A pneumatic tire includes a first tread area portion, an electric power source, a transmission device, an accelerometer, and a control unit configured to operate in a power saving mode and a normal mode. A contact of the first tread area portion with a surface is detected by sensing acceleration of the first tread area portion by the accelerometer. The control unit is configured to switch from the normal mode to the power saving mode after a detection that the first tread area portion is on a contact patch of the tire. The control unit is configured to switch from the power saving mode to the normal mode when a first specified time depending on the rotation speed of the tire has elapsed since the detection that the first tread area portion is on the contact patch. A monitoring method and a system are used with the pneumatic tire.