Ignition signal waveform

[myburb]

I might be off on my terminology but my question is-- is the scope waveform of the signal from the hei 8 to the pcm the same as the signal from the pcm back to the hei 8. This is using 6395/7427 $OE as reference.

[1project2many]

They're close but not exactly the same. The 0-5V signal out will vary slightly in width as the ecm controls dwell.