I/M Readiness (Inspection/Maintenance Readiness) indicates if your vehicle’s emissions control system has completed self-tests. It’s a basic feature accessible on most OBD2 scan tools, showing if your car is ready for state emissions inspection or if repairs have resolved issues.
Basically I use this to see if I will be able to pass state emission inspection. If I don’t see all monitors green (completed), I am not confident in passing it.
How Does I/M Readiness Work?
- Continuous Monitors: Run tests throughout the drive cycle.
- Non-Continuous Monitors: Run tests once per drive cycle when specific conditions are met.
- Completion Status: “Complete/OK” or “Incomplete/Not OK” based on test results.
Types of Readiness Monitors
| Continuous Monitors | Non-Continuous Monitors |
|---|---|
| Ignition Misfire | Catalyst Efficiency |
| Fuel System | Heated Catalyst |
| Comprehensive Component | EGR System |
| Evaporative System | |
| Heated Oxygen Sensor | |
| Secondary Air Injection | |
| Positive Crankcase Ventilation | |
| Air Conditioning (new) | |
| Thermostat (new) |
Performing a Drive Cycle
Follow these steps to reset readiness monitors:
| Step | Procedure |
|---|---|
| Start and Idle | Ensure the engine is cold. Start the vehicle and let it idle until the coolant temperature reaches 160°F (71°C). |
| Initial Acceleration | Accelerate to 40-55 MPH (65-88 KmH) and maintain a steady speed with 25% throttle for 5 minutes. |
| Deceleration | Decelerate to 20 MPH (32 KmH) or less without using the brakes, then stop the vehicle. |
| Idle and Restart | Let the engine idle for 10 seconds, then turn it off and wait 1 minute. Restart the engine and accelerate to 40-55 MPH (65-88 KmH) again. |
| Steady Speed | Maintain the speed for 2 minutes at 25% throttle. |
| Final Deceleration | Decelerate to 20 MPH (32 KmH) or less using the brakes or downshifting. Let the engine idle for 10 seconds, turn it off, and wait 1 minute. |
Checking Readiness Monitors
- Use a Scan Tool: Connect your OBD2 scan tool and check the I/M readiness status. Ensure most or all monitors show “complete” or “ready” status.
FAQs about I/M Readiness Monitors
- What does I/M Readiness mean? Indicates if a vehicle’s emissions control system has completed self-tests.
- What does OBD Readiness mean? Shows if a car’s OBD system has finished required tests to monitor emissions.
- How do I check my monitor readiness? Use an OBD2 scanner; it will display the status of emission monitors.
- How do you use readiness? Ensure your vehicle complies with emissions regulations, determining readiness for an emission inspection or potential issues.
By following these steps and understanding the importance of readiness monitors, you can ensure your vehicle is ready for emissions inspections and confirm that repairs have been successfully completed.
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko