2017 Navistar 7400 SFA 6x4 . VIN HH430895. This has a N10 engine. That is basically a DT570 with Cummins SCR grafted onto it. 609 19 "ACM not communicating on J1939" is Active. Have been over the wiring. This unit also keeps deleting info out of it's ECM. The ... Login to read more.