Why Monitors are Sometimes Displayed as NOT READY

So what makes a monitor appear as NOT READY on the NYVIP Readiness list?

To understand this, it helps to know how non-continuous monitors work.

Once any non-continuous monitor runs completely — at least one time — it will be displayed as READY, and will continue to be displayed as READY unless:

A) Someone erases DTCs with a scan tool

B) Or, power to the vehicle computer is interrupted for any reason. This commonly happens when the battery goes dead or is disconnected.

In either of these cases, non-continuous monitors change back to NOT READY. They stay that way unless the vehicle is driven until the monitors can run again.