Control system

A control system mounted on a vehicle and configured to control communication with a communication device present around the vehicle, the control system comprising:

• a detector configured to cause an electromagnetic field to be generated around an antenna in a first mode in which the detector operates under a preset first condition, and detect disturbance of the electromagnetic field on the basis of a change in impedance of the antenna;
• a communicator configured to output information for a communication device associated with the vehicle to surroundings of the vehicle by using near field communication, in a case where the disturbance is detected;
• and
• a counter configured to count the number of times the information is output, in a case where there is no response to the information even though the communicator outputs the information, wherein
• the detector is configured to shift to a second mode in which the detector operates under a second condition in which power is consumed less than in the first condition, in a case where a result of counting by the counter within a preset first period exceeds a preset number of times.