Readiness Q&A

What is a readiness monitor?

The readiness monitors identify whether the vehicle’s computer has completed a series of required drive cycles.

Vehicles can perform up to 11 system tests, depending on the year, make and model. All cars 1996 and newer are equipped with this type of monitoring system. If a test has been completed, the system status will be reported as “ready.” An uncompleted test will be reported as “not ready.”

What could cause my vehicle to be not ready?

Vehicles that are not ready do not always have something wrong with them. The following situations may cause the vehicle to be not ready, such as:

1. Recent vehicle repairs or maintenance in which Diagnostic Trouble Codes (DTCs) have been cleared with an OBD scan tool.

2. A recently disconnected or replaced battery.

How do I set my readiness monitor to be "ready?"

If the only reason that your vehicle failed inspection is because of a “not ready” monitor reading, you will most likely need to complete what is called a “drive cycle” which may take a few days to several weeks and possibly up to 1,000 miles depending on the make and model of your vehicle.

The monitors will be reset when a “drive cycle” is completed. The specific drive cycle depends on the make and model of the vehicle, and the requirements are sometimes discussed in the owner’s manual. If this information is not available, the generic drive cycle may reset the monitors.

*Consult your owner’s manual for specific drive cycle information.

How many monitors have to be ready?

Program requirements allow up to two (2) monitors to be “not ready” for model years 1996 through 2000. Vehicles 2001 and newer allow only one monitor to be “not ready.”

How do I perform a Generic Drive Cycle?


Important! If you choose to use this generic drive cycle, you must obey all traffic laws and drive in a safe manner.

1. The generic drive cycle begins with a cold start. Coolant temperatures must be below 122 °F and the difference between coolant and air temperatures read by the sensors must be within 11 degrees.

2. The ignition key must not be left on prior to the cold start; otherwise the heated oxygen sensor may not run.

3. As soon as the engine starts, idle the engine in drive for 2 1/2 minutes with the air conditioning and the rear defrost on.

4. Turn the air conditioning and the rear defrost off and accelerate to 55 mph under moderate and constant acceleration. Hold at a steady 55 mph for at least three (3) minutes.

5. Decelerate to 20 mph without braking or depressing the clutch.

6. Accelerate back to 55 to 60 mph. Hold for five (5) minutes. Decelerate to a stop without braking.

*Consult your owner’s manual for specific drive cycle information.

If I fail due to readiness monitors, can I still qualify for a waiver?

No. Readiness monitors detect and report problems by displaying Diagnostic Trouble Codes (DTCs). These DTCs are essential to determine which repairs should be performed.

I failed my emissions test because of Readiness Monitors?

Readiness monitors are programs that monitor the performance of a vehicle’s emissions control devices while the vehicle is being driven. During an emissions test, the emissions testing analyzer checks the status of the readiness monitors. The status of a completed readiness monitor will be "ready". The status of an uncompleted readiness monitor will be "not ready". If too many readiness monitors are not ready, your vehicle will fail an emissions test.