I would like to see the schematic pages from the sensor to the gauge. I may build a non-linear compensator to make the gauge closer. 09 S.

 

I do not find a complete wiring diagram for the sending units in the tank in the latest WDS so it is very possible that these are DATA lines and thus what you would like to do may not be possible.

The only way to know would be to measure the voltage on the sending units at different levels of fuel in the tank.