MODE $01 includes the Readiness Flag Status.  Readiness flag status can show if testing of each flag completed testing a minimum of one time since the memory was the last reset. This information can be used to verify a repair by running specific monitor test(s) that will flip the readiness flag to COMPLETE. State Emission Testing programs also use it as one of the requirements to pass or fail an OBD inspection. 

This example shows the readiness flag status since the memory was last cleared. Once COMPLETE, it can only be changed back to Incomplete by performing a MODE $04 diagnostic clear or removing power from or reprogramming the Engine Control Module (ECM).

Suppose all readiness flags are COMPLtoer to verify a repair or to turn out a MalfuncIndicatoriator Lamp (MIL) without resetting the memory. In that case, there is an option to view the status of the current drive cycle. At each key-on, all readiness flags will display as Incomplete. As the monitor test required to flip a readiness flag to complete runs and passes, the status will be updated to COMPLETE. If any readiness flag remains INCOMPLETE, the monitor test required to flip the flag did not run and complete. Note: this open is only available while connected to a CAN-equipped system.