Conventionally, a control system for an in-vehicle apparatus disclosed in U.S. Pat. No. 6,314,352 B1, which corresponds to JP-A-2000-127869, is known. When obtaining tunnel information from a navigation system, for example, the system activates a light device, closes a window and a sunroof, switches an airconditioner to circulate interior air, and manipulates an audio device to provide traffic information using a radio device. Further, the system intermittently activates a wiper or stops the wiper when the wiper is activated. The system returns the operation of each of the in-vehicle devices to an initial state. Alternatively, when obtaining tollgate information from a navigation device, the system controls to open a window on the drivers seat, close other windows and a sunroof, and decrease a sound volume of the audio device. Alternatively, when determining that the vehicle stops in a fuel station according to fuel station information obtained from the navigation device, the system controls to open a window of the driver's seat, open a fuel lid, and reset a trip meter. The system disclosed in U.S. Pat. No. 6,314,352 B1 notifies a driver of the above-described control contents. The system performs a control of the control contents when receiving a response from the drive to permit the control. Thus, the system is capable of performing the control reflecting an intention of the driver.
The above-described control system includes a detection unit such as a navigation system for detecting trigger information for performing a control. Thus, a control unit of the system finally determines a control content based on the detected trigger information. For example, a fuel station includes a full-service station, in which a salesclerk supplies fuel, and a self-service station, in which an occupant of a vehicle supplies fuel. Such distinction between a full-service station and a self-service station is undetectable by a detection device of a vehicle. Therefore, the system may suggest an unnecessary control such as opening of a window of the driver's seat even when an occupant of a vehicle uses a self-service station. Consequently, an occupant of the vehicle may be bothered by unnecessary suggestion. Alternatively, when it is determined that a windshield of the vehicle is fogged based on a humidity in the vehicle interior and a temperature difference between a vehicle interior and a vehicle exterior, a defroster of an airconditioner of the vehicle may be activated. It is noted that, even when it is not determined that a windshield is fogged according to detection signals of various sensors, a windshield may be fogged due to various disturbance factors. In this case, a detection device of the vehicle cannot detect trigger information for activating the defroster. Therefore, the defroster is not activated, and the windshield is not defogged for an occupant of the vehicle.