if your Jeep is like my wife's, it has an RFID tag in the key keeps people from copying it and stealing your ride. it sounds to me like this theft deterrent feature in your Jeep glitched and removing the power for an extended period of time may have allowed the computer to fully reboot and correct the error. if it was me, I'd only use the Jeep for short trips around your home for a week or so and see how it does, if it doesn't come up again, you're probably home free. if it happens again, have it towed to your mechanic to have him check it out. but don't disconnect the battery again as that clears the computer memory and your mechanic cant ID a problem. Good luck!