Skip to content
When you connect your automotive scanner to your car, the "I/M Readiness" status appears as a part of the diagnostic data.
Essentially, this status tells you if your car's onboard diagnostic system has completed its internal checks and is ready for an emissions test.
If the vehicle is showing I/M Not Ready, it indicates that certain components of the emissions system haven’t completed their self-check cycle, making it impossible for the vehicle to pass an emissions inspection.
The Key Components of I/M Readiness
The I/M readiness check monitors several important systems in your car, including the catalytic converter, oxygen sensors, evaporative emissions control, and other critical emissions components.
Catalytic Converter: The catalytic converter reduces harmful gases like carbon monoxide, hydrocarbons, and nitrogen oxides. If this system is "not ready," it could indicate issues with the converter or related components.
Oxygen Sensors: Oxygen sensors measure the amount of oxygen in the exhaust gases and adjust the engine’s air-fuel ratio for optimal performance. If they are "not ready," it may signal malfunctions in the sensors or exhaust system.
Evaporative Emissions Control: This system prevents fuel vapors from escaping into the atmosphere. If "not ready," it could point to a problem with the fuel system or vapor recovery system.
How to Check I/M Readiness Using a Scanner
Using car diagnostic tool, you can check I/M readiness by selecting the Readiness Monitor function. The scanner will communicate with the vehicle's ECM and display the results for each monitored system.
Ready: The system has passed its self-diagnostic checks and is prepared for the emissions test.
Not Ready: The system has not completed the necessary self-checks, meaning it might fail the emissions test.
Incomplete: This state means the system’s diagnostic has begun but hasn't finished, which could be due to the vehicle not being driven long enough or specific conditions not being met.
Related Reading: What OBD2 Scanner Do And Is It Worth It?
Common Causes for I/M Not Ready Status
Recent Battery Disconnection or Reset: If the vehicle’s battery has recently been disconnected or reset, the ECM might lose its stored diagnostic information, and the I/M readiness monitor will show "Not Ready" until it completes its tests again.
Short Trips or Incomplete Driving Cycles: Some components require certain driving conditions to complete their checks. If you’ve only been driving short distances, or if you’ve been idling too much, certain systems might not have had enough time to complete their checks.
Faulty Sensors or Components: Sometimes, issues with the car’s sensors or related components can cause the systems to fail the self-checks. If a sensor is malfunctioning, the ECM will not be able to complete the readiness tests.
Poor Vehicle Maintenance: Lack of regular maintenance or outdated parts can cause readiness issues. A neglected fuel system, for example, might not allow the system to pass its emissions tests.
$109.99
How to Set I/M Readiness and Pass the Emissions Test
If your I/M readiness status is "Not Ready," here are a few steps you can take to resolve the issue.
-
Drive the Vehicle Long Enough: Make sure you drive your car under normal conditions for an extended period. This is often necessary to allow the vehicle to complete its self-check cycles.
-
Fix Malfunctions: If a specific system, like the oxygen sensor or catalytic converter, is showing "Not Ready," take your vehicle to a mechanic for a professional diagnosis and repair.
-
Perform an OBD2 Drive Cycle: Some vehicles require specific driving cycles to reset the readiness monitors. An OBD2 drive cycle usually involves accelerating to a certain speed, maintaining a constant speed, and allowing the engine to idle in specific conditions.
I/M Readiness and Emissions Testing
Before heading to an emissions test, it’s always a good idea to check your vehicle’s I/M readiness.
If the scanner shows that some of the monitored systems are "Not Ready," it might be worth taking the time to drive the car a bit longer or addressing any underlying issues before the test.
In some states, vehicles may be granted a waiver or conditional pass if they are "Not Ready," but it’s always better to ensure that the vehicle passes the readiness checks.
Conclusion
I/M Readiness is crucial. A “Not Ready” status might signal that the vehicle’s emissions systems are still undergoing checks or that there’s an issue that needs addressing before you can pass your emissions test.
You can easily find ANCLE scanners online, where they offer a range of best obd scanner for all cars designed for both personal and professional use.
ANCLE's bluetooth obd2 reader is convenient for everyday drivers who want to keep track of their car’s I/M readiness, while their professional-grade scanners are perfect for mechanics or those who need more in-depth analysis.
FAQs
How long does it take for an OBD2 scanner to check I/M Readiness?
The time it takes for an OBD2 scanner to check I/M Readiness can vary depending on the scanner model and the vehicle's system. Generally, the scan can take anywhere from a few seconds to a couple of minutes. However, if the car has recently been driven, some systems might need a little more time to complete their self-check cycles before showing as "Ready."
Will my car pass emissions if the I/M Readiness is not completed?
If your I/M Readiness status shows “Not Ready,” your car may not pass an emissions test. Emission tests often require that certain systems, like the catalytic converter and oxygen sensors, be fully checked and ready. If these systems are still in the process of completing their self-tests, your vehicle will likely fail the inspection. It’s advisable to ensure the I/M Readiness shows as “Ready” before taking the car for testing.
Does a Bluetooth OBD2 scanner work the same way as a wired scanner?
Both Bluetooth OBD2 scanners and wired versions serve the same primary function of diagnosing your car’s systems, including checking the I/M Readiness status. However, Bluetooth scanners offer the added convenience of wireless connectivity, allowing you to monitor your vehicle’s status from your smartphone or tablet. The primary difference lies in convenience rather than functionality—both types can provide similar results, but Bluetooth scanners make the process more flexible and user-friendly.
