A scrambling method of data on a J1939 communication system of a vehicle involves at least moving data from one of a PGN and a PGN/SPN location to another PGN or PGN/SPN location at a first controller on the vehicle before transmitting data and then re-ordering the data at a second controller. Some embodiments further comprise encrypting data either before or after shifting, but before transmitting so as to further complicate efforts to interpret meaningful data from the transmission. The second controller may be on the vehicle or may be remotely located.