A Honda Accord idle relearn procedure is needed after battery replacement, throttle cleaning, or ECM reset. During this process, the engine control module relearns idle airflow values to maintain smooth operation. Without a proper relearn, the Accord may experience fluctuating idle, poor fuel economy, or hesitation during acceleration. The procedure typically involves warming the engine, stabilizing RPM, and letting the ECM adapt to new baseline settings. Understanding this process helps drivers restore proper engine behavior without unnecessary repairs.