Patent ID: 8253534

Claim:
A vehicle door control system comprising: a portable unit configured to receive a request signal and transmit a response signal including an ID code thereof in response to the received request signal by way of bilateral communications; a vehicle unit configured to acquire the ID code included in the response signal, compare the acquired ID code with a registered ID code, and control a vehicle door when the ID codes match; the portable unit having a registration memory section that stores an instruction of an automatic door-opening operation when predetermined registration processing is made, and being configured to transmit an instruction signal for instructing the automatic door-opening operation to the vehicle unit by way of the bilateral communications if the instruction of an automatic door-opening operation is stored; the vehicle unit having a lock condition control section that controls a lock/unlock condition of the vehicle door, and an automatic door-opening section that automatically performs a door-opening operation; the vehicle unit being configured to drive the lock condition control section and the automatic door-opening section to unlock the vehicle door and automatically open the vehicle door, respectively, when the instruction signal is received from the portable unit and the ID codes match under a condition that the vehicle is kept parked with the vehicle door being locked; the portable unit further having a switch that is manipulated to perform the predetermined registration processing; and the portable unit being configured to invalidate registration of the instruction of an automatic door-opening operation if a predetermined time from the instruction being stored in the registration memory section elapses without the portable unit performing the bilateral communications during the predetermined time.