J1939 or CAN is a network protocol many vehicles use for control module to control module communication. The “standardized system” you were commenting about is

J1939 or CAN is a network protocol many vehicles use for control module to control module communication. The “standardized system” you were commenting about is referring to access to the server side info. Currently manufacturers can pull telematics data like odometer, trouble codes and PIDs (data items like speed, brake status and very much more) which helps with service reminders and streamlining the repair process. Aftermarket shops are at a great disadvantage in this regard.