A power closing system for a door in a manual transmission vehicle, the system comprising: a gear lever for shifting a transmission gear ratio of a transmission manually; an ignition switch; an opening drive unit that opens and closes the door by a motor with a switch; a neutral sensor that detects a neutral position of the gear lever; a vehicle speed sensor; an accelerator-pedal pressing sensor that detects pressing-down of the accelerator pedal; and a control circuit connected to the ignition switch, the opening drive unit, the neutral sensor, the vehicle speed sensor and the accelerator pedal pressing sensor, wherein the control circuit allows the door to open and close by the opening drive unit if the ignition switch is off, or if the ignition switch is on, if the neutral sensor detects a neutral position and if the accelerator pedal pressing sensor does not detect pressing-down of the accelerator pedal, white the control circuit does not allow the door to open or close by the opening drive unit if the ignition switch is on, if the neutral sensor detects a neutral position and if the accelerator pedal pressing sensor detects pressing-down of the accelerator pedal, where the control circuit comprises a neutral sensor failure determining portion that determines whether to involve failure in the neutral sensor, the door being banned from opening and closing automatically by the opening drive unit if the neutral sensor failure determining portion determines a failure, if the ignition switch is on, if the neutral sensor detects a neutral position and if the accelerator pedal pressing sensor does not detect pressing-down of the accelerator pedal, and the neutral sensor failure determining portion determines that the neutral sensor has failure if the neutral sensor transmits a neutral-position detecting signal, if the vehicle-speed sensor detects running of the vehicle and if the accelerator pedal pressing sensor detects pressing-down of the accelerator pedal. a gear lever for shifting a transmission gear ratio of a transmission manually; an ignition switch; an opening drive unit that opens and closes the door by a motor with a switch; a neutral sensor that detects a neutral position of the gear lever; a vehicle speed sensor; an accelerator-pedal pressing sensor that detects pressing-down of the accelerator pedal; and a control circuit connected to the ignition switch, the opening drive unit, the neutral sensor, the vehicle speed sensor and the accelerator pedal pressing sensor, wherein the control circuit allows the door to open and close by the opening drive unit if the ignition switch is off, or if the ignition switch is on, if the neutral sensor detects a neutral position and if the accelerator pedal pressing sensor does not detect pressing-down of the accelerator pedal, white the control circuit does not allow the door to open or close by the opening drive unit if the ignition switch is on, if the neutral sensor detects a neutral position and if the accelerator pedal pressing sensor detects pressing-down of the accelerator pedal, where the control circuit comprises a neutral sensor failure determining portion that determines whether to involve failure in the neutral sensor, the door being banned from opening and closing automatically by the opening drive unit if the neutral sensor failure determining portion determines a failure, if the ignition switch is on, if the neutral sensor detects a neutral position and if the accelerator pedal pressing sensor does not detect pressing-down of the accelerator pedal, and the neutral sensor failure determining portion determines that the neutral sensor has failure if the neutral sensor transmits a neutral-position detecting signal, if the vehicle-speed sensor detects running of the vehicle and if the accelerator pedal pressing sensor detects pressing-down of the accelerator pedal.