摘要:
A physical quantity detecting device that can determine abnormality of a signal transmission system between a physical quantity detector and a controller and an electric power steering apparatus using the physical quantity detecting device are provided.. The physical quantity detecting device includes a physical quantity detector (3) configured to detect a physical quantity and to output a physical quantity detection signal and a controller (31) configured to receive the physical quantity outputted from the physical quantity detector via a transmission line and to perform a control operation on the basis of the physical quantity. The physical quantity detector (3) outputs a diagnostic signal for detecting abnormality of a transmission system between the controller and the physical quantity detector and the controller (31) includes an abnormality determining unit (31a) configured to determine abnormality of the transmission system on the basis of the diagnostic signal when receiving the diagnostic signal.