Patent attributes
A state of an oil pressure is determined based on combination of activation of an oil pressure switch and information of the temperature detected by a temperature sensor and an engine speed detected by an engine speed sensor such that determination of the oil-pressure state is conducted from a lower engine-speed range in a case in which the temperature detected by the temperature sensor is relatively low, compared with a case in which the temperature detected by the temperature sensor is relatively high. Accordingly, the oil-pressure state can be properly determined not only in a high engine-speed range but in a low engine-speed range, by utilizing the simple oil pressure switch activated to the conductive state in response to the oil pressure.