A vehicle power bus control system is disclosed. The vehicle power bus includes at least one device having an issued, maximum, positive electrical limit value, and an issued, minimum, negative electrical limit each communicated to the at least one device from a control module coupled to the at least one device. The control module includes means for expanding one or more of the issued, maximum, positive electrical limit values, and the issued, minimum, negative electrical limit values responsive to a request from the at least one device for expanding one or more of the issued, maximum positive electrical limit values and the issued, minimum, negative electrical limit values.