a power stroke, it counts that as a miss for that particular power stroke.

It's pretty dang smart of GM engineers if you ask me. The PCM is thinking FAST!!! [img]smile.gif[/img]

[black98V6]

[img]graemlins/thumbsup.gif[/img]