Fault code 3751

[Billdozer2]

So, I'm doing a forced regen for giggles and ha ha's after I changed my engine oil today. Numbers are looking good. DPF pressure is 0.5. About an hour passes and it stops. I'm thinking everything is A-O-K. So, I check active faults just to see if anything was logged. No check engine lights. Just a hunch. I find code 3751 is active. Using Quickserve, I find that 3751 is a code used only to help diag other fault codes. Using the diag tree, it basically says check the ECM software and delete the code. Anyone ever seen this fault before? Apparently, it does nothing to the "performance" of the engine. No other codes active nor inactive were logged.

BTW, 3751 is Aftertreatment SCR Catalyst System-Mechanical System Not Responding or Out of Adjustment

I think my truck is trying to tell me something. Like, Help! I want to breathe properly!