ISX will not start.

[Nilao]

J1939 is the high speed network all the computers talk on. The only exception is the abs. I think it still uses the slow speed network. Have you checked the ecm connections? I had a buddy that had power loss issues while driving. It turned out to be the Allen screw that holds the harness into the ecm had backed out enough to break connection intermittently. Once he tightened it up all his issues went away.