tinman13kup:
Many auto systems that utilize a reduced voltage system for sensors use an isolated supply to do so. Connecting a resistor to body ground will not complete the circuit.
I can ground to the same point (ie. sensor ground) not that difficult is it? No brother, I disagree with you. I work on classics to conventional cars as late as 2018 models, japanese to american to european and I've not come across a single car that has isolated power supply for engine sensors. They do have a dedicated sensor ground that meets with the general chassis ground at the ECM.