Are you sure this is a Maxxforce 7? The code you have is for an engine with down stream injection. Maxxforce 7 uses in-cylinder injection and does not have the metering unit with the fuel shut off valve. That valve is controlled by the ACM, not the ECM. The ACM is for "aftertreatment control module" and it is located at the bottom of the cab on the outside right under the drivers door. The wiring runs in behind the fender and sometimes up under the frame rail. There are lots of locations for the wiring to rub through. Open up areas where the harness zig-zags back and forth because it was too long and they just tied it up. Make sure the wires did not rub through on the inside of the loom. 99% of these codes are from wiring problems. Also make sure to check the pins inside the connectors to make sure they are in good condition and not pulled out.