There is a request response aspect to it. You have to tell it what data you are monitoring, and then it will send that data to you. Some of the requests, for example, for status of certain solenoids may trigger a "test" of the solenoid in order for it to return a "valid" status back. But you can't use it to alter engine timing or stop the flow of gasoline or something. You might be able to trigger a minute test of the fuel flow solenoid but nothing to harm the operation of the engine.

Calvin