Press L1+ L2 + L3 + R1 + R2 + R3. The screen should flash an error on the left. Now for a short period of time you will have infinite energy.

Hold Triangle + Square + Start. Release all buttons, then press Start again.

While playing a game, press L2 + R2 + R3. If you entered the code correctly, a "Limiter Released" system error message will appear, and you will have infinite energy during this time. After approximately one minute, the "OB Down" system error will appear. It will last as long as the previous error, but you will not have any energy. After "OB Down" is completed, your AC will recharge and return to normal. Make sure you finish off your enemy before you become vulnerable.