Help w Fault codes

[Zondo956]

Been having fault code 5868 and 3749 coming on for a while. About 6 months ago. Did a egr tune up and replaced outlet nox sensor and def doser injector. Usually saw them when temp was 20-40 degrees outside. Now they’re coming on at any temp. Intermittently and go away.
I was told to change out def level/quality/sending unit.
Any suggestions?

1117- I started getting after I installed KeepTruckin eld. No clue on what I could do there.

0197- Is a plug on coolant level sensor. It has 3 wires to it but only 2 are connected. Every now and then I see this code but it’s rare. It does tell me when coolant is low so I’ve left it alone. Every truck on the fleet this truck came from is wired the same way. They are also the ones that told me to change out the def sending unit. That they do it to all their trucks after certain mileage.

Truck is a 2016 T680 cm2350