Motor control device and fault diagnosis method using same

A fault diagnosis method of a motor control device, comprising:

• receiving a state output value, which varies according to whether a second signal line is opened, from a reception circuit connected to a first signal line and the second signal line to which a first input signal and a second input signal are applied;
• receiving a comparison output value between the first input signal and the second input signal from a sensing circuit connected to the first signal line and the second signal line;
• and
• determining whether the second signal line is opened using the received state output value, and determining whether the first input signal or the second input signal is abnormal using the received comparison output value,
• wherein the sensing circuit is not connected to the first signal line when the second signal line is opened and outputs “0” as the state output value, and is connected to the first signal line when the second signal line is not opened and outputs “1” as the state output value.