Is your 2007 Honda Accord failing its emissions test because the OBD2 system is “not ready”? This can be a frustrating issue, preventing you from passing inspection even if your car seems to be running fine. Understanding why your Honda Accord’s OBD2 might not be ready and how to address it is crucial for getting back on the road legally. This guide will walk you through the common causes, how to check the readiness status, and the procedures to set the readiness monitors to “ready” for your 2007 Honda Accord.
Understanding OBD2 Readiness Codes in Your 2007 Honda Accord
OBD2 (On-Board Diagnostics II) systems monitor various components of your vehicle’s engine and emissions systems. “Readiness codes,” also known as “readiness monitors,” are indicators within the OBD2 system that show whether these monitors have completed their self-tests. These tests are designed to ensure that your vehicle’s emission control systems are functioning correctly.
When your 2007 Honda Accord’s battery is disconnected, goes dead, Diagnostic Trouble Codes (DTCs) are cleared, or the Engine Control Module/Powertrain Control Module (ECM/PCM) is reset, these readiness codes are also reset to an “not ready” or “incomplete” state.
Many states and regions require these readiness monitors to be in a “ready” or “complete” state for your vehicle to pass an emissions test. If too many monitors are “not ready,” your 2007 Honda Accord might fail the test, even if there are no active DTCs or the Malfunction Indicator Lamp (MIL), also known as the check engine light, is not illuminated.
Symptoms of OBD2 Monitors Not Ready
The most common symptom of OBD2 monitors not being ready on your 2007 Honda Accord is discovering it during an emissions test. However, your vehicle can also give you a visual cue.
- MIL Indication (Readiness Check): You can perform a quick check of the readiness status without a scanner. Turn the ignition switch to the ON (II) position (do not start the engine). Observe the MIL in the instrument cluster.
- Readiness Codes Complete: If the MIL illuminates for about 15-20 seconds and then turns off, it indicates that all readiness codes are likely set to “complete.”
- Readiness Codes Not Complete: If the MIL flashes five times after the initial 15-20 seconds, it signals that one or more readiness codes are “not ready.”
Keep in mind that this MIL check is a general indicator. For precise information on which monitors are not ready, you’ll need to use an OBD2 scanner.
Common Reasons for “Not Ready” Status on a 2007 Honda Accord
Several factors can cause the OBD2 readiness monitors on your 2007 Honda Accord to be in an “not ready” state:
- Recent Battery Disconnection or Failure: Disconnecting the battery for maintenance or replacement will reset all readiness monitors. A dead battery that requires a jump start or replacement can have the same effect.
- Clearing Diagnostic Trouble Codes (DTCs): If you or a mechanic recently cleared any DTCs, even if they were minor or related to something else, the readiness monitors will be reset.
- ECM/PCM Reset: Resetting the ECM/PCM, either intentionally or unintentionally, will also erase the readiness codes.
- Recent Repairs: Some repairs, particularly those related to the emissions system, might necessitate resetting the ECM/PCM or disconnecting the battery, leading to “not ready” monitors.
- Short Drive Cycles: The OBD2 system needs specific driving conditions, known as “drive cycles,” to run and complete its self-tests. If you primarily drive short distances or in stop-and-go traffic, some monitors might not have had enough time or the correct conditions to complete.
How to Set OBD2 Readiness Monitors to “Ready” on a 2007 Honda Accord
The key to setting the readiness monitors to “ready” is to perform specific drive cycles that allow the OBD2 system to run its diagnostic tests. For a 2007 Honda Accord, here are the procedures for some common monitors:
1. Catalytic Converter Monitor Readiness Code
This monitor checks the efficiency of your catalytic converter.
Enable Criteria:
- Engine Coolant Temperature (ECT) at 158 ºF (70 ºC) or more.
- Intake Air Temperature (IAT) at -13 ºF (-25 ºC) or more.
- Vehicle Speed Sensor (VSS) reading more than 3 mph (5 km/h).
Procedure:
- Connect an OBD2 scanner (like the Honda Diagnostic System – HDS, if available, or a generic OBD2 scanner) to your vehicle’s data link connector (DLC). While not strictly necessary for setting the code, a scanner can confirm readiness status.
- Start the engine.
- Test-drive your 2007 Honda Accord under stop-and-go conditions with short periods of steady cruising.
- Drive for approximately 5 miles (8 km).
- Check the readiness code status for the Catalyst Monitor using your OBD2 scanner. It should switch to “complete.”
- If it’s still “not complete,” check for Temporary DTCs with the scanner. If no DTCs are present, repeat the drive cycle, ensuring the enable criteria are met.
Alt text: An OBD2 scanner tool is plugged into the diagnostic link connector port underneath the dashboard of a car, used for checking readiness codes.
2. Evaporative Emission (EVAP) Control System Monitor Readiness Code
This monitor tests for leaks in your fuel vapor recovery system.
Enable Criteria:
- Battery voltage more than 10.5 V.
- Engine at idle.
