The Secure Gateway Module is different from a conventional gateway module. These modules allowed components on different buses to share information with the module acting more as a translator than a security measure. The FCA/Stellantis module, though, acts as a blocking device between the vehicle modules and the diagnostic link connector. The end result is that, without security access, the technician is no longer able to access the modules on the vehicle with the exception of accessing DTCs and diagnostic data.
Any task that would require the technician to control action on the vehicle is blocked. This includes clearing codes, the use of bidirectional controls, the ability to program or code modules, and the ability to perform functional tests.