To provide a sensor fault diagnosis unit which improves detectability of sensor abnormalities as well as prevents misjudgement.

Fault judgement of a throttle sensor 14 based on deflection ΔTH between output THM of a main throttle sensor 14a and output THS of a sub throttle sensor 14b, is performed. Under a predetermined condition such as at the time of starting or stopping an engine, difference between the outputs of both the throttle sensors 14a, 14b is set as a difference study value DTH. After setting the difference study value DTH, fault judgement of the throttle sensor 14 based on the output deflection ΔTH1 of both the throttle sensors 14a, 14b in consideration of the difference study value DTH, is performed in parallel.