Patent ID: 7841318

Claim:
A control apparatus for an internal combustion engine, comprising: a crankshaft provided in the internal combustion engine; a crank angle detection unit that is provided in the internal combustion engine and that outputs a crank signal each time the crankshaft rotates by a predetermined angle; a generator that rotates in synchronization with the rotation of the crankshaft, and that outputs alternating voltage signals with one-phase; and a control unit, to which the alternating voltage signals are input, that ascertains ignition timings based on the crank signals, performs ignition control so as to spark the internal combustion engine at the ignition timings, determines a polarity of the alternating voltage signal each time the crank signal is detected, ascertains a polarity cycle of the alternating voltage signals based on the determination result of the polarity, and determines that a failure has occurred in the generator when the polarity cycles do not continuously coincide multiple times with the polarity cycles during forward rotation of the crankshaft.