Abstract: A system and method for testing the integrity of a vehicle testing/diagnostic system is provided. Examples of vehicle testing/diagnostic systems may include any equipment (portable or stationary) found in an automotive maintenance and/or testing environment (or other environment) that is capable of communicating with vehicle on-board diagnostic (OBD) systems. Prior to conducting an OBD test on one or more vehicles, an integrity testing system interfaces with a vehicle testing/diagnostic system to determine whether the vehicle testing/diagnostic system is capable of communicating via one or more predetermined communications protocols.