The factory service manual pretty much says that there is a problem with the body integrated unit.
After looking at the thread below, I would reset your ecu, let the car idle for 5-10 minutes, and then drive like you normally would and see if that fixes the problem. The car might drive funny for a few days while it's relearning, but it'll go back to normal eventually.
I usually reset the ecu by disconnecting the negative battery cable for a little while, maybe 10-15 minutes or more. I'm not sure how long you're technically supposed to wait for the ecu to reset that way. I've also read other people say you can disconnect the negative battery cable, step on or hold down the brake pedal for 15-30 seconds to discharge any remaining energy, reconnect negative battery cable, and after that your ecu should be reset. I've never tried the second method, but it sounds like it should work.
*I also forgot to ask, has anything been done to the car recently? Any changes?