ECM Relearn
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 Hyundai XG350, 2003 Hyundai Tiburon, 2003 Hyundai Sonata, 2003 Hyundai Santa Fe, and 2003 Hyundai Elantra. However, it is still accessible from the selected car via links, so may be relevant.
After disconnecting battery or replacing ECM, drive vehicle to enable ECM to relearn driveability. Inform your customer that they may experience driveability different from what they are accustomed to until ECM completes relearn function.