Chasing an intermittent idle stall (topic22349.html), but can't seem to find what the current waveform for a 2-wire idle speed control valve should look like (though there is an "Idle Speed Control Valve ISCV current" choice in the prepopulated list of channel labels in PS6. I ask because the voltage measurement would seem to observe what the valve is being commanded to do, not what it actually does. For instance, if the valve sticks closed at any given attempt to open, one might see that in the current trace. Sticking open against the spring, though, is likely not observable, at least in the current waveform.
Should I just use the current waveform for multi-point petrol indirect fuel injector as an example? Seems like it would be similar.
On any actuator Voltage will show command whereas Current will show "Work Done" by that component.
With experience, product knowledge, technical data amongst other things, a lot of diagnostic value can be gained from a current measurement !
Further more if there is no voltage command there cannot be any current flowing, on the flip side if the current flow looks good then it is a given that Voltage command will look good.