The readings may have some reference value and show open circuits, but the resistance of these units is a comparison circuit
[ measured internally w/wheatstone bridge]where the resistance is continuingly changing, and they also has a heater circuit that changes the R value of one side of the comparision.
Resistance measurement also gives meter power to the heater
on certain pins. [ changing the measured resistance]. You will also notice that resistance is polarity sensitive [ meaning you get 2 different readings from same pins if you reverse lead polarity..
So , I guess [ and someone here knows for sure] that the only way to actually tell is to monitor the output voltage/wave form to the ECU from the unit...
I would be curious to see what readings you get from the old and new with polarity in mind and the same meter..