I don't think the dropout (when the PWM goes to ground, and stays low for some time) is normal, becuase this only happens when the fault code is cycling between stored and present.
Normally the PWM is stable indeffinitely (typically at 5% for idle once upto temp) and the drop out doesn't occur.
In live data, the only time I've seen a 0% duty command is again when the fault is cycling between present and stored.
Under normal operation the duty cycle in live data matches the duty cycle measured with pico.
There is a consistant issue with the valve, with P0638 being stored again within 10miles of clearing it. The main drawback - from a diagnostic angle atleast - is that its quite difficult to actually catch it in the act of playing up, often the P0638 will set out on the road, then by the time I'm back at the workshop it remains stored only, and valve functioning is back to normal.
I experimented with unplugging different wires to the valve, using the pico break out leads. If I unplug the PWM wire
while the van is at idle I get P0638 - Open circuit
Rather than the fault I've got at the moment, which is P0638 - Short to ground, this can be simulated by unplugging the feed to the valve instead (and leaving PWM connected).
It this short to ground that further re-enforces my feeling that the periods when PWM goes low and stays low is part of the faults nature.
RE: Currents, I find it odd how in the first set of traces I uploaded with current are so different to the second set.