My vxdiag vcx Subaru SSM4 works fine on a 2014 Subaru Forester, but when I tested another 2013 Subaru Outback with SSM3, it failed to communicate. Error ‘Communication initialization failed. ‘
In SSM3 at the starting screen, if you click on the top right “I/F Box”, there is only “Subaru Diagnostic Interface”, and “Denso DST-I”.
Make sure the “I/O box” is set to “SDI (Subaru Diagnostic Interface)”, it is connecting now.
In SSM4, set up the interface as VXDIAG