speedometer pinned at 140mph

hello everyone,,i have a '99 intrigue with the 3800 motor.i recently disconnected the battery and noticed the speedometer is now pinned all the way to 140mph.is there any way to reset this.i also recall disconnecting the battery a few years ago to work on the car and the same thing happened.it began working again after a few days of driving..anyone know why this happens after disconnecting the battery ? and is there any other way to get it working again other then by chance ? thanks