SCR again...a new code

[pgls651]

Cummins ISX 15 cm2350. Hit the derate with a code I haven't seen before. 1682- Aftertreatment Diesel Exhaust Fluid Dosing Unit Input lines-Condition Exists.

Ive recently replaced the Doser. There is leaking/crystallization around the base of the pump module but not from any lines. And the truck has been sitting for a while. Any ideas that this could be a DEF pump failure? Ive never had the issue. I've got Insite, though not sure about tests I can run on diagnosing.