A hydraulic excavator includes an engine, a rotating frame, a vehicle body frame, a diesel particulate filtering device, a selective catalytic reduction device, and a connecting pipe. A content encryption key is associated with the mobile station, and a copy of the key is provided to the mobile station. The method includes at least one of detecting at least one of an ESC bias spike and an ESC current spike of the ESC, and determining when an ESC bias voltage is zero or exceeds a threshold value. , an inanimate object, or a living being such as a child or pet.