Not necessarily a serious expensive problem. But, when the code is set, the system leaves the computer powered up even if the engine is shut down.
If your batter is not dead, it soon will be.
Most likely, your problem is poor electrical connection to the battery.
Disconnect the battery, toss it if it is more than 3 yrs old, even if it tests ok.
Clean the battery terminal connections. Pay special attention to the accessory wire adjacent to the big starter cable on the positive side.
If this does not fix it, then another connection is bad and it is going to have to go to a Honda or Acura dealer.