Air Fuel Ratio (A/F) Sensor Monitor and Readiness Code

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2025 Honda Odyssey, 2024 Honda Odyssey, 2023 Honda Odyssey, 2022 Honda Odyssey, and 2021 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

During the procedure, do not turn the vehicle to the ACCESSORY mode or the OFF (LOCK) mode.
All readiness codes are cleared when the 12 volt battery is disconnected, if DTCs have been cleared, or if the PCM is reset with the HDS.

Enable Criteria

ECT SENSOR 1 at 140°F (60°C) or more.

Procedure

1. Start the engine.

2. Test-drive the vehicle under stop-and-go conditions with short periods of steady cruise. During the drive, decelerate (with the throttle fully closed) for 5 seconds. After about 3.5 miles (5.6 km), the readiness code should switch from incomplete to complete.

3. Check the readiness codes screen for the AIR FUEL RATIO (A/F) SENSOR in the DTCs MENU with the HDS.

If the HDS indicates complete, readiness is complete.
If the HDS indicates not complete, go to the next step.

4. Check for a Pending DTC. If there is no DTC, the enable criteria was probably not met. Select the DATA LIST Menu. Check ECT SENSOR 1 in the ALL DATA LIST with the HDS. If ECT SENSOR 1 is less than 140°F (60°C), run the engine until it is more than 140°F (60°C), then repeat the procedure.