CM2350 Fault Code 1683

[AlecLakeland413]

These were straight from Insite? If im missing something let me know, like I said, Im new to ISX/Insite, but any help is appreciated. I had the whole harness that runs over the top of the transmission out, going from the heater valve to ECM no rubbed or chaffed wires anywhere. Both J1 and J2 ECM plugs I had off today and they are dry and clean, no oil, bend tabs, or corrosion. Also got a message the last time I connected Insite that popped up on the screen saying, these fault codes cannot be caused by malfunctioning ECM, def dosing unit, or def dosing valve which ive never seen before. We bought six of these trucks and I have fixed a lot of bad wires already, but not seeing that here, thus far.