What Do You Mean My Car's Not Ready?!

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Imagine your surprise, and frustration, when you take your vehicle for its periodic emissions inspection and the inspector tells you she can't test your vehicle because it's "not ready." Or, you already had an inspection but your vehicle failed. You had repairs done and have now returned to the inspection station for the retest but the inspector tells you he can't test it because it's "not ready."

What?! The engine starts, the vehicle is drivable, what does "not ready" mean?

It basically means that the computer in the vehicle that monitors the emissions control systems is "not ready" to be tested because it has been recently disconnected or reset.

Newer vehicles - less than 12 years old - now require an OBD (On-Board Diagnostics) inspection. The OBD inspection is a "plug-in" computer test rather than the road simulation test that is given to vehicles that are 12 years and older.

Vehicles equipped with OBD systems continuously self-test their emissions control systems using various monitors. These tests are commonly referred to as "readiness monitors." These monitors identify whether a vehicle's computer has completed the required "self-tests" while the vehicle is being driven. Basically a continuous on-road inspection.

If a self-test has been completed, the system will be reported as "ready." An incomplete self-test will be reported as "not ready." A vehicle with "not ready" status cannot be inspected until all of the self-tests are completed and the monitors are set to "ready." This generally means driving for a while to complete at least one full drive cycle, sometimes more, and then returning to an Air Care station for an reinspection.


  • Recent vehicle repairs in which diagnostic trouble codes have been cleared with an OBD scan tool
  • The battery was recently disconnected or replaced
  • The vehicle's computer requires a software upgrade
  • A pending problem has not yet illuminated the "check engine" light


To allow the vehicle's monitors to become "ready" it must be driven so that the self-tests can be completed and the monitors can be reset to "ready." To do this, the vehicle must run through its specific drive cycle, which depends on the vehicle make and model and which monitor(s) need to be reset. In most cases, two drive cycles are required to reset the monitors.


A drive cycle generally requires combined city and highway driving and includes cool periods. You can drive the vehicle as directed in the owner's manual (look under OBD), or consult with your repair technician who should be able to tell you to complete a vehicle or monitor specific drive cycle. 

If your vehicle failed the inspection, be sure to complete the drive cycle and return within 10 days to get a free reinspection.