Can J1939 be enabled or disabled on a CM870

[Hamish]

I am trying to be proactive and save a backup of my ECM lest I should have trouble with my international 9900 cm870 which was demandated 12 years ago before I bought it (and still running fine). I can connect using Insite and it show J1939 multiplexing is disabled. Is this why I can only connect using J1708? Actually I can only connect through the dash 6 pin, and not the three pin on the engine, which seems odd to me. Saving a complete calibration using the appropriate software is estimated to take almost two hours, but always crashes around 30% in. Apparently the connection is too slow or unstable to be useful as is. Using 762 and 3.17 with inline 6 through usb on windows 7