Patent ID: 7628138

Claim:
An engine control apparatus for a multi-cylinder engine, installed on a vehicle, which has a crank sensor for detecting rotation of a crankshaft of the engine to output a crank signal depending on the rotation of the crankshaft, and a cam sensor for detecting rotation of a camshaft to output a cam signal depending on the rotation of the camshaft, the engine control apparatus comprising: first cylinder discriminating means for executing cylinder discrimination based on the crank signal and the cam signal under a normal signal mode; failure detecting means for detecting failures in the crank signal and the cam signal, respectively; and second cylinder discriminating means for executing the cylinder discrimination, in place of the first cylinder discriminating means based on the crank signal and the cam signal under the normal signal mode, in the presence of the failure in either the crank signal or the cam signal; wherein the engine control apparatus causes fuel injection and ignition to be initiated for each cylinder of the engine based on the cylinder discrimination executed by either the first cylinder discriminating means or the second cylinder discriminating means; automatic startup control means for cranking the engine upon driving a starter device until judgment is made that the engine enters a running state in the presence of judgment that a specified startup initiating condition is established; drive time limiting means for interrupting the automatic startup control means from driving the starter device when a duration time for the automatic startup control means to drive the starter device is measured upon which judgment is made that the duration time reaches a limit time; and limit time setting means for setting the limit time to a longer time than a preset time for the normal signal mode when the failure detecting means detects the failure in either the crank signal or the cam signal.