Motor vehicle door closing system and method

A door closing system of a motor vehicle, comprising:

• a body, a door, a signaling unit, an emergency power source, a power source, an electrical control unit, a control, and a closing unit, wherein the closing unit has a rotary latch and a locking bar, wherein the locking bar is arranged on the body and the rotary latch is arranged in the door, wherein the rotary latch has a receiving region, wherein the receiving region is designed to be complementary to the locking bar, wherein the power source and the emergency power source are connected to the electrical control unit, wherein the electrical control unit controls the rotary latch, wherein in the passive state the locking bar has a distance to the receiving region, wherein the closing unit is configured in an unlocked state such that the locking bar is arranged in the receiving region and allows the locking bar to move into the passive state, wherein the rotary latch has a closed position, wherein the receiving region of the rotary latch is closed in the radial direction in the closed position and the rotary latch is locked, wherein the control unit is connected to the power source, the emergency power source and the signaling unit via signaling, wherein the electrical control unit controls the rotary latch such that it can be moved into and out of a closed position, wherein the emergency power source supplies the electrical control unit in an emergency state, wherein the signaling unit generates a signal in the event of an emergency state so that the control unit switches the power supply of the electrical control unit from the power source to the emergency power source, wherein a locking element with an active state is provided, wherein the locking element is arranged on the door and/or on the body, wherein the locking element, when the passive state and the emergency state are present, is in the active state, and wherein the locking element is designed in the active state such that the closing unit is in the unlocked or passive state.