code 559

[TruckerBrent]

i have A CM2350 WITH A FRESH REBUILD about 70,000 miles ago and im starting to get code 559, i have 6 counts of it but the code is inacive, i feel loss of power for a second then it goes away, so far no check engine light on the dash just the red triangle on the navigation touch screen, i have replaced the high pressure fuel pump about a year ago. I have a lapotp with insite but im still learning how to use everything,
any help on what to do next would be much appreciated.
Truck is Kenworth t680 2015 with 754,000 ISX15 525 and its deregulated