I got curious so I tried searching the FSM. Didn't come up with a schematic.
It's probably in there, I just don't know how to find it.
You can also follow the connector/terminal info. Find the conn/terms at the sensors and follow back to ECM. Pg EC-174 says F31/4 is the ground terminal at the #1 sensor which ends up at F102/68 at the ECM, passing through connectors E106, M6, and M116.