The vehicle engineers responsible for designing computer
control systems programmed them so a scan tool could
request information or command a module to perform specific
tests and functions. Some manufacturers refer to bidirectional
controls as functional tests, actuator tests, inspection tests,
system tests or the like. Reinitialization and reprogramming
also can be included in the list of bidirectional controls.
Figure 4-16 Sample of the Actuation Test
This function allows the device to send information to and
receive information from, vehicle control modules. For
example, in the case of OBD II generic information Mode 1