Fuel Level Sensor Voltage code

Ok I’m back to ask another question. Is there any chassis ground under the car that grounds to my fuel level sensor?

It uses a shared ground with the Fuel tank pressure sensor(FTP), and looks to splice with the FTP sensor at C413, where it has two colors splicing together there. Youre not getting any Evap related codes at all, so the FTP sensor should be ok. It looks like that specific 5v ref is isolated and not shared as it is on many other sensors, so a short to ground on the Purple wire may not effect any other sensors. But did you get to check the C300 connector as a last test. I just dont want to see you send the PCM all this way if its still a connector/wire fault.

Yep. And I had no continuity or broken wires anywhere. I just wanted to make sure before I sent away the module. I have heard if the internal resistor collapses, it would trigger a permanent low fuel indicator and the gauge will stay empty all the time

They mean the current limiting resistor you can see on the wiring diagram internal to the PCM. If the PCM is just screwed together and not sealed, you can take the cover off and look for a burnt resistor. Or a capacitor that has exploded or leaking onto the board, using a magnify glass, you can spot burnt traces, resistors or capacitors pretty easy. I do a visual inspection first, and then power it up on the bench and check the 5v refs. On many of these older PCMs they share a 5v reference inside, so a short takes down a bunch of sensors, but the shared 5vRef's look like a Grey wire. It looks like there is a ground that might attach to the case inside as well. Only if you're comfortable doing so.