- ECT sensor between 176 ºF (80 ºC) and 212 ºF (100 ºC).
- Manifold Absolute Pressure (MAP) sensor less than 46.6 kPa (14 in.Hg, 350 mmHg).
- Vehicle speed 0 mph (0 km/h).
- IAT sensor between 32 ºF (0 ºC) and 212 ºF (100 ºC).
Procedure:
- Connect an OBD2 scanner to the DLC.
- Start the engine and let it idle.
- Using your scanner, navigate to the EVAP TEST menu (if available) and initiate the FUNCTION TEST. (The original article mentions HDS. With a generic scanner, you may need to look for EVAP system tests or just allow the system to run passively during idle).
- If the functions are normal (according to the scanner, or if you simply allow idle time), the readiness code should complete.
- If still “not complete,” check for temporary DTCs. If none are present, repeat the procedure and ensure all enable criteria are met.
Alt text: A detailed diagram illustrating the components of a vehicle’s Evaporative Emission (EVAP) control system, crucial for emissions monitoring.
3. Air Fuel Ratio (A/F) Sensor Monitor Readiness Code
This monitor checks the functionality of your air-fuel ratio sensors.
Enable Criteria:
- ECT at 158 ºF (70 ºC) or more.
Procedure:
- Start the engine.
- Test-drive your 2007 Honda Accord under stop-and-go conditions with short periods of steady cruise.
- During the drive, decelerate with the throttle fully closed for 5 seconds.
- Drive for approximately 3.5 miles (5.6 km).
- Check the readiness code status for the A/F Sensor Monitor using your scanner.
- If still “not complete,” check for Temporary DTCs. If no DTCs, check the ECT using the scanner’s data list to ensure it’s above 158 ºF (70 ºC). Repeat the procedure if necessary.
4. Air Fuel Ratio (A/F) Sensor Heater Monitor Readiness Code
This monitor verifies the heater circuit in your air-fuel ratio sensors.
Procedure:
- Start the engine.
- Let the engine idle for 1 minute.
- Check the readiness code status for the A/F Sensor Heater Monitor. It should switch to “complete.”
- If still “not complete,” check for temporary DTCs. If none, repeat the procedure.
5. EGR Monitor Readiness Code
This monitor tests the Exhaust Gas Recirculation (EGR) system.
Enable Criteria:
- ECT at 176 ºF (80 ºC) or more.
Procedure:
- Connect an OBD2 scanner to the DLC.
- Start the engine.
- Drive at a steady speed between 50-62 mph (80-100 km/h) in Drive (D) for automatic transmissions or 4th gear for manual transmissions for at least 10 seconds.
- Decelerate from 62 mph (100 km/h) or above by completely releasing the throttle for at least 5 seconds (in Drive or 4th gear). Do not stop the engine during this step.
- Check the OBD status screen for DTC P0401 (EGR insufficient flow) using your scanner.
- If it passes (no DTC P0401 and EGR monitor shows “complete”), readiness is set. If not, retest.
Alt text: A close-up view of an Exhaust Gas Recirculation (EGR) valve mounted on an engine, a component monitored for emissions readiness.
Monitors Always Ready:
The following monitors are typically continuously monitored and should always be in a “ready” state when the engine is running:
- Misfire Monitor
- Fuel System Monitor
- Comprehensive Component Monitor
Troubleshooting Persistent “Not Ready” Codes
If you’ve performed the appropriate drive cycles and some readiness monitors on your 2007 Honda Accord are still “not ready,” consider these troubleshooting steps:
- Check for Diagnostic Trouble Codes (DTCs): Use an OBD2 scanner to check for any pending or active DTCs. DTCs related to the emissions system can prevent readiness monitors from setting. Address any DTCs first.
- Verify Enable Criteria: Double-check the enable criteria for the specific monitor that is not setting. Ensure that your vehicle is meeting these conditions during the drive cycle (e.g., engine temperature, intake air temperature).
- Repeat Drive Cycles: Sometimes, it may take multiple drive cycles for a monitor to complete, especially if driving conditions are not perfectly aligned with the enable criteria.
- Check for Technical Service Bulletins (TSBs): Consult online resources or a Honda dealership for any TSBs related to readiness codes or emissions monitors for your 2007 Honda Accord. There might be specific issues or updated procedures.
- Professional Diagnosis: If you’ve exhausted these steps and the readiness codes remain “not ready,” it’s advisable to seek professional diagnosis from a qualified mechanic. There could be an underlying issue with a sensor, component, or the ECM/PCM itself that is preventing the monitors from completing.
Conclusion
Dealing with “not ready” OBD2 codes on your 2007 Honda Accord can be an obstacle to passing emissions tests. By understanding the reasons behind this issue and following the correct drive cycle procedures, you can often resolve it yourself. Remember to be patient and methodical, and don’t hesitate to seek professional help if needed. Getting your readiness monitors to “ready” is essential for ensuring your Honda Accord is both environmentally compliant and legally roadworthy.
